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

Abstract

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)Cl₂] (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 α₂ = 1.2 × 10⁻⁶ cm W⁻¹ M⁻¹ and n₂ = −1.5 × 10⁻¹⁰ cm² W⁻¹ M⁻¹. Compound 1 exhibits a considerably large self-defocusing property.