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Dietmar Stalke - One of the best experts on this subject based on the ideXlab platform.
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Reaction of a Base‐Stabilized Bis(silylene) [PhC(NtBu)2Si]2 with Cyclooctatetraene without Cleavage of the Si–Si Bond
European Journal of Inorganic Chemistry, 2011Co-Authors: Sakya S. Sen, Shabana I. Khan, Daniel Kratzert, Herbert W. Roesky, Dietmar StalkeAbstract:The reaction of the benzamidinato-stabilized bis(silylene) [PhC(NtBu)2Si]2 with cyclooctatetraene resulted in the formation of a colorless compound 7 whithout cleavage of the Si–Si Bond of the bis(silylene), whereas one of each Si–N(ligand) Bond is opened. Compound 7 was characterized by single-crystal X-ray diffraction, NMR spectroscopy, EI mass spectrometry, and elemental analysis. Investigation of the molecular structure shows that the Si–Si Bond length in 7 is 2.4150(7) A and is comparable to that of 6 [2.413(2) A].
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Reactions of a Bis-silylene (LSi−SiL, L = PhC(NtBu)2) and a Heteroleptic Chloro Silylene (LSiCl) with Benzil: Formation of Bis(siladioxolene) and Monosiladioxolene Analogue with Five-Coordinate Silicon Atoms in Both Ring Systems
Organometallics, 2010Co-Authors: Gasper Tavcar, Sakya S. Sen, Daniel Kratzert, Herbert W. Roesky, Jakob Hey, Dietmar StalkeAbstract:LSi−SiL (L = PhC(NtBu)2) (4) was reacted with benzil in toluene at room temperature to afford a compound that contains two siladioxolene rings connected by a Si−Si Bond. This is the first reactivity study of 4 where the central Si−Si Bond was not cleaved during the reaction. Furthermore, LSiCl (L = PhC(NtBu)2) (6) was treated with benzil at ambient temperature in toluene to yield 2,5-dioxa-1-silacyclopent-3-ene (7). Both 5 and 7 were characterized by single-crystal X-ray diffraction and additionally by NMR spectroscopy, EI-MS spectrometry, and elemental analysis. Investigation of the molecular structure shows that the Si−Si Bond length in 5 is 2.36 A, which is more than 2% shorter than the Si−Si Bond length in 4. The formal oxidation state of silicon in 5 is +3, which is in agreement with its structure. The existence of 5 and 7 as stable compounds indicates that siladioxolenes can be electronically stabilized by σ-donor ligands.
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reactions of a bis silylene lsi sil l phc ntbu 2 and a heteroleptic chloro silylene lsicl with benzil formation of bis siladioxolene and monosiladioxolene analogue with five coordinate silicon atoms in both ring systems
Organometallics, 2010Co-Authors: Gasper Tavcar, Sakya S. Sen, Daniel Kratzert, Herbert W. Roesky, Jakob Hey, Dietmar StalkeAbstract:LSi−SiL (L = PhC(NtBu)2) (4) was reacted with benzil in toluene at room temperature to afford a compound that contains two siladioxolene rings connected by a Si−Si Bond. This is the first reactivity study of 4 where the central Si−Si Bond was not cleaved during the reaction. Furthermore, LSiCl (L = PhC(NtBu)2) (6) was treated with benzil at ambient temperature in toluene to yield 2,5-dioxa-1-silacyclopent-3-ene (7). Both 5 and 7 were characterized by single-crystal X-ray diffraction and additionally by NMR spectroscopy, EI-MS spectrometry, and elemental analysis. Investigation of the molecular structure shows that the Si−Si Bond length in 5 is 2.36 A, which is more than 2% shorter than the Si−Si Bond length in 4. The formal oxidation state of silicon in 5 is +3, which is in agreement with its structure. The existence of 5 and 7 as stable compounds indicates that siladioxolenes can be electronically stabilized by σ-donor ligands.
John Robertson - One of the best experts on this subject based on the ideXlab platform.
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Binding and surface diffusion of SiH3 radicals and the roughness of hydrogenated amorphous silicon
Applied Physics Letters, 2003Co-Authors: R Dewarrat, John RobertsonAbstract:Local density formalism pseudopotential calculations find that the growth radical SiH3 binds to the hydrogen-terminated (111)Si surface. The bound site is not the three-center Si–H–Si bridging site previously assumed. It has a direct Si–Si Bond between the SiH3 and the surface Si, and the terminal hydrogen is displaced to a Bond center of a lateral surface Si–Si Bond. This site is more stable as the unpaired electron can delocalize over more Si–Si Bonds. A bound site validates the standard model of the growth of hydrogenated amorphous silicon (a-Si:H) and microcrystalline Si, in which a mobile growth species allows surface diffusion and creates smooth surfaces.
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Surface diffusion of SiH3 radicals and growth mechanism of a-Si:H and microcrystalline Si
Thin Solid Films, 2003Co-Authors: R Dewarrat, John RobertsonAbstract:Abstract Existing growth mechanisms of hydrogenated amorphous silicon (a-Si:H) and microcrystalline silicon (μc-Si) assume that the growth species SiH 3 can diffuse over the hydrogen-saturated Si surface. However, recent calculations suggest that this could not happen. We have carried out local density formalism pseudopotential calculations of the binding of SiH 3 to hydrogen-terminated (1 1 1)Si surfaces. The bound site is not the three-centre SiHSi bridging site previously assumed. It has a direct SiSi Bond between the SiH 3 and the surface Si, and the surface hydrogen is displaced to a Bond centre of a surface SiSi Bond. A bound site validates conventional models of growth of a-Si:H and μc-Si, in which a mobile growth species creates smooth surfaces.
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Surface Diffusion of SiH3 Radicals and Growth Mechanism of a-Si:H and μc-Si
MRS Proceedings, 2002Co-Authors: R Dewarrat, John RobertsonAbstract:AbstractExisting growth mechanisms of hydrogenated amorphous silicon (a-Si:H) and micro-crystalline silicon assume that the growth species SiH3 can diffuse over the hydrogen-saturated Si surface. However, recent calculations suggest that this could not happen. Local density formalism pseudopotential calculations have been carried out of binding of SiH3 to hydrogen terminated (111)Si surfaces. The bound site is not the three-centre Si-H-Si bridging site previously assumed. It has a direct Si-Si Bond between the SiH3 and the surface Si, and the surface hydrogen is displaced to a Bond centre of a surface Si-Si Bond. A bound site confirms conventional models of growth of a-Si:H and microcrystalline Si, in which a mobile growth species creates smooth surfaces.
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Binding and surface diffusion of SiH3 radicals on a growing a-Si:H surface
Journal of Non-crystalline Solids, 2001Co-Authors: R Dewarrat, John RobertsonAbstract:Abstract Local density pseudopotential calculations find that the growth radical SiH 3 binds to the hydrogen terminated (1 1 1)Si surface. The bound site is not the three-centre Si–H–Si bridging site assumed previously. Instead, it has a direct Si–Si Bond between the SiH 3 and the surface Si, and the terminal hydrogen has been displaced first to an antiBonding site and finally to a Bond centre site of a surface Si–Si Bond. A bound site validates conventional models of the growth of hydrogen amorphous silicon (a-Si:H), in which a mobile growth species is needed for smooth surfaces.
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Relative importance of the Si–Si Bond and Si–H Bond for the stability of amorphous silicon thin film transistors
Journal of Applied Physics, 2000Co-Authors: Ralf B. Wehrspohn, Steven C. Deane, Ian D. French, I. G. Gale, J. Hewett, Martin J. Powell, John RobertsonAbstract:We investigate the mechanism for Si dangling Bond defect creation in amorphous silicon thin film transistors as a result of bias stress. We show that the rate of defect creation does not depend on the total hydrogen content or the type of hydrogen Bonding in the amorphous silicon. However, the rate of defect creation does show a clear correlation with the Urbach energy and the intrinsic stress in the film. These important results support a localized model for defect creation, i.e., where a Si–Si Bond breaks and a nearby H atom switches to stabilize the broken Bond, as opposed to models involving the long-range diffusion of hydrogen. Our experimental results demonstrate the importance of optimizing the intrinsic stress in the films to obtain maximum stability and mobility. An important implication is that a deposition process where intrinsic stress can be independently controlled, such as an ion-energy controlled deposition should be beneficial, particularly for deposition temperatures below 300 °C.
Sakya S. Sen - One of the best experts on this subject based on the ideXlab platform.
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Reaction of a Base‐Stabilized Bis(silylene) [PhC(NtBu)2Si]2 with Cyclooctatetraene without Cleavage of the Si–Si Bond
European Journal of Inorganic Chemistry, 2011Co-Authors: Sakya S. Sen, Shabana I. Khan, Daniel Kratzert, Herbert W. Roesky, Dietmar StalkeAbstract:The reaction of the benzamidinato-stabilized bis(silylene) [PhC(NtBu)2Si]2 with cyclooctatetraene resulted in the formation of a colorless compound 7 whithout cleavage of the Si–Si Bond of the bis(silylene), whereas one of each Si–N(ligand) Bond is opened. Compound 7 was characterized by single-crystal X-ray diffraction, NMR spectroscopy, EI mass spectrometry, and elemental analysis. Investigation of the molecular structure shows that the Si–Si Bond length in 7 is 2.4150(7) A and is comparable to that of 6 [2.413(2) A].
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Reactions of a Bis-silylene (LSi−SiL, L = PhC(NtBu)2) and a Heteroleptic Chloro Silylene (LSiCl) with Benzil: Formation of Bis(siladioxolene) and Monosiladioxolene Analogue with Five-Coordinate Silicon Atoms in Both Ring Systems
Organometallics, 2010Co-Authors: Gasper Tavcar, Sakya S. Sen, Daniel Kratzert, Herbert W. Roesky, Jakob Hey, Dietmar StalkeAbstract:LSi−SiL (L = PhC(NtBu)2) (4) was reacted with benzil in toluene at room temperature to afford a compound that contains two siladioxolene rings connected by a Si−Si Bond. This is the first reactivity study of 4 where the central Si−Si Bond was not cleaved during the reaction. Furthermore, LSiCl (L = PhC(NtBu)2) (6) was treated with benzil at ambient temperature in toluene to yield 2,5-dioxa-1-silacyclopent-3-ene (7). Both 5 and 7 were characterized by single-crystal X-ray diffraction and additionally by NMR spectroscopy, EI-MS spectrometry, and elemental analysis. Investigation of the molecular structure shows that the Si−Si Bond length in 5 is 2.36 A, which is more than 2% shorter than the Si−Si Bond length in 4. The formal oxidation state of silicon in 5 is +3, which is in agreement with its structure. The existence of 5 and 7 as stable compounds indicates that siladioxolenes can be electronically stabilized by σ-donor ligands.
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reactions of a bis silylene lsi sil l phc ntbu 2 and a heteroleptic chloro silylene lsicl with benzil formation of bis siladioxolene and monosiladioxolene analogue with five coordinate silicon atoms in both ring systems
Organometallics, 2010Co-Authors: Gasper Tavcar, Sakya S. Sen, Daniel Kratzert, Herbert W. Roesky, Jakob Hey, Dietmar StalkeAbstract:LSi−SiL (L = PhC(NtBu)2) (4) was reacted with benzil in toluene at room temperature to afford a compound that contains two siladioxolene rings connected by a Si−Si Bond. This is the first reactivity study of 4 where the central Si−Si Bond was not cleaved during the reaction. Furthermore, LSiCl (L = PhC(NtBu)2) (6) was treated with benzil at ambient temperature in toluene to yield 2,5-dioxa-1-silacyclopent-3-ene (7). Both 5 and 7 were characterized by single-crystal X-ray diffraction and additionally by NMR spectroscopy, EI-MS spectrometry, and elemental analysis. Investigation of the molecular structure shows that the Si−Si Bond length in 5 is 2.36 A, which is more than 2% shorter than the Si−Si Bond length in 4. The formal oxidation state of silicon in 5 is +3, which is in agreement with its structure. The existence of 5 and 7 as stable compounds indicates that siladioxolenes can be electronically stabilized by σ-donor ligands.
Herbert W. Roesky - One of the best experts on this subject based on the ideXlab platform.
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Reaction of a Base‐Stabilized Bis(silylene) [PhC(NtBu)2Si]2 with Cyclooctatetraene without Cleavage of the Si–Si Bond
European Journal of Inorganic Chemistry, 2011Co-Authors: Sakya S. Sen, Shabana I. Khan, Daniel Kratzert, Herbert W. Roesky, Dietmar StalkeAbstract:The reaction of the benzamidinato-stabilized bis(silylene) [PhC(NtBu)2Si]2 with cyclooctatetraene resulted in the formation of a colorless compound 7 whithout cleavage of the Si–Si Bond of the bis(silylene), whereas one of each Si–N(ligand) Bond is opened. Compound 7 was characterized by single-crystal X-ray diffraction, NMR spectroscopy, EI mass spectrometry, and elemental analysis. Investigation of the molecular structure shows that the Si–Si Bond length in 7 is 2.4150(7) A and is comparable to that of 6 [2.413(2) A].
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Reactions of a Bis-silylene (LSi−SiL, L = PhC(NtBu)2) and a Heteroleptic Chloro Silylene (LSiCl) with Benzil: Formation of Bis(siladioxolene) and Monosiladioxolene Analogue with Five-Coordinate Silicon Atoms in Both Ring Systems
Organometallics, 2010Co-Authors: Gasper Tavcar, Sakya S. Sen, Daniel Kratzert, Herbert W. Roesky, Jakob Hey, Dietmar StalkeAbstract:LSi−SiL (L = PhC(NtBu)2) (4) was reacted with benzil in toluene at room temperature to afford a compound that contains two siladioxolene rings connected by a Si−Si Bond. This is the first reactivity study of 4 where the central Si−Si Bond was not cleaved during the reaction. Furthermore, LSiCl (L = PhC(NtBu)2) (6) was treated with benzil at ambient temperature in toluene to yield 2,5-dioxa-1-silacyclopent-3-ene (7). Both 5 and 7 were characterized by single-crystal X-ray diffraction and additionally by NMR spectroscopy, EI-MS spectrometry, and elemental analysis. Investigation of the molecular structure shows that the Si−Si Bond length in 5 is 2.36 A, which is more than 2% shorter than the Si−Si Bond length in 4. The formal oxidation state of silicon in 5 is +3, which is in agreement with its structure. The existence of 5 and 7 as stable compounds indicates that siladioxolenes can be electronically stabilized by σ-donor ligands.
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reactions of a bis silylene lsi sil l phc ntbu 2 and a heteroleptic chloro silylene lsicl with benzil formation of bis siladioxolene and monosiladioxolene analogue with five coordinate silicon atoms in both ring systems
Organometallics, 2010Co-Authors: Gasper Tavcar, Sakya S. Sen, Daniel Kratzert, Herbert W. Roesky, Jakob Hey, Dietmar StalkeAbstract:LSi−SiL (L = PhC(NtBu)2) (4) was reacted with benzil in toluene at room temperature to afford a compound that contains two siladioxolene rings connected by a Si−Si Bond. This is the first reactivity study of 4 where the central Si−Si Bond was not cleaved during the reaction. Furthermore, LSiCl (L = PhC(NtBu)2) (6) was treated with benzil at ambient temperature in toluene to yield 2,5-dioxa-1-silacyclopent-3-ene (7). Both 5 and 7 were characterized by single-crystal X-ray diffraction and additionally by NMR spectroscopy, EI-MS spectrometry, and elemental analysis. Investigation of the molecular structure shows that the Si−Si Bond length in 5 is 2.36 A, which is more than 2% shorter than the Si−Si Bond length in 4. The formal oxidation state of silicon in 5 is +3, which is in agreement with its structure. The existence of 5 and 7 as stable compounds indicates that siladioxolenes can be electronically stabilized by σ-donor ligands.
Daniel Kratzert - One of the best experts on this subject based on the ideXlab platform.
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Reaction of a Base‐Stabilized Bis(silylene) [PhC(NtBu)2Si]2 with Cyclooctatetraene without Cleavage of the Si–Si Bond
European Journal of Inorganic Chemistry, 2011Co-Authors: Sakya S. Sen, Shabana I. Khan, Daniel Kratzert, Herbert W. Roesky, Dietmar StalkeAbstract:The reaction of the benzamidinato-stabilized bis(silylene) [PhC(NtBu)2Si]2 with cyclooctatetraene resulted in the formation of a colorless compound 7 whithout cleavage of the Si–Si Bond of the bis(silylene), whereas one of each Si–N(ligand) Bond is opened. Compound 7 was characterized by single-crystal X-ray diffraction, NMR spectroscopy, EI mass spectrometry, and elemental analysis. Investigation of the molecular structure shows that the Si–Si Bond length in 7 is 2.4150(7) A and is comparable to that of 6 [2.413(2) A].
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Reactions of a Bis-silylene (LSi−SiL, L = PhC(NtBu)2) and a Heteroleptic Chloro Silylene (LSiCl) with Benzil: Formation of Bis(siladioxolene) and Monosiladioxolene Analogue with Five-Coordinate Silicon Atoms in Both Ring Systems
Organometallics, 2010Co-Authors: Gasper Tavcar, Sakya S. Sen, Daniel Kratzert, Herbert W. Roesky, Jakob Hey, Dietmar StalkeAbstract:LSi−SiL (L = PhC(NtBu)2) (4) was reacted with benzil in toluene at room temperature to afford a compound that contains two siladioxolene rings connected by a Si−Si Bond. This is the first reactivity study of 4 where the central Si−Si Bond was not cleaved during the reaction. Furthermore, LSiCl (L = PhC(NtBu)2) (6) was treated with benzil at ambient temperature in toluene to yield 2,5-dioxa-1-silacyclopent-3-ene (7). Both 5 and 7 were characterized by single-crystal X-ray diffraction and additionally by NMR spectroscopy, EI-MS spectrometry, and elemental analysis. Investigation of the molecular structure shows that the Si−Si Bond length in 5 is 2.36 A, which is more than 2% shorter than the Si−Si Bond length in 4. The formal oxidation state of silicon in 5 is +3, which is in agreement with its structure. The existence of 5 and 7 as stable compounds indicates that siladioxolenes can be electronically stabilized by σ-donor ligands.
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reactions of a bis silylene lsi sil l phc ntbu 2 and a heteroleptic chloro silylene lsicl with benzil formation of bis siladioxolene and monosiladioxolene analogue with five coordinate silicon atoms in both ring systems
Organometallics, 2010Co-Authors: Gasper Tavcar, Sakya S. Sen, Daniel Kratzert, Herbert W. Roesky, Jakob Hey, Dietmar StalkeAbstract:LSi−SiL (L = PhC(NtBu)2) (4) was reacted with benzil in toluene at room temperature to afford a compound that contains two siladioxolene rings connected by a Si−Si Bond. This is the first reactivity study of 4 where the central Si−Si Bond was not cleaved during the reaction. Furthermore, LSiCl (L = PhC(NtBu)2) (6) was treated with benzil at ambient temperature in toluene to yield 2,5-dioxa-1-silacyclopent-3-ene (7). Both 5 and 7 were characterized by single-crystal X-ray diffraction and additionally by NMR spectroscopy, EI-MS spectrometry, and elemental analysis. Investigation of the molecular structure shows that the Si−Si Bond length in 5 is 2.36 A, which is more than 2% shorter than the Si−Si Bond length in 4. The formal oxidation state of silicon in 5 is +3, which is in agreement with its structure. The existence of 5 and 7 as stable compounds indicates that siladioxolenes can be electronically stabilized by σ-donor ligands.