Cs0.49NbPS6

Abstract

The quaternary thio­phosphate, Cs0.49NbPS6, caesium hexa­thio­niobiophosphate(V), has been synthesized by the reactive halide flux method. The title compound is isotypic with Rb0.46TaPS6 and is made up of a bicapped trigonal–biprismatic [Nb2S12] unit and a tetra­hedral [PS4] group. The [Nb2S12] units linked by the [PS4] tetra­hedra form infinite chains, yielding a three-dimensional network with rather large van der Waals gaps along the c axis in which the disordered Cs+ ions reside. The electrons released by the Cs atoms are transferred to the pairwise niobium metal site and there are substantial inter­metallic Nb—Nb bonding inter­actions. This leads to a significant decrease of the inter­metallic distance in the title compound compared to that in TaPS6. The classical charge balance of the title compound may be represented as [Cs+]0.49[Nb4.51+][P5+][S2−]4[S2 2−]