Singlet fission is a photophysical process that has promise for increasing the efficiency of solar cells. The dynamics depend on triplet spin states and can be influenced by external magnetic fields. In 4-electron systems, fission takes an initial singlet state into a superposition of triplet pair states. Direct evidence for this superposition state is provided by quantum beats in the delayed f...

Kinetic pathways of triplet energy transfer from photoexcited PbS QDs to surface-anchored tetracene and pentacene derivatives are dictated by charge-transfer energetics at the QD/molecule interface.

An analytical theory of the optical transitions of a molecule bound at the surface of a He droplet is developed for the case of a strong softening of the excited-state nearest neighbor dynamics. The optical bandwidth is found to be determined by the zero-point kinetic energy released at the transition. The theory is applied to the triplet-triplet optical transition in Na2 molecule, for which an...

The radical yield in the electron t ransfer reactions between thionine tr iplet and various halogenanilines, as measured by kinetic flash spectroscopy in the microsecond time region, decreases by application of magnetic fields up to 4 kGauss . The relative magnetic field effect parallels the influence of the heavy atom substi tuents on the intersystem crossing ra te constant in the triplet exci...

The radical yield in the electron transfer reactions ?etween ~hionine trip.let and. various halo· genanilines as measured by kinetic flash spectroscopy m the mIcrosecond tIme regIon, decreases by applica;ion of magnetic fields up to 4 kGauss: The relative m~gnetic field effect. parallels. the influence of the heavy atom substituents on the mtersystem crossmg rate. constant m the. trIplet excipl...

Although flash and laser techniques have been widely applied to the spectroscopical investigation of small molecules, it appears that up to now, they have not been extensively used to study the primary photo— degradation processes in polymeric materials. The study of polyvinylphe— nylketone shows that laser flash spectroscopy permits the identification of a particular kinetic decay of a quenche...

The experimental ultrafast photophysics of thioxanthone in several aprotic organic solvents at room temperature is presented, measured using femtosecond transient absorption together with high-level ab initio CASPT2 calculations of the singlet- and triplet-state manifolds in the gas phase, including computed state minima and conical intersections, transition energies, oscillator strengths, and ...