Predicting Inversion of MO Energy Levels by DFT Calculations in Tricarbonylpolypyridylrhenium(I) Complexes

CATTANEO, MAURICIO; FAGALDE, FLORENCIA; KATZ, NÉSTOR E

Córdoba

Workshop; Workshop argentino de solvatación y reactividad a escala molecular:; 2011

Asociación Argentina de Investigación Fisicoquímica

  Theoretical calculations emerged as a powerful tool to help experimental results to explain different parameters in molecular properties and reactivity. DFT has considerably increased its applications in coordination chemistry by its considerably low computational costs and good concordance with experimental results. Recently, considerations of electron density, MO and electronic transitions have been published for different polipyridine complexes.1 Tricarbonyl Rhenium(I) are an interesting small group where modifying the polipyridine ligand we can visualize different effects on physical properties. We already report a series of compound of formulae [Re(CO)3(4,4?-X2-bpy)(PCA)]+ (with X = Me, H, Ph, CO2Me; and PCA = 1,4-di(4-pyridil)-2,3-diazabutadieno or 4-pyridinaldazine) where the physical properties as reduction or potentials, vibrational transitions for -CΞO, electronic transitions, changes as the electron density change by the influence of the substitution on the bipyridine ligand.2 But the luminiscense abruptly change in the middle of the series, explained by a less effective quenching of PCA by an inversion of molecular orbitals. Now we can probe this statement by DFT calculations of the complexes at the ground state with the CPCM salvation model and TDDFT for electronic transitions. These results are consistent with the inversions of the molecular orbital observed in a similar complex but influenced by protonation in the ligands.3 A summary of these results and perspectives will be presented. Referencias: [1]  Vlček, A. J.; Záli?, S. Coord. Chem. Rev. 2007, 251, 258-287. [2] (a) Cattaneo, M.; Fagalde, F.; Katz, N. E.; Leiva A. M.; Schmehl, R. Inorg. Chem. 2006, 45, 127-136. (b) Cattaneo, M.; Fagalde, F.; Katz, N. E. Inorg. Chem. 2006, 45, 6884-6891. (c) Cattaneo, M.; Fagalde, F.; Katz, N. E.; Borsarelli C. D.; Parella, T. Eur. J. Inorg. Chem. 2007, 34, 5323-5332. Cover Picture p. 5309. [3] Cattaneo, M.; Fagalde, F.; Borsarelli C. D.; Katz, N. E. Inorg. Chem. 2009, 48, 3012-3017.