Investigation of a new organic/inorganic hybrid crystal tri(p-chloro-anilium) pentabromocadmate(II) by in situ PXRD and FTIR methods: Thermal stability and the route to suppress its decomposition

A new organic/inorganic hybrid crystal tri(p-chloro-anilium) pentabromocadmate(II) ((p-Cl-C6H4-NH3)(3)CdBr5) was grown by a programmed cooling method, and its structure was determined using an X-ray diffraction method. This hybrid crystal crystallizes in the monoclinic space group P2(1)/c with unit cell parameters a = 15.033(2) angstrom, b = 8.0189(12) angstrom, c = 23.103(4) angstrom, beta = 99.649(8)degrees, V = 2745.6(7) angstrom(3), Z=4, R[F-2 > 2 sigma(F-2)] = 0.0538, wR(F-2) = 0.0833. The heating processes of the hybrid crystals were investigated by TGA-DTA, in situ X-ray diffraction (XRD) and Fourier transform infrared (FTIR) measurements. The results revealed that the crystal decomposed in two stages. First, p-chlorobenzenamine hydrobromide (p-Cl-C6H4-NH2HBr) was produced from the crystal when subjected to temperatures above 170 degrees C, the gas products of p-Cl-C6H4-NH2HBr then followed as the temperature increased continuously. Furthermore, the in situ FTIR spectra collected at high pressure demonstrated that its dissociation temperature increased by similar to 22 degrees C in a nitrogen atmosphere of 4.0 MPa.