| Dokumentenart: | Artikel | ||||
|---|---|---|---|---|---|
| Titel eines Journals oder einer Zeitschrift: | Inorganic Chemistry | ||||
| Verlag: | AMER CHEMICAL SOC | ||||
| Ort der Veröffentlichung: | WASHINGTON | ||||
| Band: | 39 | ||||
| Nummer des Zeitschriftenheftes oder des Kapitels: | 4 | ||||
| Seitenbereich: | S. 770-777 | ||||
| Datum: | 2000 | ||||
| Institutionen: | Chemie und Pharmazie > Institut für Physikalische und Theoretische Chemie > Chair of Chemistry III - Physical Chemistry (Molecular Spectroscopy and Photochemistry) > Prof. Dr. Hartmut Yersin | ||||
| Identifikationsnummer: |
| ||||
| Stichwörter / Keywords: | LOCALIZED (3)PI-PI(ASTERISK) STATE; ORGANOMETALLIC DIIMINE COMPLEXES; PHOSPHORESCENT TRIPLET-STATE; LOWEST EXCITED-STATES; TIME-RESOLVED SPECTRA; RADIATIVE PROPERTIES; ELECTRONIC STATES; RHODIUM COMPLEXES; SPECTROSCOPY; FIELD | ||||
| Dewey-Dezimal-Klassifikation: | 500 Naturwissenschaften und Mathematik > 540 Chemie | ||||
| Status: | Veröffentlicht | ||||
| Begutachtet: | Ja, diese Version wurde begutachtet | ||||
| An der Universität Regensburg entstanden: | Ja | ||||
| Dokumenten-ID: | 74417 |
Web of ScienceZusammenfassung
The first spectroscopic investigation of Pd(qol)(2) (qol(-) = 8-quinolinolato-N,O = oxinate) dissolved in an n-octane matrix (Shpol'skii matrix) is reported. Application of several spectroscopic methods at liquid helium temperatures (typically, T = 1.2 K), such as site-selective and highly resolved luminescence and excitation spectroscopy, time-resolved emission spectroscopy, optically detected ...
Zusammenfassung
The first spectroscopic investigation of Pd(qol)(2) (qol(-) = 8-quinolinolato-N,O = oxinate) dissolved in an n-octane matrix (Shpol'skii matrix) is reported. Application of several spectroscopic methods at liquid helium temperatures (typically, T = 1.2 K), such as site-selective and highly resolved luminescence and excitation spectroscopy, time-resolved emission spectroscopy, optically detected magnetic resonance, microwave recovery, phosphorescence microwave double-resonance, and magnetic fields, allows us to characterize the lowest excited electronic states in detail. In accord with previous assignments for the related Pt(qol)(2) it is shown that these lowest states represent intraligand charge-transfer states, namely, (ILCT)-I-1 and (ILCT)-I-3. The electronic origin of the (ILCT)-I-1 state lies at 20 617 cm(-1) (site A). It exhibits a nearly homogeneous line width with a half-width of about 80 cm(-1) (fwhm), which corresponds to a lifetime of tau((ILCT)-I-1) approximate to 2 x 10(-13) s. This value is even shorter than that found for Pt(qol)(2), presumably due to intersystem crossings and relaxations to dd* states. The electronic origin of the (ILCT)-I-3 state lies at 16 090 cm(-1) (site A), and its zero-field splittings (zfs) into three sublevels are 2E = 2356 MHz (0.0785 cm(-1)) and D - E = 5241 MHz (0.175 cm(-1)). The emission decay times of the three sublevels are determined as tau(I) = 90 +/- 30 ms, tau(II) = 180 +/- 10 mu s, and tau(III) = 80 +/- 10 mu s. (Slightly different values are found for a second site B at 16 167 cm(-1).) From the small values of zfs and the long emission decay times it is concluded that metal-d or MLCT admixtures to (ILCT)-I-3 are very small. This result clearly reflects the ligand-centered character of the transition. The assignment as an ILCT transition is supported by the occurrence of relatively strong vibrational satellites of Pd-N and Pd-O character in highly resolved emission spectra. Although the transition is ascribed to a charge-transfer process, the geometry changes between the ground state and (ILCT)-I-3 are very small. The results found for Pd(qol)(2) are compared to those of companion studies of Pt(qot)(2) and Pt(qtl)(2) (qtl- = 8-quinolinethiolato-N,S).
Metadaten zuletzt geändert: 19 Dez 2024 15:59
Altmetric