Picosecond excited-state solvation dynamics of 9,9'-bianthryl in alcohol solutions
Picosecond time-resolved emission spectroscopy has been used to measure the rate of charge transfer and solvation of 9,9'-bianthryl in several solvents and solvent mixtures. In nonpolar and aprotic polar solvents no rise times were detected, indicating that all charge transfer and solvation occur within the 10-ps experimental resolution. In linear alcohols, complex biexponential fluorescence rise times are seen. These are interpreted in terms of an initial charge transfer (approx. 30-60 ps) forming a weakly solvated charge-transfer state which subsequently (approx. 50-500 ps, increasing with solvent viscosity) reacts with the solvent to form a hydrogen-bonded exciplex. Evidence or hydrogen bonding comes from deuterium exchange measurements; excited-state proton transfer can occur at the 10 and 10' positions. Solvation times in alcohol-alkane mixtures are slower than in comparable alcohols. This is interpreted as being due to the locally low alcohol concentrations associated with solvation of the nonpolar BA ground state. The role of dielectrical relaxation in these systems is also discussed.
- Research Organization:
- Lawrence Berkeley Lab., CA
- OSTI ID:
- 6137713
- Journal Information:
- J. Phys. Chem.; (United States), Vol. 91:13
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ALCOHOLS
SOLVENT PROPERTIES
ALKANES
AROMATICS
ELECTRON TRANSFER
EXCITED STATES
SOLVATION
DEUTERIUM
ISOTOPE EFFECTS
DEUTERIUM COMPOUNDS
CHEMICAL BONDS
CHEMICAL REACTION KINETICS
EXPERIMENTAL DATA
HYDROGEN
MIXTURES
SOLVENTS
VISCOSITY
DATA
DISPERSIONS
ELEMENTS
ENERGY LEVELS
HYDROCARBONS
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
HYDROXY COMPOUNDS
INFORMATION
ISOTOPES
KINETICS
LIGHT NUCLEI
NONMETALS
NUCLEI
NUMERICAL DATA
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
REACTION KINETICS
STABLE ISOTOPES
400201* - Chemical & Physicochemical Properties