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

Structures, electronic spectra, infrared and NMR spectra of three [RuCl(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. The crystal structure of trans [RuCl(2mqn)2NO] was determined with X-ray diffraction method, good agreement between the optimized geometries of three isomer complexes and structural parameters from crystal structures had been achieved. UV–Vis, IR and 1H NMR spectra of three isomers 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 to analyze the geometries and spectra of isomers. Frontier orbital analyses supported that the peculiarity of {Ru(II)-NO+} group affects the structure and reactivity of nitrosylruthenium (II) complexes containing 8-quinolinolate and its derivatives. The structural and spectral analyses combined with DFT calculations provides a new way to well understand physicochemical properties and reactivity of the [RuCl(2mqn)2NO] isomeric complexes.

Graphical AbstractGood agreement between the optimized geometries and crystal structures of three [RuCl(2mqn)2NO] (H2mqn = 2-methyl-8-quinolinol) isomers had been achieved. Their molecular orbitals, UV–Vis, IR and NMR spectra were calculated and analyzed with density functional theory (DFT) at B3LYP level with 6-311++G(d,p) and Aug-cc-pVDZ-PP as basis set.Figure optionsDownload as PowerPoint slide