Spectroscopic studies on some new cationic complexes of platinum(II)

The preparation of some new cationic platinum complexes of general formula PtXL(PEt3)2+ ClO4–[L = py, PEt3, PPh3, P(OMe)3, P(OPh)3, CN·C6H4·OMe, CN·CMe3, Co; X = H, Cl, Br, m-FC6H4, p-FC6H4] is described. The i.r. and n.m.r. spectra of these complexes are presented and discussed. The ligands L can be arranged in a series of increasing ‘trans-influence’, defined as the ability of a ligand to weaken the bond trans to itself. The importance of σ-effects in determining the order in this series and in considering the value of a ‘π-acceptor series’ based on the 19F n.m.r. spectra is discussed.