Synthesis, crystal structures and calculated nonlinear optical properties of seven di-nuclear metal (0, I) carbonyl cyclohexanthiolates, [M2(μ-SC6H11)x(CO)y]n− (M = Mo, W; x = 2, 3; y = 6, 8; n = 0, 1, 2)

Seven novel di-nuclear molybdenum and tungsten metal cluster complexes with cyclohexanthiolate ligand, [Et4N]2[Mo2(SC6H11)2(CO)8] (1), [Et4N][Mo2(SC6H11)3(CO)6] (2), [Ph4P][Mo2(SC6H11)3(CO)6] (3), [(CH3)3PhCH2N][Mo2(SC6H11)3(CO)6] (4), [Et4N]2[W2(SC6H11)2(CO)8] (5), [W2(SC6H11)2(CO)8] (6) and [Et4N][W2(SC6H11)3(CO)6] (7) have been synthesized and characterized. The crystal structure determinations reveal that 1 and 5 contain a planar [M(0)2S2] unit, 6 contains a planar [M(I)2S2] unit and 2, 3, 4 and 7 contain a [M(I)2S3] core with a planar M2S2 unit coordinated by a third chair form SC6H11 bridging ligand (M = Mo, W). IR of these seven complexes was measured. Theory calculation indicated that compounds 2 and 7 possess large first-order hyperpolarizability of 13 × 10−30 esu and 8 × 10−30 esu, respectively, which could be an IR second-order nonlinear optical candidate materials.