Synthesis and crystal structure of (NH4)3Cu4Ho2Br13. Further bromides of the (NH4)3Cu4M2Br13 Type (M = Dy-Lu, Y) and on Rb3Cu4Ho2Br13

Article abstract of DOI:10.1002/zaac.19966220417

Single crystals of (NH₄)₃Cu₄Ho₂Br₁₃ were obtained for the first time from the reaction of CuBr with HoBr₃ which was contaminated with NH₄Br: cubic, space group Pn3, Z = 2, a = 1101.71(5) pm. The crystal structure may be considered as a variant of the fluorite type according to [(HoBr₆)₄] [(NH₄)₆Cu₄Br)₂] ≡ Ca₄F₈. Pure products can be prepared from the binary halides in glass ampoules at 350°C. The bromides (NH₄)₃Cu₄M₂Br₁₃ (M = Dy-Lu, Y) and Rb₃Cu₄Ho₂Br₁₃ are isotypic with (NH₄)₃Cu₄Ho₂Br₁₃. Johann Ambrosius Barth 1996.