Intermolecular potential energy surface and second virial coefficients for the nonrigid water-CO dimer

Noncovalently bound molecular complexes beyond diatom–diatom systems: full-dimensional, fully coupled quantum calculations of rovibrational states

The methodological advances made in recent years have significantly extended the range and dimensionality of noncovalently bound molecular complexes for which full-dimensional quantum calculations of their rovibrational states are feasible.

Explicitly correlated ab initio potential energy surface and predicted rovibrational spectra for H2O-N2 and D2O-N2 complexes

An ab initio intermolecular potential energy surface (PES) for the van der Waals complex of H₂O-N₂ that explicitly incorporates the intramolecular Q₂ bending normal mode of the H₂O monomer is presented. The electronic structure computations have been carried out at the explicitly correlated coupled cluster theory [CCSD(T)-F12] with an augmented correlation-consistent triple zeta basis set and an additional bond function. Analytic five-dimensional intermolecular PESs for ν₂(H₂O) = 0 and 1 are obtained by fitting to the multi-dimensional Morse/long-range potential function form. These fits to 40 890 points have the root-mean-square (rms) discrepancy of 0.88 cm^-1 for interaction energies less than 2000.0 cm^-1. The resulting vibrationally averaged PESs provide good representations of the experimental microwave and infrared data: for microwave transitions of H₂O-N₂, the rms discrepancy is only 0.0003 cm^-1, and for infrared transitions of the A₁ symmetry of the H₂O(ν₂ = 1 ← 0)-N₂, the rms discrepancy is 0.001 cm^-1. The calculated infrared band origin shifts associated with the ν₂ bending vibration of water are 2.210 cm^-1 and 1.323 cm^-1 for H₂O-N₂ and D₂O-N₂, respectively, in good agreement with the experimental values of 2.254 cm^-1 and 1.266 cm^-1. The benchmark tests and comparisons of the predicted spectral properties are carried out between CCSD(T)-F12a and CCSD(T)-F12b approaches.

An accurate full-dimensional permutationally invariant potential energy surface for the interaction between H2O and CO

The first full-dimensional accurate potential energy surface was developed for the CO + H₂O system based onca.102 000 points calculated at the CCSD(T)-F12a/AVTZ level using a permutation invariant polynomial-neural network (PIP-NN) method.

The water–carbon monoxide dimer: new infrared spectra, ab initio rovibrational energy level calculations, and an interesting in-termolecular mode

Bound state rovibrational energy level calculations using a high-level intermolecular potential surface are reported for H₂O–CO and D₂O–CO.

Micro-solvation of CO in water: infrared spectra and structural calculations for (D2O)2–CO and (D2O)3–CO

The weakly-bound molecular clusters (D₂O)₂–CO and (D₂O)₃–CO are observed in the C–O stretch fundamental region (≈2150 cm⁻¹), and their rotationally-resolved infrared spectra yield precise rotational parameters.

Interaction of H2O with CO: potential energy surface, bound states and scattering calculations

We present the first scattering calculations for the H₂O–CO system based on a high accuracy potential energy surface.

VUV photochemistry of the H2O⋯CO complex in noble-gas matrices: formation of the OH⋯CO complex and the HOCO radical

VUV photolysis of the H₂O⋯CO complexes leads to the formation of the OH⋯CO radical–molecule complexes and trans-HOCO radicals.

Topological insights into the 1/1 diacetyl/water complex gained using a new methodological approach

The 1/1 diacetyl/water complex is of atmospheric relevance. Previous experimental and theoretical studies have focused on two isomeric forms, and geometry optimizations were carried out on them. Herein, we propose a six-step methodological approach based on topological properties to search for and characterize all of the isomeric forms of the 1/1 noncovalent diacetyl/water complex: (1) a molecular electrostatic potential (MESP) study to get an overview of the V min and V max regions on the molecular surfaces of the separate molecules (diacetyl and water); (2) a topological (QTAIM and ELF) study allowing thorough characterization of the electron densities (QTAIM) and irreducible ELF basins of the separate molecules; (3) full optimization of the predicted structures based on the interaction between complementary reaction sites; (4) energetic characterization based on a symmetry-adapted perturbation theory (SAPT) analysis; (5) topological characterization of the optimized complexes; (6) analysis of the complexes in terms of orbital overlaps (natural bond orbitals, NBO analysis). Using this approach, in addition to achieving the topological characterization of the two isomeric forms already reported, a third possible isomer was identified and characterized. Graphical Abstract Topological tools to study monohydrated complexes.

Transition-metal-free, ambient-pressure carbonylative cross-coupling reactions of aryl halides with potassium aryltrifluoroborates

A transition-metal-free, ambient-pressure, and general methodology for carbonylative Suzuki coupling has been developed.

From strong van der Waals complexes to hydrogen bonding: From CO⋯H2O to CS⋯H2O and SiO⋯H2O complexes

Structures and interaction energies of complexes valence isoelectronic to the important CO⋯H(2)O complex, namely SiO⋯H(2)O and CS⋯H(2)O, have been studied for the first time using high-level ab initio methods. Although CO, SiO, and CS are valence isoelectronic, the structures of their complexes with water differ significantly, owing partially to their widely varied dipole moments. The predicted dissociation energies D(0) are 1.8 (CO⋯H(2)O), 2.7 (CS⋯H(2)O), and 4.9 (SiO⋯H(2)O) kcal∕mol. The implications of these results have been examined in light of the dipole moments of the separate moieties and current concepts of hydrogen bonding. It is hoped that the present results will spark additional interest in these complexes and in the general non-covalent paradigms they represent.