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Zhang J, Li B, Zhou Z, Zhang J. Durable Superhydrophobic Surfaces with Self-Generated Wenzel Sites for Efficient Fog Collection. Small 2024:e2312112. [PMID: 38409650 DOI: 10.1002/smll.202312112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Revised: 02/05/2024] [Indexed: 02/28/2024]
Abstract
Harvesting freshwater from fog is one of the possible solutions to the global water scarcity crisis. Surfaces with both hydrophobic and hydrophilic regions are extensively employed for this purpose. Nevertheless, the longevity of these surfaces is still constrained by their delicate surface structures. The hydrophilic zones may become damaged or contaminated after repeated use, thereby compromising their effectiveness in fog collection. The preparation of generally applicable durable superhydrophobic coatings with self-generated Wenzel sites is reported here for long-term efficient and stable fog collection. The coatings are prepared by depositing the poly(tannic acid) coating as the primer layer on various substrates, self-assembly of trichlorovinylsilane into staggered silicone nanofilaments, and then thiol-ene click reaction with 1H,1H,2H,2H-perfluorodecanethiol. The coatings demonstrate remarkable static superhydrophobicity, robust impalement resistance, and stable self-generated Wenzel sites for water droplets. Therefore, the fog collection rate (FCR) of the coatings reaches 2.13 g cm-2 h-1 during 192 h continuous fog collection, which is triple that of bare substrate and outperforms most previous studies. Moreover, the systematic experiments and models have revealed that the key factors for achieving high FCR on superhydrophobic coatings are forming condensed droplets ≈1 mm in critical radius and a Wenzel site proportion of 0.3-0.4.
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Affiliation(s)
- Jiaren Zhang
- Center of Eco-Material and Green Chemistry, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Bucheng Li
- Center of Eco-Material and Green Chemistry, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, P. R. China
| | - Zhengqiang Zhou
- Gansu Water Investment Co., Ltd., Lanzhou, 730000, P. R. China
| | - Junping Zhang
- Center of Eco-Material and Green Chemistry, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, P. R. China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
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Nafisifard M, Alaghehmand H, Soleimani L, Mokhtarpour F. Effect of 4-META on microtensile bond strength of cements to ceramics. Dent Res J (Isfahan) 2024; 21:19. [PMID: 38476715 PMCID: PMC10929730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 10/07/2023] [Accepted: 11/11/2023] [Indexed: 03/14/2024] Open
Abstract
Background This study assessed the effect of different concentrations of 4-methacryloyloxyethy trimellitate anhydride (4-META) added to silane on microtensile bond strength (µTBS) of light-cure and dual-cure resin cement to hybrid and zirconia-reinforced lithium silicate ceramics. Materials and Methods This in vitro, experimental study was conducted on 32 Celtra Duo and 32 VITA Enamic ceramics bonded to Allcem Veneer light-cure and Allcem dual-cure resin cements using silane impregnated with 4-META in 0%, 2.5%, 5%, and 10 wt% concentrations in 16 groups (n = 4). The µTBS of specimens was measured by a universal testing machine and analyzed by the Kruskal-Wallis and Mann-Whitney tests, and the mode of failure was determined under a stereomicroscope and analyzed by the Chi-square test (alpha = 0.05). Results The lowest mean µTBS was recorded in the Enamic ceramic group with 4-META (0%) bonded to dual-cure cement (14.26 MPa), and the highest mean µTBS was recorded in Enamic ceramic with 4-META (10%) bonded to light-cure cement (18.59 MPa) (P < 0.001). The µTBS of Celtra Duo was significantly higher than that of Enamic in bonding to light-cure cement using 4-META (2.5%) (P = 0.003). All failures (100%) were adhesive in most groups. The frequency of adhesive failure was the lowest (90%) in Celtra Duo bonded to dual-cure cement with 4-META (5%). Conclusion According to the results of this pilot study, the addition of 4-META (10%) to silane caused a significant improvement in µTBS to light-cure cement. The addition of 4-META in all concentrations significantly improved the µTBS to Enamic ceramic in the use of dual-cure cement; however, it had no significant effect on µTBS of Celtra Duo. Nonetheless, the results should be interpreted with caution due to the relatively small sample size.
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Affiliation(s)
- Maliheh Nafisifard
- Dental Materials Research Center, Student Research Committee, Babol University of Medical Sciences, Babol, Iran
| | - Homayoon Alaghehmand
- Dental Materials Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran
| | - Laleh Soleimani
- Oral Health Research Center, Health Reserch Institute, Babol University of Medical Sciences, Babol, Iran
| | - Faraneh Mokhtarpour
- Oral Health Research Center, Health Reserch Institute, Babol University of Medical Sciences, Babol, Iran
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3
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Garg B, Bisht T, Ling YC. A Heteroatom-Containing Functional Poly(Silylenevinylene): Synthesis, Anion Binding, and Sensing of Anion Extraction Processes. Macromol Rapid Commun 2024; 45:e2300527. [PMID: 37990851 DOI: 10.1002/marc.202300527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 10/29/2023] [Indexed: 11/23/2023]
Abstract
Catalytic hydrosilylation is one of the important synthetic approaches to prepare functional organosilicon polymers. Herein, a functional silicon copolymer is constructed by polyhydrosilylation reaction between a novel 3,7-bis(dimethyl silane)-10-(2-ethylhexyl)-10H-phenothiazine monomer and a neutral tetrapyrrolic macrocycle, namely, 5,5,10,15,15,20-hexamethyl-10α, 20α-bis(4-[ethynylphenyl]) calix[4]pyrrole. The as-constructed copolymer (Mn = 9609, PDI = 2.2) is investigated as an extractant for organic anions as their tetrabutylammonium salts under interfacial aqueous-organic (water-chloroform) conditions. In this context, a distinctive naked-eye colorimetric as well as fluorescence detection method is developed based on anion-directed hydrogen-bonding interactions. This kind of color/fluorescence monitoring serves as a handy tool for rapid screening of anion extraction processes. The copolymer exhibits high selectivity toward extraction of chloride anion. This study augments the field of polycarbosilanes, poly(silylenevinylene)s in particular, allowing access to a new application window that can be further advanced with good grace in near future.
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Affiliation(s)
- Bhaskar Garg
- Department of Chemistry, IIT Roorkee, Roorkee, 247667, India
- Department of Chemistry, School of Basic Sciences and Technology, IIMT University, Meerut, Uttar Pradesh, 250001, India
| | - Tanuja Bisht
- Department of Chemistry, Indira Priyadarshini Government Girls P. G. College of Commerce, Haldwani, Uttarakhand, 263139, India
| | - Yong-Chien Ling
- Department of Chemistry, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu, 30013, Taiwan
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Cichomski M, Wrońska N, Dudek M, Jędrzejczak A, Lisowska K. Tribological and Antimicrobial Properties of Two-Component Self-Assembled Monolayers Deposited on Ti-Incorporated Carbon Coatings. Materials (Basel) 2024; 17:422. [PMID: 38255590 PMCID: PMC10817511 DOI: 10.3390/ma17020422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 01/07/2024] [Accepted: 01/11/2024] [Indexed: 01/24/2024]
Abstract
In this work, Ti-incorporated carbon coatings were used as substrates for modification with one- and two-component self-assembled monolayers of organosilane compounds using a polydimethylsiloxane (PDMS) stamp. This enabled the selective functionalization of surfaces with micrometric dimensions. The topography of the modified surfaces was defined using an atomic force microscope (AFM). The effectiveness of the modification was confirmed by measurements of the water contact angle and surface free energy using the Oss and Good method. Using a T-23 microtribometer with counterparts in the shape of balls that were made of steel, silicon nitride (Si3N4), and zirconium dioxide (ZrO2), the tribological properties of the obtained coatings were tested. These investigations showed that modification by using a PDMS stamp makes it possible to produce two-component ultrathin silane layers on Ti-containing carbon substrates. Two-component organosilane layers had higher hydrophobicity, a lower friction coefficient, and a smaller width of wear tracks than the one-component analogs. It was also found that the work of adhesion of the created surfaces had a significant influence on the value of the friction coefficient and the percentage value of the growth inhibition of bacteria.
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Affiliation(s)
- Michał Cichomski
- Department of Materials Technology and Chemistry, Faculty of Chemistry, University of Lodz, Pomorska 163, 90-236 Lodz, Poland
| | - Natalia Wrońska
- Department of Industrial Microbiology and Biotechnology, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland; (N.W.); (K.L.)
| | - Mariusz Dudek
- Institute of Materials Science and Engineering, Lodz University of Technology, Stefanowskiego 1/15, 90-924 Lodz, Poland; (M.D.); (A.J.)
| | - Anna Jędrzejczak
- Institute of Materials Science and Engineering, Lodz University of Technology, Stefanowskiego 1/15, 90-924 Lodz, Poland; (M.D.); (A.J.)
| | - Katarzyna Lisowska
- Department of Industrial Microbiology and Biotechnology, Faculty of Biology and Environmental Protection, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland; (N.W.); (K.L.)
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Halford J, Chen CF. The Role of APTES as a Primer for Polystyrene Coated AA2024-T3. Micromachines (Basel) 2023; 15:93. [PMID: 38258212 PMCID: PMC10820139 DOI: 10.3390/mi15010093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 12/26/2023] [Accepted: 12/29/2023] [Indexed: 01/24/2024]
Abstract
(3-Aminopropyl)triethoxysilane (APTES) silane possesses one terminal amine group and three ethoxy groups extending from each silicon atom, acting as a crucial interface between organic and inorganic materials. In this study, after APTES was deposited on the aluminum alloy AA2024-T3 as a primer for an optional top coating with polystyrene (PS), its role with regard to stability as a protection layer and interaction with the topcoat were studied via combinatorial experimentation. The aluminum alloy samples primed with APTES under various durations of concentrated vapor deposition (20, 40, or 60 min) with an optional post heat treatment and/or PS topcoat were comparatively characterized via electrochemical impedance spectroscopy (EIS) and surface energy. The samples top-coated with PS on an APTES layer primed for 40 min with a post heat treatment revealed excellent performance regarding corrosion impedance. A primed APTES surface with higher surface energy accounted for this higher corrosion impedance. Based on the SEM images and the surface energy calculated from the measured contact angles on the APTES-primed surfaces, four mechanisms are suggested to explain that the good protection performance of the APTES/PS coating system can be attributed to the enhanced wettability of PS on the cured APTES primer with higher surface energy. The results also suggest that, in the early stages of exposure to the corrosion solution, a thinner APTES primer (deposited for 20 min) enhances protection against corrosion, which can be attributed to the hydrolytic stability and hydrolyzation/condensation of the soaked APTES and the dissolution of the naturally formed aluminum oxide pre-existing in the bare samples. An APTES primer subjected to additional heat treatment will increase the impedance of the coating system significantly. APTES, and silanes, in general, used as adherent agents or surface modifiers, have a wide range of potential applications in micro devices, as projected in the Discussion section.
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Affiliation(s)
| | - Cheng-fu Chen
- Department of Mechanical Engineering, University of Alaska Fairbanks, Fairbanks, AK 99775-5905, USA;
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Reuter MB, Javier-Jiménez DR, Bushey CE, Waterman R. Group I Alkoxides and Amylates as Highly Efficient Silicon-Nitrogen Heterodehydrocoupling Precatalysts for the Synthesis of Amino silanes. Chemistry 2023; 29:e202302618. [PMID: 37728424 DOI: 10.1002/chem.202302618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 09/19/2023] [Accepted: 09/20/2023] [Indexed: 09/21/2023]
Abstract
Group I alkoxides are highly active precatalysts in the heterodehydrocoupling of silanes and amines to afford aminosilane products. The broadly soluble and commercially available KOt Amyl was utilized as the benchmark precatalyst for this transformation. Challenging substrates such as anilines were found to readily couple primary, secondary, and tertiary silanes in high conversions (>90 %) after only 2 h at 40 °C. Traditionally challenging silanes such as Ph3 SiH were also easily coupled to simple primary and secondary amines under mild conditions, with reactivity that rivals many rare earth and transition-metal catalysts for this transformation. Preliminary evidence suggests the formation of hypercoordinated intermediates, but radicals were detected under catalytic conditions, indicating a mechanism that is rare for Si-N bond formation.
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Affiliation(s)
- Matthew B Reuter
- Department of Chemistry, University of Vermont, 82 University Place, 05405, Burlington, VT, USA
| | - Diego R Javier-Jiménez
- Department of Chemistry, University of Vermont, 82 University Place, 05405, Burlington, VT, USA
| | - Claire E Bushey
- Department of Chemistry, University of Vermont, 82 University Place, 05405, Burlington, VT, USA
| | - Rory Waterman
- Department of Chemistry, University of Vermont, 82 University Place, 05405, Burlington, VT, USA
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Czakaj J, Sztorch B, Romanczuk-Ruszuk E, Brząkalski D, Przekop RE. Organosilicon Compounds in Hot-Melt Adhesive Technologies. Polymers (Basel) 2023; 15:3708. [PMID: 37765562 PMCID: PMC10534555 DOI: 10.3390/polym15183708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 09/01/2023] [Accepted: 09/05/2023] [Indexed: 09/29/2023] Open
Abstract
Hot-melt adhesives (HMAs) are thermoplastic materials that can bond various substrates by solidifying rapidly upon cooling from the molten state, and their modification with organosilicon compounds can result in crosslinking behavior, characteristic of gels. Organosilicon compounds are hybrid molecules that have both inorganic and organic components and can enhance the properties and performance of HMAs. The gel aspect of HMA with and without organosilicon modifiers can be considered in organosilicon-modified systems, the modifiers are often either sol-gel condensation products or their mechanism of action on the adherent surface can be considered of sol-gel type. The purpose of this manuscript is to present the current state of the art on the formulation, characterization, and application of HMAs and optimize their performance with organosilicon compounds for application in various industries such as automotive, construction, and photovoltaics. This review covers articles published within the period of 2018-2022. The article is divided into sections, in which information about hot-melt adhesives is described at the beginning. The following part of the presented review focuses on the composition of hot-melt adhesives, which takes into account the use of organosilicon compounds. The last part of this review outlines the future trends in hot-melt adhesives.
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Affiliation(s)
- Jakub Czakaj
- Faculty of Chemistry, Adam Mickiewicz University in Poznań, Uniwersytetu Poznańskiego 8, 61-614 Poznań, Poland;
- Centre for Advanced Technologies, Adam Mickiewicz University in Poznań, Uniwersytetu Poznańskiego 10, 61-614 Poznań, Poland; (B.S.); (D.B.)
- Almara Sp. Z o.o. Sp.k., 3/627 Mozarta, 02-736 Warsaw, Poland
| | - Bogna Sztorch
- Centre for Advanced Technologies, Adam Mickiewicz University in Poznań, Uniwersytetu Poznańskiego 10, 61-614 Poznań, Poland; (B.S.); (D.B.)
- Almara Sp. Z o.o. Sp.k., 3/627 Mozarta, 02-736 Warsaw, Poland
| | - Eliza Romanczuk-Ruszuk
- Institute of Biomedical Engineering, Faculty of Mechanical Engineering, Bialystok University of Technology, Wiejska 45C Street, 15-351 Bialystok, Poland;
| | - Dariusz Brząkalski
- Centre for Advanced Technologies, Adam Mickiewicz University in Poznań, Uniwersytetu Poznańskiego 10, 61-614 Poznań, Poland; (B.S.); (D.B.)
| | - Robert E. Przekop
- Centre for Advanced Technologies, Adam Mickiewicz University in Poznań, Uniwersytetu Poznańskiego 10, 61-614 Poznań, Poland; (B.S.); (D.B.)
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Fathpour K, Astaraki E, Zandian A, Fathi A, Mirmohammadi H. Shear bond strength of composite resins to lithium disilicate ceramics using universal bonding and different methods of surface preparation. Dent Res J (Isfahan) 2023; 20:82. [PMID: 37674574 PMCID: PMC10478835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 03/14/2023] [Accepted: 05/10/2023] [Indexed: 09/08/2023] Open
Abstract
Background Porcelain fracture or chipping is one of the limitations of all ceramic restorations. This study investigated the shear bond strength (SBS) of composite resins to lithium disilicate ceramics using universal bondings and different methods of surface preparation. Materials and Methods In this experimental study, 72 specimens of e.max computer-aided design and computer-aided manufacturing (CAD/CAM) ceramic blocks were divided into six groups of 12 according to surface treatment: Group I-Hydrofluoric (HF) acid etching + All-Bond Universal bonding (ABU), Group II-Bur roughening (BR) + HF + ABU, Group III-BR + HF + Bis-Silane (Si) + ABU, Group IV-Sandblasting (SB) + ABU, Group V-SB + HF + ABU, Group VI-SB + HF + Si + ABU. After bonding of composite resin to the prepared ceramic surface and storage of samples in distilled water for 24 h, SBS test was done using the universal testing machine at a crosshead speed of 0.5 mm/min. Data were analyzed using the analysis of variance and Tukey's post hoc test (α = 0.05). Results The mean values of SBS in six studied groups were 6.65 ± 2.78 MPa, 8.56 ± 2.69 MPa, 8.49 ± 2.14 MPa, 3.13 ± 1.66 MPa, 7.94 ± 2.4 MPa, and 10.04 ± 2.47 MPa, respectively. The mean values of SBS were significantly different (P < 0.001). The highest value of SBS was observed in Group VI and the lowest in Group IV. Conclusion Ceramic sandblasting followed by HF etching, Bis Si, and ABU resulted in a higher SBS of composite resins to lithium disilicate ceramics.
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Affiliation(s)
- Kamyar Fathpour
- Department of Restorative Dentistry, Dental Materials Research Center, Dental Research Institute, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Elham Astaraki
- Dental Student's Research Committee, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Amin Zandian
- Department of Restorative Dentistry, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Amirhossein Fathi
- Dental Prosthodontics Department, Dental Materials Research Center, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Hesam Mirmohammadi
- Department of Endodontology, Academic Centre for Dentistry Amsterdam (ACTA), Universiteit van Amsterdam and Vrije Universiteit, Amsterdam, the Netherlands
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Indumathy B, Sathiyanathan P, Prasad G, Reza MS, Prabu AA, Kim H. A Comprehensive Review on Processing, Development and Applications of Organofunctional Silanes and Silane-Based Hyperbranched Polymers. Polymers (Basel) 2023; 15:polym15112517. [PMID: 37299316 DOI: 10.3390/polym15112517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 05/04/2023] [Accepted: 05/12/2023] [Indexed: 06/12/2023] Open
Abstract
Since the last decade, hyperbranched polymers (HBPs) have gained wider theoretical interest and practical applications in sensor technology due to their ease of synthesis, highly branched structure but dimensions within nanoscale, a larger number of modified terminal groups and lowering of viscosity in polymer blends even at higher HBP concentrations. Many researchers have reported the synthesis of HBPs using different organic-based core-shell moieties. Interestingly, silanes, as organic-inorganic hybrid modifiers of HBP, are of great interest as they resulted in a tremendous improvement in HBP properties like increasing thermal, mechanical and electrical properties compared to that of organic-only moieties. This review focuses on the research progress in organofunctional silanes, silane-based HBPs and their applications since the last decade. The effect of silane type, its bi-functional nature, its influence on the final HBP structure and the resultant properties are covered in detail. Methods to enhance the HBP properties and challenges that need to be overcome in the near future are also discussed.
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Affiliation(s)
- Balaraman Indumathy
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore 632 014, Tamil Nadu, India
| | - Ponnan Sathiyanathan
- Department of Advanced Materials Engineering for Information & Electronics, College of Engineering, Kyung Hee University, Yongin-si 17104, Republic of Korea
| | - Gajula Prasad
- School of Energy, Materials and Chemical Engineering, Korea University of Technology and Education, 1600, Cheonan-si 31253, Republic of Korea
| | - Mohammad Shamim Reza
- Department of Advanced Materials Engineering for Information & Electronics, College of Engineering, Kyung Hee University, Yongin-si 17104, Republic of Korea
| | - Arun Anand Prabu
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore 632 014, Tamil Nadu, India
| | - Hongdoo Kim
- Department of Advanced Materials Engineering for Information & Electronics, College of Engineering, Kyung Hee University, Yongin-si 17104, Republic of Korea
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Sowińska-Baranowska A, Maciejewska M. Potential Utilization of Ground Eggshells as a Biofiller for Natural Rubber Biocomposites. Materials (Basel) 2023; 16:2988. [PMID: 37109824 PMCID: PMC10143961 DOI: 10.3390/ma16082988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 04/03/2023] [Accepted: 04/07/2023] [Indexed: 06/19/2023]
Abstract
The aim of this work was application of ground eggshells in various amounts by weight as a biofiller for natural rubber (NR) biocomposites. Cetyltrimethylammonium bromide (CTAB), ionic liquids (ILs), i.e., 1-butyl-3-methylimidazolium chloride (BmiCl) and 1-decyl-3-methylimidazolium bromide (DmiBr), and silanes, i.e., (3-aminopropyl)-triethoxysilane (APTES) and bis [3-(triethoxysilyl)propyl] tetrasulfide (TESPTS), were used to increase the activity of ground eggshells in the elastomer matrix and to ameliorate the cure characteristics and properties of NR biocomposites. The influence of ground eggshells, CTAB, ILs, and silanes on the crosslink density, mechanical properties, and thermal stability of NR vulcanizates and their resistance to prolonged thermo-oxidation were explored. The amount of eggshells affected the curing characteristics and crosslink density of the rubber composites and therefore their tensile properties. Vulcanizates filled with eggshells demonstrated higher crosslink density than the unfilled sample by approximately 30%, whereas CTAB and ILs increased the crosslink density by 40-60% compared to the benchmark. Owing to the enhanced crosslink density and uniform dispersion of ground eggshells, vulcanizates containing CTAB and ILs exhibited tensile strength improved by approximately 20% compared to those without these additives. Moreover, the hardness of these vulcanizates was increased by 35-42%. Application of both the biofiller and the tested additives did not significantly affect the thermal stability of cured NR compared to the unfilled benchmark. Most importantly, the eggshell-filled vulcanizates showed improved resistance to thermo-oxidative aging compared to the unfilled NR.
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Dobrosielska M, Dobrucka R, Brząkalski D, Kozera P, Martyła A, Gabriel E, Kurzydłowski KJ, Przekop RE. Polyamide 11 Composites Reinforced with Diatomite Biofiller-Mechanical, Rheological and Crystallization Properties. Polymers (Basel) 2023; 15:polym15061563. [PMID: 36987343 PMCID: PMC10053006 DOI: 10.3390/polym15061563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 03/13/2023] [Accepted: 03/14/2023] [Indexed: 03/30/2023] Open
Abstract
Amorphic diatomaceous earth is derived from natural sources, and polyamide 11 (PA11) is produced from materials of natural origin. Both of these materials show a low harmfulness to the environment and a reduced carbon footprint. This is why the combination of these two constituents is beneficial not only to improve the physicochemical and mechanical properties of polyamide 11 but also to produce a biocomposite. For the purpose of this paper, the test biocomposite was produced by combining polyamide 11, as well as basic and pre-fractionated diatomaceous earth, which had been subjected to silanization. The produced composites were used to carry out rheological (melt flow rate-MFR), mechanical (tensile strength, bending strength, impact strength), crystallographic (X-ray Diffraction-XRD), thermal and thermo-mechanical (differential scanning calorimetry-DSC, dynamic mechanical thermal analysis-DMTA) analyses, as well as a study of hydrophobic-hydrophilic properties of the material surface (wetting angle) and imaging of the surface of the composites and the fractured specimens. The tests showed that the additive 3-aminopropyltriethoxysilane (APTES) acted as an agent that improved the elasticity of composites and the melt flow rate. In addition, the produced composites showed a hydrophilic surface profile compared to pure polylactide and polyamide 11.
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Affiliation(s)
- Marta Dobrosielska
- Faculty of Materials Science and Engineering, Warsaw University of Technology, ul. Wołoska 141, 02-507 Warsaw, Poland
| | - Renata Dobrucka
- Faculty of Materials Science and Engineering, Warsaw University of Technology, ul. Wołoska 141, 02-507 Warsaw, Poland
- Department of Non-Food Products Quality and Packaging Development, Institute of Quality Science, Poznań University of Economics and Business, al. Niepodległości 10, 61-875 Poznań, Poland
| | - Dariusz Brząkalski
- Centre for Advanced Technologies, Adam Mickiewicz University in Poznań, ul. Uniwersytetu Poznańskiego 10, 61-614 Poznań, Poland
| | - Paulina Kozera
- Faculty of Materials Science and Engineering, Warsaw University of Technology, ul. Wołoska 141, 02-507 Warsaw, Poland
| | - Agnieszka Martyła
- Centre for Advanced Technologies, Adam Mickiewicz University in Poznań, ul. Uniwersytetu Poznańskiego 10, 61-614 Poznań, Poland
| | - Ewa Gabriel
- Centre for Advanced Technologies, Adam Mickiewicz University in Poznań, ul. Uniwersytetu Poznańskiego 10, 61-614 Poznań, Poland
| | - Krzysztof J Kurzydłowski
- Faculty of Mechanical Engineering, Bialystok University of Technology, ul. Wiejska 45c, 15-351 Bialystok, Poland
| | - Robert E Przekop
- Centre for Advanced Technologies, Adam Mickiewicz University in Poznań, ul. Uniwersytetu Poznańskiego 10, 61-614 Poznań, Poland
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12
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Lambert H, Corn S, Léger R, Ienny P, Slangen P, Fages M. Ceramic Bonding Interface under Shear-Compression Stress: Ultra-High-Speed Imaging Contribution. J Dent Res 2023; 102:295-301. [PMID: 36562502 DOI: 10.1177/00220345221138500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The aim of this study is to visualize and characterize by ultra-high-speed imaging (UHSI) the failure phenomena at the resin-ceramic bonding interface of lithium disilicate (LiSi2) samples bonded with gold-standard protocol (Monobond Plus [MB]) and the nontoxic one (Monobond Etch & Prime [MEP]) subjected to mechanical loading. Unprecedented frame rate, image resolution, and recording time were reached by using the most advanced UHSI camera. The finite element analysis (FEA) of the proposed mechanical test confirmed that the specific design of our samples enables a combined shear and compression stress state, prone to test the bonding interface while being close to physiological stresses. Ten LiSi2 samples were pretreated by gold standard (MB, n = 5) and self-etching primer (MEP, n = 5). Axial compression loading gradually increased until catastrophic failure was performed. As shown by the FEA, the angle between the bonding interface and load direction leads to shear-compression stresses at the resin-ceramic bonding interface. Failure was recorded by UHSI at 300,000 fps. All recorded images were analyzed to segregate events and isolate the origin of fracture. For the first time, thanks to the image recording setup, it was observed that debonding is the first event before breakage, highlighting that sample fracture occurs by interfacial rupture followed by slippage and cohesive failure of materials. Failure mode could be described as mixed. MEP and MB showed similar results and behavior.
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Affiliation(s)
- H Lambert
- Laboratory Bioengineering and Nanosciences, University of Montpellier, Montpellier, France.,Department of Prosthetic Dentistry, Faculty of Odontology, Montpellier University, France
| | - S Corn
- LMGC, Univ Montpellier, IMT Mines Ales, CNRS, Ales, France
| | - R Léger
- LMGC, Univ Montpellier, IMT Mines Ales, CNRS, Ales, France
| | - P Ienny
- LMGC, Univ Montpellier, IMT Mines Ales, CNRS, Ales, France
| | - P Slangen
- EuroMov Digital Health in Motion, Univ Montpellier, IMT Mines Ales, Ales, France
| | - M Fages
- Laboratory Bioengineering and Nanosciences, University of Montpellier, Montpellier, France.,Department of Prosthetic Dentistry, Faculty of Odontology, Montpellier University, France
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13
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Peng Y, Oestreich M. B(C 6 F 5 ) 3 -Catalyzed Regioselective Ring Opening of Cyclic Amines with Hydro silanes. Chemistry 2023; 29:e202203721. [PMID: 36448647 DOI: 10.1002/chem.202203721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 11/29/2022] [Accepted: 11/30/2022] [Indexed: 12/02/2022]
Abstract
Opening the ring of cyclic amines by regioselective fission of one of the carbon-nitrogen bonds greatly expands the repertoire of available nitrogen-containing skeletons. Unlike approaches starting from cyclic tertiary amines, methods that can directly open secondary amines are still scarce. The present work discloses an efficient reductive ring opening of either of these cyclic amines using PhSiH3 under B(C6 F5 )3 catalysis. By this, the direct transformation of unstrained cyclic amines into the corresponding acyclic amines is achieved in a simple one-pot operation. A stepwise mechanism proceeding through the intermediacy of silylammonium ions followed by reductive cleavage of a carbon-nitrogen bond was experimentally verified.
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Affiliation(s)
- Yi Peng
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
| | - Martin Oestreich
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
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14
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Coffinet A, Specklin D, Le Dé Q, Bennaamane S, Muñoz L, Vendier L, Clot E, Mézailles N, Simonneau A. Assessing Combinations of B(C 6 F 5 ) 3 and N 2 -Derived Molybdenum Nitrido Complexes for Heterolytic Bond Activation. Chemistry 2023; 29:e202203774. [PMID: 36805704 DOI: 10.1002/chem.202203774] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 02/10/2023] [Accepted: 02/20/2023] [Indexed: 02/22/2023]
Abstract
Two different dinitrogen-derived molybdenum nitrido complexes varying by their geometry, ligand spheres and oxidations states were shown to engage their N ligand in dative bonding with the strong Lewis acid B(C6 F5 )3 . The stable adducts were assessed for frustrated Lewis pair-type heterolytic E-H bond splitting of hydrosilanes (E=Si) and HB(C6 F5 )2 . Whereas Si-H bond activation was achieved, HB(C6 F5 )2 was shown to substitute B(C6 F5 )3 in a quantitative or equilibrated fashion, depending on the nature of the nitrido complex. No B-H bond splitting was observed. Thermodynamics of these reactions, computed by DFT, are in agreement with the experimental outcomes.
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Affiliation(s)
- Anaïs Coffinet
- LCC-CNRS, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, BP44099, F-31077, Toulouse cedex 4, France
| | - David Specklin
- LCC-CNRS, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, BP44099, F-31077, Toulouse cedex 4, France
| | - Quentin Le Dé
- LCC-CNRS, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, BP44099, F-31077, Toulouse cedex 4, France
| | - Soukaina Bennaamane
- Laboratoire Hétérochimie Fondamentale et Appliquée, Université Paul Sabatier, CNRS, 118 Route de Narbonne, 31062, Toulouse, France
| | - Luna Muñoz
- LCC-CNRS, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, BP44099, F-31077, Toulouse cedex 4, France
| | - Laure Vendier
- LCC-CNRS, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, BP44099, F-31077, Toulouse cedex 4, France
| | - Eric Clot
- ICGM, Univ. Montpellier, CNRS, ENSCM, 34000, Montpellier, France
| | - Nicolas Mézailles
- Laboratoire Hétérochimie Fondamentale et Appliquée, Université Paul Sabatier, CNRS, 118 Route de Narbonne, 31062, Toulouse, France
| | - Antoine Simonneau
- LCC-CNRS, Université de Toulouse, CNRS, UPS, 205 route de Narbonne, BP44099, F-31077, Toulouse cedex 4, France
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15
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Messersmith RE, Sage FC, Johnson JK, Langevin SA, Forsyth ER, Hart MT, Hoffman CM. Iron Sequestration by Galloyl-Silane Nano Coatings Inhibits Biofilm Formation of Sulfitobacter sp. Biomimetics (Basel) 2023; 8:biomimetics8010079. [PMID: 36810410 PMCID: PMC9944052 DOI: 10.3390/biomimetics8010079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 02/08/2023] [Accepted: 02/10/2023] [Indexed: 02/15/2023] Open
Abstract
Microbially-induced corrosion is the acceleration of corrosion induced by bacterial biofilms. The bacteria in the biofilms oxidize metals on the surface, especially evident with iron, to drive metabolic activity and reduce inorganic species such as nitrates and sulfates. Coatings that prevent the formation of these corrosion-inducing biofilms significantly increase the service life of submerged materials and significantly decrease maintenance costs. One species in particular, a member of the Roseobacter clade, Sulfitobacter sp., has demonstrated iron-dependent biofilm formation in marine environments. We have found that compounds that contain the galloyl moiety can prevent Sulfitobacter sp. biofilm formation by sequestering iron, thus making a surface unappealing for bacteria. Herein, we have fabricated surfaces with exposed galloyl groups to test the effectiveness of nutrient reduction in iron-rich media as a non-toxic method to reduce biofilm formation.
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Affiliation(s)
- Reid E. Messersmith
- Research and Exploratory Development Department, The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723, USA
| | - F. Connor Sage
- Asymmetric Operations Sector, The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723, USA
| | - James K. Johnson
- Asymmetric Operations Sector, The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723, USA
| | - Spencer A. Langevin
- Research and Exploratory Development Department, The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723, USA
| | - Ellen R. Forsyth
- Asymmetric Operations Sector, The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723, USA
| | - Meaghan T. Hart
- Research and Exploratory Development Department, The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723, USA
| | - Christopher M. Hoffman
- Research and Exploratory Development Department, The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723, USA
- Correspondence:
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16
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Bloux H, Dahiya A, Hébert A, Fabis F, Schoenebeck F, Cailly T. Base-Mediated Radio-Iodination of Arenes by Using Organosilane and Organogermane as Radiolabelling Precursors. Chemistry 2023; 29:e202203366. [PMID: 36607172 DOI: 10.1002/chem.202203366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 01/05/2023] [Accepted: 01/06/2023] [Indexed: 01/07/2023]
Abstract
The radio-iodination of arenes is investigated from organosilane and organogermane precursors using ipso-electrophilic halogenation (IEH). Discovery of a mild base mediated process allows radio-iodination in HFIP (1,1,1,3,3,3-hexafluoro-2-propanol) of either aryl silane or germane, with germanes being more reactive. Clinical potential of arylgermanes as radio-iodination precursors is demonstrated through the labelling of [125 I]IMTO (iodometomidate) and [125 I]MIBG (meta-iodobenzylguanidine) thus offering an alternative to radio-iododestannylation processes using non-toxic precursors.
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Affiliation(s)
- Hugo Bloux
- Centre d'Etudes et de Recherche sur le Médicament de Normandie (CERMN), Normandie Univ, UNICAEN, 14000, Caen, France
| | - Amit Dahiya
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074, Aachen, Germany
| | - Alexandra Hébert
- Centre d'Etudes et de Recherche sur le Médicament de Normandie (CERMN), Normandie Univ, UNICAEN, 14000, Caen, France
| | - Frédéric Fabis
- Centre d'Etudes et de Recherche sur le Médicament de Normandie (CERMN), Normandie Univ, UNICAEN, 14000, Caen, France
| | - Franziska Schoenebeck
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074, Aachen, Germany
| | - Thomas Cailly
- Centre d'Etudes et de Recherche sur le Médicament de Normandie (CERMN), Normandie Univ, UNICAEN, 14000, Caen, France.,IMOGERE, Normandie Univ, UNICAEN, 14000, Caen, France.,Department of Nuclear Medicine, CHU Côte de Nacre, 14000, Caen, France.,Institut Blood and Brain @Caen-Normandie (BB@C), Boulevard Henri Becquerel, 14074, Caen, France
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17
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Dobrosielska M, Dobrucka R, Pajewska-Szmyt M, Kozera P, Gabriel E, Głowacka J, Brząkalski D, Kurzydłowski KJ, Przekop RE. Effect of Wax Additives and Silanization of Diatom Surfaces on Thermomechanical Properties of Polylactide Composites. Polymers (Basel) 2022; 14. [PMID: 36559878 DOI: 10.3390/polym14245511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 12/02/2022] [Accepted: 12/09/2022] [Indexed: 12/23/2022] Open
Abstract
In the present study, tests were conducted on high-filled composite samples on a polylactide matrix, modified with diatomaceous earth, three types of silanes, and natural and synthetic wax. The obtained samples were characterized in terms of the effect of modifications on mechanical properties (tensile strength, flexural strength, and impact resistance) or processing properties, e.g., melt flow rate (MFR). The study showed that the modification had a favorable effect on the processing properties of the composites, associated with up to an eight-fold increase in flow rate index compared with the reference sample, especially for samples treated with methyltrimethoxysilane (MTMOS), and up to a ten-fold increase under low shear-rate flow conditions. The effect of the addition of waxes of different origins (synthetic and natural) was also determined, and it was shown that beeswax tended to reduce the flow rate of the composites regardless of the silane used. The addition of synthetic wax to composites increased the tendency to agglomerate diatomaceous earth, while natural wax had a positive effect on filler dispersion.
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18
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Wedler V, Quinones D, Peisert H, Schäffer E. A Quick and Reproducible Silanization Method by Using Plasma Activation for Hydrophobicity-Based Kinesin Single Molecule Fluorescence-Microscopy Assays. Chemistry 2022; 28:e202202036. [PMID: 35925842 PMCID: PMC9826530 DOI: 10.1002/chem.202202036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Indexed: 01/11/2023]
Abstract
Single-molecule assays often require functionalized surfaces. One approach for microtubule assays renders surfaces hydrophobic and uses amphiphilic blocking agents. However, the optimal hydrophobicity is unclear, protocols take long, produce toxic waste, and are susceptible to failure. Our method uses plasma activation with hydrocarbons for hexamethyldisilazane (HMDS) silanization in the gas phase. We measured the surface hydrophobicity, its effect on how well microtubule filaments were bound to the surface, and the number of nonspecific interactions with kinesin motor proteins. Additionally, we tested and discuss the use of different silanes and activation methods. We found that even weakly hydrophobic surfaces were optimal. Our environmentally friendly method significanty reduced the overall preparation effort and resulted in reproducible, high-quality surfaces with low variability. We expect the method to be applicable to a wide range of other single-molecule assays.
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Affiliation(s)
- Viktoria Wedler
- Eberhard Karls Universität Tübingen, Cellular Nanoscience (ZMBP)Auf der Morgenstelle 3272076TübingenGermany
| | - Dustin Quinones
- Eberhard Karls Universität TübingenInstitute of Physical and Theoretical ChemistryAuf der Morgenstelle 1872076TübingenGermany
| | - Heiko Peisert
- Eberhard Karls Universität TübingenInstitute of Physical and Theoretical ChemistryAuf der Morgenstelle 1872076TübingenGermany
| | - Erik Schäffer
- Eberhard Karls Universität Tübingen, Cellular Nanoscience (ZMBP)Auf der Morgenstelle 3272076TübingenGermany
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19
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Luta EP, Miller BL. Development of Methods for Specific Capture of Biological Targets on Aluminum Substrates: Application to Bacillus subtilis Spore Detection as a Model for Anthrax. Sensors (Basel) 2022; 22:3441. [PMID: 35591130 DOI: 10.3390/s22093441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 03/20/2022] [Accepted: 04/26/2022] [Indexed: 02/04/2023]
Abstract
Many (if not most) biosensors rely on functional silane coatings as a first step toward covalent immobilization of specific capture molecules. While methods for silanization of silica (SiO2) surfaces are very well developed, less has been done to develop and characterize silanization methods for alternative substrates, such as alumina (Al2O3). In particular, the behavior of Al2O3 coatings grown on aluminum under ambient conditions has not been studied. To address this issue, we have tested solution-phase deposition of two silanes on Al2O3 (3-aminopropyl triethoxysilane and 3-triethoxysilyl)propylsuccinic anhydride) and their applicability to analyte-specific biosensing. Contact angle measurements and imaging via Scanning Electron Microsopy (SEM) were employed to characterize surfaces. We find that 3-aminopropyl triethoxysilane produces well-behaved films and demonstrate that this surface can undergo further reaction with glutaraldehyde followed by an anti-Bacillus subtilis antibody to yield functionalized Al2O3 surfaces capable of specific capture of B. subtilis spores (a model of B. anthracis, the causative organism of Anthrax). In contrast, 3-triethoxysilyl)propylsuccinic anhydride did not behave well with Al/Al2O3 under the reaction conditions tested. In addition to providing specific protocols for Al/Al2O3 functionalization, this work highlights the importance of surface chemistry assessment in the development of new sensors.
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20
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Lainer T, Dange D, Pillinger M, Fischer RC, Kelterer AM, Jones C, Haas M. An NHC-Mediated Metal-Free Approach towards an NHC-Coordinated Endocyclic Disilene. Chemistry 2022; 11:e202100240. [PMID: 35142081 PMCID: PMC8889510 DOI: 10.1002/open.202100240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 01/27/2022] [Indexed: 11/15/2022]
Abstract
A convenient metal‐free approach towards an N‐heterocyclic carbene (NHC)‐coordinated disilene 2 is described. Compound 2, featuring the disilene incorporated in cyclopolysilane framework, was obtained in good yield and characterized using NMR spectroscopy and X‐ray crystallography. Density functional theory (DFT) calculations of the reaction mechanism provide a rationale for the observed reactivity and give detailed information on the bonding situation of the base‐stabilized disilene. Compound 2 undergoes thermal or light‐ induced (λ=456 nm) NHC loss, and a dimerization process to give a corresponding dimer with a Si10 skeleton. In order to shed light on the dimerization mechanism, DFT calculations were performed. Moreover, the reactivity of 2 was examined with selected examples of transition metal carbonyl compounds.
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Affiliation(s)
- Thomas Lainer
- Institute of Inorganic Chemistry, Graz University of Technology, Stremayrgasse 9/IV, 8010, Graz, Austria
| | - Deepak Dange
- School of Chemistry, Monash University, PO Box 23, Australia
| | - Michael Pillinger
- Institute of Inorganic Chemistry, Graz University of Technology, Stremayrgasse 9/IV, 8010, Graz, Austria
| | - Roland C Fischer
- Institute of Inorganic Chemistry, Graz University of Technology, Stremayrgasse 9/IV, 8010, Graz, Austria
| | - Anne-Marie Kelterer
- Institute of Physical and Theoretical Chemistry, Stremayrgasse 9/I, 8010, Graz, Austria
| | - Cameron Jones
- School of Chemistry, Monash University, PO Box 23, Australia
| | - Michael Haas
- Institute of Inorganic Chemistry, Graz University of Technology, Stremayrgasse 9/IV, 8010, Graz, Austria
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21
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Abstract
Herein, we report that a cobalt catalyst permits the general synthesis of substituted alkynylsilanes through dehydrogenative coupling of alkynylsilanes and hydrosilanes. Several silylated alkynes, including di‐ and trisubstituted ones, were prepared in a one‐step procedure. Thirty‐seven compounds were synthesized for the first time by applying our catalyst system. The alkynylsilanes bearing hydrosilyl moieties provide an opportunity for further functionalization (e. g., hydrosilylation). The use of primary silanes as substrates and precatalyst activators permits the use of inexpensive and easily accessible 3d metal precatalysts, and avoids the presence of additional activators.
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Affiliation(s)
- Hanna Stachowiak
- Department of Chemistry and Technology of Silicon Compounds, Faculty of Chemistry, Adam Mickiewicz University in Poznań, Uniwersytetu Poznańskiego 8, 61-614, Poznań, Poland
| | - Krzysztof Kuciński
- Department of Chemistry and Technology of Silicon Compounds, Faculty of Chemistry, Adam Mickiewicz University in Poznań, Uniwersytetu Poznańskiego 8, 61-614, Poznań, Poland
| | - Fabian Kallmeier
- Inorganic Chemistry II-Catalyst Design, Sustainable Chemistry Centre, University of Bayreuth, 95440, Bayreuth, Germany
| | - Rhett Kempe
- Inorganic Chemistry II-Catalyst Design, Sustainable Chemistry Centre, University of Bayreuth, 95440, Bayreuth, Germany
| | - Grzegorz Hreczycho
- Department of Chemistry and Technology of Silicon Compounds, Faculty of Chemistry, Adam Mickiewicz University in Poznań, Uniwersytetu Poznańskiego 8, 61-614, Poznań, Poland.,Centre for Advanced Technologies, Adam Mickiewicz University in Poznań, Uniwersytetu Poznańskiego 10, 61-614, Poznań, Poland
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22
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Fernandes AC. Reductive Depolymerization of Plastic Waste Catalyzed by Zn(OAc) 2 ⋅ 2H 2 O. ChemSusChem 2021; 14:4228-4233. [PMID: 33667328 DOI: 10.1002/cssc.202100130] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 03/02/2021] [Indexed: 06/12/2023]
Abstract
Plastic pollution is one of the biggest problems all over the world. Beyond change/awareness of consumer behavior, there is an urgent need to search for efficient, economical and environmentally friendly catalysts for the valorization of plastic waste to value-added compounds. This work describes the reductive depolymerization of several types of plastic waste into value-added compounds, including 1,6-hexanediol, 1,2-propanediol, p-xylene and tetrahydrofuran, in good yields using the eco-friendly, air-stable, commercially available and very cheap catalyst Zn(OAc)2 ⋅ 2H2 O. This is the first example of the reductive depolymerization of polyester waste catalyzed by a zinc catalyst. Moreover, the catalytic system silane/Zn(OAc)2 ⋅ 2H2 O was successfully applied to the reduction of polycaprolactone (PCL) on the gram scale with good yield and also to the selective reductive depolymerization of plastic mixtures. Finally, this work demonstrated that the catalyst Zn(OAc)2 ⋅ 2H2 O can be used in at least 7 cycles with good yields.
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Affiliation(s)
- Ana C Fernandes
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001, Lisboa, Portugal
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23
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Burton KI, Elser I, Waked AE, Wagener T, Andrews RJ, Glorius F, Stephan DW. Bipyridinium and Phenanthrolinium Dications for Metal-Free Hydrodefluorination: Distinctive Carbon-Based Reactivity. Chemistry 2021; 27:11730-11737. [PMID: 34107119 DOI: 10.1002/chem.202101534] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Indexed: 01/06/2023]
Abstract
The development of novel Lewis acids derived from bipyridinium and phenanthrolinium dications is reported. Calculations of Hydride Ion Affinity (HIA) values indicate high carbon-based Lewis acidity at the ortho and para positions. This arises in part from extensive LUMO delocalization across the aromatic backbones. Species [C10 H6 R2 N2 CH2 CH2 ]2+ (R=H [1 a]2+ , Me [1 f]2+ , tBu [1 g]2+ ), and [C12 H4 R4 N2 CH2 CH2 ]2+ (R=H [2 a]2+ , Me [2 b]2+ ) were prepared and evaluated for use in the initiation of hydrodefluorination (HDF) catalysis. Compound [2 a]2+ proved highly effective towards generating catalytically active silylium cations via Lewis acid-mediated hydride abstraction from silane. This enabled the HDF of a range of aryl- and alkyl- substituted sp3 (C-F) bonds under mild conditions. The protocol was also adapted to effect the deuterodefluorination of cis-2,4,6-(CF3 )3 C6 H9 . The dications are shown to act as hydride acceptors with the isolation of neutral species C16 H14 N2 (3 a) and C16 H10 Me4 N2 (3 b) and monocationic species [C14 H13 N2 ]+ ([4 a]+ ) and [C18 H21 N2 ]+ ([4 b]+ ). Experimental and computational data provide further support that the dications are initiators in the generation of silylium cations.
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Affiliation(s)
- Katherine I Burton
- Department of Chemistry, Davenport Research Laboratories, University of Toronto, Toronto, Ontario, M5S 3H6, Canada
| | - Iris Elser
- Department of Chemistry, Davenport Research Laboratories, University of Toronto, Toronto, Ontario, M5S 3H6, Canada
| | - Alexander E Waked
- Department of Chemistry, Davenport Research Laboratories, University of Toronto, Toronto, Ontario, M5S 3H6, Canada
| | - Tobias Wagener
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Correnstraβe 40, 48149, Münster, Germany
| | - Ryan J Andrews
- Department of Chemistry, Davenport Research Laboratories, University of Toronto, Toronto, Ontario, M5S 3H6, Canada
| | - Frank Glorius
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Correnstraβe 40, 48149, Münster, Germany
| | - Douglas W Stephan
- Department of Chemistry, Davenport Research Laboratories, University of Toronto, Toronto, Ontario, M5S 3H6, Canada
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24
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Roesler F, Kovács M, Bruhn C, Kelemen Z, Pietschnig R. Phosphetes via Transition Metal Free Ring Closure - Taking the Proper Turn at a Thermodynamic Crossing. Chemistry 2021; 27:9782-9790. [PMID: 33971050 PMCID: PMC8361766 DOI: 10.1002/chem.202101298] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Indexed: 11/24/2022]
Abstract
A transition metal free route to phosphetes featuring an exocyclic alkene unit is presented. In this approach phosphanides are added to a variety of diynes generating phosphaallylic intermediates which depending on the reaction conditions transform either to phosphetes or the corresponding phospholes. Investigation of the reaction mechanism by combined quantum chemical and experimental means identifies phosphole formation as thermodynamically controlled reaction path, whereas kinetic control furnishes the corresponding phosphetes. Structural and luminescence properties of the rare class of phosphetes are explored, as well as for selected key intermediates.
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Affiliation(s)
- Fabian Roesler
- Institute for Chemistry and CINSaTUniversity of KasselHeinrich Plett-Straße 4034132KasselGermany
| | - Máté Kovács
- Department of Inorganic and Analytical ChemistryBudapest University of Technology and EconomicsSzt. Gellért tér 4H-1111BudapestHungary
| | - Clemens Bruhn
- Institute for Chemistry and CINSaTUniversity of KasselHeinrich Plett-Straße 4034132KasselGermany
| | - Zsolt Kelemen
- Department of Inorganic and Analytical ChemistryBudapest University of Technology and EconomicsSzt. Gellért tér 4H-1111BudapestHungary
| | - Rudolf Pietschnig
- Institute for Chemistry and CINSaTUniversity of KasselHeinrich Plett-Straße 4034132KasselGermany
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25
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Hermannsdorfer A, Driess M. Silicon Tetrakis(trifluoromethanesulfonate): A Simple Neutral Silane Acting as a Soft and Hard Lewis Superacid. Angew Chem Int Ed Engl 2021; 60:13656-13660. [PMID: 33826216 PMCID: PMC8252640 DOI: 10.1002/anie.202103414] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 04/01/2021] [Indexed: 11/10/2022]
Abstract
A facile synthesis and isolation of pristine silicon tetrakis(trifluoromethanesulfonate), Si(OTf)4, is reported, acting as the first neutral silicon‐based Lewis superacid suitable towards soft and hard Lewis bases. Its OTf groups have a dual function: they are excellent leaving groups and modulate the degree of reactivity towards soft and hard Lewis bases. Exposed to soft Lewis donors, Si(OTf)4 leads to [L2Si(OTf)4] complexes (L=isocyanide, thioether and carbonyl compounds) with retention of all Si−OTf bonds. In contrast, it can cleave C−X bonds (X=F, Cl) of hard organic Lewis bases with a high tendency to form SiX4 (X=F, Cl) after halide/triflate exchange. Most notable, Si(OTf)4 allows a gentle oxydefluorination of mono‐ and bis(trifluoromethyl)benzenes, resulting in the formation of the corresponding benzoylium species, which are stabilized by the weakly coordinating [Si(OTf)6] dianion.
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Affiliation(s)
- André Hermannsdorfer
- Department of Chemistry: Metalorganics and Inorganic Materials, Technische Universität Berlin, Strasse des 17. Juni 115, Sekr. C2, 10623, Berlin, Germany
| | - Matthias Driess
- Department of Chemistry: Metalorganics and Inorganic Materials, Technische Universität Berlin, Strasse des 17. Juni 115, Sekr. C2, 10623, Berlin, Germany
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26
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Valian A, Salehi EM, Mahmoudzadeh M, Dabagh NK. Effect of different surface treatment on the repair bond strength of feldspathic porcelain. Dent Med Probl 2021; 58:107-113. [PMID: 33847469 DOI: 10.17219/dmp/130101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Considering the use of silane-containing universal adhesives to enhance the repair bond strength of porcelain restorations, a question arises whether the application of these adhesives eliminates the need for a separate application of silane or not. OBJECTIVES This study aimed to assess the effect of various kinds of surface treatment, including hydrofluoric acid (HF) etching, the application of bis-silane and the use of universal adhesives, on the repair bond strength of feldspathic porcelain. MATERIAL AND METHODS In this experimental in vitro study, 70 porcelain disks were fabricated and divided into 7 groups (n = 10) for the following types of surface treatment: C (control group) – HF etching + silane + Porcelain Bond; HSB – HF etching + Single Bond; HSSB – HF etching + silane + Single Bond; HAB – HF etching + All Bond; HSAB – HF etching + silane + All Bond; HFB – HF etching + FuturaBond®; and HSFB – HF etching + silane + FuturaBond. After applying different kinds of surface treatment, the specimens were light-cured and the Filtek® Z250 composite was bonded to the treated surfaces. The specimens were incubated in distilled water at 37°C for 24 h, and then underwent 5,000 thermal cycles. The repair bond strength of porcelain was measured and the mode of failure was determined under a stereomicroscope. Data was analyzed using the one-way analysis of variance (ANOVA) and Tukey’s test. RESULTS Differences between the groups in the porcelain repair bond strength were significant (p < 0.0001). Bond strength for Single Bond (p < 0.001) and All Bond (p < 0.001) along with silane was significantly higher than for the application of these adhesives without a separate silane application step. This difference was not significant for FuturaBond. Mixed failure was the dominant mode of failure in all groups. CONCLUSIONS The application of silane, irrespective of the use of universal adhesives with or without silane, increased the porcelain repair bond strength. Thus, a separate silane application step following HF etching and the use of universal adhesives with or without silane can enhance the repair bond strength of feldspathic porcelain.
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Affiliation(s)
- Azam Valian
- Department of Restorative Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | | | - Neda Kheirkhah Dabagh
- Department of Restorative Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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27
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Wu S, Huang Z, Jiang X, Yan F, Li Y, Du CX. Recyclable Oxofluorovanadate-Catalyzed Formylation of Amines by Reductive Functionalization of CO 2 with Hydro silanes. ChemSusChem 2021; 14:1763-1766. [PMID: 33587333 DOI: 10.1002/cssc.202100117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/14/2021] [Indexed: 06/12/2023]
Abstract
An efficient method has been developed for the reductive amination of CO2 by using readily available and recyclable oxofluorovanadates as catalysts. Various amines are transformed into the desired N-formylated products in moderate to excellent yields at room temperature in the presence of phenylsilane. Mechanistic studies based on in situ infrared spectroscopy suggest a reaction pathway initiated through F-Si interactions. The activated phenylsilane allows for CO2 insertion to produce phenylsilyl formate, which undergoes attack by the amine to generate the target product.
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Affiliation(s)
- Shanxuan Wu
- College of Chemistry, Zhengzhou University, Zhengzhou, 450001, P.R. China
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Suzhou Research Institute of LICP, Center for Excellence in Molecular Synthesis, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, P. R. China
| | - Zijun Huang
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Suzhou Research Institute of LICP, Center for Excellence in Molecular Synthesis, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, P. R. China
- College of Chemistry and Chemical Engineering, Hunan Institute of Engineering, Xiangtan, 411104, P. R. China
| | - Xiaolin Jiang
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Suzhou Research Institute of LICP, Center for Excellence in Molecular Synthesis, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, P. R. China
| | - Fachao Yan
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Suzhou Research Institute of LICP, Center for Excellence in Molecular Synthesis, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, P. R. China
| | - Yuehui Li
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Suzhou Research Institute of LICP, Center for Excellence in Molecular Synthesis, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, P. R. China
| | - Chen-Xia Du
- College of Chemistry, Zhengzhou University, Zhengzhou, 450001, P.R. China
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Abstract
Compounds of main‐group elements such as silicon are attractive candidates for green and inexpensive catalysts. For them to compete with state‐of‐the‐art transition‐metal complexes, new reactivity modes must be unlocked and controlled, which can be achieved through strain. Using a tris(2‐skatyl)methylphosphonium ([TSMPH3]+) scaffold, we prepared the strained cationic silane [TSMPSiH]+. In stark contrast with the generally hydridic Si−H bond character, it is acidic with an experimental pKaDMSO within 4.7–8.1, lower than in phenol, benzoic acid, and the few hydrosilanes with reported pKa values. We show that ring strain significantly contributes to this unusual acidity along with inductive and electrostatic effects. The conjugate base, TSMPSi, activates a THF molecule in the presence of CH‐acids to generate a highly fluxional alkoxysilane via trace amounts of [TSMPSiH]+ functioning as a strain‐release Lewis acid. This reaction involves a formal oxidation‐state change from SiII to SiIV, presenting intriguing similarities with transition‐metal‐mediated processes.
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Affiliation(s)
- Serhii Tretiakov
- Utrecht University, Organic Chemistry & Catalysis, Institution Debye Institute for Nanomaterials Science, Faculty of Science, 3584 CG, Utrecht, The Netherlands
| | - Léon Witteman
- Utrecht University, Organic Chemistry & Catalysis, Institution Debye Institute for Nanomaterials Science, Faculty of Science, 3584 CG, Utrecht, The Netherlands
| | - Martin Lutz
- Utrecht University, Structural Biochemistry, Bijvoet Centre for Biomolecular Research, Faculty of Science, 3584 CH, Utrecht, The Netherlands
| | - Marc-Etienne Moret
- Utrecht University, Organic Chemistry & Catalysis, Institution Debye Institute for Nanomaterials Science, Faculty of Science, 3584 CG, Utrecht, The Netherlands
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29
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Bernal-Ortega P, Anyszka R, Morishita Y, di Ronza R, Blume A. Comparison between SBR Compounds Filled with In-Situ and Ex-Situ Silanized Silica. Polymers (Basel) 2021; 13:281. [PMID: 33467129 DOI: 10.3390/polym13020281] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Revised: 01/11/2021] [Accepted: 01/14/2021] [Indexed: 11/16/2022] Open
Abstract
The main advantages of the use of silica instead of carbon black in rubber compounds are based on the use of a silane coupling agent. The use of a coupling agent to modify the silica surface improves the compatibility between the silica and the rubber. There are two different possibilities of modifying the silica surface by silane: ex-situ and in-situ. The present work studies the differences between these processes and how they affect the in-rubber properties of silica filled SBR compounds.
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30
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de Almeida LD, Wang H, Junge K, Cui X, Beller M. Recent Advances in Catalytic Hydrosilylations: Developments beyond Traditional Platinum Catalysts. Angew Chem Int Ed Engl 2021; 60:550-565. [PMID: 32668079 PMCID: PMC7839722 DOI: 10.1002/anie.202008729] [Citation(s) in RCA: 85] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Indexed: 12/26/2022]
Abstract
Hydrosilylation reactions, which allow the addition of Si-H to C=C/C≡C bonds, are typically catalyzed by homogeneous noble metal catalysts (Pt, Rh, Ir, and Ru). Although excellent activity and selectivity can be obtained, the price, purification, and metal residues of these precious catalysts are problems in the silicone industry. Thus, a strong interest in more sustainable catalysts and for more economic processes exists. In this respect, recently disclosed hydrosilylations using catalysts based on earth-abundant transition metals, for example, Fe, Co, Ni, and Mn, and heterogeneous catalysts (supported nanoparticles and single-atom sites) are noteworthy. This minireview describes the recent advances in this field.
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Affiliation(s)
| | - Hongli Wang
- State Key Laboratory for Oxo Synthesis and Selective OxidationLanzhou Institute of Chemical PhysicsChinese Academy of SciencesNo. 18, Tianshui Middle RoadLanzhou730000China
| | - Kathrin Junge
- Leibniz-Institute for CatalysisAlbert-Einstein-Str. 29a18059RostockGermany
| | - Xinjiang Cui
- State Key Laboratory for Oxo Synthesis and Selective OxidationLanzhou Institute of Chemical PhysicsChinese Academy of SciencesNo. 18, Tianshui Middle RoadLanzhou730000China
| | - Matthias Beller
- Leibniz-Institute for CatalysisAlbert-Einstein-Str. 29a18059RostockGermany
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31
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Kawatsu T, Choi JC, Sato K, Matsumoto K. Facile Synthesis of Sequence-Defined Oligo(Dimethylsiloxane-co-Diphenylsiloxane)s. Macromol Rapid Commun 2020; 42:e2000593. [PMID: 33270333 DOI: 10.1002/marc.202000593] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 10/26/2020] [Indexed: 11/07/2022]
Abstract
1,1,3,3,5,5,7,7-Octamethyltetrasiloxane (H MD2 MH ), which is reported to release Me2 SiH2 via a B(C6 F5 )3 -catalyzed redistribution, acts as a good Me2 SiH2 precursor in the B(C6 F5 )3 -catalyzed dehydrocarbonative condensation of alkoxysilanes. A series of oligo(dimethylsiloxane-co-diphenylsiloxane)s that are uniformly sized and sequence-defined at the atomic level are synthesized by a one-pot controlled iteration of a B(C6 F5 )3 -catalyzed dehydrocarbonative condensation of alkoxysilanes with H MD2 MH or Ph2 SiH2 and a B(C6 F5 )3 -catalyzed hydrosilylation of carbonyl compounds, followed by the subsequent B(C6 F5 )3 -catalyzed dehydrogenative condensation of silanols.
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Affiliation(s)
- Takahiro Kawatsu
- National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8565, Japan
| | - Jun-Chul Choi
- National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8565, Japan
| | - Kazuhiko Sato
- National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8565, Japan
| | - Kazuhiro Matsumoto
- National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8565, Japan
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32
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Liang H, Wang LJ, Ji YX, Wang H, Zhang B. Selective Electrochemical Hydrolysis of Hydro silanes to Silanols via Anodically Generated Silyl Cations. Angew Chem Int Ed Engl 2020; 60:1839-1844. [PMID: 33058450 DOI: 10.1002/anie.202010437] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Indexed: 01/08/2023]
Abstract
The first electrochemical hydrolysis of hydrosilanes to silanols under mild and neutral reaction conditions is reported. The practical protocol employs commercially available and cheap NHPI as a hydrogen-atom transfer (HAT) mediator and operates at room temperature with high selectivity, leading to various valuable silanols in moderate to good yields. Notably, this electrochemical method exhibits a broad substrate scope and high functional-group compatibility, and it is applicable to late-stage functionalization of complex molecules. Preliminary mechanistic studies suggest that the reaction appears to proceed through a nucleophilic substitution reaction of an electrogenerated silyl cation with H2 O.
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Affiliation(s)
- Hao Liang
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 210009, China
| | - Lu-Jun Wang
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 210009, China
| | - Yun-Xing Ji
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 210009, China
| | - Han Wang
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 210009, China
| | - Bo Zhang
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 210009, China
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33
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Yang Z, Doddipatla S, He C, Krasnoukhov VS, Azyazov VN, Mebel AM, Kaiser RI. Directed Gas Phase Formation of Silene (H 2 SiCH 2 ). Chemistry 2020; 26:13584-13589. [PMID: 32500564 DOI: 10.1002/chem.202002359] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Indexed: 11/10/2022]
Abstract
The silene molecule (H2 SiCH2 ; X1 A1 ) has been synthesized under single collision conditions via the bimolecular gas phase reaction of ground state methylidyne radicals (CH) with silane (SiH4 ). Exploiting crossed molecular beams experiments augmented by high-level electronic structure calculations, the elementary reaction commenced on the doublet surface through a barrierless insertion of the methylidyne radical into a silicon-hydrogen bond forming the silylmethyl (CH2 SiH3 ; X2 A') complex followed by hydrogen migration to the methylsilyl radical (SiH2 CH3 ; X2 A'). Both silylmethyl and methylsilyl intermediates undergo unimolecular hydrogen loss to silene (H2 SiCH2 ; X1 A1 ). The exploration of the elementary reaction of methylidyne with silane delivers a unique view at the widely uncharted reaction dynamics and isomerization processes of the carbon-silicon system in the gas phase, which are noticeably different from those of the isovalent carbon system thus contributing to our knowledge on carbon silicon bond couplings at the molecular level.
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Affiliation(s)
- Zhenghai Yang
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, HI, 96822, USA
| | - Srinivas Doddipatla
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, HI, 96822, USA
| | - Chao He
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, HI, 96822, USA
| | | | - Valeriy N Azyazov
- Samara National Research University, Samara, 443086, Russian Federation.,Lebedev Physical Institute, Samara, 443011, Russian Federation
| | - Alexander M Mebel
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida, 33199, USA
| | - Ralf I Kaiser
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, HI, 96822, USA
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34
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Yang B, Yang W, Guo Y, You L, He C. Enantioselective Silylation of Aliphatic C-H Bonds for the Synthesis of Silicon-Stereogenic Dihydrobenzosiloles. Angew Chem Int Ed Engl 2020; 59:22217-22222. [PMID: 32841459 DOI: 10.1002/anie.202009912] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 08/15/2020] [Indexed: 01/01/2023]
Abstract
A rhodium(I)-catalyzed enantioselective silylation of aliphatic C-H bonds for the synthesis of silicon-stereogenic dihydrobenzosiloles is demonstrated. This reaction involves a highly enantioselective intramolecular C(sp3 )-H silylation of dihydrosilanes, followed by a stereospecific intermolecular alkene hydrosilylation leading to the asymmetrically tetrasubstituted silanes. A wide range of dihydrosilanes and alkenes displaying various functional groups are compatible with this process, giving access to a variety of highly functionalized silicon-stereogenic dihydrobenzosiloles in good to excellent yields and enantioselectivities.
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Affiliation(s)
- Bo Yang
- Shenzhen Grubbs Institute and Department of Chemistry, Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology, Shenzhen, 518055, Guangdong, China
| | - Wu Yang
- Shenzhen Grubbs Institute and Department of Chemistry, Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology, Shenzhen, 518055, Guangdong, China
| | - Yonghong Guo
- Shenzhen Grubbs Institute and Department of Chemistry, Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology, Shenzhen, 518055, Guangdong, China
| | - Lijun You
- Shenzhen Grubbs Institute and Department of Chemistry, Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology, Shenzhen, 518055, Guangdong, China
| | - Chuan He
- Shenzhen Grubbs Institute and Department of Chemistry, Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology, Shenzhen, 518055, Guangdong, China
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35
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Herbig M, Gevorgyan L, Pflug M, Wagler J, Schwarzer S, Kroke E. CO 2 Capture with Silylated Ethanolamines and Piperazines. ChemistryOpen 2020; 9:894-902. [PMID: 32908811 PMCID: PMC7464113 DOI: 10.1002/open.201900269] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 10/25/2019] [Indexed: 11/30/2022] Open
Abstract
Amine treatment is commonly used to capture CO2 from exhaust gases and from ambient air. The Si-N bond in aminosilanes is capable of reacting with CO2 more readily than amines. In the current study we have synthesized trimethylsilylated ethanolamines, diethanolamines and piperazines and investigated their reaction toward CO2. All products were characterized by 1H, 13C, and 29Si NMR, RAMAN spectroscopy as well as mass spectrometry. The product of a twofold CO2-insertion into bis-trimethylsilylated piperazine was analysed by single-crystal X-ray diffraction. Furthermore, quantum chemical calculations (DFT) were used to supplement the experimental results. Geometry optimizations and NBO calculations for each starting material were carried out at the B3LYP level with different basis sets. DFT calculations at the B3LYP, WB97XD and M062x level were conducted for geometry optimization and frequency calculations to examine the thermochemical data. The calculations were carried out both for the gas phase and in solvent environment. The calculated reaction enthalpies varied between -37 and -107 kJ mol-1, while experimental values around -100 kJ mol-1 were determined.
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Affiliation(s)
- Marcus Herbig
- Institut für Anorganische ChemieTU Bergakademie FreibergLeipziger Str. 2909599FreibergGermany
| | - Lia Gevorgyan
- Institut für Anorganische ChemieTU Bergakademie FreibergLeipziger Str. 2909599FreibergGermany
| | - Moritz Pflug
- Institut für Anorganische ChemieTU Bergakademie FreibergLeipziger Str. 2909599FreibergGermany
| | - Jörg Wagler
- Institut für Anorganische ChemieTU Bergakademie FreibergLeipziger Str. 2909599FreibergGermany
| | - Sandra Schwarzer
- Institut für Anorganische ChemieTU Bergakademie FreibergLeipziger Str. 2909599FreibergGermany
| | - Edwin Kroke
- Institut für Anorganische ChemieTU Bergakademie FreibergLeipziger Str. 2909599FreibergGermany
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36
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Taczała J, Sawicki J, Pietrasik J. Chemical Modification of Cellulose Microfibres to Reinforce Poly(methyl methacrylate) Used for Dental Application. Materials (Basel) 2020; 13:E3807. [PMID: 32872190 DOI: 10.3390/ma13173807] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 08/24/2020] [Accepted: 08/26/2020] [Indexed: 11/16/2022]
Abstract
The mechanical properties of dental acrylic resins have to be improved in the case of a thin denture plate. This can be achieved by cellulose addition, playing the role of active filler. But to provide the excellent dispersion of cellulose microfibres within the hydrophobic polymer matrix, its surface has to be modified. Cellulose microfibres with average length from 8 to 30 μm were modified with octyltriethoxysilane and (3-methacryloxypropyl)methyldimethoxysilane. The latter also participated in the polymerisation reaction of methyl methacrylate. Dental composites were prepared following the general procedure provided by the supplier. The successful modification of the microfibres led to the improved compatibility of the cellulose and poly(methyl methacrylate). The fibres after modification were uniformly distributed within the matrix, resulting in the improved mechanical performance of obtained materials. Cellulose microfibres are good candidates for the dental materials to be used as the active filler. The simple and straightforward approach for the cellulose modifications with silanes provides good potential for its future practical application.
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Brió
Pérez M, Cirelli M, de Beer S. Degrafting of Polymer Brushes by Exposure to Humid Air. ACS Appl Polym Mater 2020; 2:3039-3043. [PMID: 34124685 PMCID: PMC8192051 DOI: 10.1021/acsapm.0c00474] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 07/08/2020] [Indexed: 05/22/2023]
Abstract
It is well-known that polymer brushes can degraft in aqueous liquids. Here we show that brushes can deteriorate in humid air too. We observe that the detachment rate of the brushes increases with increasing relative humidity and hydrophilicity of the brushes. We relate this to the increase in water absorption as these parameters are increased. Our results imply that protective measures that are at present being developed for applications of brushes in liquids will also be key in enabling the long-term storage and utilization of hydrophilic brushes in air.
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Affiliation(s)
- Maria Brió
Pérez
- Materials Science and Technology of
Polymers, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Marco Cirelli
- Materials Science and Technology of
Polymers, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Sissi de Beer
- Materials Science and Technology of
Polymers, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
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38
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Abstract
The strong boron Lewis acid tris(pentafluorophenyl)borane B(C6 F5 )3 is known to catalyze the dehydrogenative coupling of certain amines and hydrosilanes at elevated temperatures. At higher temperature, the dehydrogenation pathway competes with cleavage of the C-N bond and defunctionalization is obtained. This can be turned into a useful methodology for the transition-metal-free reductive deamination of a broad range of amines as well as heterocumulenes such as an isocyanate and an isothiocyanate.
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Affiliation(s)
- Huaquan Fang
- Institut für ChemieTechnische Universität BerlinStrasse des 17. Juni 11510623BerlinGermany
| | - Martin Oestreich
- Institut für ChemieTechnische Universität BerlinStrasse des 17. Juni 11510623BerlinGermany
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39
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Winchester WR, Seymour J. Computational and dynamic NMR investigation of 2,2-dimesityl-1,1,1,3,3,3-hexamethyltrisilane. Magn Reson Chem 2020; 58:312-318. [PMID: 31912540 DOI: 10.1002/mrc.4991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 12/30/2019] [Accepted: 01/02/2020] [Indexed: 06/10/2023]
Abstract
The structure and rotational barrier for the mesityl-silicon bond of 2,2-dimesityl-1,1,1,3,3,3-hexamethyltrisilane have been investigated by 1 H- and 13 C-variable temperature nuclear magnetic resonance (NMR) as well as by density functional theory structural calculations. The calculations show that the lowest energy structure has C2 symmetry with nonequivalent ortho methyl groups, consistent with the crystal structure and solution NMR. The nonequivalent ortho methyl groups exchange through a Cs transition state with a calculated relative free energy of 11.0 kcal mol-1 . The barrier for this rotation found by dynamic NMR is 13.4 ± 0.2 kcal mol-1 at 298 K.
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Affiliation(s)
| | - Jenna Seymour
- Department of Chemistry, Grand Valley State University, Allendale, MI
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40
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Han JL, Qin Y, Ju CW, Zhao D. Divergent Synthesis of Vinyl-, Benzyl-, and Boryl silanes: Aryl to Alkyl 1,5-Palladium Migration/Coupling Sequences. Angew Chem Int Ed Engl 2020; 59:6555-6560. [PMID: 31981459 DOI: 10.1002/anie.201914740] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 12/19/2019] [Indexed: 12/31/2022]
Abstract
Organosilicon compounds have been extensively utilized both in industry and academia. Studies on the syntheses of diverse organosilanes is highly appealing. Through-space metal/hydrogen shifts allow functionalization of C-H bonds at a remote site, which are otherwise difficult to achieve. However, until now, an aryl to alkyl 1,5-palladium migration process seems to have not been presented. Reported herein is the remote olefination, arylation, and borylation of a methyl group on silicon to access diverse vinyl-, benzyl-, and borylsilanes, constituting a unique C(sp3 )-H transformation based on a 1,5-palladium migration process.
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Affiliation(s)
- Jie-Lian Han
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, 94 Weijin Road, Tianjin, 300071, China
| | - Ying Qin
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, 94 Weijin Road, Tianjin, 300071, China
| | - Cheng-Wei Ju
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, 94 Weijin Road, Tianjin, 300071, China
| | - Dongbing Zhao
- State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, 94 Weijin Road, Tianjin, 300071, China
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41
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Scharfbier J, Gross BM, Oestreich M. Stereospecific and Chemoselective Copper-Catalyzed Deaminative Silylation of Benzylic Ammonium Triflates. Angew Chem Int Ed Engl 2020; 59:1577-1580. [PMID: 31730248 PMCID: PMC7003868 DOI: 10.1002/anie.201912490] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Indexed: 12/16/2022]
Abstract
A method for the synthesis of benzylsilanes starting from the corresponding ammonium triflates is reported. Silyl boronic esters are employed as silicon pronucleophiles, and the reaction is catalyzed by copper(I) salts. Enantioenriched benzylic ammonium salts react stereospecifically through an SN 2-type displacement of the ammonium group to afford α-chiral silanes with inversion of the configuration. A cyclopropyl-substituted substrate does not undergo ring opening, thus suggesting an ionic reaction mechanism with no benzyl radical intermediate.
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Affiliation(s)
- Jonas Scharfbier
- Institut für ChemieTechnische Universität BerlinStrasse des 17. Juni 11510623BerlinGermany
| | - Benjamin M. Gross
- Institut für ChemieTechnische Universität BerlinStrasse des 17. Juni 11510623BerlinGermany
| | - Martin Oestreich
- Institut für ChemieTechnische Universität BerlinStrasse des 17. Juni 11510623BerlinGermany
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42
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Dalle Vacche S, Damjanovic D, Michaud V, Leterrier Y. Interface-Dominated Time-Dependent Behavior of Poled Poly(Vinylidene Fluoride-Trifluoroethylene)/Barium Titanate Composites. Materials (Basel) 2020; 13:E225. [PMID: 31947988 DOI: 10.3390/ma13010225] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 12/26/2019] [Accepted: 01/01/2020] [Indexed: 11/17/2022]
Abstract
Composites in which particles of ferroelectric ceramic phase are randomly dispersed in a polymeric matrix are of interest because of flexibility, conformability, and ease of processing. However, their piezoelectric properties are rather low, unless very high volume fractions of ceramics are used. This brings agglomeration and porosity issues due to the large mismatch between the surface energies of the ceramics and of the polymer. Particle surface modification is a common approach for better dispersion; however, it may bring other effects on the properties of the composites, which are usually concealed by the huge improvement in performance due to the more homogenous microstructure. In this work, we compared poly(vinylidene fluoride–trifluoroethylene)/barium titanate composites containing 15 vol.% and 60 vol.% of pristine ceramic particles or particles modified with an aminosilane or a fluorosilane. Similar morphology, with good particle dispersion and low porosity, was achieved for all composites, owing to an efficient dispersion method. The materials were poled with two different poling procedures, and the piezoelectric coefficient d33, the relative permittivity, and the poling degree of barium titanate were followed in time. We highlighted that, although similar d33 were obtained with all types of particles, the nature of the particles surface and the poling procedure were associated with different charge trapping and influenced the evolution of d33 with time.
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43
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Fan X, Chen R, Han J, He Z. Convergent Synthesis of Polysubstituted Furans via Catalytic Phosphine Mediated Multicomponent Reactions. Molecules 2019; 24:E4595. [PMID: 31888142 DOI: 10.3390/molecules24244595] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 12/10/2019] [Accepted: 12/13/2019] [Indexed: 11/29/2022] Open
Abstract
Tri- or tetrasubstituted furans have been prepared from terminal activated olefins and acyl chlorides or anhydrides by a multicomponental convergent synthesis mode. Instead of stoichiometric nBu3P, only catalytic nBu3P or nBu3P=O is needed to furnish the furans in modest to excellent yields with a good functional group tolerance under the aid of reducing agent silane. This synthetic method features a silane-driven catalytic intramolecular Wittig reaction as a key annulation step and represents the first successful application of catalytic Wittig reaction in multicomponent cascade reaction.
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44
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Burns DA, Press EM, Siegler MA, Klausen RS, Thoi VS. 2D Oligosilyl Metal-Organic Frameworks as Multi-state Switchable Materials. Angew Chem Int Ed Engl 2019; 59:763-768. [PMID: 31665559 DOI: 10.1002/anie.201912911] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Indexed: 12/14/2022]
Abstract
We report the synthesis of a set of 2D metal-organic frameworks (MOFs) constructed with organosilicon-based linkers. These oligosilyl MOFs feature linear Sin Me2n (C6 H4 CO2 H)2 ligands (lin-Sin , n=2, 4) connected by Cu paddlewheels. The stacking arrangement of the 2D sheets is dictated by van der Waals interactions and is tunable by solvent exchange, leading to reversible structural transformations between many crystalline and amorphous phases.
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Affiliation(s)
- David A Burns
- Department of Chemistry, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD, 21218, USA
| | - Eric M Press
- Department of Chemistry, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD, 21218, USA
| | - M A Siegler
- Department of Chemistry, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD, 21218, USA
| | - Rebekka S Klausen
- Department of Chemistry, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD, 21218, USA
| | - V Sara Thoi
- Department of Chemistry, Johns Hopkins University, 3400 N Charles Street, Baltimore, MD, 21218, USA
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45
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Khedaioui D, Boisson C, D'Agosto F, Montarnal D. Polyethylene Aerogels with Combined Physical and Chemical Crosslinking: Improved Mechanical Resilience and Shape-Memory Properties. Angew Chem Int Ed Engl 2019; 58:15883-15889. [PMID: 31498536 DOI: 10.1002/anie.201908257] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 08/30/2019] [Indexed: 11/11/2022]
Abstract
While the introduction of polymers into aerogels strongly enhances their toughness, truly elastic monolithic aerogels which restore their dimensions upon extensive compression are still challenging to synthesize. In this context hydrophobic semi-crystalline polymers with low glass transition temperatures, and combined stiffness and flexibility, have only recently attracted attention. Shown here is that polyethylene aerogels with a low density, and combined chemical crosslinking and high crystallinity, display high moduli and excellent mechanical resilience. To maximize the crystallinity of these aerogels while maintaining a high crosslinking density, polyethylene networks with well-defined segments were synthesized by hydrosilylation crosslinking of telechelic, vinyl-functionalized oligomers obtained from catalyzed chain-growth polymerization. Recoverable deformations both above and below the melting temperature of polyethylene affords remarkable shape-memory properties.
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Affiliation(s)
- Douriya Khedaioui
- Univ Lyon. Université Claude Bernard Lyon 1, CPE Lyon, CNRS, UMR 5265, Chemistry, Catalysis, Polymers and Processes, 43 Bvd du 11 Novembre 1918, 69616, Villeurbanne, France
| | - Christophe Boisson
- Univ Lyon. Université Claude Bernard Lyon 1, CPE Lyon, CNRS, UMR 5265, Chemistry, Catalysis, Polymers and Processes, 43 Bvd du 11 Novembre 1918, 69616, Villeurbanne, France
| | - Franck D'Agosto
- Univ Lyon. Université Claude Bernard Lyon 1, CPE Lyon, CNRS, UMR 5265, Chemistry, Catalysis, Polymers and Processes, 43 Bvd du 11 Novembre 1918, 69616, Villeurbanne, France
| | - Damien Montarnal
- Univ Lyon. Université Claude Bernard Lyon 1, CPE Lyon, CNRS, UMR 5265, Chemistry, Catalysis, Polymers and Processes, 43 Bvd du 11 Novembre 1918, 69616, Villeurbanne, France
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46
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Liu ZL, Yang C, Xue QY, Zhao M, Shan CC, Xu YH, Loh TP. Copper-Catalyzed Asymmetric Silylation of Propargyl Dichlorides: Access to Enantioenriched Functionalized Allenyl silanes. Angew Chem Int Ed Engl 2019; 58:16538-16542. [PMID: 31532868 PMCID: PMC6899605 DOI: 10.1002/anie.201908343] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 08/27/2019] [Indexed: 02/04/2023]
Abstract
A copper‐catalyzed silylation of propargyl dichlorides was developed to access chloro‐substituted allenylsilanes under mild reaction conditions. Moreover, enantioenriched chloro‐substituted allenylsilanes can be synthesized in moderate to high yields and good enantioselectivities with this protocol.
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Affiliation(s)
- Zheng-Li Liu
- Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Chao Yang
- Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Qi-Yan Xue
- Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Meng Zhao
- Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Cui-Cui Shan
- Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Yun-He Xu
- Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Teck-Peng Loh
- Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, China.,Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 637616, Singapore, Singapore
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47
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Griffo A, Liu Y, Mahlberg R, Alakomi HL, Johansson LS, Milani R. Design and Testing of a Bending-Resistant Transparent Nanocoating for Optoacoustic Cochlear Implants. ChemistryOpen 2019; 8:1100-1108. [PMID: 31406657 PMCID: PMC6682933 DOI: 10.1002/open.201900172] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Indexed: 12/25/2022] Open
Abstract
A nanosized coating was designed to reduce fouling on the surface of a new type of cochlear implant relying on optoacoustic stimulation. This kind of device imposes novel design principles for antifouling coatings, such as optical transparency and resistance to significant constant bending. To reach this goal we deposited on poly(dimethylsiloxane) a PEO-based layer with negligible thickness compared to the curvature radius of the cochlea. Its antifouling performance was monitored upon storage by quartz crystal microbalance, and its resistance upon bending was tested by fluorescence microscopy under geometrical constraints similar to those of implantation. The coating displayed excellent antifouling features and good stability, and proved suitable for further testing in real-environment conditions.
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Affiliation(s)
- Alessandra Griffo
- VTT Technical Research Centre of Finland Ltd. P.O. Box 1000 FI-02044VTT Espoo Finland.,Department of Bioproducts and Biosystems Aalto University P.O. Box 16100 FI-00076Aalto Espoo Finland
| | - Yingying Liu
- VTT Technical Research Centre of Finland Ltd. P.O. Box 1000 FI-02044VTT Espoo Finland
| | - Riitta Mahlberg
- VTT Technical Research Centre of Finland Ltd. P.O. Box 1000 FI-02044VTT Espoo Finland
| | - Hanna-L Alakomi
- VTT Technical Research Centre of Finland Ltd. P.O. Box 1000 FI-02044VTT Espoo Finland
| | - Leena-S Johansson
- Department of Bioproducts and Biosystems Aalto University P.O. Box 16100 FI-00076Aalto Espoo Finland
| | - Roberto Milani
- VTT Technical Research Centre of Finland Ltd. P.O. Box 1000 FI-02044VTT Espoo Finland
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48
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Ríos P, Fouilloux H, Díez J, Vidossich P, Lledós A, Conejero S. σ-Silane Platinum(II) Complexes as Intermediates in C-Si Bond-Coupling Processes. Chemistry 2019; 25:11346-11355. [PMID: 31246316 DOI: 10.1002/chem.201902226] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 06/26/2019] [Indexed: 12/15/2022]
Abstract
Platinum complexes [Pt(NHC')(NHC)][BArF ] (in which NHC' denotes a cyclometalated N-heterocyclic carbene ligand, NHC) react with primary silanes RSiH3 to afford the cyclometalated platinum(II) silyl complexes [Pt(NHC-SiHR')(NHC)][BArF ] through a process that involves the formation of C-Si and Pt-Si bonds with concomitant extrusion of H2 . Low-temperature NMR studies indicate that the process proceeds through initial formation of the σ-SiH complexes [Pt(NHC')(NHC)(HSiH2 R)][BArF ], which are stable at temperatures below -10 °C. At higher temperatures, activation of one Si-H bond followed by a C-Si coupling reaction generates an agostic SiH platinum hydride derivative [Pt(H)(NHC'-SiH2 R)(NHC)][BArF ], which undergoes a second Si-H bond activation to afford the final products. Computational modeling of the reaction mechanism indicates that the stereochemistry of the silyl/hydride ligands after the first Si-H bond cleavage dictates the nature of the products, favoring the formation of a C-Si bond over a C-H bond, in contrast to previous results obtained for tertiary silanes. Furthermore, the process involves a trans-to-cis isomerization of the NHC ligand before the second Si-H bond cleavage.
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Affiliation(s)
- Pablo Ríos
- Instituto de Investigaciones Químicas (IIQ), Departamento de Química, Inorgánica, Centro de Innovación en Química Avanzada (ORFEO-CINCA), CSIC and Universidad de Sevilla, C/ Américo Vespucio 49, 41092, Sevilla, Spain
| | - Hugo Fouilloux
- Instituto de Investigaciones Químicas (IIQ), Departamento de Química, Inorgánica, Centro de Innovación en Química Avanzada (ORFEO-CINCA), CSIC and Universidad de Sevilla, C/ Américo Vespucio 49, 41092, Sevilla, Spain
| | - Josefina Díez
- Laboratorio de Compuestos Organometálicos y Catálisis (Unidad asociada al CSIC), Departamento de Química Orgánica e Inorgánica, Universidad de Oviedo, C/ Julián Clavería 8, 33008, Oviedo, Spain
| | - Pietro Vidossich
- Departament de Química, Centro de Innovación en Química Avanzada (ORFEO-CINCA), Universitat Autònoma de Barcelona, Campus UAB, 08193, Cerdanyola del Vallès, Spain.,COBO Computational Bio-Organic Chemistry Bogotá, Department of Chemistry, Universidad de los Andes, Carrera 1 #18A-12, 111711, Bogotá, Colombia
| | - Agustí Lledós
- Departament de Química, Centro de Innovación en Química Avanzada (ORFEO-CINCA), Universitat Autònoma de Barcelona, Campus UAB, 08193, Cerdanyola del Vallès, Spain
| | - Salvador Conejero
- Instituto de Investigaciones Químicas (IIQ), Departamento de Química, Inorgánica, Centro de Innovación en Química Avanzada (ORFEO-CINCA), CSIC and Universidad de Sevilla, C/ Américo Vespucio 49, 41092, Sevilla, Spain
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49
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Talavera M, von Hahmann CN, Müller R, Ahrens M, Kaupp M, Braun T. C-H and C-F Bond Activation Reactions of Fluorinated Propenes at Rhodium: Distinctive Reactivity of the Refrigerant HFO-1234yf. Angew Chem Int Ed Engl 2019; 58:10688-10692. [PMID: 31102565 DOI: 10.1002/anie.201902872] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 04/28/2019] [Indexed: 02/02/2023]
Abstract
The reaction of [Rh(H)(PEt3 )3 ] (1) with the refrigerant HFO-1234yf (2,3,3,3-tetrafluoropropene) affords an efficient route to obtain [Rh(F)(PEt3 )3 ] (3) by C-F bond activation. Catalytic hydrodefluorinations were achieved in the presence of the silane HSiPh3 . In the presence of a fluorosilane, 3 provides a C-H bond activation followed by a 1,2-fluorine shift to produce [Rh{(E)-C(CF3 )=CHF}(PEt3 )3 ] (4). Similar rearrangements of HFO-1234yf were observed at [Rh(E)(PEt3 )3 ] [E=Bpin (6), C7 D7 (8), Me (9)]. The ability to favor C-H bond activation using 3 and fluorosilane is also demonstrated with 3,3,3-trifluoropropene. Studies are supported by DFT calculations.
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Affiliation(s)
- Maria Talavera
- Department of Chemistry, Humboldt Universität zu Berlin, Brook-Taylor-Strasse 2, 12489, Berlin, Germany
| | - Cortney N von Hahmann
- Department of Chemistry, Humboldt Universität zu Berlin, Brook-Taylor-Strasse 2, 12489, Berlin, Germany
| | - Robert Müller
- Institut für Chemie, Theoretische Chemie/Quantenchemie, Sekr. C7, Technische Universität Berlin, Strasse des 17. Juni 135, 10623, Berlin, Germany
| | - Mike Ahrens
- Department of Chemistry, Humboldt Universität zu Berlin, Brook-Taylor-Strasse 2, 12489, Berlin, Germany
| | - Martin Kaupp
- Institut für Chemie, Theoretische Chemie/Quantenchemie, Sekr. C7, Technische Universität Berlin, Strasse des 17. Juni 135, 10623, Berlin, Germany
| | - Thomas Braun
- Department of Chemistry, Humboldt Universität zu Berlin, Brook-Taylor-Strasse 2, 12489, Berlin, Germany
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50
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Sturm AG, Santowski T, Schweizer JI, Meyer L, Lewis KM, Felder T, Auner N, Holthausen MC. Making Use of the Direct Process Residue: Synthesis of Bifunctional Mono silanes. Chemistry 2019; 25:8499-8502. [PMID: 31026105 DOI: 10.1002/chem.201901881] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Indexed: 11/08/2022]
Abstract
The industrial production of monosilanes Men SiCl4-n (n=1-3) through the Müller-Rochow Direct Process generates disilanes Men Si2 Cl6-n (n=2-6) as unwanted byproducts ("Direct Process Residue", DPR) by the thousands of tons annually, large quantities of which are usually disposed of by incineration. Herein we report a surprisingly facile and highly effective protocol for conversion of the DPR: hydrogenation with complex metal hydrides followed by Si-Si bond cleavage with HCl/ether solutions gives (mostly bifunctional) monosilanes in excellent yields. Competing side reactions are efficiently suppressed by the appropriate choice of reaction conditions.
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Affiliation(s)
- Alexander G Sturm
- Institut für Anorganische Chemie, Goethe-Universität, Max-von-Laue-Strasse 7, 60438, Frankfurt/Main, Germany
| | - Tobias Santowski
- Institut für Anorganische Chemie, Goethe-Universität, Max-von-Laue-Strasse 7, 60438, Frankfurt/Main, Germany
| | - Julia I Schweizer
- Institut für Anorganische Chemie, Goethe-Universität, Max-von-Laue-Strasse 7, 60438, Frankfurt/Main, Germany
| | - Lioba Meyer
- Institut für Anorganische Chemie, Goethe-Universität, Max-von-Laue-Strasse 7, 60438, Frankfurt/Main, Germany
| | - Kenrick M Lewis
- Momentive Performance Materials, 769 Old Saw Mill River Rd., Tarrytown, NY, 10591, USA
| | - Thorsten Felder
- Momentive Performance Materials, Chempark, 51368, Leverkusen, Germany
| | - Norbert Auner
- Institut für Anorganische Chemie, Goethe-Universität, Max-von-Laue-Strasse 7, 60438, Frankfurt/Main, Germany
| | - Max C Holthausen
- Institut für Anorganische Chemie, Goethe-Universität, Max-von-Laue-Strasse 7, 60438, Frankfurt/Main, Germany
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