The strongly anisotropic thioarsenates A 3Ta 2AsS 11 are stabilized in a polysulfide flux. All compounds contain the same parallel 1/∞ [Ta 2AsS 11 3-] polymeric anionic chains, but the size of the alkali-metals has a profound effect on the packing of the chains. The K + or Rb + favor noncentrosymmetric packing of the chains, whereas the larger Cs + favors the centrosymmetric packing. The chains feature the combination of two asymmetric units [Ta 2S 11] and [AsS 3] and exhibit strong nonlinear optical (NLO) second harmonic generation (SHG) response. Polycrystalline samples exhibit is up to × 15 times stronger SHG than that of commercially used AgGaSe 2.
ASJC Scopus subject areas
- Colloid and Surface Chemistry