Diphenylnitrilimine adds to the phosphazene bovid of the azaphosphole 1. A
single-crystal X-ray investigation of the cycloadduct 3 shows a planar bicy
clo[3.3.0]octane skeleton meridional to the trigonal bipyramidal phosphorus
. The structural data are compared to those of the starting compound 1, to
those of the trifluoroacetone adduct 2, and to the change from ideal tetrah
edral to ideal tbp geometry. (C) 1999 John Wiley & Sons, Inc.