Structural Transformation from Trinuclear Linear to Tetranuclear Cubane Heterobimetallic Selenium Compounds. Structure and Optical Linearities of [Et4N]2[(μ-WSe4)(CuCl)2]

Abstract

Reactions of [Et4N]2[WSe4] with two equivalents of [CuX] powder gave trinuclear linear compounds [Et4N]2[(μ-WSe4)(CuX)2] (X = Cl 1, Br 2). Treatment of 1 or 2 with PPh3 in CH2Cl2 resulted in the formation of tetranuclear cubane-like compounds (μ3-X)(μ3-WSe4)(CuPPh3)3 (X = Cl 3, Br 4). The structures of the heterobimetallic selenium compounds 1 and 4・MeCN were confirmed by single-crystal X-ray diffraction. The nonlinear optical properties of 1 were investigated at λ = 532 nm with a pulse width of 7 ns