Formation of new organometallic W/Cu/S clusters from reactions of [{(η 5-C 5Me 5)WS 3} 3Cu 7(MeCN) 9](PF 6) 4 with donor ligands. Crystal structures and optical limiting properties of [(η 5-C 5Me 5)WS 3Cu 3(Py) 6](PF 6) 2, [(η 5-C 5Me 5)WS 3Cu 3Br(PPh 3) 3](PF 6), and [(η 5-C 5Me 5)WS 3Cu 4(Py)Cl(dppm) 2](PF 6) 2

Abstract

Treatment of a preformed cluster {(η 5-C 5Me 5)WS 3} 3Cu 7(MeCN) 9](PF 6) 4 ( 1) in MeCN with excess pyridine afforded a tetranuclear cationic cluster [(η 5-C 5Me 5)WS 3Cu 3(Py) 6](PF 6) 2 ( 2). On the other hand, reactions of 1 with excess PPh 3 under the presence of LiBr gave rise to the other tetranuclear cationic cubane-type cluster [(η 5-C 5Me 5)WS 3Cu 3Br(PPh 3) 3](PF 6) ( 3) while analogous reactions of 1 with dppm and LiCl followed by addition of excess pyridine generated an intriguing pentanuclear cationic cluster [(η 5-C 5Me 5)WS 3Cu 4(Py)Cl(dppm) 2](PF 6) 2 ( 4). Compounds 2– 4 were fully characterized by spectroscopy and X-ray crystallography. The cluster dication of 2 adopts an incomplete WS 3Cu 3 cubane-like structure while the cluster cation of 3 contains a WS 3Cu 3Br cubane-like structure. The structure of the cluster dication of 4 consists of an unique WS 3Cu 4Cl framework in which an open cubane-like WS 3Cu 3Cl fragment and a Cu(dppm) 2 fragment are connected by one Cu–Cl bond and two Cu–dppm–Cu bridges. The optical limiting (OL) properties of the MeCN solutions of 1– 4 were investigated with 7-ns laser pulses at 532 nm.