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Full Paper
Electronic and Optical Properties of Ladder-Type Heteraborins
Article first published online: 5 JUL 2007
DOI: 10.1002/chem.200700622
Copyright © 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Additional Information
How to Cite
Agou, T., Kobayashi, J. and Kawashima, T. (2007), Electronic and Optical Properties of Ladder-Type Heteraborins. Chemistry - A European Journal, 13: 8051–8060. doi: 10.1002/chem.200700622
Publication History
- Issue published online: 19 SEP 2007
- Article first published online: 5 JUL 2007
- Manuscript Received: 24 APR 2007
Funded by
- 21st Century COE Program
- Scientific Research
- Ministry of Education, Culture, Sports, Science and Technology of Japan
- Japan Society for the Promotion of Science for Young Scientists
Keywords:
- conjugation;
- heterocycles;
- optical properties;
- pi interactions;
- X-ray crystallography
Graphical Abstract
Ladder-type heteraborins: Ladder-type π-conjugated molecules (see graphic) based on heteraborins were synthesized, and their optical and electronic properties were studied both experimentally and theoretically.
Abstract
Ladder-type π-conjugated molecules bearing heteraborin (azaborine or thiaborin) units were synthesized, and X-ray crystallographic analysis of pentacene-type molecules showed that these molecules have rigid and planar structures. UV-visible spectroscopy and theoretical calculations revealed the enhancement of electronic interaction between heteraborin units, the decrease in HOMO–LUMO energy gaps, and the strong effect of the bridging main-group elements (nitrogen or sulfur) on the electronic states. The ladder-type molecules emitted strong fluorescence both in solution and in the solid state, and the emission-band shapes were different from each other, indicating the existence of intermolecular interactions in the solid state. Complex formation of the ladder molecules with fluoride ion was monitored by UV-visible spectroscopy, which revealed that the Lewis acidity of these molecules can be controlled by the elongation of π systems and the change of the bridging main-group elements.