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Synthesis and characterization of (NH 4 ) 2 CuBr 2 Cl 2 ·2H 2 O crystals
Author(s) -
Amirthaganesan G.,
Kandhaswamy M. A.,
Srinivasan V.
Publication year - 2005
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.200410327
Subject(s) - orthorhombic crystal system , crystallinity , crystallography , thermal analysis , stoichiometry , bromine , analytical chemistry (journal) , thermal decomposition , chemistry , crystal structure , powder diffraction , infrared spectroscopy , fourier transform infrared spectroscopy , evaporation , single crystal , crystal (programming language) , thermal , organic chemistry , meteorology , computer science , physics , quantum mechanics , programming language , thermodynamics
Single crystals of a new compound, (NH 4 ) 2 CuBr 2 Cl 2 .2H 2 O, were grown from saturated aqueous solution at room temperature by slow evaporation method. The grown crystals were characterized through elemental, powder XRD, thermal and DSC analyses and FTIR and far IR spectra. The elemental analysis and the decomposition pattern formulated using the TG‐DTG studies confirm the stoichiometry of the compound. The crystallinity of the compound is confirmed from the powder XRD pattern. A preliminary single crystal X‐ray diffraction structural analysis reveals that the title compound belongs to the orthorhombic system with a = 7.7466 Å, b = 7.783 Å and c = 8.1211 Å. The low temperature DSC shows thermal anomalies at –161.1, –156.5, –152.4, –145.2, –134, –18.5, and 1.4°C during the heating run and at –4.3, –54.8, –66.1, –90.6, –109.7 and –147.2 °C during the cooling run. The thermal hysterses indicate first order phase transitions in the title compound at these temperatures. The FTIR spectra were used to assign the characteristic vibrational frequencies due to NH 4 + , CuX 4 2– ions and other chemical bonds. The effect of substitution of two bromine atoms on the phase transitions of a closely related crystal, diammonium tetrachloro cuprate dihydrate is also discussed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)