Effect of substituent dtp to optical properties of heterobimetallic M/Ag/S nest-shaped clusters (M = Mo, W)

Clusters [MoS4Ag3(PPh3)3{S2P(OPri)2}] (1), [WS4Ag3(PPh3)3{S2P(OPri)2}] (2) and [WOS3Ag3(PPh3)3{S2P(OPri)2}] (3) were synthesized by the reaction of (NH4)2MoS4/(NH4)2WS4, (NH4)2WOS3 with Ag[S2P(OPri)2]. Their structures have been characterized by X-ray diffraction. The clusters consist of a distorted tetrahedral MS4 (or MOS3) (M = Mo, W) with three Ag atoms and three sulfur atom bridges (Fig. 1), and resemble roughly that of cubane-like clusters. The nonlinear optical (NLO) properties were studied with an 8 ns pulsed laser at 532 nm. Its optical response to the incident light exhibits good optical absorptive and refractive effects, with α2 = 1.56 × 10−10 m W−1, n2 = 3.87 × 10−17 m2 W−1 for cluster 1; α2 = 1.33 × 10−10 m W−1, n2 = 6.52 × 10−17 m2 W−1for cluster 2; and α2 = 2.54 × 10−10 m W−1, n2 = 4.07 × 10−17 m2 W−1 for cluster 3 for a 1.56 × 10−4 mol dm−3 CH2Cl2 solution.