Crystal structure, thermal studies, Hirshfeld surface analysis, vibrational and DFT investigation of organic-inorganic hybrid compound [C 9 H 6 NOBr 2 ] 2 CuBr 4 ·2H 2 O

• DOI: 10.1016/j.molstruc.2016.06.069
• Publication Date: 2016-07-01T14:15:11Z
• Authors: Radhia Mesbeh; Besma Hamdi; Ridha Zouari
• Keywords: Monoclinic crystal system; Thermogravimetric analysis; Differential thermal analysis

Abstract Single crystals of a hybrid organic/inorganic material with the formula [C9H6NOBr2]2CuBr4·2H2O were studied by X-ray diffraction. The compound crystallizes in the monoclinic system, space group C2/c with the following unit cell parameters: a = 7.8201 (12) Ǻ, b = 18.203 (3) Ǻ, c = 19.486 (3) Ǻ, β = 98.330 (5)°, Z = 4, V = 2744.6 (7) Ǻ3. Crystal structure was solved with a final R = 5.66% for 3483 independent reflections. The atomic arrangement shows an alternation of organic and inorganic layers. Between layers, the cohesion is performed via O H⋯Br, C H⋯Br, N H⋯Br, N H⋯O and O H⋯O hydrogen bending. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) measurements have been carried out on [C9H6NOBr2]2CuBr4·2H2O crystal in the temperature range between 50 and 500 °C. The assignment of the observed bands in the solid state FTIR and Raman spectra of the compound was assisted by the theoretically predicted frequencies and compared with data previously reported for similar compounds. The theoretical geometrical parameters in the ground state have been investigated by density functional theory (DFT) with the B3LYP/LanL2DZ level of theory. The optical properties were investigated by optical absorption and show two bands at 279, 300 nm. The percentages of hydrogen bonding interactions are analyzed by Fingerprint plots of Hirshfeld surface.