Synthesis, crystal structure and third-order nonlinear optical properties of a hexanuclear cluster [WOS 3Cu 2(4- tBuPy) 2] 2 (4- tBuPy = 4- tert-butylpyridine)

Abstract

Reaction of (NH 4) 2[WOS 3] with 2 equiv. of CuI in 4- tert-butylpyridine (4- t BuPy) and methanol afforded a hexanuclear neutral cluster [WOS 3Cu 2(4- t BuPy) 2] 2. This compound was characterized by elementary analysis, IR, UV–vis, 1H NMR, thermogravimetric analysis, and its crystal structure was determined by X-ray single crystal diffraction. The compound contains a hexagonal prismatic cage structure in which two butterfly-shaped [WOS 3Cu 2(4- t BuPy) 2] cluster fragments are interlinked through four Cu S bonds. The nonlinear optical properties were studied with a 30 ps pulsed laser at 532 nm. The compound exhibited strong nonlinear absorption effect with α 2 = 2.5 × 10 −10 mW −1, χ (3) = 8.5 × 10 −14 esu, and γ = 4.8 × 10 −30 esu.