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An Electron Diffraction Determination of the Molecular Structure of Hexamethylcarbodiphosphorane in the Gas Phase
Author(s) -
Ebsworth E. A. V.,
Fraser Thomas E.,
Rankin David W. H.,
Gasser Oswald,
Schmidbaur Hubert
Publication year - 1977
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.19771101106
Subject(s) - chemistry , gas phase , crystallography , electron diffraction , molecule , stereochemistry , diffraction , physics , organic chemistry , optics
The molecular structure of hexamethylcarbodiphosphorane, (CH 3 ) 3 PCP(CH 3 ) 3 , in the gas phase has been determined by electron diffraction. Principle bond lengths ( r a ) are: PC, 181.4(3) pm, PC, 159.4(3) pm; CH, 108.9(4) pm. The angles between the PC (methyl) bonds are 101.4(3)°, and the apparent PCP angle is 147.6(5)°. The single structure that fits the experimental data closest has C 2 overall symmetry, but an even closer fit is obtained if free rotation about the PC bonds is assumed. This and other evidence indicates that the molecule is probably a symmetric top, and that the PCP unit is linear in the average structure, with shrinkage caused by a low frequency bending vibration giving rise to the apparent non‐linearity.