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

•Good agreement between the optimized geometries and crystal structures had been achieved.•UV–vis and IR NMR spectra were successfully assigned with DFT calculations.•NMR spectra were calculated with GIAO method and compared with experimental data.•The frontier orbitals of complex isomers were analyzed for better understanding their reactivities.

Structures, electronic spectra, infrared and NMR spectra of three [Ru(OAc)(2mqn)2NO] (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 1H 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.

Graphical abstractMolecular geometry, electronic spectra, infrared and NMR spectra of [Ru(OAc)(2mqn)2NO] (H2mqn = 2-methyl-8-quinolinol) isomers were studied with density functional theory (DFT) at B3LYP level with 6-311++G(d,p) and Aug-cc-pVDZ-PP as basis set.Figure optionsDownload full-size imageDownload as PowerPoint slide