Humbs, Werner and Yersin, Hartmut (1996) Characterization of the lowest excited states of [Rh(bpy-h(8))(n)(bpy-d(8))(3-n)](3+) by highly resolved emission and excitation spectra. INORGANIC CHEMISTRY, 35 (8). pp. 2220-2228. ISSN 0020-1669, 1520-510X
Full text not available from this repository.Abstract
Highly resolved emission, excitation, and resonantly line-narrowed spectra, as well as emission decay properties of [Rh(bpy-h(8))(n)(bpy-d(8))(3-n)](3+) (n = 0, 2, 3; bpy = 2,2'-bipyridine) doped into [Zn(bpy-h(8))(3)](ClO4)(2) are presented for the first time. [Rh(bpy-h(8))(3)](3+) and [Rh(bpy-d(8))(3)](3+) exhibit one low-lying triplet T-1 at 12 757 +/- 1 and 22 818 +/- 1 cm(-1), respectively (blue shift 61 cm(-1)), while [Rh(bpy-h(8))(2)(bpy-d(8))](3+) has two low-lying triplets at 22 757 +/- 1 and 22 818 +/- 1 cm(-1). The well-resolved vibrational satellite structures show, that the equilibrium positions of the triplet and the singlet ground S-0 state are not very different and that the force constants in T-1 are mostly slightly smaller than in S-0. Moreover, the vibrational satellite structure is strongly dominated by vibrational ligand modes, which demonstrates the pi pi* character of the corresponding transition. However, the occurrence of several very weak vibrational modes of metal-ligand character displays a small influence of the metal ion. This is supported by the emission decay behavior. [Rh(bpy-h(8))(2)(bpy-d(8))](3+) exhibits an emission which is clearly assignable to the protonated ligand(s), even when the deuterated ligand is selectively excited. Obviously, an efficient intramolecular energy transfer from the deuterated to the protonated ligand(s) occurs, presumably mediated by the small Rh3+ d-admixture. A so-called ''dual emission'' is not observed. Moreover, a series of spectroscopic properties of the lowest excited state of [Rh(bpy)(3)](3+) (energies of electronic origins. emission decay times, zero-field splittings, structures of vibrational satellites, etc.) is compared to properties of bpy, [Pt(bpy)(2)](2+), [Ru(bpy)(3)](2+), and [Os(bpy)(3)](2+). This comparison displays in a systematic way the increasing importance of the metal d and/or MLCT character for the lowest excited states and thus provides guidelines fur an experimentally based classification. In particular, the lowest excited states of [Rh(bpy)(3)](2+) may be ascribed as being mainly of (3) pi pi* character confined to one ligand in contrast to the situation found for [Ru(bpy)(3)](2+) where these states are covalently delocalized over the whole complex.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | DETECTED MAGNETIC-RESONANCE; TRIPLET-STATE; COORDINATION-COMPOUNDS; METAL-COMPLEXES; PHOSPHORESCENCE; RHODIUM(III); LUMINESCENCE; LOCALIZATION; SPECTROSCOPY; <RU(BPY)3>2+ |
| Subjects: | 500 Science > 540 Chemistry & allied sciences |
| Divisions: | Chemistry and Pharmacy > Institut für Physikalische und Theoretische Chemie > Chair of Chemistry III - Physical Chemistry (Molecular Spectroscopy and Photochemistry) > Prof. Dr. Hartmut Yersin |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 02 Nov 2023 06:45 |
| Last Modified: | 02 Nov 2023 06:45 |
| URI: | https://pred.uni-regensburg.de/id/eprint/51784 |
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