| Abstract
| - Two novel Ga/Sb C-centered geminal organodimetallic complexes have been synthesized from the addition of Me3Ga to a stiba-alkene (−SbC). The expected 1,2-addition product undergoes thermal elimination of CH4 to give a chiral (R,R) complex with a bicyclo[2.2.]-type core. The solid-state structure of both complexes has been determined by X-ray crystallography.
- The 1,2-addition of Me3Ga in thf to the stiba-alkene species [2-Pyr(SiMe3)2CSbC(SiMe3)2-Pyr] results in the mixed Sb/Ga geminal C-centered organodimetallic complex {[2-Pyr(SiMe3)2]CSb(Me)C[2-Pyr(SiMe3)]Ga(Me)2} (Pyr = C5H4N), 2, which on heating eliminates CH4 toform a new Sb/Ga geminal organodimetallic complex adopting a structure with a distortedbicyclo[2.2.2]-type core, 3. Both complexes have been structurally authenticated by single-crystal X-ray diffraction; 2 is isostructural with its Al analogue in forming a bimetallic six-membered heterocycle, while CH4 elimination between the −GaMe2 and Me3Si− groups in2 results in the heterocycle being bridged by a −Ga−CH2−Si− unit and the formation ofthe new complex, 3. Both complexes are chiral, with 2 being present as both diastereoisomers,R,S and S,R (space group P21/n), while 3 is found exclusively in the R,R configuration, spacegroup P212121. 1H and 13C NMR spectra confirmed the composition of the complexes andrevealed that 2 could not be quantitatively converted into 3 without significant decomposition.They also reveal that the structure of 3 is rigid in solution.
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