Novel Luminescent Tetranuclear and Pentanuclear Copper(I)-Dithiolates

Tetranuclear [Cu4((mu)2-dppm)3((mu)2-(mu)2-NS2)( (mu)2-(mu)4-NS2)] (1) and pentanuclear [Cu5((mu)2-dppm)4((mu)3-(mu)-3-NS2)2]PF6 (2·PF6) (dppm = bis(diphenylphoshino)methane, NS22- = 1,8-naphthalenedithiolate) were synthesized from the reactions between NS22and [Cu2((mu)2-dppm)2(CH3CN)2](PF6)2. Compound 1 features a square Cu4 core capped by a 5-coordinate S atom while 2·PF6 exhibits an unprecedented square planar Cu5 core. Both complexes display dual emissions at 480 and 620 nm which arise from ligandcentered n(pi)* and ligand-metal charge-transfer excited states, respectively.