Electronic eigenvalue (EEVA): a new QSAR/QSPR descriptor for electronic substituent effects based on molecular orbital energies. A QSAR approach to the Ah receptor binding affinity of polychlorinated biphenyls (PCBs), dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs)

A new descriptor of molecular structure for use in the derivation of predic tive QSAR and QSPR models, electronic eigenvalue (EEVA), is described. This is a modification of the recently proposed EVA approach, but is based on c omputationally-derived molecular orbital energies instead of vibrational fr equencies. Like EVA, it is also invariant as to the alignment of the struct ures concerned. Its performance has been tested with respect to the Ah rece ptor binding of PCBs, PCDDs and PCDFs, and its predictive ability has been clearly demonstrated. In particular, it seems to be suitable for 'pure' ele ctronic substituent effects, i.e., for cases in which both hydrophobic and steric factors are of minor importance. (C) 2000 Elsevier Science Ltd. All rights reserved.