Semiempirical quantum chemical methods: testing of thermodynamic and molecular properties of cyclic non-aromatic hydrocarbons and unsaturated heterocycles

摘要

Using the semiempirical all-valence MNDO, AM1 and PM3 methods, standard values of entropy, heats and Gibbs energies of formation, first ionization potentials and dipole moments of the molecules have been calculated for two series of compounds: 90 monocyclic and condensed bi-, tri- and polycyclic non-aromatic hydrocarbons and spirocyclic ones, 148 three-, five-, six- and seven-membered nitrogen-, oxygen-, sulphur-, selenium- and boron-containing unsaturated heterocycles. Linear dependences P_(exper) = bP_(theor) (where P is any of the mentioned properties) have been stated. Deviations from the above correlations have been noted. Similar data for the combined sequence containing substances of the above series, as well as for 64 acyclic and aromatic compounds with various functional groups, have been analyzed.