Crystal structure, thermochromic and magnetic properties of organic-inorganic hybrid compound: (C 7 H 7 N 2 S) 2 CuCl 4

• DOI: 10.1016/j.molstruc.2017.03.076
• Publication Date: 2017-03-21T11:07:20Z
• Authors: Ashok K. Vishwakarma; Reema Kumari; Prasanna S. Ghalsasi; Navamoney Arulsamy
• Keywords: 01 natural sciences; 0104 chemical sciences

Abstract The synthesis, thermal analysis, crystal structure and magnetic properties of (2-aminobenzothiazolium)2CuCl4, organic-inorganic hybrid compound, have been described. The compound crystallizes in the monoclinic space group P21/c with two formula units in a unit cell of dimensions a = 6.9522(4) A, b = 9.6979(4) A, c = 13.9633(6) A, β = 97.849(3)° and volume 930.83(8) A3 at 150(2) K. The structure consists of isolated nearly square planer [CuC14]2− units, with somewhat longer than normal Cu Cl bond lengths [Cu Cl (average) = 2.2711 A]. The magnetic measurements of (2-aminobenzothiazolium)2CuCl4 using SQUID magnetometer show paramagnetic nature of the compound. Thermal measurements (TG-DTA and DSC) on this compound showed reversible phase transition at 83 °C. This transition is accompanied by the reversible change in colour of the prismatic crystal from green to dark brown, thermochromic behaviour. Temperature dependent EPR measurements on powdered sample ascertain change in coordination sphere around Cu(II) with shift in g|| = 2.150 and g⊥ = 2.071 at room temperature, typical of square planar, to g|| = 2.201 and g⊥ = 2.182 at 170 °C, typical of distorted tetrahedral geometry.