Transient phenomena in the pulse radiolysis of retinyl polyenes. 5. Association of radical cations with parent molecules
At relatively high concentrations (1-10 mM) in O/sub 2/-saturated acetone, pulse radiolysis of all-trans-retinal, -retinoic acid, and -methyl retinoate gives rise to fast transient absorption processes that are best explained in terms of association of radical cations with parent polyenes to form dimers. From the concentration dependence of initial decay/formation kinetics, equilibrium constants (K) for monomer/dimer interconversion are measured to be 220-440 M/sup -1/ (in acetone). On going from acetone to 1,2-dichloroethane, K values for retinal and retinoic acid increase almost by an order of magnitude. For all trans-retinol and retinyl acetate, radical cation dimer formation appears to be negligible in the concentration range 1-10 mM of the polyene substrates (based on the lack of transient absorption changes seen with retinal and retinoic acid/ester). 24 references, 6 figures, 1 table.
- Research Organization:
- Univ. of Notre Dame, IN
- OSTI ID:
- 5889649
- Journal Information:
- J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 90:5; ISSN JPCHA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400600* -- Radiation Chemistry
ABSORPTION SPECTROSCOPY
ACETONE
ACTIVATION ENERGY
BEAMS
CARBOXYLIC ACID ESTERS
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMISTRY
DATA
DECOMPOSITION
DIMERS
ELECTRON BEAMS
ELEMENTS
ENERGY
ESTERS
EXPERIMENTAL DATA
FREE ENTHALPY
HYDROCARBONS
INFORMATION
KETONES
KINETICS
LEPTON BEAMS
MONOMERS
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
OXYGEN
PARTICLE BEAMS
PHYSICAL PROPERTIES
POLYENES
PULSE TECHNIQUES
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIOLYSIS
REACTION INTERMEDIATES
REACTION KINETICS
RETINOIC ACID
SOLVENT PROPERTIES
SPECTRA
SPECTROSCOPY
THERMODYNAMIC PROPERTIES
TRANSIENTS
VISIBLE SPECTRA