Solid-state syntheses of M–Cu–S (M=Mo and W) clusters, crystal structure and non-linear optical properties of {MS4[Cu(p-MeOC6H4)3P]2}·0.5C6H12

The title compounds {MS4[Cu(p-MeOC6H4)3P]2}·0.5C6H12 [M=Mo (1) or W (2)] were synthesized for non-linear optical studies by a solid state reaction of (NH4)2MS4, CuI and (p-MeOC6H4)3P. A single crystal X-ray analysis reveals that 1 possesses a linear skeleton with a Mo center slightly distorted from tetrahedron and two Cu centers distorted from trigonal planar. The non-linear optical properties of 1 were investigated by the Z-scan and picosecond time-resolved pump-probe measurements at 532 nm. The results obtained revealed that thermally induced non-linear effect was dominant in the nanosecond time-scale while stimulated Rayleigh-wing scattering was observed in the picosecond measurement. Its non-linear refractive index was determined to be −3.52×10−17 m2 W−1 for nanosecond time-scale and 4.32×10−19 m2 W−1. Nonlinear optical properties of compound 2 were investigated at same condition similar to 1, no non-linear optical behavior was observed for 2, although it might have a similar structure to that of compound 1.