Platinum complexes of 5,6-dihydroacenaphtho[5,6-cd]-1,2-dichalcogenoles

Abstract

Six bis(phosphane)platinum complexes bearing dichalcogen acenaphthene ligands have been prepared by metathesis from cis-[PtCl2(PR 3)2] (R3 = Ph3, Ph2Me, PhMe2) and the dilithium salts of the parent 5,6-dihydroacenaphtho[5, 6-cd]-1,2-dichalcogenoles (AcenapE2, L1 E = S, L2 E = Se). For their synthesis, the appropriate disulfide or diselenide species was treated with super hydride [LiBEt3H] to afford the dilithium salt by in situ reduction of the AcenapE2 E-E bond. Further reaction, by metathetical addition to the cis-platinum precursor afforded the respective platinum(II) complexes [Pt(5,6-AcenapE2)(PR3)2] (R 3 = Ph3: E = S 1, Se 2; R3 = Ph2Me: E = S 3, Se 4; R3 = PhMe2: E = S 5, Se 6). All six complexes have been fully characterised, principally by multinuclear magnetic resonance spectroscopy, IR spectroscopy and MS. The selenium complexes 4 and 6 provide examples of AA′X spin systems, as displayed by their 31P{1H} NMR spectra. The X-ray structures of L1, L2, 1, 2, 5 and 6 were determined and, where appropriate, the platinum metal geometry, peri-atom displacement, splay angle magnitude, acenaphthene ring torsion angles and E···E interactions were analysed. The platinum atoms were found to adopt a distorted square-planar geometry in all four complexes, and the nature of the AcenapE2 ligand plays little part in the conformation of the substituents bound to the trivalent phosphorus atoms. Six bis(phosphane)platinum complexes bearing 5,6-dihydroacenaphtho[5,6-cd]-1,2- dichalcogenoles (AcenapE2, E = S, Se) have been prepared. They were formed from the metathetical addition of the dilithium precursors to cis-[PtCl2(PR3)2] (R3 = Ph 3, Ph2Me, PhMe2). Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.