Solvent and temperature effects on the tautomerization of a carbonitrile molecule: A conductor-like polarizable continuum model (CPCM) study

This research examined the effects of solvent polarity and temperature on the tautomerization of a carbonitrile molecule at CAM-B3LYP/6-311G (d,p) level of theory. The selected solvents were n-hexane, diethyl ether, pyridine, ethanol, methanol, and water. The solvent effects were examined by the self-consistent reaction field theory (SCRF) based on conductor-like polarizable continuum model (CPCM). The solvent effects were explored on the energy barrier, frontier orbitals energies, and HOMO-LUMO gap. Dependencies of thermodynamic parameters (ΔG and ΔH) on the dielectric constants of solvents were also tested. Specifically, the temperature dependencies of the thermodynamics parameters were studied within 100–1000 K range. The rate constant of the tautomerism reaction was computed from 300 to 1200 K, in the gas phase.

Evolution of the interaction between C20cage and Cr(CO)5: A solvent effect, QTAIM and EDA investigation

This study used mpw1pw91 quantum chemical calculations in gas and solution phases to clarify the interaction between C20and Cr(CO)5fragment. It also sought to clarify the effects of solvent polarity on dipole moment, structural parameters, and frontier orbital energies of the complex. Energy decomposition analysis (EDA) was applied to analyze the bonding interaction between the C20and Cr(CO)5fragment. Percentage composition in terms of the defined groups of frontier orbitals for the complex was evaluated to characterize the metal–ligand bonds. The Cr–C bonds within the complex were examined using quantum theory of atoms in molecules (QTAIM) analysis. In order to determine the back-bonding effects in these bonds, QTAIM analysis was applied to calculate of the quadrupole polarization of the carbon atom.