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The H + CH3OH reaction, which plays an important role in combustion and the interstellar medium, presents a prototypical system with multi channels and tight transition states. However, no globally reliable potential energy surface (PES) has been available to date. Here we develop global analytical PESs for this system using the permutation-invariant polynomial neural network (PIP-NN) and the high-dimensional neural network (HD-NN) methods based on a large number of data points calculated at the level of the explicitly correlated unrestricted coupled cluster single, double, and perturbative triple level with the augmented correlation corrected valence triple-ζ basis set (UCCSD(T)-F12a/AVTZ). We demonstrate that both machine learning PESs are able to accurately describe all dynamically relevant reaction channels. At a collision energy of 20 kcal/mol, quasi-classical trajectory calculations reveal that the dominant channel is the hydrogen abstraction from the methyl site, yielding H2 + CH2OH. The reaction of this major channel takes place mainly via the direct rebound mechanism. Both the vibrational and rotational states of the H2 product are relatively cold, and large portions of the available energy are converted into the product translational motion.

In the preparation of carbon dots (C dots) through pyrolysis, organic molecules with multiple functional groups are popular, and monosubstituted compounds, such as aliphatic amines, are used only a...

The reaction OH + SO → H + SO2 plays an important role in the combustion of sulfur-containing fuels and the environment. Its reaction profile resembles that of OH + CO → H + CO2, which presents a prototypical reaction with the formation of deep complexes. In this work, a new potential energy surface (PES) for the OH + SO → H + SO2 reaction is developed based on ca. 39 200 data points calculated at the level of the explicitly correlated unrestricted coupled cluster method with single, double, and perturbative triple excitations with the augmented correlation-consistent polarized triple zeta basis set (CCSD(T)-F12a/AVTZ). The PES is invariant with respect to the permutation of the two identical oxygen atoms, which is guaranteed by the permutation-invariant polynomials as the input layer of the neural network. Using this PES, the quasiclassical trajectory method is employed to study the collision energy transfer between H and SO2 at the experimental translational energy of 59 kcal mol–1. The predicted large ...

Photoelectron-photofragment coincidence (PPC) spectroscopy was used to characterize the energetics and dynamics of the OH + CH4 → H2O + CH3 reaction initiated by photodetachment of the OH-(CH4) anion complex. PPC measurements at a photon energy of 3.20 eV yielded stable (OH-CH4 + e-) and dissociative (OH + CH4 (ν1 or ν3, v = 0, 1) + e-) channels. The main channel is dissociation to OH + CH4 + e- with a low kinetic energy release (KER), peaking at 0.04 eV. Interpretation of the experimental results was supported by quantum chemistry and quasiclassical trajectory calculations. The anion potential energy surface was constructed at the correlated coupled cluster singles, doubles, and perturbative triples level with augmented correlation consistent polarized valence triple-ζ basis set, and previously calculated neutral potential energy surfaces were used. Quasiclassical simulation of the dynamics of the OH-CH4 complex was carried out by selecting the momenta and coordinates from the Wigner distribution for the anion, providing the starting point for 4000 trajectories on the neutral potential energy surface. In agreement with the experimental results, most of the trajectories yield slowly recoiling OH + CH4 reactants while some are trapped in the entrance channel van der Waals well.

Despite extensive research on transition metal-catalyzed Fujiwara–Moritani type C–H olefinations, the alkenes used in these transformations are still mainly limited to active acrylate esters and styrenes. Selective aryl C–H olefination with electron-rich alkenes is recognized as a challenging issue. We herein report that simple and readily accessible electron-deficient [CpRh(III)] and [CpCF3Rh(III)] (CpCF3 = C5Me4CF3) complexes are powerful catalysts for dehydrogenative arylation of electron-rich alkenes, including vinyl acetates, enamides, and vinyl ethers. Employing an electron-withdrawing Cp or CpCF3 ligand instead of the privileged Cp* (C5Me5) ligand not only can facilitate the electrophilic aryl C–H rhodation but also can lower the olefin insertion barrier. Both electron-withdrawing and electron-donating directing groups such as -CONR2 and -NHAc could be employed in these reactions, which provides convenient routes toward a series styryl acetates, N-acetylindoles, and aryl methyl ketones.