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Hypercoordinate Carbon in Trigoldbis(silyl)methanium Cations
Author(s) -
Bommers Sebastian,
Beruda Holger,
Dufour Nathalie,
Paul Martin,
Schier Annette,
Schmidbaur Hubert
Publication year - 1995
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19951280209
Subject(s) - chemistry , silylation , crystallography , trigonal bipyramidal molecular geometry , metal , carbon fibers , atom (system on chip) , molecule , bent molecular geometry , yield (engineering) , silicon , stereochemistry , crystal structure , catalysis , organic chemistry , materials science , composite number , computer science , embedded system , composite material , metallurgy
The reactions of organolithium compounds of the type (R 3 Si) 2 CHLi (R 3 = Me 3 or Me 2 Ph) with the gold(I) complex Ph 3 PAuCl afford the monoaurated bis(silyl)methanes (R 3 Si) 2‐ CHAuPPh 3 ( 1a, b ) in high yield. These compounds are converted into complex salts with hypercoordinate methanium cations {(R 3 Si) 2 C[Au(PPh 3 )] 3 } + BF − 4 ( 3a, b ) by treatment with {[(Ph 3 P)Au] 3 O} + BF − 4 . In the reaction mixtures small amounts of the neutral dinuclear intermediates {(R 3 Si) 2 C[Au(PPh 3 )] 2 } ( 2a, b ) have been detected and characterized by their spectroscopic data. Compounds 1a, b and 3a, b have been studied by single crystal X‐ray diffraction analyses. While the mononuclear molecules 1a, b have conventional structures with parameters representing classical types of bonding, the novel trinuclear complexes 3a, b feature cations with a pentacoordinate carbon atom in a distorted trigonal‐bipyramidal environment of two silicon atoms and one gold atom in equatorial positions and the remaining two gold atoms at the axial vertices of the polyhedra. The main axis of the bipyramid is strongly bent at the central carbon atoms. This distortion leads to short axial/equatorial Au…Au distances indicating peripheral metal‐metal bonding.