Syntheses, structures, and optical properties of heteroselenometallic W-Se-Ag polymer compounds {[Et₄N][(μ-WSe₄)Ag]}_nand {[Ln(Me₂SO)₈][(μ₃-WSe₄)₃Ag₃]}_n(Ln = Pr, Er)

The one-dimensional linear polymer W-Se-Ag compound {[Et4N][(μ-WSe4)Ag]}n(1) was obtained from the reaction of [Et4N]2[WSe4] and AgNO3in a mixed solvent, MeCN/DMF (1:10). Treatment of a solution of 1 in Me2SO with Ln(NO3)3· 6H2O resulted in the formation of a helical chain polymer compound {[Ln(Me2SO)8][(μ3-WSe4)3Ag3]}n(Ln = Pr 2, Er 3). The solid-state structures of the three polymer compounds 1, 2, and 3 have been established by X-ray crystallography. The third-order non-linear optical properties of the linear polymer compound 1 were determined by z-scan techniques with 7 ns pulses at 532 nm.