Silyl Cations Stabilized by Pincer Type Ligands with Adjustable Donor Atoms

Novel E,C,E'-pincer supported silyl cations (E, E' = O, S, Se, Au) were prepared in three steps starting from 2,6-F2C6H3SiMe2H (1a) and 2,6-Br2C6H3SiMe2H (1b), which were first converted in two complementary ways into 2,6-(Ph2P)(2)C6H3SiMe2H (2). The oxidation of 2 with H2O2 center dot urea, S-8, and Se-8 afforded 2,6-(Ph2PE)(2)C6H3SiMe2H (3a, E = O; 3b, E = S; 3c, E = Se) and 2-(Ph2PE)-6-(Ph2P)-C6H3SiMe2H (4b, E = S; 4c, E = Se), which were reacted to the E,C,E-supported silyl cations [2,6-(Ph2PE)(2)C6H3SiMe2](+) (5a, E = O, counterion Br-3(-); 5b, E = S, counterion B(C6F5)(4)(-); 5c, E = Se, counterion B(C6F5)(4)(-)), the E,C-supported silyl cations [2-(Ph2PE)-6-(Ph2P)C6H3SiMe2](+) (6b, E = S, not isolated; 6c, E = Se, not isolated), the O,C,S-supported silyl cation [2-(Ph2PS)-6-(Ph2PO)C6H3SiMe2](+) (7, counterion B(C6F5)(4)(-)) as well as the E,C,Au-supported silyl cations [2-(Ph2PAuC6F5)-6-(Ph2PE)C6H3SiMe2](+) (8b, E = S, counterion [B{3,5-(CF3)(2)C6H3}(4)](-); 8c, E = Se, [B{3,5-(CF3)(2)C6H3}(4)](-)) using Br-2, O-2, S-8, (tht)AuC6F5, Ph3C[B(C6F5)(4)] and Ph3C[B{3,5-(CF3)(2)C6H3}(4)]. All compounds were characterized by multinuclear (H-1, C-13, F-19, Si-29, P-31, Se-77) NMR spectroscopy, ESI MS spectrometry and X-ray crystallography (2, 3a center dot H2O, 3b, 3c, 4b, 5a, 5c, 7, 8b, 8c). The gas phase structures of 2, 3a-c, 5a-c (fully optimized) and 8b, 8c (single-point calculations) were studied at the B3PW91/6-311+G(2df,p) level of theory. A set of real-space bonding indicators (RSBIs) derived from the theoretically calculated electron and pair densities were analyzed utilizing the atoms-in molecules (AIM) and electron-localizability indicator (ELI-D) space partitioning schemes

From multifunctional, siliconorganic building blocks to pincer-stabilized silicon cations.

Starting with 1,3-Dihalogenebenzene new metalorganic compounds 2,6-dihalogene-1-dimethylsilylbenzenes (1a, 1b, 1c), 3-bromo-2-dimethylilyl-1-diphenylphosphinebenzene (4), 1-bromo-2-dimethylsilyl-1-diphenylphosphinochalcogenidebenzenes (4a, 4b), (3-bromo- 3-bromo-2-dimethylsilyl)phenyl)(methyl)diphenylphosphoniumiodide (4c), dimethylsilyl-1-tributylstannylbenzene(5), 2,3-bis(dimethylsilyl)-1-diphenylphosphinebenzene (6), 3,2,-bis(dimethylsilyl)-1-diphenylphosphine-3-diphenylphosphinechalcogenidbenzene (6a, 6b), 2-dimethylsilyl-1,3-bis(diphenylphosphine)benzene (7), 2-dimethylsilyl-1-diphenylphospine-3-diphenylphosphinechalcogenidebenzenes (7a, 7b), (2-(dimethylsilyl)-3-(diphenylphosphanyl)phenyl)(methal)diphenylphosphonium iodide (7c), 2-dimethylsilyl-1,3-bis(diphenylphosphinechalcogenide)benzenes (8a, 8b, 8c), (2-(dimethyllsilyl)-1,3-phenylene)bis(methyldiphenylphosphonium) diiodide (8d), 1,3-dihalogene-2-tributylstannylbenzenes (14a, 14b, 14c), bis(2,6-dihalogene-1-dimethylsilylbenzenes) (15a, 15b, 15c), 1,7-bis(diphenylphosphine)biphenylene (16), 1,7-bis(diphenylsulfidophosphine)biphenylene (17) were synthesized and characterized. This compounds were used as precursor for a variety of reactions, mainly for the preparation of new pentacoordinated silylcations 2-dimethylsilyl-1,3-diphenylphosphineoxido)phenyl tribromide (10), 2-dimethylsilyl-3-diphenylphosphin-1-diphenylsulfidophosphinepehnyl tetrakis(pentafluorophenyl)borate (11), 2-dimetrhylsilyl1,3-bis(diphenylphosphinesulfido)phenyl tetrakis(pentafluorophenyl)borate (12), 2-dimethylsilyl-3-diphenylphosphineoxido-1-diphenylphosphinesulfidophenyl tetrakis(pentafluorophenyl)borate (12a) and 2-dimethylsilyl-1,3-bis(diphenylphosphineselenido)phenyl tetrakis(pentafluorophenyl)borate (13)

Von multifunktionalen, siliziumorganischen Bausteinen zu Pinzetten-stabilisierten Silylkationen

Starting with 1,3-Dihalogenebenzene new metalorganic compounds 2,6-dihalogene-1-dimethylsilylbenzenes (1a, 1b, 1c), 3-bromo-2-dimethylilyl-1-diphenylphosphinebenzene (4), 1-bromo-2-dimethylsilyl-1-diphenylphosphinochalcogenidebenzenes (4a, 4b), (3-bromo- 3-bromo-2-dimethylsilyl)phenyl)(methyl)diphenylphosphoniumiodide (4c), dimethylsilyl-1-tributylstannylbenzene(5), 2,3-bis(dimethylsilyl)-1-diphenylphosphinebenzene (6), 3,2,-bis(dimethylsilyl)-1-diphenylphosphine-3-diphenylphosphinechalcogenidbenzene (6a, 6b), 2-dimethylsilyl-1,3-bis(diphenylphosphine)benzene (7), 2-dimethylsilyl-1-diphenylphospine-3-diphenylphosphinechalcogenidebenzenes (7a, 7b), (2-(dimethylsilyl)-3-(diphenylphosphanyl)phenyl)(methal)diphenylphosphonium iodide (7c), 2-dimethylsilyl-1,3-bis(diphenylphosphinechalcogenide)benzenes (8a, 8b, 8c), (2-(dimethyllsilyl)-1,3-phenylene)bis(methyldiphenylphosphonium) diiodide (8d), 1,3-dihalogene-2-tributylstannylbenzenes (14a, 14b, 14c), bis(2,6-dihalogene-1-dimethylsilylbenzenes) (15a, 15b, 15c), 1,7-bis(diphenylphosphine)biphenylene (16), 1,7-bis(diphenylsulfidophosphine)biphenylene (17) were synthesized and characterized. This compounds were used as precursor for a variety of reactions, mainly for the preparation of new pentacoordinated silylcations 2-dimethylsilyl-1,3-diphenylphosphineoxido)phenyl tribromide (10), 2-dimethylsilyl-3-diphenylphosphin-1-diphenylsulfidophosphinepehnyl tetrakis(pentafluorophenyl)borate (11), 2-dimetrhylsilyl1,3-bis(diphenylphosphinesulfido)phenyl tetrakis(pentafluorophenyl)borate (12), 2-dimethylsilyl-3-diphenylphosphineoxido-1-diphenylphosphinesulfidophenyl tetrakis(pentafluorophenyl)borate (12a) and 2-dimethylsilyl-1,3-bis(diphenylphosphineselenido)phenyl tetrakis(pentafluorophenyl)borate (13)