Electronic spectra of ruthenium nitrosyl complexes with macrocyclic ligands

Electronic spectra of ruthenium(II) nitrosyl complexes [Ru(NO)(salen)(X)](n) (X = Cl, H2O; n = 0, 1) and [Ru(NO)(P)(ONO)] with tetradentate pi-conjugated ligands N,N'-ethylenebis(salicylideniminato) dianion (salen) and porphinate dianion (P) were calculated by the TD DFT and CINDO/Cl methods. The data obtained were compared to the results of previous calculations of the spectra of trans-[Ru(NO)(NH3)(4)(L)](3+) complexes with nitrogen-containing heterocyclic ligands L. It was found that charge-transfer transitions to pi* orbitals of the RuNO group dominate in the long-wave part of the spectrum irrespective of the other ligands.