Mohamed Kamoun

Differential scanning calorimetry and infrared spectroscopic study of (C9H19NH3)2CdCl4

Abstract DSC and Infrared spectroscopic studies of (C9H19NH3)CdCl4 reveal the existence of two first-order phase transitions. The main transition with the largest enthalpy variation (T 1 0 = 294·3 K, ΔH= 19·917 kJ mol−1) corresponds to the onset of “chain melting” at the same time as dynamic twofold rotational disordering of the chains. The minor transition (T 2 0 = 301·3 K, DΔH = 4·952kJmol1) corresponds to a further melting of the chains, but the total “melting” is not reached. Comparison of the DSC results of CnCd compounds with 6 ≤ n ≤ 18 shows that the series with 7 ≤ n ≤ 12 have the same number and sequence of phase transitions. All of these compounds undergo two first-order transition related to the dynamics of the alkylammonium chain.