Diphosphine Compounds, Part III: UV/Visible Spectroscopy and Novel Routes to Functionalized Diphosphine-M(CO)₆ Complexes (M = W, Mo, or Cr)

Abstract

Reaction of coordinated (diphenylphosphino)methane and ketones or aldehydes have been characterized by 31P{H1}-NMR, 1H{31P}-NMR, and UV/vis spectroscopy in dichloromethane. Group VI metals hexacarbonyl [M(CO)6 where M = Cr, Mo, and W] reacted with (diphenylphosphino)methane, [(Ph2P)2CH2], to give [(OC)4M{(Ph2P)2CH2}] depending upon the reaction conditions. Condensation of [(CO)4M{(Ph2P)2CH2}] with different ketones or aldehydes forms [(CO)4M{(Ph2P)2C = CR1R2}]. Complexes of the types [(OC)4M{(Ph2P)2C = CR1R2}] reacted with hydrazine in a Michael addition to give [(CO)4M{(Ph2P)2CHC(R1R2)NHNH2}](1.3a–e), which condensed with different ketones and aldehydes to give complex of the type [(CO)4M{(Ph2P)2CHC(R1R2)NHN = C(R3)] (1.4a–e). The structures of the complexes are discussed on the basis of elemental analysis (EA), IR,1H-NMR, 31P-NMR spectroscopic data, and FAB mass spectra. The UV/vis spectra show two absorption bands with the low energy band moving to lower energy with increasing substitution on the (diphenylphosphino) methane (dppm) (a bathochromic effect).