How neutral nitrogen-containing compounds are oxidized in oxidative-denitrogenation of liquid fuel with TiO@carbon.

Oxidative-denitrogenation (ODN) of indole (IND) and methyl-substituted INDs (methyl-INDs), representative neutral nitrogen-containing compounds (NCCs), was carried out with TiO@C and HO as heterogeneous catalyst and oxidant, respectively, under ultrasound irradiation. The oxidation of INDs progressed through radical formation, as evidenced by electron spin resonance and radical scavenger experiments. The oxidized position of INDs in the ODN process was checked via characterization of the obtained products.

Optimization of Three State Conical Intersections by Adaptive Penalty Function Algorithm in Connection with the Mixed-Reference Spin-Flip Time-Dependent Density Functional Theory Method (MRSF-TDDFT).

A new adaptive algorithm for penalty function optimization for minimum-energy three-states conical intersections (ME3CI) is suggested. The new algorithm differs from the original penalty function algorithm by (a) removing the redundancy in the target function, (b) using an adaptive increment for the penalty function weighting factor, and (c) using tighter convergence criteria for the energy gap. The latter was introduced to guarantee convergence to a true conical intersection rather than to a narrowly avoided crossing geometry.

Entangled iodine and hydrogen peroxide formation in ice.

Ice-core records show that anthropogenic pollution has increased the global atmospheric concentrations of hydrogen peroxide and iodine since the mid-20th century. Here, for the first time, we demonstrate a highly efficient mechanism that synergistically produces them in icy water conditions. This reaction is aided by a key intermediate IOH, formed by an I ion with a dissolved O in acidic icy water, which produces both I as well as OH radicals.

One-Dimensional Projection of Collective Variables for Effective Sampling of Complex Chemical Reaction Coordinates.

A one-dimensional projection (ODP) technique is introduced to overcome the challenges in multidimensional sampling. With the help of a projected "advancement of reaction (ξ)" control parameter, it was demonstrated that multidimensional samplings could be performed with a single parameter, thus dramatically reducing the computational overhead. In our test studies, the ODP technique successfully yielded the free energy surface of the double proton transfer reaction of the acetic acid dimer and the hydrolysis of the methyl diazonium ion.