DETERMINATION OF THE GAS-PHASE MOLECULAR-STRUCTURES OF TETRAPHENYLSILANE, TETRAPHENYLGERMANE, AND TETRAPHENYLTIN BY ELECTRON-DIFFRACTION

The structures of free Ph4M molecules (MSi, Ge, Sn) have been analysed by electron diffraction. Only a limited amount of reliable structural information could be determined since several models (D2d, S4, D2) fit the experimental data equally well. The phenyl rings are slightly elongated. Assuming that b = c and γ = 120°, the rg parameters (with estimated total errors) have been obtained: {A table is presented}. The bond configuration of the central atom is tetrahedral, but the individual CMC bond angles as well as b-a and α are poorly determined because of their correlation with the conformations assumed in the analysis. Molecular parameters are consistent with those in the crystal phase. © 1990.