Syntheses and NLO properties of 1D heterothiometallic anionic W/S/Ag clusters possessing solvento-ytterbium cation-directed isomeric skeletons

Abstract

The sequential addition to [WS₄]²⁻ of different solvent-coordinated ytterbium cations as templates and silver iodide as Ag⁺ source afforded the heterothiometallic clusters {[Yb(DMSO)₇][Yb(DMSO)₈][W₆S₂₄Ag₆]}_n1 (DMSO = dimethyl sulfoxide), {[Yb(DMF)₈][W₃S₁₂Ag₃]}_n2 (DMF = N,N′-dimethylformamide) and {[Yb(HMP)₄(NO₃)₂][WS₄Ag]}_n3 (HMP = hexamethylphosphoramide) with isomeric anionic skeletons and in high yields. 1–3 have been fully characterized by elemental analysis, IR and UV-vis spectroscopies, and single-crystal X-ray crystallographic studies. 1 possesses a 1D anionic helical chain with unusual hexavalent repeat units, a structure directed by the combination of seven- and eight-coordinated ytterbium cations, 2 exhibits an unusual 1D anionic zigzag chain, while 3 contains a 1D anionic linear chain. Z-scan studies (532 nm, 8 ns pulses) reveal that 1 and 2 possess strong third-order nonlinear optical properties. Density functional theory and time-dependent density functional theory calculations at the B3LYP/LanL2DZf+6-31G* level were performed on 1–3 to rationalize their experimental absorption spectra.