A refinement of the crystal structures of K 2 ReCl 6 , K 2 ReBr 6 , and K 2 PtBr 6

Abstract

The crystal structures of K 2 ReCl 6 , K 2 ReBr 6 , and K 2 PtBr 6 have been refined using data collected on a single-crystal X-ray diffractometer to give weighted agreement indices ranging from 0.026 to 0.054 for 75 to 90 nonequivalent reflections. The following bond lengths were obtained: Re—Cl = 235 pm, Re—Br = 248 pm, Pt—Br = 246 pm, K—Cl = 348 pm, and K—Br = 367 and 364 pm in the Re and Pt compounds, respectively. The differences in the root-mean-square angles of libration of the MX 6 2− ions in these and a number of isomorphous crystals are discussed.