Kristallstruktur und Schwingungsspektren von Li 5 CrCl 8 / Crystal Structure and Vibrational Spectra of Li 5 CrCl 8

The crystal structure of the novel pink Li 5 CrCl 8 oC28 has been determined by both single crystal X-ray and neutron powder studies. The title compound crystallizes in a hitherto unknown structure type (space group C mmm, Z = 2). The final R values are R = 3.4% (715 independent reflections with I > 3a I ) and R wp = 11.5%, respectively (a = 1019.79(3), b = 723.94(2) and c = 726.16(3) pm). The structure consists of edge-connected Li(l)Cl 6 and alternating edge-connected Li(2)Cl 6 and CrCl 6 octahedra, respectively. It is related to the NaCl super structure SnMn 2 S 4 type. IR and Raman spectra as well as symmetry coordinates are given and discussed in terms of CrCl 6 and LiCl 6 breathing modes.