title: The electronic structure and spectra of Ru(II) and Ru(III) complexes with imidazole and its derivatives.
abstract: The calculations of the electronic structure and spectra of [Ru(NH3)5L]2+ (L = imidazole, histidine) and [Ru(NH3)5L]3+ (L = imidazole, N-imidazolate anion, 4-methylimidazole, 4-methyl-1N-imidazolate anion and 1N-bound histidine) complexes are performed in the framework of the CI method in the INDO/CNDO approximation. The MO diagram is obtained. The assignment of all transitions with energies of 4-5 eV is made and the nature of corresponding excited states is discussed. For the Ru(II) complexes, the lower energy observable transition is assigned to d-->pi* type, whereas the higher energy one is assigned to pi-->pi* type. In the spectra of the Ru(III) complexes with charged ligands both transitions are of pi-->d character, while in the case of uncharged ligands, the higher energy transition mostly incorporates pi-->pi* excitations.
authors.affiliation: Chemistry Faculty, St. Petersburg University, Russia.
authors.forename: I V
authors.initials: IV
authors.lastname: Rogachevsky
authors.forename: V I
authors.initials: VI
authors.lastname: Baranovski
mesh_terms: D006639:Histidine / Q000737:chemistry; D007093:Imidazoles / Q000737:chemistry*; D008968:Molecular Conformation; D012428:Ruthenium / Q000737:chemistry*; D017975:Ruthenium Compounds / Q000737:chemistry*; D013057:Spectrum Analysis
chemical_list: D007093:Imidazoles; D017975:Ruthenium Compounds; D006639:Histidine; D012428:Ruthenium