Thermochromism of intramolecular charge transfer emission bands. Probing the temperature dependence of Franck—Condon factors
✍ Scribed by Ronald J. Tepper; Matthew B. Zimmt
- Publisher
- Elsevier Science
- Year
- 1995
- Tongue
- English
- Weight
- 468 KB
- Volume
- 241
- Category
- Article
- ISSN
- 0009-2614
No coin nor oath required. For personal study only.
✦ Synopsis
The temperature dependence of the charge transfer emission band, Franck-Condon maximum has been determined for two donor-spacer-acceptor molecules in six solvents with dielectric constants between 4 and 10. The CT band maximum shifted to higher energies (27 cm-1 K-1 in Et20, 14 cm-1 K-1 in C1CH2CH2CI) with increasing temperature. Analysis of the thermochromism solvent dependence using a continuum model yielded values of the geometric factor, e2(1/rA + 1/r D --2/R¢¢), of 22.9 and 28.5 kK for DSAs 1 and 2. Solvent-independent thermochromism of = 8 cm-1 K-1 was found in both DSA molecules. Possible sources of this thermochromism are discussed.