Novel metformin complexes: Geometry optimization, non‐isothermal kinetic parameters, DNA binding, on–off light switching and docking studies

Novel three water‐soluble chromium(III) complexes of types [Cr(Cl)(gly‐H)2(met)H2O] (1), [Cr(Cl)(met)(pro‐H)2H2O] (2) and [Cr(Cl)(his‐H)2(met)H2O] (3) (met = metformin, gly = glycine, pro = proline and his = histidine) have been synthesized. The geometrical structures have been shown to be octahedral, with substantial evidence from spectroanalytical techniques. Thermal investigations show the degradation pattern of the compounds from which the kinetic and thermodynamic parameters for the complexes' degradation were calculated using the Coats–Redfern 13 distinct kinetic models. The quantum chemical parameters were computed using the energies of the molecular orbital structures, developed from optimized geometrical structures, to evaluate the stability of the complexes. The groove binding of the complexes with CT‐DNA was confirmed by absorption and emission spectroscopy, viscosity measurements, gel electrophoresis and molecular docking studies. Chromium(III) ternary complexes of metformin with on–off light switching properties bound to DNA via groove binding, the stability of complexes established from high activation energies and calculated from HOMO‐LUMO energies.