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Zitz R, Pöcheim A, Baumgartner J, Marschner C. A 1,5-Oligosilanylene Dianion as Building Block for Oligosiloxane Containing Cages, Ferrocenophanes, and Cyclic Germylenes and Stannylenes. Molecules 2020; 25:E1322. [PMID: 32183200 PMCID: PMC7144727 DOI: 10.3390/molecules25061322] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 03/05/2020] [Accepted: 03/11/2020] [Indexed: 11/16/2022] Open
Abstract
Starting out from dipotassium 1,5-oligosiloxanylene diide 2, a 3,7,10-trioxa-octasilabicyclo[3.3.3]undecane was prepared, which represents the third known example of this cage structure type. Reaction of 1,3-dichlorotetramethyldisiloxane with 1,1'-bis[bis(trimethylsilyl)potassiosilyl]ferrocene gave a ferrocenophane with a disiloxane containg bridge. The compound can be further derivatized by conversion into a 1,5-oligosilanyl diide. Reacting 1,5-oligosiloxanylene diide 2 with SnCl2 or GeCl2·dioxane in the presence of PMe3 gave cyclic disilylated tetrylene PMe3 adducts. Release of the base-free stannylene led to a dimerization process which gave a bicyclic distannene as the final product. Abstraction of the PMe3 from the cyclic disilylated germylene PMe3 adduct with B(C6F5)3 caused oxidative addition of the germylene into a para-C-F bond of Me3P·B(C6F5)3.
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Affiliation(s)
| | | | - Judith Baumgartner
- Institut für Anorganische Chemie, Technische Universität Graz, Stremayrgasse 9, A-8010 Graz, Austria; (R.Z.); (A.P.)
| | - Christoph Marschner
- Institut für Anorganische Chemie, Technische Universität Graz, Stremayrgasse 9, A-8010 Graz, Austria; (R.Z.); (A.P.)
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Zitz R, Baumgartner J, Marschner C. Chemistry of a 1,5-Oligosilanylene Dianion Containing a Disiloxane Unit. Organometallics 2019; 38:1159-1167. [PMID: 30880866 PMCID: PMC6415795 DOI: 10.1021/acs.organomet.9b00013] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Indexed: 11/30/2022]
Abstract
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Synthesis of a number
of disiloxane containing cyclo- and bicyclooligosilanes
is described starting from the dipotassium 1,5-oligosiloxanylene diide
derived from 1,3-bis[tris(trimethylsilyl)silyl]tetramethyldisiloxane.
In addition, the use of this particular fragment as ligand for zinc
and group 4 metallocene complexes was studied. Both types of compounds
exhibit marked structural differences compared to related compounds
containing Si-Si-Si units instead of the Si-O-Si fragment.
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Affiliation(s)
- Rainer Zitz
- Institut für Anorganische Chemie, Technische Universität Graz, Stremayrgasse 9, 8010 Graz, Austria
| | - Judith Baumgartner
- Institut für Anorganische Chemie, Technische Universität Graz, Stremayrgasse 9, 8010 Graz, Austria
| | - Christoph Marschner
- Institut für Anorganische Chemie, Technische Universität Graz, Stremayrgasse 9, 8010 Graz, Austria
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Fugel M, Hesse MF, Pal R, Beckmann J, Jayatilaka D, Turner MJ, Karton A, Bultinck P, Chandler GS, Grabowsky S. Covalency and Ionicity Do Not Oppose Each Other-Relationship Between Si-O Bond Character and Basicity of Siloxanes. Chemistry 2018; 24:15275-15286. [PMID: 29999553 DOI: 10.1002/chem.201802197] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 07/11/2018] [Indexed: 11/07/2022]
Abstract
Covalency and ionicity are orthogonal rather than antipodal concepts. We demonstrate for the case of siloxane systems [R3 Si-(O-SiR2 )n -O-SiR3 ] that both covalency and ionicity of the Si-O bonds impact on the basicity of the Si-O-Si linkage. The relationship between the siloxane basicity and the Si-O bond character has been under debate since previous studies have presented conflicting explanations. It has been shown with natural bond orbital methods that increased hyperconjugative interactions of LP(O)→σ*(Si-R) type, that is, increased orbital overlap and hence covalency, are responsible for the low siloxane basicity at large Si-O-Si angles. On the other hand, increased ionicity towards larger Si-O-Si angles has been revealed with real-space bonding indicators. To resolve this ostensible contradiction, we perform a complementary bonding analysis, which combines orbital-space, real-space, and bond-index considerations. We analyze the isolated disiloxane molecule H3 SiOSiH3 with varying Si-O-Si angles, and n-membered cyclic siloxane systems Si2 H4 O(CH2 )n-3 . All methods from quite different realms show that both covalent and ionic interactions increase simultaneously towards larger Si-O-Si angles. In addition, we present highly accurate absolute hydrogen-bond interaction energies of the investigated siloxane molecules with water and silanol as donors. It is found that intermolecular hydrogen bonding is significant at small Si-O-Si angles and weakens as the Si-O-Si angle increases until no stable hydrogen-bond complexes are obtained beyond φSiOSi =168°, angles typically displayed by minerals or polymers. The maximum hydrogen-bond interaction energy, which is obtained at an angle of 105°, is 11.05 kJ mol-1 for the siloxane-water complex and 18.40 kJ mol-1 for the siloxane-silanol complex.
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Affiliation(s)
- Malte Fugel
- University of Bremen, Department 2-Chemistry/Biology, Institute of Inorganic Chemistry and Crystallography, Leobener Str. 3 and 7, 28359, Bremen, Germany
| | - Maxie F Hesse
- University of Bremen, Department 2-Chemistry/Biology, Institute of Inorganic Chemistry and Crystallography, Leobener Str. 3 and 7, 28359, Bremen, Germany
| | - Rumpa Pal
- University of Bremen, Department 2-Chemistry/Biology, Institute of Inorganic Chemistry and Crystallography, Leobener Str. 3 and 7, 28359, Bremen, Germany
| | - Jens Beckmann
- University of Bremen, Department 2-Chemistry/Biology, Institute of Inorganic Chemistry and Crystallography, Leobener Str. 3 and 7, 28359, Bremen, Germany
| | - Dylan Jayatilaka
- University of Western Australia, School of Molecular Sciences, 35 Stirling Highway, Perth, WA, 6009, Australia
| | - Michael J Turner
- University of Western Australia, School of Molecular Sciences, 35 Stirling Highway, Perth, WA, 6009, Australia
| | - Amir Karton
- University of Western Australia, School of Molecular Sciences, 35 Stirling Highway, Perth, WA, 6009, Australia
| | - Patrick Bultinck
- Ghent University, Department of Chemistry, Krijgslaan 281 (S3), 9000, Gent, Belgium
| | - Graham S Chandler
- University of Western Australia, School of Molecular Sciences, 35 Stirling Highway, Perth, WA, 6009, Australia
| | - Simon Grabowsky
- University of Bremen, Department 2-Chemistry/Biology, Institute of Inorganic Chemistry and Crystallography, Leobener Str. 3 and 7, 28359, Bremen, Germany
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