A QSPR-approach to the estimation of the pK(HB) of six-membered nitrogen-heterocycles using quantum mechanically derived descriptors.
Descriptors derived from semiempirical (AM1) molecular orbital calculations have been used to construct a quantitative structure-property relationship (QSPR) for the thermodynamic hydrogen-bond basicity, p K(HB), of a series of six-membered aromatic nitrogen-heterocycles. The resulting model uses four-descriptors (the Coulson charge on the nitrogen atom, the energy of the localized nitrogen lone-pair orbital, the p-orbital contribution to this MO and an accessibility angle). The model gives r2(cv)=0.95 for 51 compounds with a standard deviation between calculation and experiment of 0.13 log units.
Computer-Chemie-Centrum der Friedrich-Alexander-Universität Erlangen-Nürnberg, Nägelsbachstrasse 25, 91054 Erlangen, Germany.
Matthias
M
Hennemann
Timothy
T
Clark
D006573:Heterocyclic Compounds, 1-Ring / Q000737:chemistry*; D007700:Kinetics; D008958:Models, Molecular; D015394:Molecular Structure; D009584:Nitrogen; D011789:Quantum Theory
D006573:Heterocyclic Compounds, 1-Ring; D009584:Nitrogen