DFT calculations for model diimine-iron complexes with nitric oxide and water ligands

DFT, TDDFT and ZINDO/S calculations were carried out for the nitrosyl-aqua (I) and di-aqua (II) iron complexes with diimines as equatorial ligands. The electronic structure of the nitric oxide complex can be characterized as a low spin d6 iron cation bonded to the NO moiety.On the basis of TDDFT and ZINDO/S calculations, the two bands of divalent iron with nitric oxide, water and Me4[14]tetraeneN4 ligand (1) at about 600 and 400 nm are found to consist of d → d, d→πNO∗, πNO∗→d and d→πdiimine∗ transitions. In the case of di-aqua complex, the band at 575 nm is assigned as a d→πdiimine∗ transition.

Graphical abstractDFT, TDDFT and ZINDO/S calculations of the electronic structure and spectra were carried out for the nitrosyl-aqua and di-aqua iron complexes with diimines as equatorial ligands. The electronic structure of the nitric oxide complex can be characterized as a low spin d6 iron cation bonded to the NO moiety.Figure optionsDownload full-size imageDownload as PowerPoint slide