Synthesis and characterization of new Pt(II) and Pt(IV) orthometallated complexes incorporating 1-arylazo-2-ethyl sulfanyl benzene

The new ligands 1-arylazo-2-ethyl sulfanyl benzene, LH (1) [LH is 2-(RC6H4–NN)C6H4SEt; R = p-H (for L1H), p-Me (for L2H) and p-Cl (for L3H), H of LH represents the dissociable proton upon orthometallation] and their orthoplatinated complexes of the type PtII(L)Cl have been synthesized by the reaction of LH with K2PtCl4 where [L]− ligands bind the metal in a tridentate (C, N, S) fashion. On the other hand, new platinum (IV) cyclometallates, PtIV(L)I3, were obtained directly on treating K2PtI4 with LH. The complexes and ligands were characterized from spectroscopic data. The X-ray structure of Pt(L)I3 authenticated its formation.

Reaction of 1-arylazo-2-ethyl sulfanyl benezene (LH) with K2PtCl4 and K2PtI4 has been studied. In both the cases orthoplatinated compounds were isolated and characterized. K2PtCl4 afforded Pt(II) complexes, Pt(L)Cl, while K2PtI4 produced the Pt(IV) compounds, Pt(L)I3. The oxidations of Pt in the case of Pt(L)I3 have been believed to occur as a result of unusual oxidative addition of LH.Figure optionsDownload as PowerPoint slide