Diazaphosphole Carbonyl Complexes of Group Vib Metals

Reactions of group VI B metal carbonyls with cis and trans 3,4-dihydro-2,3,4, 5-tetraphenyl-2H-1,2,3-diazaphosphole (DAP) have yielded the corresponding new derivatives (CO) 5 M(DAP) in which the ligand is bonded through the phosphorus atom. On heating (CO) 5 Mo( cis -DAP) in n -octane with additional cis -DAP formation of a cis - trans mixture of disubstituted tetracarbonyls (CO) 4 Mo( cis -DAP) 2 occurs. Under the same conditions (CO) 5 Mo( trans -DAP) and trans -DAP afford only trans -(CO) 4 Mo( trans -DAP) 2 . The nature of DAP to metal bonding could be ascertained from ir, H nmr and mass Spectral analyses.