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), Vol. 90:5
- Country of Publication:
- United States
- Language:
- English
Similar Records
Transient phenomena in the pulse radiolysis of retinyl polyenes. l. Radical anions
Transient phenomena in the pulse radiolysis of retinyl polyenes. 3. Radical cations
Related Subjects
DIMERS
ACTIVATION ENERGY
CHEMICAL REACTION KINETICS
FREE ENTHALPY
OXYGEN
SOLVENT PROPERTIES
POLYENES
RADIOLYSIS
REACTION INTERMEDIATES
RETINOIC ACID
ABSORPTION SPECTROSCOPY
ACETONE
ELECTRON BEAMS
EXPERIMENTAL DATA
MONOMERS
PULSE TECHNIQUES
TRANSIENTS
VISIBLE SPECTRA
BEAMS
CARBOXYLIC ACID ESTERS
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
DATA
DECOMPOSITION
ELEMENTS
ENERGY
ESTERS
HYDROCARBONS
INFORMATION
KETONES
KINETICS
LEPTON BEAMS
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
PARTICLE BEAMS
PHYSICAL PROPERTIES
RADIATION CHEMISTRY
RADIATION EFFECTS
REACTION KINETICS
SPECTRA
SPECTROSCOPY
THERMODYNAMIC PROPERTIES
400600* - Radiation Chemistry