Synthesis and structure of 2,2'-biphosphirenes

摘要

The reaction of an excess of the transient terminal phosphinidene complex [PhP -> W(CO)_5] with selected 1,3-diynes at 110 deg C in toluene affords the corresponding 2,2'-biphosphirene-W_2(CO)_(10) complexes as a 1:1 meso + rac mixture; according to the X-ray crystal structure analysis of one of the rac-complexes, some delocalisation takes place within the diene sub-unit of these bi-phosphirenes.