M. Chauhan et al., CRYSTALLOGRAPHIC EVIDENCE OF HEXACOORDINATION AT PHOSPHORUS VIA INTRAMOLECULAR COORDINATION OF DONOR GROUPS ON PHOSPHANE AND PHOSPHANE SULFIDE, Journal of organometallic chemistry, 510(1-2), 1996, pp. 173-179
The X-ray structure analysis of bis(8-dimethylamino-1-naphthyl)phenylp
hosphane (3) and of the corresponding sulphide 4 has revealed hexacoor
dination at phosphorus in both cases, the N ... P separations being le
ss than the sum of the van der Waal radii. Furthermore, in both cases
the overall geometry corresponds to a distorted bicapped tetrahedron.
The optimum geometry calculated for 4 via the HYPERCHEM program develo
ped by Autodesk (MM + method) suggests that the structure of the molec
ule is a function not only of steric requirements but also of electron
ic effects.