Coordination isomerism in salicylhydroxamate complexes of platinum(II) and palladium(II)

摘要

The syntheses of a range of platinum(II) and palladium(II) complexes containing salicylhydroxamate ligands are described. The ancillary ligands, together with the synthetic route, influence the coordination mode of the salicylhydroxamate ligand. Reaction of cis-[PtCl_2(PPh_3)_2] with salicylhydroxamic acid and trimethylamine in hot methanol gave O,O'-bonded [Pt{OC(=NO)C_6H_4OH}(PPh_3)_2], but [PtCl_2(cod)] (cod = cycloocta-1,5-diene) gave N,O-bonded [Pt{OC_6H_4C(O)NOH}(cod)]. Ligand substitution gives other N,O bonded complexes, including [Pt{OC_6H_4C(O)NOH}(PPh_3)_2]. Reaction of K_2PtCl_4 with 2 equiv. of EPh_3 (E = As or Sb), salicylhydroxamic acid and excess trimethylamine gives products whose structures depend on E; AsPh_3 gives [Pt{OC(=NO)C_6H_4OH}(AsPh_3)_2, while SbPh_3 gives [Pt{OC_6H_4(O)NOH}(SbPh_3)_2].