| Autor: |
Olga V. Przhonska, Yuriy L. Slominsky, Honghua Hu, Julia L. Bricks, Alexander A. Viniychuk, Scott Webster, A.D. Kachkovski |
| Rok vydání: |
2013 |
| Předmět: |
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| Zdroj: |
Chemical Physics. 411:17-25 |
| ISSN: |
0301-0104 |
| DOI: |
10.1016/j.chemphys.2012.11.017 |
| Popis: |
A comprehensive quantum chemical analysis along with spectral-luminescence measurements has been performed for a new series of 2-azaazulene dyes with different conjugation lengths (n) to better understand the nature of their electronic transitions. The remarkably large red shift of their main absorption bands at relatively small n is connected with the existence of totally delocalized HOMO and LUMO. Symmetry breaking is observed experimentally at n = 3 in polar solvents and theoretically at n = 5 in vacuum. Analysis shows the existence of two types of molecular orbitals (MOs): local with the charge mainly localized within the terminal groups, and delocalized with the charge distributed throughout the molecule. Correspondingly, three types of electronic transitions are present: between delocalized MOs; between one local and one delocalized MO, and between local MOs only, which is important for predicting the positions of electronic transitions to the chain length. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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Full Text from ScienceDirect