THERMOLUMINESCENCE AND ELECTRON PARAMAGNETIC RESONANCE OF AMINO ACIDS. POLYPEPTIDES AND PROTEINS IRRADIATED WITH ULTRAVIOLET LIGHT
Abstract
The research reported in this thesis has shown that certain amino acids, other closely related molecules, amino acid polymers and proteins develop metastable excited states with very long lifetimes (hours) when irradiated with ultraviolet light at 77 K. Transitions from these states to states of lower energy result in the emission of light. This light, in the form of thermoluminescence, has been observed upon heating the compounds following ultraviolet irradiation. The wavelength of excftlng light is in the range 2400 < or = lambda < or = 3900 A. The maximum of the observed thermoluminescence is in the region from 4000 to 4500 A. Experimental results are consistent with the hypothesis that the metastable excited state is molecular rather than crystalline in nature. (1) Thermoluminescence has been detected from compounds in aqueous solution and after freeze drying. (2) The luminescence intensfy can be described in terms of monomolecular kinetics. (3) The wavelength of the absorbing light is in the region of an absorption band of the molecules involved. The metastable state involved is believed to arise in a charge trapping complex of the molecule and a metallic ion. A new expression for thermoluminescence intensity from polymers, based on a Markov process charge migration model, has been derived.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1962
- Accession Number
- AD0294395
Entities
People
- J. Gill
- M. Weissbluth
Organizations
- Stanford University