Synthesis and characterisation of organo-platinum(II) complexes of the N,O-donor ligands hippuric acid (N-benzoylglycine) and N-phenylanthranilic acid

Abstract

Reaction of [PtCl₂(cod)] (cod = cyclo-octa-1,5-diene) with either hippuric acid [PhC(O)NHCH₂COOH] or N-phenylanthranilic acid (ortho-PhNHC₆H₄COOH) in refluxing dichloromethane in the presence of silver(I) oxide gave the new organoplatinum derivatives [Pt{N(COPh)CH₂COO}(cod)] and [Pt{N(Ph)C₆H₄COO}(cod)] respectively. Ligand substitution reactions of the cod ligand in [Pt{N(COPh)CH₂COO}(cod)] provided a facile route to a selection of phosphine-substituted analogues [Pt{N(COPh)CH₂COO}L₂] [L = phosphatriazaadamantane (pta), PPh3, or L₂ = Ph₂PCH₂CH₂PPh₂ or Fe(η⁵-C₅H₄PPh₂) ₂] via displacement of the labile cod ligand. The complexes were characterised using NMR spectroscopy, IR spectroscopy, and ESI mass spectrometry. The X-ray structure of [Pt{N(COPh)CH₂COO}(cod)] is also reported.