Crystal structure of cesium sodium hexathiocyanatobismuthate Cs₂Na[Bi(SCN)₆] and characterization of Cs₂Na[Bi(SCN)_6−x Cl _x ] and Cs₂Na[Bi₂(SCN)_9−x Cl _x ] complexes by X-ray powder diffraction

Abstract

Cs₂Na[Bi(SCN)₆] crystallizes in the trigonal space group$P\bar 3$ with one formal molecule per unit cell.M=846.25,a=7.189(1),c=10.580(2) Å,V=473.5(1) Å,D _x =2.967 g cm⁻³, μ(MoKα)=13.70 mm⁻¹,F(000)=378. FinalR=0.029 for 917 absorption-corrected reflections. The structure consists of infinite[Bi(SCN)₆Na] ²⁻_∞ anionic chains along thec axis with slightly distorted octahedral Bi−6S and Na−6N coordination and Cs⁺ ions surrounded by three anionic chains with irregular coordination by six N and three S atoms. X-ray powder diffractograms of three complexes, Cs₂Na[Bi(SCN)_6−x Cl _x ] withx=2, 3 and 4, indicate that the mixed complexes are not isostructural and can be indexed in different orthorombic unit cells witha=14.617(8),b=12.32(1),c=10.769(6) Å forx=2;a=15.37(1),b=10.81(1),c=10.287(6) Å forx=3 anda=14.662(7),b=14.366(7),c=7.932(4) Å forx=4. The two dinuclear complexes Cs₂Na[Bi₂(SCN)_9−x Cl _x ] withx=2 and 3, despite the large similarity of their diffractograms, are not isostructural and can be indexed in different orthorombic unit cells witha=14.79(1),b=13.72(1),c=10.591(5) Å forx=2 anda=18.423(8),b=15.657(7),c=7.410(7) Å forx=3.