Synthesis and nonlinear optical absorptive and refractive properties of several novel nest-shaped clusters, and crystal structures of [MoI(bPy)2][MoOS3Cu3I2(bPy)] and [MoOS3Cu3I(Phen)2]

Nest-shaped clusters [MI(bPy)2][MOS3Cu3I2(bPy)] (M=Mo, 1; M=W, 2) were synthesized by the treatment of (NH4)2MO2S2, CuI and Et4NI with 2,2′-bipyridyl (bPy) in CH3CN. Both clusters show a very interesting structure, and consist of two parts: a nest-shaped structural unit [MOS3Cu3I2(bPy)]− and complex ion [MI(bPy)2]+. By the reaction of [Et4N]4[Mo2O2S6Cu6I6] with Phen (1,10-phenanthroline), or bPy, or bMe-bPy (4,4′-dimethyl-2,2′-bipyridyl), we prepared nest-shaped clusters [MoOS3Cu3IR2] (R=Phen, 3; R=bPy, 4; R=bMe-bPy, 5). The crystal structures of [MoI(bPy)2][MoOS3Cu3I2(bPy)] (1) and [MoOS3Cu3I(Phen)2] (3) were characterized by X-ray diffraction. Their nonlinear optical (NLO) properties were studied with a 7-ns pulsed laser at 532 nm. Cluster 1 has large NLO absorption and NLO refraction, its α2 and n2 values were calculated as 3.0×10−10 m W−1 and −3.0×10−17 m2 W−1 in a 3.4×10−5 mol dm−3 DMF solution, respectively. Cluster 2 only exhibits very strong NLO absorptive property, its α2 value is 1.0×10−9 m W−1 when measured in a 4.8×10−5 mol dm−3 DMF solution. Clusters 4 and 5 have strong NLO absorption too. Their α2 values were calculated as 7×10−11 m W−1 and 3.5×10−10 m W−1, respectively. Cluster 3 only shows moderate NLO absorption, its α2 value is ∼10−11 m W−1.