| Autor: |
Ravaglia, Marcella, Garavelli, Marco, Polson, Matthew, Scandola, Franco |
| Předmět: |
|
| Zdroj: |
AIP Conference Proceedings; 12/26/2007, Vol. 963 Issue 2, p659-662, 4p, 1 Chart, 2 Graphs |
| Abstrakt: |
The present investigation has a twofold aim. In the first place, the ground-state spectroscopic features of three IrIII polypyridyl complexes were studied by computational means, in order to elucidate the nature of their UV-visible spectra and electrochemical behaviour. Coincidentally, the limited but variegated set of molecules was employed to analyse how different exchange-correlation functionals model the properties of interest in the presence of transition metal atoms. These iridium complexes involve various terdentate ligands: a N∧N∧N bonded ttpy derivative (ttpy = 4′-tolyl-2:2′,6′:2″-terpyridine), a C∧N∧C bonded dppy derivative (dppy = 2,6-diphenyl-pyridine), a C∧N∧N pbp derivative (pbp = 6-phenyl-2:2′-bipyridine). The axially-symmetric-homoleptic or heteroleptic-arrangement gives the low-lying excited states of these molecules a unique directional nature. Analysis of the electronic transitions calculated by first-principle method based on time-dependent density functional theory (TDDFT) gives insight on their steady-state visible absorption bands. The comparison of generalised-gradient approximation (GGA) functionals (BLYP and G96LYP) with hybrid GGA functionals (B3LYP and PBE0) values the consequences of the nonlocal Hartree–Fock exchange embedded in the latter. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
