Azulenic Chromophores For Optical Limiting and Other Nonlinear Optical Applications
Abstract
We summarize our studies of the chemical, photophysical, optical limiting, and other nonlinear optical properties of long wavelength-absorbing azulene derivatives; namely, fluorinated azulenes, azulenic donor-acceptor molecules, and reverse saturable aborber azulenic symmetrical dye chromophores. The effect of fluorine and other substituents on the excited singlet state properties of azulene and, in particular, the enhancement of first excited state lifetimes and fluorescence quantum yields was investigated. Both Hyper-Raleigh Scattering and Resonance Raman measurements of azulenic donor-acceptor chromophores revealed the involvement of more than one excited state in the lowest energy electronic transitions contrary to accepted models. An ultrafast transient absorption spectroscopic study of a series of guaiazulenic polymethine dyes indicated the presence of several discrete short-lived excited singlet state species that absorb over the entire visible region. A ring-locked azulenic dye dimer formed at low temperature and was studied by variable temperature NMR. Optical quality polymer films of azulenic dyes were prepared by doping and, in one case, by a novel chemical transformation of the polymer host. Unexpected thermochromic behavior was observed for a trimethine dye. A novel series of cross-conjugated azulene derivatives, potentially useful as two-photon absorbers, was also prepared.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 22, 2003
- Accession Number
- ADA414484
Entities
People
- Alfred E. Asato
- Robert S. Liu
Organizations
- University of Hawaiʻi System