Reactivity of [{M(C₆F₅)₂(<i>μ</i>-OH)}₂]²^- (M = Pd or Pt) toward Aromatic Amines and Malononitrile

Abstract

Binuclear μ-hydroxo-μ-arylamido complexes [Pd2(C6F5)4(μ-OH)(μ-NHR)]2- (R = C6H5, C6H4Cl-p, C6H4F-p) and di-μ-arylamido complexes [M2(C6F5)4(μ-NHR)2]2- (M = Pd, R = C6H5, C6H4Cl-p, C6H4F-p, C6H4NO2-p, C6F5; M = Pt, R = C6H4NO2-p, C6F5) have been prepared by reaction of [M2(C6F5)4(μ-OH)2]2- with the corresponding arylamine RNH2 in 1:1 or 1:2 molar ratio, respectively. The reaction of [Pd2(C6F5)4(μ-NHPh)2]2- with CS2 leads to the formation of the mononuclear dithiocarbamate complex [Pd(C6F5)2(S2CNHPh)]-. Malononitrile and methyl cyanoacetate react with [Pd2(C6F5)4(μ-OH)2]2- in methanol to give the binuclear complexes [Pd2(C6F5)4{μ-CH(CN)CN}2]2- and [Pd2(C6F5)4{μ-CH(CO2Me)CN}2]2-. However the reaction of [Pd2(C6F5)4(μ-OH)2]2- with malononitrile in boiling methanol gives the mononuclear diiminato complex [Pd(C6F5)2{NHC(OMe)CHC(OMe)NH}]-. In wet toluene [Pd2(C6F5)4(μ-OH)2]2- produces the cyclotrimerization of malononitrile, giving 4,6-diamino-2-cyanomethyl-3,5-pyridinedicarbonitrile. The structures of [Pd2(C6F5)4(μ-NHC6F5)2]2- and [Pd2(C6F5)4{μ-CH(CN)CN}2]2- have been determined by X-ray diffraction.