Structural study, Hirshfeld surface analysis, spectroscopic properties and DFT investigation of a new hybrid compound: (C6H10(NH3)2)3[CoCl4](Cl)4•3H2O

The cobalt chloride with the diaminocyclohexane cation as a ligand yields to a new non-centrosymmetric organic-inorganic compound synthesized in an aqueous solution by slow evaporation technique. Afterwards, it is characterized by X-ray diffraction, infrared, Raman and UV-Vis spectroscopy. The newly prepared compound belongs to the hexagonal system (P6(3) space group) with the following unit cell dimensions: a = b = 14.283(4) angstrom, c = 9.952(3) angstrom, alpha = beta = 90 degrees and gamma = 120 degrees. The structure consists of [CoCl4](2-) tetrahedral forming an hexagonal tunnel running along the c axis. The crystal packing is governed by the N-H center dot center dot center dot Cl, O-H center dot center dot center dot Cl and non-classical C-H center dot center dot center dot Cl hydrogen bonding interactions between the organic network and the inorganic one, in which they may be effective in the stabilization of the crystal structure. Moreover to gain an insight into the behavior of these weak interactions, Hirschfeld surfaces analysis have been investigated. The theoretical calculations were conducted using DFT approach with the B3LYP/LanL2DZ basis set for studying the structural parameters and the vibrational spectra of the title compound. The optical properties were studied by DFT calculation and show a good accordance between the experimental UV-Visible spectrum and the simulated spectra and confirm the contribution of metal orbital to the HOMO-LUMO boundary. The 1,2-diammoniumcyclohexane tetra-chlorocobaltate(II) tetrachloride trihydrate compound has a large NLO response computed to be 40.08 10-31 esu. Here, the significant effect of isolated halogen linked to the organic ring by hydrogen bonds qualifies it as a good candidate for NLO applications. (C) 2017 Elsevier B.V. All rights reserved.