Terdentate (P–N–O) complexes formed from Z,E-PPh2CH2C-(But)N–NCH(C6H4OH-2) or Z,E-PPh2CH2C(But)N–NCH-[C6H2(OH-2)(OMe)2-4,6] and nickel, palladium, platinum, rhodium or iridium

Abstract

Condensation of Z-PPh₂CH₂C(Bu^t)NNH₂ with salicylaldehyde or 4,6-dimethoxysalicylaldehyde gave the azine phosphines Z,E-PPh₂CH₂C(Bu^t)N–NCH(C₆H₄OH-2)1a or Z,E-PPh₂CH₂C(Bu^t)N–NCH[C₆H₂(OH-2)(OMe)₂-4,6]1b, respectively. Treatment of 1a with [PdCl₂(cod)](cod = cyclo- octa-1,5-diene) gave the bidentate chelate complex [[graphic omitted]CH(C₆H₄OH-2)}]3. The phosphine 1a reacts with Na₂PdCl₄ in the presence of NaO₂CMe to give the terdentate chelate complex [[graphic omitted])}]4a Treatment of the latter with Nal or MgMel gave the corresponding iodopalladium(II) complex 4b or the methylpalladium(II) complex 4c, respectively. The analogous methylplatinum(II) complex [[graphic omitted])}]4d was prepared by treating [PtMe₂(cod)] with 1a. Fluxional nickel(II) complexes of type [[graphic omitted])}](X = Cl 4e or Br 4f) were also prepared from NiX₂·nH₂O. When Ni(O₂CMe)₂·4H₂O was treated with two mol equivalents of 1a a paramagnetic octahedral nickel(II) complex [[graphic omitted])}₂]5 was formed. Treatment of [PtCl₂(cod)] with two mol equivalents of 1a in the presence of NaO₂CMe gave a monocationic platinum(II) chloride salt, which with NH₄PF₆ gave the PF₆ salt. Treatment of 1b with [IrCl(CO)₂(MeC₆H₄NH₂-p)] or 0.5 equivalents of [Rh₂Cl₂(CO)₄] in the presence of NEt₃ gave the square-planar complexes [[graphic omitted](OMe)₂-4,6]}](M = Ir 7a or Rh 7b). The carbonyliridium(I) complex 7a underwent oxidative-addition reactions with Mel, allyl chloride, acetyl chloride or propargyl chloride to give the halogenocarbonyliridium(III) complexes [[graphic omitted](OMe)₂-4,6]}]8a–8d respectively. In contrast, the reaction of the carbonylrhodium(I) complex 7b with allyl chloride gave the π-allylrhodium(III) complex [[graphic omitted](OMe)₂-4,6]}]9. Proton, ³¹P-{¹H} and some ¹³C-{¹H} NMR data have been attained.