Preparation and crystal structure of quaternary chromium sulfide halide CrSBr0.67Cl0.331

Quaternary CrSBr0.67Cl0.33 was obtained as black needles by heating chromium powder with a mixture of S2Br2 and S2Cl2 at 1273 K. It was found from X-ray precession photographs and an X-ray diffraction powder structure determination to be isostructural with CrSBr crystallizing in the FeOCl structure type (space group Pmmn, a = 476.73(4), b = 346.65(3), and c = 779.25(8) pm; Rexp = 9.7%). The reason of the partly opposite change of the Cr–X (X = halogen) and Cr–S distances on going from CrSBr to CrSBr0.67Cl0.33, compared with that expected for substitution of bromium ions by smaller chlorium ones, is discussed.