Molecular connectivity: intermolecular accessibility and encounter simulation

The simple molecular connectivity indices are interpreted as summations of bond accessibilities to bimolecular encounters with another, identical molecule. To transcend this model, a molecule is treated as disjecta membra with each bond modeled as a discrete cell in a dynamic simulation of many molecules. Each bond accessibility is transformed into a cellular automata rule. The dynamics are run for each of 38 alkanes, recording the average number of cell encounters, beta. The beta values show a high correlation with the boiling points. The significance of the bond accessibilities and the concept of intermolecular encounters explaining the molecular connectivity indices is supported by these findings. (C) 2001 Elsevier Science Inc. All rights reserved.