dimorphous. The crystal structures of the two forms were determined by X-ray diffraction. The low temperature modifications are tetragonal with a space group I 4 , the high temperature forms are cubic with the space group F 4 3m. In both structures tetrahedral M(NC)4-and Hg(CN)4- groups are connected by M-CN-Hg bridges to a three dimensional framework of cristobalite type structure with cavaties, of which
摘要四元
氰基
汞酸盐 NR4+ [
MHg(CN)4]− 与 R = Et,Pr; M = Li,Na, K,Cu,由 NR4CN、MCN 和 Hg(CN)2 在极性溶剂中反应得到,是二晶型的。两种形式的晶体结构通过 X 射线衍射确定。低温变体为四方体,空间群为I 4 ,高温变体为立方体,空间群为F 4 3m。在这两种结构中,四面体 M(NC)4-和 Hg(CN)4- 基团通过 M-CN-Hg 桥连接到具有空腔的
方石英型结构的三维框架,其中 NR4+ 阳离子位于其中。已通过 DTA/
DSC、X 射线衍射、拉曼和 MAS-NMR 光谱研究的可逆相变具有一级和位移特性。