The Preparation and Structure of [Pt(S₂N₂){P(OR)_nR′_3–n}₂] and [Pt(SeSN₂){P(OMe)_nPh_3–n}₂] (n = 0–3)

Abstract

Abstract Dissolution of [S 4 N 3 ]Cl in liquid ammonia produces a reactive solution which on treatment with cis [PtCl 2 (PR 3 ) 2 ] gives [S 2 N 2 ] 2– complexes in 32–76 % yields. Similarly, SeCl 4 and [S 4 N 3 ]Cl in a ratio of 5:1 react cleanly with cis ‐[PtCl 2 {P(OMe) n Ph 3– n }] to give the desired selenosulfur dinitrido, [SeSN 2 ] 2– complexes with no phosphorus containing starting material evident by 31 P NMR spectroscopy. The new complexes were characterised by IR, 31 P NMR, microanalysis and X‐ray crystallography with nine crystal structures being reported. In 31 P nmr the 1 J PtP coupling constants are influenced by the oxygen content of their phosphorus ligands. In the mixed chalcogen complexes the Pt–N bond lengths appear to follow a simple trend as a consequence of the electronic properties of the phosphorus ligand and these trends can be interpreted empirically by examination of the LUMO but are not well supported by DFT calculations.