Intercalation and formation of complexes in the system of lead(II) iodide-ammonia

Interaction between lead(II) iodide and ammonia was studied with the help of an X-ray in Situ analysis, DTA-TG analysis, DSC measurements and IR spectroscopy. A two-stage mechanism of the reaction was defined. At the first stage of the reaction two phases with trigonal symmetry and a phase with monoclinic symmetry are developed. At the second stage of the reaction the structure changes lead to formation of a compound with orthorhombic symmetry. The results were discussed along with the data of thermal analysis and IR spectroscopy. The value of enthalpy of formation for the compound PbI2(NH3)(4) was determined. (C) 2003 Elsevier Inc. All rights reserved.