Computational study on intermolecular charge transfer complex of 2,2′-bipyridine with picric acid: TD-DFT, NBO and QTAIM analysis

In this research work, the charge transfer complex of 2,2'-bipyridine with picric acid a 1:1 stoichiometry has been investigated by using quantum chemical calculations B3LYP/6-311(++)G(d, p), CAM-B3LYP/6-311(++)G(d, p), PBE0/6-311(++)G(d, p) and M06-2X/6-311(++)G(d, p) level of theory. Binding energies (Delta E-int, Delta H-int and Delta G(int)), reactivity descriptors, HOMO and LUMO orbitals, TD-DFT, NBO and QTAIM analysis have been determined. The results demonstrate that the complex formation is energetically favorable in vacuum and in chloroform. Furthermore, TD-DFT, NBO and QTAIM analysis suggest that a charge transfer occurs by the establishment of H-bond interaction essentially between O(8) of the picric acid and H(19) of 2,2'-bipyridine.