作者:M. Loukil、A. Kabadou、I. Svoboda、A. Ben Salah、H. Fuess                                    
                                    
                                        DOI:10.1016/j.jallcom.2004.05.061
                                    
                                    
                                        日期:2005.1
                                    
                                    NH4HgI3.H2O crystallizes in the monoclinic system, space group Cc (No. 9), with: a = 10.9865(11) Angstrom; b = 9.7683(10)Angstrom: c = 8.6759(9) Angstrom: beta = 90.395(8)degrees; V = 931.07(16) Angstrom(3) and Z = 4 (T = 163 K). Refinement of single crystal X-ray data lead to R-(F) = 0.0271. The structure consists of tetrahedra [HgI4] linked by common corners to infinite chains, running parallel to [001]. The ammonium groups and water molecules are located between the chains ensuring the stability of the structure by hydrogen bonding contacts: N-H...I, O-H...I and N-H...O. Differential scanning calorimetry reveals three anomalies at 219, 345 and 375 K. The peak at 219 K. according to the Single crystal X-ray diffraction, was attributed to an orientational disorder of ammonium groups. IR-spectroscopy shows that the NH4HgI32H2O compound loses crystallization water gradually in the temperature range (350-540 K). (C) 2004 Elsevier B.V. All rights reserved.