CHEMICAL OXIDATION AND ELECTRONIC-SPECTRA OF THE COMPLEXES TRANS-[M(CNR)2(PH2PCH2CH2PPH2)2] (M=MO OR W)

Oxidation of the complexes trans-[M(CNR)2(dppe)2] (A) (M = Mo or W; R = Me, But or CH3C6H4-4; dppe = Ph2PCH2CH2PPh2) with diiodine or silver (I) salts gives the paramagnetic cations trans-[M(CNR)2(dppe)2]+, (M = Mo, R = CH3C6H4-4; M = W, R = But) and trans-[M(CNR)2(dppe)2]2+ (M = Mo, R = Me or CH3C6H4-4; M = W, R = Me or But). Mixtures of products are generally produced when dichlorine or dibromine are the oxidising agents, however pure salts, the seven-coordinate complex cations [MX(CNC6H4CH3-4)2(dppe)2]+ (B, X = Cl or Br) have been isolated. A simple molecular orbital scheme is proposed for complexes (A) and used to discuss their electronic spectra and their oxidation. © 1979.