Cavity-modified molecular dipole switching dynamics.

Polaritonic states, which are formed by resonances between a molecular excitation and the photonic mode of a cavity, have a number of useful properties that offer new routes to control molecular photochemistry using electric fields. To provide a theoretical description of how polaritonic states affect the real-time electron dynamics in molecules, a new method is described where the effects of strong light-molecule coupling are implemented using real-time electronic structure theory. The coupling between the molecular electronic states and the cavity is described by the Pauli-Fierz Hamiltonian, and transitions between polaritonic states are induced via an external time-dependent electric field using time-dependent configuration interaction (TDCI) theory, producing quantum electrodynamics TDCI (QED-TDCI).

Tailoring light-induced charge transfer and intersystem crossing in FeCO using time-dependent spin-orbit configuration interaction.

Real-time (RT) electronic structure methods provide a natural framework for describing light-matter interactions in arbitrary time-dependent electromagnetic fields (EMF). Optically induced excited state transitions are of particular interest, which require tuned EMF to drive population transfer to and from the specific state(s) of interest. Intersystem crossing, or spin-flip, may be driven through shaped EMF or laser pulses.

The water trimer reaction OH + (HO)→ (HO)OH + HO.

All important stationary points on the potential energy surface (PES) for the reaction OH + (HO)→ (HO)OH + HO have been fully optimized using the "gold standard" CCSD(T) method with the large Dunning correlation-consistent cc-pVQZ basis sets. Three types of pathways were found. For the pathway without hydrogen abstraction, the barrier height of the transition state (TS1) is predicted to lie 5.

Energetics and mechanisms for the acetonyl radical + O reaction: An important system for atmospheric and combustion chemistry.

The acetonyl radical (CHCOCH) is relevant to atmospheric and combustion chemistry due to its prevalence in many important reaction mechanisms. One such reaction mechanism is the decomposition of Criegee intermediates in the atmosphere that can produce acetonyl radical and OH. In order to understand the fate of the acetonyl radical in these environments and to create more accurate kinetics models, we have examined the reaction system of the acetonyl radical with O using highly reliable theoretical methods.

Characterization of the 2-methylvinoxy radical + O reaction: A focal point analysis and composite multireference study.

Vinoxy radicals are involved in numerous atmospheric and combustion mechanisms. High-level theoretical methods have recently shed new light on the reaction of the unsubstituted vinoxy radical with O. The reactions of 1-methylvinoxy radical and 2-methylvinoxy radical with molecular oxygen have experimental high pressure limiting rate constants, k, 5-7 times higher than that of the vinoxy plus O reaction.

Prototypical Transition-Metal Carbenes, (CO)Cr═CH, (CO)Fe═CH, (CO)Ni═CH, (CO)Mo═CH, (CO)Ru═CH, (CO)Pd═CH, (CO)W═CH, (CO)Os═CH, and (CO)Pt═CH: Challenge to Experiment.

Transition-metal carbenes are useful in organometallic chemistry due to their demonstrated use as catalysts in carbon-carbon bond-forming reactions. Yet the prototypical transition-metal carbenes, consisting of a single metal center doubly bonded to a methylene ligand and surrounded by carbonyls, have been elusive to experimental synthesis. This theoretical work examines the structures and properties of nine prototypical transition-metal carbenes.

High-level theoretical characterization of the vinoxy radical (CHCHO) + O reaction.

Numerous processes in atmospheric and combustion chemistry produce the vinoxy radical (CHCHO). To understand the fate of this radical and to provide reliable energies needed for kinetic modeling of such processes, we have examined its reaction with O using highly reliable theoretical methods. Utilizing the focal point approach, the energetics of this reaction and subsequent reactions were obtained using coupled-cluster theory with single, double, and perturbative triple excitations [CCSD(T)] extrapolated to the complete basis set limit.