Syntheses, crystal structures and non-linear optical properties of two novel windmill-shaped clusters: [M2Pd4S8(dppm)(2)]center dot 4DMF (M = W or Mo)

Novel cluster compounds [M2Pd4S8(dppm)(2)]. 4DMF (M=W 1 or Mo 2) were synthesized by the reaction of [NEt4](2)[MS4] and [Pd(dppm)Cl-2] (dppm=Ph2PCH2PPh2) in CH2Cl2 and CH3CN, and their crystal structures have been characterized by X-ray diffraction. Both clusters have novel new skeletal structures with eight atoms in a plane. The non-linear optical properties of 1 were studied with a 7 ns pulsed laser at 532 nm. The effective third-order non-linearities were determined yielding alpha(2)=1.2x10(-6) cm W-1 M-1 and n(2)=-1.5x10(-10) cm(2) W-1 M-1. Compound 1 exhibits a considerably large self-defocusing property.