A Triplet Mechanism for Magnetic Field Modulation of Photochemical Quantum Yields
نویسنده
چکیده
A mechanism is described whereby the influence of an external magnetic field on the sublevels of a triplet exciplex, subject to heavy-atom-induced sublevel-selective deactivation, modulates the radical dissociation yield of the exciplex. A sublevel selection rule for the heavy atom effect on T, So intersystem crossing in the triplex exciplex is derived. The magnetic field influence is treated on the basis of an approximate solution of a stochastic Liouville equation, leading to a simple analytic expression for the magnetic field effect on the radical yield. The result is applied to explain a previously observed magnetic field effect. The mechanism described may induce magnetic field effects on any triplet reaction competing with sublevel-selective deactivation.
منابع مشابه
Energy states and exchange energy of coupled double quantum dot in a magnetic field
The ground state energies of two interacting electrons confined in a coupled double quantum dot (DQD) presented in a magnetic field has been calculated by solving the relative Hamiltonian using variational and exact diagonalization methods. The singlet-triplet transitions in the angular momentum and spin of the quantum dot ground state had been shown .We have studied the magnetic field versus c...
متن کاملEnergy states and exchange energy of coupled double quantum dot in a magnetic field
The ground state energies of two interacting electrons confined in a coupled double quantum dot (DQD) presented in a magnetic field has been calculated by solving the relative Hamiltonian using variational and exact diagonalization methods. The singlet-triplet transitions in the angular momentum and spin of the quantum dot ground state had been shown .We have studied the magnetic field versus c...
متن کاملSynthesis, photophysical and photochemical properties of tetra- and octa-substituted gallium and indium phthalocyanines
The synthesis, photophysical and photochemical properties of the tetraand octa-[4-(benzyloxyphenoxy)] substituted gallium(III) and indium(III) phthalocyanines are reported for the first time. The new compounds have been characterized by elemental analysis, IR, H NMR spectroscopy and electronic spectroscopy. General trends are described for quantum yields of photodegredation, fluorescence quantu...
متن کاملPhotophysical and Photochemical Properties of 2,3-Dihydro-4(l H)- quinolinones. Part II. Rates and Mechanism of Primary Processes
Fluorescence quantum yields, singlet lifetimes and triplet yields for 2-methyl-2,3-dihydro4(1 H)-quinolinone and N-methyl-2,3-dihydro-4(l H)-quinolinone were determined as a func tion o f temperature. In non-polar solvents, an efficient non-radiative process identified as an indirect singlet —*• triplet transition occurring through S2(n,jr*) was found to depopulate the lowest S 1(7t,7E*) state...
متن کاملPhotochemical synthesis and photophysical features of ethynylphenanthrenes studied by emission and transient absorption measurements.
Phenanthrenes substituted with trimethylsilylethynyl and phenylethynyl groups were photochemically prepared, and their photophysical properties were systematically investigated based on measurements of fluorescence quantum yields, lifetimes, and transient absorption. Introducing ethynyl groups into the phenanthrene skeleton caused an increase in the fluorescence quantum yields compared to that ...
متن کامل