Synthesis and Structural Analysis of BaCrS(2).

A new ternary chromium sulfide, BaCrS(2), was synthesized. This solid state compound crystallizes in the orthorhombic, centrosymmetric space group Pmmn (No. 59) with a = 4.2606(6) Å, b = 4.7944(7) Å, c = 9.443(1) Å, V = 192.89(5) Å(3), and Z = 2. The solid is similar to a previously known structure BaNiS(2) in which the Ni atom is coordinated to five sulfur atoms in a square pyramidal fashion. In BaCrS(2), the square pyramid distorts such that the two S(basal)-Cr-S(basal) angles are no longer equal. Thus the BaCrS(2) solid is orthorhombic whereas BaNiS(2) is tetragonal. The distortion from the square pyramidal coordination in the title compound is traced to the broken degeneracy of the d(xy)() and d(xz)() set by a computational analysis.