Reactions of [Et 4 N][Tp*W(μ 3 ‐S)(μ‐S) 2 (CuSCN) 2 ] with Nitrogen Donor Ligands: Syntheses, Structures, and Third‐Order Nonlinear Optical Properties

Reactions of the preformed cluster [Et 4 N][Tp*W(μ 3 ‐S)(μ‐S) 2 (CuSCN) 2 ] ( 1 ) with pyridine (py), 4,4′‐bipyridine (4,4′‐bipy), or 1,3‐bis(4‐pyridyl)propane (bpp) led to the formation of three neutral [Tp*W(μ 3 ‐S)(μ‐S) 2 Cu 2 ]‐based compounds [Tp*W(μ 3 ‐S)(μ‐S) 2 Cu 2 (SCN)(py) 2 ] ( 2 ), [{Tp*W(μ 3 ‐S)(μ‐S) 2 Cu 2 (SCN)} 2 (4,4′‐bipy)] · 3.5H 2 O ( 3· 3.5H 2 O), and [Tp*W(μ 3 ‐S)(μ‐S) 2 Cu 2 (SCN)(bpp)] 2 ( 4 ), respectively. Compounds 2 – 4 were characterized by elemental analysis, IR spectra, UV/Vis spectra, 1 H NMR, and X‐ray analysis. There are two linkage isomers [Tp*W(μ 3 ‐S)(μ‐S) 2 Cu 2 (SCN)(py) 2 ] and [Tp*W(μ 3 ‐S)(μ‐S) 2 Cu 2 (NCS)(py) 2 ], each of which has its own enantiomeric pair in the crystal of 2 . Compound 3 has a double butterfly‐shaped structure in which two [Tp*W(μ 3 ‐S)(μ‐S) 2 Cu 2 (SCN)] fragments are linked with a single 4,4′‐bipy bridge. For 4 , the two butterfly‐shaped [Tp*W(μ 3 ‐S)(μ‐S) 2 Cu 2 (SCN)] fragments are interconnected by a pair of bpp bridges. The third‐order nonlinear optical (NLO) performances of 2 – 4 in DMF were also investigated by Z ‐scan techniques.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)