A coordination compound of erbium perchlorate With L-alpha-glutamic acid, [Er-2(L-Glu)2(H2O)(6)](ClO4)(4).6H(2)O(S), was synthesized. By chemical analysis, elemental analysis, FTIR, TG/DTG and comparison with relevant literature, its chemical composition and structure were established. The purity was found to be >99.0%, without melting point. Low-temperature heat capacities were measured by a precision automated adiabatic calorimeter from 78 to 318 K. An endothermic peak in the heat-capacity curve was observed over the temperature region of 290-316 K, which was ascribed to a solid-to-solid phase transition. The temperature T the enthalpy Delta H-trans(m) and the entropy Delta S-trans(m) of the phase transition for the compound were determined to be: 308.73 +/- 0.45 K, 10.49 +/- 0.05 U mol(-1) and 33.9 +/- 0.2 J K-1 mol(-1). Polynomial equation of heat capacities as a function of the temperature in the region of 78-290 K was fitted by the least square method. (C) 2007 Elsevier B.V. All rights reserved.