1
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Yunyaeva O, Hean D, Wolf MO. Restricted rotation and tunable fluorescence in atropisomeric naphthyl pyridine chromophores. Org Biomol Chem 2023. [PMID: 38018711 DOI: 10.1039/d3ob01819a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2023]
Abstract
Enhanced fluorescence quantum yields are enabled by simple reactions at the heterocyclic nitrogen in naphthyl-pyridine chromophores in which the electronic properties can be tuned through protonation, oxidation, and alkylation at the nitrogen center. Fluorescence quantum yield is increased by reacting the pyridine lone pair with either a proton or an alkyl group. Restricted intramolecular rotation (RIR) was observed upon alkylation, as evidenced by the presence of atropisomers. These simple structural changes allow application-driven tuning of electronic properties.
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Affiliation(s)
- Olga Yunyaeva
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1.
| | - Duane Hean
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1.
| | - Michael O Wolf
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1.
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2
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Bahng HW, Ertl CD, Yuan J, Wolf MO. Light-Controlled Switching of Perylene Bisimide Assemblies. J Phys Chem Lett 2023; 14:10369-10377. [PMID: 37948746 DOI: 10.1021/acs.jpclett.3c02468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
Light-driven changes in supramolecular interactions in perylene bisimides (PBIs) with pendant sulfur-containing functional groups at the bay position are demonstrated. In the ground state, a noncovalent S···X interaction between the σ-hole on sulfur and a heteroatom, X (X = O, N, S), of a neighboring molecule is the main driving force for intermolecular interactions, while in the excited state it is the π-π interaction between PBI scaffolds which drives assembly. The presence of heteroatoms in the solvent results in acceleration of the π-stacking process via the formation of a PBI-solvent complex. The excited-state dynamics involved in the assembly process were revealed via time-resolved fluorescence and transient absorption spectroscopies, while steady-state spectroscopy was used to evaluate the structure of the supramolecular assembly.
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Affiliation(s)
- Hee-Won Bahng
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada
| | - Cathrin D Ertl
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada
| | - Jennifer Yuan
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada
| | - Michael O Wolf
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada
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3
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Removski N, Wolf MO. The unexpected effect of ferrocenyl substituents on the photochemistry of dianthryl sulfoxides. Chem Commun (Camb) 2023; 59:13006-13009. [PMID: 37830327 DOI: 10.1039/d3cc04345b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2023]
Abstract
Photoexcitation of ferrocenyl substituted dianthryl sulfoxide results in photochemical reaction products that differ from all known compounds of this class. This is enabled by energy transfer to a low-lying state, even in the case of the oxidized ferrocenium-containing compound.
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Affiliation(s)
- Nicole Removski
- Department of Chemistry, 2036 Main Mall, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada.
| | - Michael O Wolf
- Department of Chemistry, 2036 Main Mall, University of British Columbia, Vancouver, BC, V6T 1Z1, Canada.
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4
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Tong KM, Toigo J, Patrick BO, Wolf MO. Rhenium(I) Complexes with Sulfur-Bridged Dipyridyl Ligands: Structural, Photophysical, and Computational Studies. Inorg Chem 2023; 62:13662-13671. [PMID: 37555810 DOI: 10.1021/acs.inorgchem.3c02124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/10/2023]
Abstract
A series of six new rhenium(I) tricarbonyl complexes [Re(CO)3(N-N)Br] bearing sulfur-bridged dipyridyl (N-N) ligands with three different oxidation states (sulfide (S), sulfoxide (SO), and sulfone (SO2)) are described. Spectroscopic studies show that changing the oxidation state of the ligands influences the photophysical properties of the complexes, with complexes 3 and 6 containing the sulfone ligand exhibiting a lower energy MLCT absorption band tailing into the visible region. Solution-state emission measurements show that these complexes exhibit readily tunable emission energies from 480 to 610 nm, depending on the oxidation state of the sulfur bridge and the presence of substituents on the pyridyl rings. Solid-state emission measurements show that the emission is significantly red-shifted upon oxidation of the sulfur bridge to sulfone with enhanced photoluminescence quantum yield.
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Affiliation(s)
- Ka-Ming Tong
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Jessica Toigo
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Brian O Patrick
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Michael O Wolf
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
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5
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Yuan J, Jiang L, Nishimura T, Sauvé ER, Hean D, Maeda K, Wolf MO. Effect of Oxidation on the Chiroptical Properties of Sulfur-Bridged Binaphthyl Dimers. J Org Chem 2022; 87:12315-12322. [PMID: 36066048 DOI: 10.1021/acs.joc.2c01516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A series of axially chiral sulfur-bridged dimers were prepared from 1,1'-binaphthyl-2,2'-diol and subsequently oxidized to the respective sulfones. The chiroptical properties of the chiral chromophores were studied as a function of the oxidation state. Upon oxidation, an increase in quantum yields was observed for directly linked sulfur bridged binaphthyls (0.04 to 0.32), and a modest increase in dissymmetry factor was observed for diphenylsulfide-bridged binaphthyls (-8.9 × 10-4 to -1.4 × 10-3). Computational calculations were used to elucidate the changes in photophysical properties.
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Affiliation(s)
- Jennifer Yuan
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1
| | - Lanting Jiang
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1
| | - Tatsuya Nishimura
- Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
| | - Ethan R Sauvé
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1
| | - Duane Hean
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1
| | - Katsuhiro Maeda
- Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.,Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
| | - Michael O Wolf
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1
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6
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Xu Z, Hean D, Yuan J, Wolf MO. Control of photoluminescence quantum yield and long-lived triplet emission lifetime in organic alloys. Chem Sci 2022; 13:6882-6887. [PMID: 35774161 PMCID: PMC9200050 DOI: 10.1039/d2sc01922a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Accepted: 05/17/2022] [Indexed: 11/21/2022] Open
Abstract
Two-component crystalline organic alloys with a wide range of compositional ratios (from 30% to 90% of one component) are employed to tune excited-state lifetimes and photoluminescence quantum yields (PLQYs). Alloy crystals exhibit homogeneous distribution of parent compounds by X-ray crystallography and differential scanning calorimetry. The alloys display a 1.5- to 5-fold enhancement in thermally activated delayed fluorescence (TADF) lifetime, compared to the parent compounds. PLQYs can also be tuned by changing alloy composition. The reverse intersystem crossing and long-lived lifetime of the parent compounds give rise to long-lived TADF in the alloys. Organic alloys enable tunability of both lifetime and efficiency, providing a new perspective on the development of organic long-lived emissive materials beyond the rules established for host-guest doped systems.
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Affiliation(s)
- Zhen Xu
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver BC V6T 1Z1 Canada
| | - Duane Hean
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver BC V6T 1Z1 Canada
| | - Jennifer Yuan
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver BC V6T 1Z1 Canada
| | - Michael O Wolf
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver BC V6T 1Z1 Canada
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7
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Yuan J, Xu Z, Wolf MO. Sulfur-bridged chromophores for photofunctional materials: using sulfur oxidation state to tune electronic and structural properties. Chem Sci 2022; 13:5447-5464. [PMID: 35694344 PMCID: PMC9116371 DOI: 10.1039/d2sc01128j] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 04/09/2022] [Indexed: 01/22/2023] Open
Abstract
The use of a heteroatom, such as sulfur, as a linker or bridge, in π-conjugated materials has advantages over purely carbon-based ones due to the accessibility of higher oxidation states as a result of hypervalence. Materials containing a sulfide bridge (S) can be systemically oxidized into sulfoxides (SO) and sulfones (SO2), each of which can then influence how a material interacts with light, playing a large role in dictating the photophysical and sometimes photochemical properties. In this perspective, we summarize the progress that our group and others have made, showing how oxidation of a sulfur bridge in symmetric bichromophoric dimers and in diimine ligands can influence the excited state behavior in organic π-conjugated materials and metal complexes.
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Affiliation(s)
- Jennifer Yuan
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver British Columbia V6T 1Z1 Canada
| | - Zhen Xu
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver British Columbia V6T 1Z1 Canada
| | - Michael O Wolf
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver British Columbia V6T 1Z1 Canada
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8
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Abstract
Two emissive Pt(II) complexes containing dynamic "flexible" Lewis pair (FlexLP) ligands are reported. The FlexLP ligand encompasses a diphenylphosphine oxide Lewis base and a dimesitylborane Lewis acid attached to a bithiophene scaffold, which can switch between an open unbound Lewis pair and a bound P-O-B Lewis adduct depending on the hydrogen bond-donating (HBD) strength of the solvent. [Pt(FlexLP)2] contains two FlexLP ligands, and [Pt(FlexLP)(Py)] contains one FlexLP ligand and one pyrene ligand. UV-vis absorption and fluorescence studies demonstrate that the FlexLP ligands switch between the open Lewis pair and the closed Lewis adduct in MeOH, a strong HBD solvent, and acetone, a weak HBD solvent, respectively, and exhibit tunable emission color depending on the acetone/MeOH solvent ratio. Transient absorption spectroscopy reveals a large difference in the triplet-state lifetime depending on the conformation of the FlexLP ligands for both complexes. In the closed form, the triplet-state lifetimes of the two complexes are over an order of magnitude longer compared to that of the complexes in the open conformation. Calculations of optimized geometries suggest that this difference in triplet-state lifetime is due to a difference in the thiophene-thiophene torsion angle between the two conformations.
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Affiliation(s)
- Nicole E Arsenault
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Zhen Xu
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Michael O Wolf
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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9
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Wright T, Vlok M, Shapira T, Olmstead AD, Jean F, Wolf MO. Photodynamic and Contact Killing Polymeric Fabric Coating for Bacteria and SARS-CoV-2. ACS Appl Mater Interfaces 2022; 14:49-56. [PMID: 34978405 PMCID: PMC8751017 DOI: 10.1021/acsami.1c14178] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 11/30/2021] [Indexed: 05/13/2023]
Abstract
The development of low-cost, non-toxic, scalable antimicrobial textiles is needed to address the spread of deadly pathogens. Here, we report a polysiloxane textile coating that possesses two modes of antimicrobial inactivation, passive contact inactivation through amine/imine functionalities and active photodynamic inactivation through the generation of reactive oxygen species (ROS). This material can be coated and cross-linked onto natural and synthetic textiles through a simple soak procedure, followed by UV cure to afford materials exhibiting no aqueous leaching and only minimal leaching in organic solvents. This coating minimally impacts the mechanical properties of the fabric while also imparting hydrophobicity. Passive inactivation of Escherichia coli (E. coli) and methicillin-resistant Staphylococcus aureus (MRSA) is achieved with >98% inactivation after 24 h, with a 23× and 3× inactivation rate increase against E. coli and MRSA, respectively, when green light is used to generate ROS. Up to 90% decrease in the infectivity of SARS-CoV-2 after 2 h of irradiated incubation with the material is demonstrated. These results show that modifying textiles with dual-functional polymers results in robust and highly antimicrobial materials that are expected to find widespread use in combating the spread of deadly pathogens.
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Affiliation(s)
- Taylor Wright
- Department
of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver BC V6T 1Z1, Canada
| | - Marli Vlok
- Department
of Biochemistry & Molecular Biology, University of British Columbia, 2350 Health Sciences Mall, Vancouver BC V6T 1Z3, Canada
| | - Tirosh Shapira
- Life
Sciences Institute, Department of Microbiology and Immunology, University of British Columbia, Vancouver BC V6T 1Z3, Canada
| | - Andrea D. Olmstead
- Life
Sciences Institute, Department of Microbiology and Immunology, University of British Columbia, Vancouver BC V6T 1Z3, Canada
| | - François Jean
- Life
Sciences Institute, Department of Microbiology and Immunology, University of British Columbia, Vancouver BC V6T 1Z3, Canada
| | - Michael O. Wolf
- Department
of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver BC V6T 1Z1, Canada
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10
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Wright T, Zhang Z, Michal CA, Hatzikiriakos SG, Wolf MO. Photo-oxidative cross-linking of thiol polydimethylsiloxane co-polymers via disulfide formation. Polym Chem 2022. [DOI: 10.1039/d1py01335a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Disulfide bonds are often employed as reductively cleavable sites in biomaterials and polymers. Here we demonstrate the aerobic photo-cross-linking of thiol-containing polymers through disulfide formation using a sensitizer and telluride catalyst.
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Affiliation(s)
- Taylor Wright
- Department of Chemistry, 2036 Main Mall, University of British Columbia, Vancouver, BC, Canada, V6T 1Z1
| | - Ziyue Zhang
- Department of Chemical and Biological Engineering, 2360 East Mall, University of British Columbia, Vancouver, BC, Canada, V6T 1Z3
| | - Carl A. Michal
- Department of Chemistry, 2036 Main Mall, University of British Columbia, Vancouver, BC, Canada, V6T 1Z1
- Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada, V6T 1Z1
| | - Savvas G. Hatzikiriakos
- Department of Chemical and Biological Engineering, 2360 East Mall, University of British Columbia, Vancouver, BC, Canada, V6T 1Z3
| | - Michael O. Wolf
- Department of Chemistry, 2036 Main Mall, University of British Columbia, Vancouver, BC, Canada, V6T 1Z1
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11
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Xu Z, Hean D, Climent C, Casanova D, Wolf MO. Switching between TADF and RTP: anion-regulated photoluminescence in organic salts and co-crystals. Mater Adv 2021; 2:5777-5784. [PMID: 34527950 PMCID: PMC8406714 DOI: 10.1039/d1ma00314c] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 07/28/2021] [Indexed: 06/13/2023]
Abstract
Thermally activated delayed fluorescence (TADF) and room temperature phosphorescence (RTP) are two photophysical phenomena which utilize triplet excitons. In this work, we demonstrate how variation of the anion in organic salts with carbazole and phenothiazine-5,5-dioxide donors and pyridinium and quinolinium acceptors may be used to switch between TADF and RTP. These compounds adopt similar molecular structures and packing modes with different anions and exhibit different types of photophysical behavior due to the electronic effects of the anions. With bromide anions, the salts exhibit TADF with some RTP. These compounds show fast reverse intersystem crossing and a short delayed lifetime, which is key to application in efficient and robust OLEDs. With BF4 - and PF6 - anions, RTP with long-lived lifetimes and afterglow are observed by eye. This behavior can be utilized for data encryption and anti-counterfeiting applications. Emission wavelengths and lifetimes are also anion-dependent. These results open up an avenue for developing novel luminescent materials through anion tuning and present a molecular model to understand the interplay of RTP and TADF.
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Affiliation(s)
- Zhen Xu
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver BC V6T 1Z1 Canada
| | - Duane Hean
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver BC V6T 1Z1 Canada
| | - Clàudia Climent
- Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid E-28049 Madrid Spain
| | - David Casanova
- Donostia International Physics Center (DIPC) Paseo Manuel de Lardizabal 4 20018 Donostia Euskadi Spain
- IKERBASQUE, Basque Foundation for Science 48013 Bilbao Euskadi Spain
| | - Michael O Wolf
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver BC V6T 1Z1 Canada
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12
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Wright T, Karis D, Millik SC, Tomkovic T, Hatzikiriakos SG, Nelson A, Wolf MO. Photocross-Linked Antimicrobial Amino-Siloxane Elastomers. ACS Appl Mater Interfaces 2021; 13:22195-22203. [PMID: 33944560 DOI: 10.1021/acsami.1c02863] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Mechanically robust bulk antimicrobial polymers are one way to address disease transmission via contaminated surfaces. Here, we demonstrate the visible light photo-oxidative cross-linking of amine-containing PDMS using a single-component, solvent-free system where amines have a dual role as antimicrobial functionalities and cross-linking sites. Rose Bengal, a xanthene dye used as a fluorescent stain, is thermally reacted with the polymer to give a solvent-free liquid siloxane that can generate reactive singlet oxygen upon aerobic green light irradiation, coupling the amine functionalities into imine cross-links. Photorheological experiments demonstrate that light intensity is the largest kinetic factor in the photo-oxidative curing of these polymers. Room temperature irradiation under an ambient atmosphere results in free-standing elastic materials with mechanical properties that depend on the amount of Rose Bengal present. An ultimate elongation strain of 117% and Young's modulus of 2.15 MPa were observed for the highest dye loading, with both mechanical properties found to be higher than those for the same solution-based dye amounts. We demonstrate that the solvent-free nature of the material can be exploited to generate 3D structures using low-temperature deposition as well as direct-write patterning and photolithography on glass substrates. The antimicrobial activity was investigated, with the cross-linked material demonstrating greater efficacy against E. coli (Gram negative) compared with MRSA (Gram positive) bacterial strains and inducing complete cell lysis of incubated CHO-K1 mammalian cells, demonstrating applicability as a mechanically robust single-component antimicrobial elastomer.
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Affiliation(s)
- Taylor Wright
- Department of Chemistry, 2036 Main Mall, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Dylan Karis
- Department of Chemistry, 109 Bagley Hall, University of Washington, Seattle, Washington 98195-1700, United States
| | - S Cem Millik
- Department of Chemistry, 109 Bagley Hall, University of Washington, Seattle, Washington 98195-1700, United States
| | - Tanja Tomkovic
- Department of Chemical and Biological Engineering, 2360 East Mall, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Savvas G Hatzikiriakos
- Department of Chemical and Biological Engineering, 2360 East Mall, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Alshakim Nelson
- Department of Chemistry, 109 Bagley Hall, University of Washington, Seattle, Washington 98195-1700, United States
| | - Michael O Wolf
- Department of Chemistry, 2036 Main Mall, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
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13
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Abstract
A stimuli-responsive fluorophore, encompassing a Lewis acid-base pair, binds to primary amines on mesoporous silica nanoparticles, which may serve as environment-sensitive drug carriers. The fluorophore switches conformation, exhibiting different emission color and lifetimes, allowing for the detection of the water content of the nanoparticles' surroundings through fluorescence spectroscopy and microscopy.
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Affiliation(s)
- Nicole E Arsenault
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada.
| | - Kathleen T Downey
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada.
| | - Michael O Wolf
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada.
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14
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Xu Z, Climent C, Brown CM, Hean D, Bardeen CJ, Casanova D, Wolf MO. Controlling ultralong room temperature phosphorescence in organic compounds with sulfur oxidation state. Chem Sci 2020; 12:188-195. [PMID: 34163589 PMCID: PMC8178747 DOI: 10.1039/d0sc04715e] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 10/13/2020] [Indexed: 12/24/2022] Open
Abstract
Sulfur oxidation state is used to tune organic room temperature phosphorescence (RTP) of symmetric sulfur-bridged carbazole dimers. The sulfide-bridged compound exhibits a factor of 3 enhancement of the phosphorescence efficiency, compared to the sulfoxide and sulfone-bridged analogs, despite sulfone bridges being commonly used in RTP materials. In order to investigate the origin of this enhancement, temperature dependent spectroscopy measurements and theoretical calculations are used. The RTP lifetimes are similar due to similar crystal packing modes. Computational studies reveal that the lone pairs on the sulfur atom have a profound impact on enhancing intersystem crossing rate through orbital mixing and screening, which we hypothesize is the dominant factor responsible for increasing the phosphorescence efficiency. The ability to tune the electronic state without altering crystal packing modes allows the isolation of these effects. This work provides a new perspective on the design principles of organic phosphorescent materials, going beyond the rules established for conjugated ketone/sulfone-based organic molecules.
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Affiliation(s)
- Zhen Xu
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver BC V6T 1Z1 Canada
| | - Clàudia Climent
- Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid E-28049 Madrid Spain
| | - Christopher M Brown
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver BC V6T 1Z1 Canada
| | - Duane Hean
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver BC V6T 1Z1 Canada
| | - Christopher J Bardeen
- Department of Chemistry, University of California Riverside 501 Big Springs Road Riverside California 92521 USA
| | - David Casanova
- Donostia International Physics Center (DIPC) Paseo Manuel de Lardizabal 4 20018 Donostia Euskadi Spain
- IKERBASQUE, Basque Foundation for Science 48013 Bilbao Euskadi Spain
| | - Michael O Wolf
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver BC V6T 1Z1 Canada
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15
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Brown CM, Auvray T, DeLuca EE, Ezhova MB, Hanan GS, Wolf MO. Controlling photocatalytic reduction of CO 2 in Ru(II)/Re(I) dyads via linker oxidation state. Chem Commun (Camb) 2020; 56:10750-10753. [PMID: 32789403 DOI: 10.1039/d0cc04597g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Electronic communication between the linked metal centers in Ru(ii)-Re(i) dyads is tuned using the oxidation state (S and SO2) of sulfur-bridged ligands. Higher catalytic activity is seen for the SO2-bridged dyad in the photocatalytic reduction of CO2.
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Affiliation(s)
- Christopher M Brown
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada.
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16
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Thomas SR, Bonsignore R, Sánchez Escudero J, Meier-Menches SM, Brown CM, Wolf MO, Barone G, Luk LYP, Casini A. Exploring the Chemoselectivity towards Cysteine Arylation by Cyclometallated Au III Compounds: New Mechanistic Insights. Chembiochem 2020; 21:3071-3076. [PMID: 32511840 PMCID: PMC7689846 DOI: 10.1002/cbic.202000262] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [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: 04/29/2020] [Revised: 06/05/2020] [Indexed: 12/15/2022]
Abstract
To gain more insight into the factors controlling efficient cysteine arylation by cyclometallated AuIII complexes, the reaction between selected gold compounds and different peptides was investigated by high‐resolution liquid chromatography electrospray ionization mass spectrometry (HR‐LC‐ESI‐MS). The deduced mechanisms of C−S cross‐coupling, also supported by density functional theory (DFT) and quantum mechanics/molecular mechanics (QM/MM) calculations, evidenced the key role of secondary peptidic gold binding sites in favouring the process of reductive elimination.
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Affiliation(s)
- Sophie R Thomas
- School of Chemistry, Cardiff University Main Building, Park Place, CF10 3AT, Cardiff, UK
| | - Riccardo Bonsignore
- School of Chemistry, Cardiff University Main Building, Park Place, CF10 3AT, Cardiff, UK
| | - Jorge Sánchez Escudero
- School of Chemistry, Cardiff University Main Building, Park Place, CF10 3AT, Cardiff, UK
| | - Samuel M Meier-Menches
- Department of Analytical Chemistry Faculty of Chemistry, University of Vienna, Waehringer Str. 38, 1090, Vienna, Austria
| | - Christopher M Brown
- Department of Chemistry, University of British Columbia, 2036 Main Mall, V6T 1Z1, Vancouver, BC, Canada
| | - Michael O Wolf
- Department of Chemistry, University of British Columbia, 2036 Main Mall, V6T 1Z1, Vancouver, BC, Canada
| | - Giampaolo Barone
- Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche, Università degli Studi di Palermo, Viale delle Scienze, Edificio 17, 90128, Palermo, Italy
| | - Louis Y P Luk
- School of Chemistry, Cardiff University Main Building, Park Place, CF10 3AT, Cardiff, UK
| | - Angela Casini
- Department of Chemistry, Technical University of Munich, Lichtenbergstrasse 4, 85747, Garching, Germany
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17
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Wright T, Petel Y, Zellman CO, Sauvé ER, Hudson ZM, Michal CA, Wolf MO. Room temperature crystallization of amorphous polysiloxane using photodimerization. Chem Sci 2020; 11:3081-3088. [PMID: 34122813 PMCID: PMC8157530 DOI: 10.1039/c9sc06235a] [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] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 02/13/2020] [Indexed: 11/21/2022] Open
Abstract
Bulk crystallization in flexible polymeric systems is difficult to control due to the random orientation of the chains. Here we report a photo cross-linking strategy that results in simultaneous cross-linking and crystallization of polysiloxane chains into millimeter sized leaf-like polycrystalline structures. Polymers containing pendant anthracene groups are prepared and undergo [4+4] photocycloaddition under 365 nm irradiation at room temperature. The growth and morphology of the crystalline structures is studied using polarized optical microscopy (POM) and atomic force microscopy and is found to progress through three unique stages of nucleation, growth, and constriction. The mobility of the individual chains is probed using pulsed-field gradient (PFG) NMR to provide insights into the diffusion processes that may govern chain transport to the growing crystal fronts. The room temperature crystallization of this conventionally amorphous polymer system may allow for a new level of morphological control for silicone materials.
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Affiliation(s)
- Taylor Wright
- Department of Chemistry, University of British Columbia Vancouver BC Canada V6T 1Z1
| | - Yael Petel
- Department of Chemistry, University of British Columbia Vancouver BC Canada V6T 1Z1
| | - Carson O Zellman
- Department of Chemistry, Simon Fraser University 8888 University Drive Burnaby BC Canada V5A 1S6
| | - Ethan R Sauvé
- Department of Chemistry, University of British Columbia Vancouver BC Canada V6T 1Z1
| | - Zachary M Hudson
- Department of Chemistry, University of British Columbia Vancouver BC Canada V6T 1Z1
| | - Carl A Michal
- Department of Chemistry, University of British Columbia Vancouver BC Canada V6T 1Z1
- Department of Physics and Astronomy, University of British Columbia Vancouver BC Canada V6T 1Z1
| | - Michael O Wolf
- Department of Chemistry, University of British Columbia Vancouver BC Canada V6T 1Z1
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18
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Xu Z, Liu QT, Wang X, Liu Q, Hean D, Chou KC, Wolf MO. Quinoline-containing diarylethenes: bridging between turn-on fluorescence, RGB switching and room temperature phosphorescence. Chem Sci 2020; 11:2729-2734. [PMID: 34084331 PMCID: PMC8157510 DOI: 10.1039/c9sc05697a] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Accepted: 01/31/2020] [Indexed: 01/08/2023] Open
Abstract
Simple structural modifications using oxidation and methylation of a quinoline-containing diarylethene result in dramatic variation of photophysical properties. Turn-on fluorescence, room temperature phosphorescence (RTP) and red-green-blue (RGB) switching were achieved in three different related compounds. Photoswitchable diarylethenes (DAEs) that exhibit turn-on fluorescence are in high demand for super-resolution microscopy, and the development of purely organic phosphorescent materials in the amorphous state is attractive but challenging. The findings reported here provide a novel toolkit for designing turn-on fluorescence DAEs for super-resolution microscopy and extending the scope of amorphous RTP materials. More importantly, we bridge between these two fundamentally significant photochemical and photophysical phenomena, and reveal structure-property relationships between DAE photochromism and RTP.
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Affiliation(s)
- Zhen Xu
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver BC V6T 1Z1 Canada
| | - Qian T Liu
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver BC V6T 1Z1 Canada
| | - Xiaozhu Wang
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver BC V6T 1Z1 Canada
| | - Qian Liu
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver BC V6T 1Z1 Canada
| | - Duane Hean
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver BC V6T 1Z1 Canada
| | - Keng C Chou
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver BC V6T 1Z1 Canada
| | - Michael O Wolf
- Department of Chemistry, University of British Columbia 2036 Main Mall Vancouver BC V6T 1Z1 Canada
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19
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Brown CM, Arsenault NE, Cross TNK, Hean D, Xu Z, Wolf MO. Structural, electrochemical and photophysical behavior of Ru( ii) complexes with large bite angle sulfur-bridged terpyridyl ligands. Inorg Chem Front 2020. [DOI: 10.1039/c9qi01009b] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Sulfur-bridged terpyridyl ligands expand the bite angles in Ru(ii) species leading to geometries very close to that of a “perfect” octahedron. Altering the donor strength of substituents results in systematic tuning of the redox properties.
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Affiliation(s)
| | | | | | - Duane Hean
- Department of Chemistry
- University of British Columbia
- Vancouver
- Canada
| | - Zhen Xu
- Department of Chemistry
- University of British Columbia
- Vancouver
- Canada
| | - Michael O. Wolf
- Department of Chemistry
- University of British Columbia
- Vancouver
- Canada
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20
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Abstract
Spinel CoCr2O4 nanostructured catalysts for methane oxidation were prepared by a facile solvothermal method using benzyl alcohol as both a structure-directing agent and a reagent.
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Affiliation(s)
- Yiling Dai
- Department of Chemistry
- University of British Columbia
- Vancouver
- Canada
| | - Haiyan Wang
- Department of Chemical and Biological Engineering
- University of British Columbia
- Vancouver
- Canada
| | - Shida Liu
- Department of Chemical and Biological Engineering
- University of British Columbia
- Vancouver
- Canada
| | - Kevin J. Smith
- Department of Chemical and Biological Engineering
- University of British Columbia
- Vancouver
- Canada
| | - Michael O. Wolf
- Department of Chemistry
- University of British Columbia
- Vancouver
- Canada
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21
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Yuan J, Christensen PR, Wolf MO. Dynamic anti-counterfeiting security features using multicolor dianthryl sulfoxides. Chem Sci 2019; 10:10113-10121. [PMID: 32055366 PMCID: PMC6991183 DOI: 10.1039/c9sc03948a] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 08/29/2019] [Indexed: 01/17/2023] Open
Abstract
A new concept for difficult-to-replicate security inks for use in advanced anti-counterfeiting applications is presented. Inks fabricated from a mixture of photoactive dyes result in a unique fluorescent color upon irradiation that differs from the starting fluorescence. The dyes are substituted 9,9'-dianthryl sulfoxides that undergo photochemical extrusion of a sulfoxide moiety (SO) to produce emissive red, blue, and green emitters. The resulting emissive feature has specific Commission international de l'éclairage (CIE) coordinates that are used for authentication. Additionally, the temporal evolution of the fluorescence can be monitored, introducing a dynamic nature to these security features. The three compounds show different rates of photoconversion dependent on the irradiation wavelength, allowing selective wavelengths for activation to be used for additional security. CIE coordinates can be extracted from patches containing the three compounds using an inexpensive, commercially available smartphone application (app) and compared against a known value to confirm the validity of the method.
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Affiliation(s)
- Jennifer Yuan
- Department of Chemistry , University of British Columbia , 2036 Main Mall , Vancouver , British Columbia V6T 1Z1 , Canada .
| | - Peter R Christensen
- Department of Chemistry , University of British Columbia , 2036 Main Mall , Vancouver , British Columbia V6T 1Z1 , Canada .
| | - Michael O Wolf
- Department of Chemistry , University of British Columbia , 2036 Main Mall , Vancouver , British Columbia V6T 1Z1 , Canada .
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22
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Cruz CD, Yuan J, Climent C, Tierce NT, Christensen PR, Chronister EL, Casanova D, Wolf MO, Bardeen CJ. Using sulfur bridge oxidation to control electronic coupling and photochemistry in covalent anthracene dimers. Chem Sci 2019; 10:7561-7573. [PMID: 31489171 PMCID: PMC6713866 DOI: 10.1039/c8sc05598j] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Accepted: 06/15/2019] [Indexed: 12/02/2022] Open
Abstract
For anthracene dimers bridged by a sulfur atom, modulating the sulfur oxidation state profoundly affects excited state behavior. The SO2-bridge supports long-lived states and photodimerization, while the S-bridge undergoes intersystem crossing.
Covalently tethered bichromophores provide an ideal proving ground to develop strategies for controlling excited state behavior in chromophore assemblies. In this work, optical spectroscopy and electronic structure theory are combined to demonstrate that the oxidation state of a sulfur linker between anthracene chromophores gives control over not only the photophysics but also the photochemistry of the molecules. Altering the oxidation state of the sulfur linker does not change the geometry between chromophores, allowing electronic effects between chromophores to be isolated. Previously, we showed that excitonic states in sulfur-bridged terthiophene dimers were modulated by electronic screening of the sulfur lone pairs, but that the sulfur orbitals were not directly involved in these states. In the bridged anthracene dimers that are the subject of the current paper, the atomic orbitals of the unoxidized S linker can actively mix with the anthracene molecular orbitals to form new electronic states with enhanced charge transfer character, different excitonic coupling, and rapid (sub-nanosecond) intersystem crossing that depends on solvent polarity. However, the fully oxidized SO2 bridge restores purely through-space electronic coupling between anthracene chromophores and inhibits intersystem crossing. Photoexcitation leads to either internal conversion on a sub-20 picosecond timescale, or to the creation of a long-lived emissive state that is the likely precursor of the intramolecular [4 + 4] photodimerization. These results illustrate how chemical modification of a single atom in the covalent bridge can dramatically alter not only the photophysics but also the photochemistry of molecules.
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Affiliation(s)
- Chad D Cruz
- Department of Chemistry , University of California Riverside , 501 Big Springs Road, Riverside , California 92521 , USA .
| | - Jennifer Yuan
- Department of Chemistry , University of British Columbia , 2036 Main Mall , Vancouver , BC , Canada V6T 1Z1
| | - Clàudia Climent
- Departamento de Física Teórica de la Materia Condensada , Universidad Autónoma de Madrid , E-28049 Madrid , Spain
| | - Nathan T Tierce
- Department of Chemistry , University of California Riverside , 501 Big Springs Road, Riverside , California 92521 , USA .
| | - Peter R Christensen
- Department of Chemistry , University of British Columbia , 2036 Main Mall , Vancouver , BC , Canada V6T 1Z1
| | - Eric L Chronister
- Department of Chemistry , University of California Riverside , 501 Big Springs Road, Riverside , California 92521 , USA .
| | - David Casanova
- Donostia International Physics Center (DIPC) , Paseo Manuel de Lardizabal 4 , 20018 Donostia , Euskadi , Spain.,IKERBASQUE , Basque Foundation for Science , 48013 Bilbao , Euskadi , Spain
| | - Michael O Wolf
- Department of Chemistry , University of British Columbia , 2036 Main Mall , Vancouver , BC , Canada V6T 1Z1
| | - Christopher J Bardeen
- Department of Chemistry , University of California Riverside , 501 Big Springs Road, Riverside , California 92521 , USA .
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23
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Brown CM, Li C, Carta V, Li W, Xu Z, Stroppa PHF, Samuel IDW, Zysman-Colman E, Wolf MO. Influence of Sulfur Oxidation State and Substituents on Sulfur-Bridged Luminescent Copper(I) Complexes Showing Thermally Activated Delayed Fluorescence. Inorg Chem 2019; 58:7156-7168. [DOI: 10.1021/acs.inorgchem.8b03500] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Christopher M. Brown
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Chenfei Li
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St. Andrews, St. Andrews, Fife KY16 9ST, U.K
| | - Veronica Carta
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Wenbo Li
- Organic Semiconductor Centre, SUPA School of Physics and Astronomy, University of St. Andrews, St. Andrews, Fife KY16 9SS, U.K
| | - Zhen Xu
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Pedro Henrique Fazza Stroppa
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St. Andrews, St. Andrews, Fife KY16 9ST, U.K
| | - Ifor D. W. Samuel
- Organic Semiconductor Centre, SUPA School of Physics and Astronomy, University of St. Andrews, St. Andrews, Fife KY16 9SS, U.K
| | - Eli Zysman-Colman
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St. Andrews, St. Andrews, Fife KY16 9ST, U.K
| | - Michael O. Wolf
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
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24
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Affiliation(s)
- Yang Cao
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Nicole E. Arsenault
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Duane Hean
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Michael O. Wolf
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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25
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Caron E, Brown CM, Hean D, Wolf MO. Variable oxidation state sulfur-bridged bithiazole ligands tune the electronic properties of ruthenium(ii) and copper(i) complexes. Dalton Trans 2019; 48:1263-1274. [DOI: 10.1039/c8dt04588g] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The synthesis of homoleptic and heteroleptic ruthenium(ii) and copper(i) complexes containing sulfur-bridged bithiazole ligands of varying oxidation states are reported.
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Affiliation(s)
- Elise Caron
- Department of Chemistry
- University of British Columbia
- Vancouver
- Canada
| | | | - Duane Hean
- Department of Chemistry
- University of British Columbia
- Vancouver
- Canada
| | - Michael O. Wolf
- Department of Chemistry
- University of British Columbia
- Vancouver
- Canada
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26
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Affiliation(s)
- Taylor Wright
- Department of Chemistry, 2036 Main Mall, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - Tanja Tomkovic
- Department of Chemical and Biological Engineering, 2360 East Mall, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Savvas G. Hatzikiriakos
- Department of Chemical and Biological Engineering, 2360 East Mall, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Michael O. Wolf
- Department of Chemistry, 2036 Main Mall, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
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27
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Affiliation(s)
- Nicole E. Arsenault
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Zhen Xu
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Michael O. Wolf
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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28
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Affiliation(s)
- Emile E. DeLuca
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Zhen Xu
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Jasper Lam
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Michael O. Wolf
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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29
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Xu Z, Cao Y, Patrick BO, Wolf MO. Photoswitching of Copper(I) Chromophores with Dithienylethene-Based Ligands. Chemistry 2018; 24:10315-10319. [DOI: 10.1002/chem.201801940] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 05/28/2018] [Indexed: 12/16/2022]
Affiliation(s)
- Zhen Xu
- Department of Chemistry; University of British Columbia; Vancouver British Columbia Canada
| | - Yang Cao
- Department of Chemistry; University of British Columbia; Vancouver British Columbia Canada
| | - Brian O. Patrick
- Department of Chemistry; University of British Columbia; Vancouver British Columbia Canada
| | - Michael O. Wolf
- Department of Chemistry; University of British Columbia; Vancouver British Columbia Canada
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30
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Therrien JA, Wolf MO, Patrick BO. Synthesis and comparison of nickel, palladium, and platinum bis(N-heterocyclic carbene) pincer complexes for electrocatalytic CO 2 reduction. Dalton Trans 2018; 47:1827-1840. [PMID: 29302661 DOI: 10.1039/c7dt04089j] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A valence isoelectronic and isostructural series of charged bis(N-heterocyclic carbene) pincer complexes [M(bC^N^bC)X]OTf and [M(bC^N^bC)CH3CN](OTf)2 (where M = Ni, Pd, and Pt, bC^N^bC = 1,1'-(pyridine-2,6-diylbis(methylene))bis(3-butylbenzo[d]imidazol-2-ylidene)) were synthesized, characterized, modelled by density functional theory calculations, and compared for their electrochemical properties and reactivity with CO2. Although the electrochemical response of each complex is altered by the presence of CO2, controlled potential electrolysis experiments demonstrated the superior ability of [Pd] to reduce CO2 to CO in faradaic efficiencies up to 58% in the presence of trifluoroacetic acid, compared to [Pt] and [Ni] which showed only marginal production of CO, giving the trend [Pd] ≫ [Pt] > [Ni] for this series.
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Affiliation(s)
- J A Therrien
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia, V6T 1Z1 Canada.
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31
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Dai Y, Pavan Kumar V, Zhu C, MacLachlan MJ, Smith KJ, Wolf MO. Mesoporous Silica-Supported Nanostructured PdO/CeO 2 Catalysts for Low-Temperature Methane Oxidation. ACS Appl Mater Interfaces 2018; 10:477-487. [PMID: 29261280 DOI: 10.1021/acsami.7b13408] [Citation(s) in RCA: 24] [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] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Nanostructured PdO/CeO2 supported on mesoporous SBA-15 silica was synthesized using a combination of incipient wetness impregnation and surface-assisted reduction. After calcination, the materials showed good activity as catalysts for the low-temperature oxidation of methane, with a sample having 5 wt % Pd loading showing 50% conversion to CO2 at ∼290 °C and complete conversion below 360 °C. The stability of catalysts in the presence of water was studied. The formation of Pd(0) during the methane oxidation reaction increases the oxygen vacancies on the surface of catalysts, improving the catalytic activity.
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Affiliation(s)
- Yiling Dai
- Department of Chemistry, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Vanama Pavan Kumar
- Department of Chemistry, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Chujie Zhu
- Department of Chemical and Biological Engineering, University of British Columbia , 2360 East Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Mark J MacLachlan
- Department of Chemistry, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Kevin J Smith
- Department of Chemical and Biological Engineering, University of British Columbia , 2360 East Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Michael O Wolf
- Department of Chemistry, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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32
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Brown CM, Kitt MJ, Xu Z, Hean D, Ezhova MB, Wolf MO. Tunable Emission of Iridium(III) Complexes Bearing Sulfur-Bridged Dipyridyl Ligands. Inorg Chem 2017; 56:15110-15118. [DOI: 10.1021/acs.inorgchem.7b02439] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Christopher M. Brown
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Mitchell J. Kitt
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Zhen Xu
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Duane Hean
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Maria B. Ezhova
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Michael O. Wolf
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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33
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Cao Y, Wang X, Shi X, Clee SM, McGeer PL, Wolf MO, Orvig C. Biological Imaging with Medium-Sensitive Bichromatic Flexible Fluorescent Dyes. Angew Chem Int Ed Engl 2017; 56:15603-15606. [DOI: 10.1002/anie.201708529] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 10/10/2017] [Indexed: 01/14/2023]
Affiliation(s)
- Yang Cao
- Department of Chemistry; University of British Columbia; Vancouver British Columbia Canada
| | - Xiaozhu Wang
- Department of Chemistry; University of British Columbia; Vancouver British Columbia Canada
| | - Xiaolei Shi
- The Kinsmen Laboratory of Neurological Research; University of British Columbia; Vancouver British Columbia Canada
| | - Susanne M. Clee
- Canada Research Chair in the Genetics of Obesity and Diabetes, Department of Cellular and Physiological Sciences; University of British Columbia; Vancouver British Columbia Canada
| | - Patrick L. McGeer
- The Kinsmen Laboratory of Neurological Research; University of British Columbia; Vancouver British Columbia Canada
| | - Michael O. Wolf
- Department of Chemistry; University of British Columbia; Vancouver British Columbia Canada
| | - Chris Orvig
- Department of Chemistry; University of British Columbia; Vancouver British Columbia Canada
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34
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Cao Y, Wang X, Shi X, Clee SM, McGeer PL, Wolf MO, Orvig C. Biological Imaging with Medium-Sensitive Bichromatic Flexible Fluorescent Dyes. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201708529] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Yang Cao
- Department of Chemistry; University of British Columbia; Vancouver British Columbia Canada
| | - Xiaozhu Wang
- Department of Chemistry; University of British Columbia; Vancouver British Columbia Canada
| | - Xiaolei Shi
- The Kinsmen Laboratory of Neurological Research; University of British Columbia; Vancouver British Columbia Canada
| | - Susanne M. Clee
- Canada Research Chair in the Genetics of Obesity and Diabetes, Department of Cellular and Physiological Sciences; University of British Columbia; Vancouver British Columbia Canada
| | - Patrick L. McGeer
- The Kinsmen Laboratory of Neurological Research; University of British Columbia; Vancouver British Columbia Canada
| | - Michael O. Wolf
- Department of Chemistry; University of British Columbia; Vancouver British Columbia Canada
| | - Chris Orvig
- Department of Chemistry; University of British Columbia; Vancouver British Columbia Canada
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35
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Affiliation(s)
- Elise Caron
- Department of Chemistry,
2036 Main Mall, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - Michael O. Wolf
- Department of Chemistry,
2036 Main Mall, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
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36
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Climent C, Barbatti M, Wolf MO, Bardeen CJ, Casanova D. The photophysics of naphthalene dimers controlled by sulfur bridge oxidation. Chem Sci 2017; 8:4941-4950. [PMID: 28959417 PMCID: PMC5607855 DOI: 10.1039/c7sc01285c] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 04/20/2017] [Indexed: 12/13/2022] Open
Abstract
In this study we investigate in detail the photophysics of naphthalene dimers covalently linked by a sulfur atom. We explore and rationalize how the oxidation state of the sulfur-bridging atom directly influences the photoluminescence of the dimer by enhancing or depriving its radiative and non-radiative relaxation pathways. In particular, we discuss how oxidation controls the amount of electronic transfer between the naphthalene moieties and the participation of the SO n bridge in the low-lying electronic transitions. We identify the sulfur electron lone-pairs as crucial actors in the non-radiative decay of the excited sulfide and sulfoxide dimers, which are predicted to proceed via a conical intersection (CI). Concretely, two types of CI have been identified for these dimers, which are associated with the photo-induced pyramidal inversion and reverse fragmentation mechanisms found in aryl sulfoxide dimers. The obtained results and conclusions are general enough to be extrapolated to other sulfur-bridged conjugated dimers, therefore proportionating novel strategies in the design of strongly photoluminescent organic molecules with controlled charge transfer.
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Affiliation(s)
- Clàudia Climent
- Departament de Ciència de Materials i Química Física , Institut de Química Teòrica i Computacional (IQTCUB) , Universitat de Barcelona , Martí i Franquès 1-11 , Barcelona 08028 , Spain
| | | | - Michael O Wolf
- Department of Chemistry , University of British Columbia , 2036 Main Mall , Vancouver , BC V6T 1Z1 , Canada
| | - Christopher J Bardeen
- Department of Chemistry , University of California Riverside , 501 Big Springs Road , Riverside , California 92521 , USA
| | - David Casanova
- Kimika Facultatea , Euskal Herriko Unibertsitatea (UPV/EHU) , Donostia International Physics Center , Paseo Manuel de Lardizabal, 4 , Donostia 20018 , Spain .
- IKERBASQUE , Basque Foundation for Science , Bilbao 48013 , Spain
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37
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Therrien JA, Wolf MO. The Influence of para Substituents in Bis(N-Heterocyclic Carbene) Palladium Pincer Complexes for Electrocatalytic CO 2 Reduction. Inorg Chem 2017; 56:1161-1172. [PMID: 28071907 DOI: 10.1021/acs.inorgchem.6b02213] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The effect of modifying the pyridyl para position of lutidine-linked bis(N-heterocyclic carbene) Pd pincer complexes is studied both experimentally (R = OMe, H, Br, and COOR) and computationally, showing a strong effect on the first reduction potential of the complex and allowing the reduction potential to be tuned over a wide range in relation to the Hammett σp constant of the para substituent. The effect of the pyridyl para substituent on electron density of the metal center, frontier orbital energies, and dissociation energy of the trans ligand are also investigated in the context of reactivity with CO2 through electrochemical characterization of the complexes under N2 and CO2 and controlled potential electrolysis experiments where CO2 is reduced to CO.
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Affiliation(s)
- Jeffrey A Therrien
- Department of Chemistry, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Michael O Wolf
- Department of Chemistry, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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38
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Affiliation(s)
- Yang Cao
- Department of Chemistry, 2036 Main Mall, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Michael O. Wolf
- Department of Chemistry, 2036 Main Mall, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Brian O. Patrick
- Department of Chemistry, 2036 Main Mall, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
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39
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Majewski MB, Smith JG, Wolf MO, Patrick BO. Cover Picture: Long‐Lived, Emissive Excited States in Direct and Amide‐Linked Thienyl‐Substituted Ru
II
Complexes (Eur. J. Inorg. Chem. 10/2016). Eur J Inorg Chem 2016. [DOI: 10.1002/ejic.201690021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Marek B. Majewski
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia, V6T 1Z1, Canada, http://https://groups.chem.ubc.ca/wolf/
| | - Jeremy G. Smith
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia, V6T 1Z1, Canada, http://https://groups.chem.ubc.ca/wolf/
| | - Michael O. Wolf
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia, V6T 1Z1, Canada, http://https://groups.chem.ubc.ca/wolf/
| | - Brian O. Patrick
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia, V6T 1Z1, Canada, http://https://groups.chem.ubc.ca/wolf/
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40
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Majewski MB, Smith JG, Wolf MO, Patrick BO. Long‐Lived, Emissive Excited States in Direct and Amide‐Linked Thienyl‐Substituted Ru
II
Complexes. Eur J Inorg Chem 2016. [DOI: 10.1002/ejic.201501436] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Marek B. Majewski
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia, V6T 1Z1, Canada, http://https://groups.chem.ubc.ca/wolf/
| | - Jeremy G. Smith
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia, V6T 1Z1, Canada, http://https://groups.chem.ubc.ca/wolf/
| | - Michael O. Wolf
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia, V6T 1Z1, Canada, http://https://groups.chem.ubc.ca/wolf/
| | - Brian O. Patrick
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia, V6T 1Z1, Canada, http://https://groups.chem.ubc.ca/wolf/
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41
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Majewski MB, Smith JG, Wolf MO, Patrick BO. Long‐Lived, Emissive Excited States in Direct and Amide‐Linked Thienyl‐Substituted Ru
II
Complexes. Eur J Inorg Chem 2016. [DOI: 10.1002/ejic.201600285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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42
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Howarth AJ, Majewski MB, Brown CM, Lelj F, Wolf MO, Patrick BO. Emissive Ir(III) complexes bearing thienylamido groups on a 1,10-phenanthroline scaffold. Dalton Trans 2015; 44:16272-9. [PMID: 26278384 DOI: 10.1039/c5dt02691a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The synthesis, structures and photophysical properties of a series of bis-cyclometallated Ir(iii) complexes bearing phenylpyrazole (ppz) cyclometallating ligands and phenanthroline-based ancillary ligands containing thienyl- and bithienylamido groups are reported. All complexes are emissive in solution, while in PMMA films strong emission is observed from the thienylamido substituted complex with no emission from the bithienylamido complex. The bithienylamido substituted complex has an excited state lifetime which is significantly longer than the emission lifetime, attributed to the population of non-equilibrated (3)MLCT and (3)LC states in this complex. This represents a rare example of this unusual excited state behaviour. DFT calculations show that the emitting (3)MLCT state and the dark (3)LC state on bithiophene are close in energy and that a large change in the triplet state geometry occurs upon excitation that effectively lowers the energy of the (3)MLCT state below that of the dark (3)LC state. The low quantum yield of the bithienylamido complex is attributed to a structural rearrangement upon relaxation back to the ground state, opening a non-radiative decay pathway.
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Affiliation(s)
- Ashlee J Howarth
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6 T 1Z1, Canada.
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43
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Abstract
Phenanthro- and pyreno-annulated N-heterocyclic carbenes (NHCs) have been incorporated into lutidine-linked bis-NHC Pd pincer complexes to investigate the effect of these polyannulated NHCs on the ability of the complexes to electrochemically reduce CO2 to CO in the presence of 2,2,2-trifluoroacetic acid and 2,2,2-trifluoroethanol as proton sources. These complexes are screened for their ability to reduce CO2 and modeled using density functional theory calculations, where the annulated phenanthrene and pyrene moieties are shown to be additional sites for redox activity in the pincer ligand, enabling increased electron donation. Electrochemical and computational studies are used to gain an understanding of the chemical significance of redox events for complexes of this type, highlighting the importance of anion binding and dissociation.
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Affiliation(s)
- Jeffrey A Therrien
- Department of Chemistry, University of British Columbia , Vancouver, British Columbia V6T 1Z1, Canada
| | - Michael O Wolf
- Department of Chemistry, University of British Columbia , Vancouver, British Columbia V6T 1Z1, Canada
| | - Brian O Patrick
- Department of Chemistry, University of British Columbia , Vancouver, British Columbia V6T 1Z1, Canada
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44
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Cruz CD, Christensen PR, Chronister EL, Casanova D, Wolf MO, Bardeen CJ. Sulfur-Bridged Terthiophene Dimers: How Sulfur Oxidation State Controls Interchromophore Electronic Coupling. J Am Chem Soc 2015; 137:12552-64. [DOI: 10.1021/jacs.5b05457] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Chad D. Cruz
- Department
of Chemistry, University of California Riverside, 501 Big Springs Road, Riverside, California 92521, United States
| | - Peter R. Christensen
- Department
of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1 Canada
| | - Eric L. Chronister
- Department
of Chemistry, University of California Riverside, 501 Big Springs Road, Riverside, California 92521, United States
| | - David Casanova
- Kimika Facultatea, Euskal Herriko Unibertsitatea (UPV/EHU), Donostia International Physics Center, P.K: 1072, Donostia 20080, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao, Euskadi 48013, Spain
| | - Michael O. Wolf
- Department
of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1 Canada
| | - Christopher J. Bardeen
- Department
of Chemistry, University of California Riverside, 501 Big Springs Road, Riverside, California 92521, United States
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45
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Gomathi A, Vickers SM, Gholami R, Alyani M, Man RWY, MacLachlan MJ, Smith KJ, Wolf MO. Nanostructured Materials Prepared by Surface-Assisted Reduction: New Catalysts for Methane Oxidation. ACS Appl Mater Interfaces 2015; 7:19268-19273. [PMID: 26287568 DOI: 10.1021/acsami.5b05189] [Citation(s) in RCA: 7] [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] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Cerium formate hollow spheres and cerium hydroxycarbonate nanorods with residual formate groups are effective for reducing palladium(II) salts onto their surfaces. Calcination of the new materials obtained by this surface-assisted reduction method gives highly active PdO/CeO2 nanostructures with Pd well dispersed on the substrate. Temperature-programmed oxidation experiments showed that these nanomaterials are good catalysts for the low-temperature oxidation of methane, with 50% conversion temperatures (T(50%)) at ∼300 °C.
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Affiliation(s)
- A Gomathi
- Department of Chemistry, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Susan M Vickers
- Department of Chemistry, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Rahman Gholami
- Department of Chemical and Biological Engineering, University of British Columbia , 2360 East Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Mina Alyani
- Department of Chemical and Biological Engineering, University of British Columbia , 2360 East Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Renee W Y Man
- Department of Chemistry, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Mark J MacLachlan
- Department of Chemistry, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Kevin J Smith
- Department of Chemical and Biological Engineering, University of British Columbia , 2360 East Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Michael O Wolf
- Department of Chemistry, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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46
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Affiliation(s)
- Yang Cao
- Department
of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Jeffrey K. Nagle
- Department
of Chemistry, Bowdoin College, Brunswick, Maine 04011, United States
| | - Michael O. Wolf
- Department
of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Brian O. Patrick
- Department
of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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47
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Howarth AJ, Davies DL, Lelj F, Wolf MO, Patrick BO. Tuning the emission lifetime in bis-cyclometalated iridium(III) complexes bearing iminopyrene ligands. Inorg Chem 2014; 53:11882-9. [PMID: 25347609 DOI: 10.1021/ic501032t] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Bis-cyclometalated Ir(III) complexes with the general formula Ir(ppz)2(X^NPyrene), where ppz = 1-phenylpyrazole and X^NPyrene is a bidentate chelate with X = N or O, are reported. Modifications on the ancillary ligand containing pyrene drastically affect the emission lifetimes observed (0.329 to 104 μs). Extended emission lifetimes in these complexes compared to model complexes result from reversible electronic energy transfer or the observation of dual emission containing along-lived pyrene ligand-centered triplet ((3)LC) component. A combination of steady-state and time-resolved spectroscopic techniques are used to observe reversible electronic energy transfer in solution between the iridium core and pyrene moiety in the complex [Ir(ppz)2(NMe^NCH2Pyr)][PF6] (2), where NMe^NCH2Pyr = N-(pyren-1-ylmethyl)-1-(pyridin-2-yl)ethaneimine. Studies on [Ir(ppz)2(NMe^NCH2Pyr)][PF6] in a poly(methyl methacrylate) (PMMA) film reveal that reversible energy transfer is no longer effective, and instead, dual emission with a long-lived (3)LC component from pyrene is observed. Dual emission is observed in additional cyclometalated iridium complexes bearing pyrene-containing ancillary ligands N^NPyrene and O^NPyrene when the complexes are dispersed in a PMMA film.
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Affiliation(s)
- Ashlee J Howarth
- Department of Chemistry, University of British Columbia , Vancouver, British Columbia V6T 1Z1, Canada
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48
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Abstract
A series of pyridine- and lutidine-linked bis-N-heterocyclic carbene (NHC) palladium pincer complexes were electrochemically characterized and screened for CO2 reduction capability with 2,2,2-trifluoroethanol, acetic acid, or 2,2,2-trifluoroacetic acid (TFA) as proton sources. The lutidine-linked pincer complexes electrocatalytically reduce CO2 to CO at potentials as low as -1.6 V versus Ag/AgNO3 in the presence of TFA. The one-electron reduction of these complexes is shown to be chemically reversible, yielding a monometallic species, with density functional theory studies indicating charge storage on the redox-active ligand, thus addressing a major source of deactivation in earlier triphosphine electrocatalysts.
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Affiliation(s)
- Jeffrey A Therrien
- Department of Chemistry, University of British Columbia , Vancouver, British Columbia V6T 1Z1, Canada
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49
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Howarth AJ, Patia R, Davies DL, Lelj F, Wolf MO, Singh K. Elucidating the Origin of Enhanced Phosphorescence Emission in the Solid State (EPESS) in Cyclometallated Iridium Complexes. Eur J Inorg Chem 2014. [DOI: 10.1002/ejic.201402495] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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50
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Affiliation(s)
- Lyndsey D. Earl
- Department of Chemistry, University of British Columbia, Vancouver, Bristish Columbia V6T 1Z1, Canada
| | - Jeffrey K. Nagle
- Department of Chemistry, Bowdoin College, Brunswick, Maine 04011, United States
| | - Michael O. Wolf
- Department of Chemistry, University of British Columbia, Vancouver, Bristish Columbia V6T 1Z1, Canada
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