Synthesis, Raman spectrum and crystal structure of [Ba(XeF_2)_4](PF_6)_2

摘要

In the system BaF_2/PF_5/XeF_2/anhydrous hydrogen fluoride a new coordination compound, [Ba(XeF_2)_4](PF_6)_2, was isolated. The XeF_2 molecules are interacting as ligands directly with the Ba~(2+) cations. The compound crystallizes in the triclinic space group P1-bar with a = 8.739(2) A, b = 8.912(2) A, c = 25.855(7) A, alpha = 76.331(6), beta = 83.085(6), gamma = 81.212(6), V= 1926.2(8) A3 at 200 K and Z = 4. The structure consists of two crystallographically independent barium atoms with the coordination numbers 10 and 12. The barium atoms and the bridging XeF_2 molecules form double layers which are further interconnected into the 3-D network by the weak Xe...F (PF_6~-) interactions. The Raman spectrum of [Ba(XeF_2)_4](PF_6)_2 clearly shows the presence of bridging XeF_2 molecules.