Optoelectronic and structural studies of a Ni(II) complex including bicyclic guanidine ligands: DFT calculations

Structural and optoelectronic properties of NiCl2C14H26N6 complex (1) using DFT calculations by various exchange correlation potentials including PBE-Generalized Gradient Approximation (PBE-GGA) and hybrid density functional B3LYP are investigated. The complex belongs to monoclinic crystallographic system with P2(1)/n space group, Z = 4. Selected 1 as monomeric unit (1-mon) through C-H center dot center dot center dot Cl hydrogen bonds (HBs) constructs a 2-D coordination polymeric plane. The dispersion corrected density functional theory (DFT-D) calculations determine the binding energies of the non-conventional C-H center dot center dot center dot Cl HBs constructor of the crystalline network (1-net). The calculated-B3LYP/LANL2DZ/6-311+G(d, p) electronic spectrum in gas phase shows four major bands in the range of 200-240 nm that could assigned to MLCT and LMCT transitions with n -> pi* and it pi* -> sigma* characters. The calculated results of electronic transitions in water using PCM method include broad bands with blue shifts in comparison with the vacuo one. Density of states results by the PBE-GGA show that this complex has a wide band gap (3.0 eV). The optoelectronic properties predict that it can be efficiently used in the optoelectronic molecular devices. (C) 2017 Elsevier B.V. All rights reserved.