Abstract

MAZA, Julio R; TORRES, Raúl E  and  DAZA, Edgar E. CONTOUR TREE FUNCTIONS OVER MOLECULAR SCALAR FIELDS REPRESENTATIONS. A MOLECULAR SIMILARITY STUDY. Rev.Colomb.Quim. [online]. 2011, vol.40, n.3, pp.305-320. ISSN 0120-2804.

In this job, Contour Tree Functions were implemented to establish molecular similarity measures. The study was carried by using 73 organic molecules, divided in 8 functional groups and optimized at theory level DFT//B3LYP/6-31G(d,p). The molecular electrostatic potential and the Laplacian of the electron density in a 3D grid for each one were calculated. From the values of these properties, characterizing and encoding the topology, we generated graphs (trees) that are compared with the proposed function. The characterization and classification of the organic molecules with the molecular electrostatic potential show a separation corresponding to molecules that have heteroatoms in their structure with at least similar chemical functions; with the Laplacian of the electron density we achieved a classification according to the number of free pairs of electrons associated to the heteroatoms in the molecules and to the nature provided by the heteroatoms. This is evidence that Contour Tree Functions proposed in this study are a quick alternative to broadly classify organic molecules.

Keywords : Molecular electrostatic potential; Laplacian of the electron density; molecular similarity; graphs; molecular classification; TARIS; tree functions.