Breu, Josef and Stossel, P. and Schrader, S. and Starukhin, A. and Finkenzeller, Walter J. and Yersin, Hartmut (2005) Crystal structure of fac-Ir(ppy)(3) and emission properties under ambient conditions and at high pressure. CHEMISTRY OF MATERIALS, 17 (7). pp. 1745-1752. ISSN 0897-4756, 1520-5002
Full text not available from this repository. (Request a copy)Abstract
Solution and refinement of the crystal structure of fac-Ir(ppy)(3) is severely hampered by systematic twinning and pseudo-symmetry.fac-Ir(ppy)(3) Crystallizes in the centrosymmetric space group P (3) over bar as has been deduced from single-crystal structure refinement and investigations of the second harmonic generation (SHG) of fac-Ir(ppy)(3) powder as compared to two standard materials. The topology of the molecular packing of fac-Ir(ppy)(3) is identical to the packing observed for [Ru(bpy)(3)](0), however, the site symmetry of all Ir(ppy)(3) molecules is necessarily lowered from D-3 to C-3. Packing motifs with intermolecular "pi-pi interactions" of T-shaped and "shifted pi stack" geometry are realized. The systematic twinning leads to the occurrence of crystalline domains with rigorously alternating chirality within the bulk of the domains but with homochiral fac-Ir(ppy)(3) contacts at the domain interfaces. These differences in packing motifs are displayed in the emission spectra and in the high-pressure-induced shifts of the emission. The emission maximum of the bulk material at 18 350 cm(-1) (545 nm) and of the domain interfaces at 19 700 cm-1 (507 nm) experience for p < 25 kbar and T = 295 K red shifts of Delta nu/Delta p = -(12 +/- 2) cm(-1)/kbar, and -(22 +/- 4) cm(-1)/kbar, respectively.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | AROMATIC INTERACTIONS; BENZENE DIMER; SPECTROSCOPIC PROPERTIES; TEMPERATURE-DEPENDENCE; CYCLOMETALATED RH3+; MOLECULAR-CRYSTALS; IRIDIUM COMPLEXES; ELECTRONIC STATES; PT(II) COMPOUNDS; CHARGE-TRANSFER; |
| 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: | 17 May 2021 06:56 |
| Last Modified: | 17 May 2021 06:56 |
| URI: | https://pred.uni-regensburg.de/id/eprint/36267 |
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