Growth, morphology, structure and properties of Na(3)BaCl(5)2H(2)O crystals

Single crystals of Na3BaCl5.2H(2)O were obtained from saturated aqueous sol utions at two different temperatures (27 degrees C and 32 degrees C) The cr ystal size increases with increasing temperature. The crystals obtained wer e subjected to a systematic morphological, X-ray and thermal analyses. The study of as-groan crystal morphology and surface morphology of Na3BaCl5.2H( 2)O crystals clearly indicate the requirement of a slow rate of evaporation at temperatures 27 to 28 degrees C, moderate supersaturation in order to o btain high quality single crystals of Na3BaCl5.2H(2)O. The X-ray diffractio n studies give the following cell parameters for the title compound: monocl inic, P2(1)/n, a = 8.5773(9), b = 9.5502(4), c = 5.2873(3) Angstrom, beta = 92.069 degrees, V = 432.8 Angstrom(3), Z = 2. The study of TGA curves indic ate the occurrence of dehydration process at around 200 degrees C and not t he decomposition of the compound. Similarly, the low temperature DSC study indicates a thermal anomaly at 267 K, and the high temperature DSC study (3 23 K to 873 K) indicates the transition from dihydrate to monohydrate and i n turn anhydrous state at 454.6 It for Na3BaCl5.2H(2)O crystals. Thus both the TGA & DSC curves conclude that the Na3BaCl5.2H(2)O crystals contain two molecules of water of crystallization and its molecular formula is Na3BaCl 5.2H(2)O.