Synthesis and crystal structures of (CF3)2As-N=PPh3, [Os3(CO)11{(CF3)2As=N=PPh 3}] and [Os3(μ-H)2(CO)9{(CF3) 2As=N=PPh3}]

Abstract

Bis(trifluoromethyl)arsinous azide (CF3)2AsN3 undergoes a Staudinger reaction with PPh3 to give the arsinophosphazene (CF3)2As-N=PPh3 which reacts with [Os3(CO)11(MeCN)] and [Os3(μ-H)2(CO)10] to give [Os3(CO)11{(CF3)2As=N=PPh 3}] 1 and [Os3(μ-H)2(CO)9{(CF3) 2As=N=PPh3}] 2 respectively. Single-crystal X-ray structural studies show that upon complexation (CF3)2As-N=PPh3 assumes a highly delocalized electronic structure over the unsymmetrical As-N=P segment with the As-N bond distance assuming that of an As=N double bond. These two complexes represent the first examples of neutral compounds containing a highly delocalized As=N=P non-linear structure.