Reaction of cis-bis[1,2-bis(dimethylphosphino)ethane]dicarbonyl-chromium and -molybdenum complexes with silver(I) salts. Reduction of nitrite ion to dinitrogen oxide

Abstract

The complexes cis-[M(CO)₂(dmpe)₂](M = Cr or Mo; dmpe is Me₂PCH₂CH₂PMe₂) undergo one-electron oxidation by Ag[BF₄] in solution to give paramagnetic complexes trans-[M(CO)₂(dmpe)₂][BF₄]. Oxidation of cis-[Mo(CO)₂(dmpe)₂] with silver(I) salts of co-ordinating anions Ag_nX (n= 1, X =[NCS]^–, [NO₃]^–, or [NO₂]^–; n= 2, X =[CO₃]^2– or [SO₄]^2–) produces the seven-co-ordinate molybdenum(II) complexes cis-[MoX(CO)₂(dmpe)₂]X (X = NCS or NO₃), [MoX(CO)(NO)(dmpe)₂](X = NO₂), and zwitterions cis-[Mo(OZO_m)(CO)₂(dmpe)₂](Z = C, m= 2; Z= S, m= 3). Photolysis of cis-[Mo(OSO₃)(CO)₂(dmpe)₂] gives [Mo(O₂SO₂)(CO)(dmpe)₂]. The mechanisms of the elimination reactions are discussed and comparisons are made with the reactions of some isoelectronic systems. Disproportionation of molybdenum(I) in trans-[Mo(CO)₂(dmpe)₂]⁺ ion is recognised as an important feature of certain oxidations.