Monomeric and Dimeric (Aminomethylidene)phosphines and -Arsines

Abstract

E= Pi: E= As 1 E= P 1: E= As !! R= ClCH3l3 .Q.: CH3.Q.: C6HS.£.E=P~:E=As §.rotation of the dimethylamino group is hindered by a barrier o f 50 to 55 kJmol-1 -analogous to the corresponding amidines. In order to evaluate the influence of this conjugative effect upon the P=C and (P)-C-N bond lengths, single crystal x-ray structure determinations of la and 2a have been carried out.For comparison, the cyclic (aminomethylidene)phosphine IH-l,3-benzazaphosphole