Assembly of two cluster-based coordination polymers with good NLO performance from one NLO-inactive precursor cluster [Et4N][Tp*W(μ3–S)3(CuCl)3

Abstract

Reactions of the precursor cluster [Et4N][Tp*W(μ3–S)3(CuCl)3] (Tp* = hydridotris(3,5-dimethylpyrazol-1-yl)borate) (1) with 2 equiv of AgSCN produced one 1D [Tp*W(μ3–S)3Cu3]-based coordination polymer [Tp*W(μ3–S)3Cu2Cu(μ–SCN)(μ3–SCN)]2·Et2O (2·Et2O) while analogous reactions of 1 with Nadca (dca = dicyanamide) formed one 2D [Tp*W(μ3–S)3Cu3]-based coordination polymer [Tp*W(μ3–S)3Cu3(μ1,5–dca)(μ1(3),5–dca)]2·CH2Cl2 (3·CH2Cl2). Compounds 2–3 were characterized by elemental analysis, IR spectra, UV-vis spectra, 1H NMR spectra, and the crystal structures of 2·Et2O and 3·CH2Cl2 were determined by single-crystal X-ray crystallography. The structure of 2 consists of the incomplete cubanelike [Tp*W(μ3–S)3Cu3] cores which are interlinked by SCN bridges. Compound 3 contains repeating dimeric [Tp*W(μ3–S)3Cu3(μ1(3),5–dca)]2 units, which are further interconnected by four Cu–μ–dca–Cu bridges to form a 2D layer with a 63 topology. The third-order nonlinear optical (NLO) properties of 1–3 in DMF were also investigated using femtosecond a degenerate four-wave mixing DFWM technique. The two assemblies 2 and 3 exhibited good third-order NLO performances through connecting the cluster [Tp*W(μ3–S)3Cu3] cores of 1 bearing no NLO properties via thiocyanate or dicyanamide bridges.