Structures and spectroscopic properties of three [Ru(OAc)(2mqn)2NO] (H2mqn = 2-methyl-8-quinolinol) isomers: An experimental and density functional theoretical insight

Abstract Structures, electronic spectra, infrared and NMR spectra of three [Ru(OAc)(2mqn) 2 NO] (H2mqn = 2-methyl-8-quinolinol) isomers were calculated at the B3LYP level with 6-311++G(d,p) and Aug-cc-pVDZ-PP as the basis set. Good agreement between the optimized geometries and structural parameters from crystal structures had been achieved. UV–vis absorption and vibration spectra were experimentally measured and theoretically assigned with DFT calculations. The calculated spectra reasonably correspond to the recorded spectra and the results indicated that DFT calculation is reliable and helpful to analyze the geometries and spectra of isomers. With the gauge independent atomic orbital (GIAO) method, chemical shifts in 1 H NMR of these isomers were also calculated, which could match with the experimental data. There was a large degree of mixing between NO orbitals and the metal d orbitals in the frontier orbitals, which suggested that the peculiarity of {Ru(II)-NO + } group affect the structure and reactivity of nitrosylruthenium(II) complexes containing 8-quinolinolate and its derivatives.