Modeling the molar refraction and the chromatographic retention by using Szeged topological indices as molecular descriptors, is presented.
The newly proposed matrix, CJ u (unsymmetric Cluj matrix) is examplified for cycle-containing structures. Its relation with the matrix SZ u (unsymmetric Szeged matrix) is discussed both as definition and related indices. The derived "Cluj" numbers are compared to the Wiener matrix-and Szeged matrix-derived numbers and tested for discriminating and… (More)
A novel unsymmetric square matrix, W PU , is proposed for calculating both Wiener, W , 1 and hyper-Wiener, WW, 2 numbers. This matrix is constructed by using single endpoint characterization of paths 3. Its relations with Wiener-type numbers are discussed.
The Hosoya polynomial is defined as a distance-based increasing power sequence. Analytical formulas for calculating this polynomial in several classes of toroidal nets are given. The Wiener number, derived from the first derivative of the Hosoya polynomial (in x = 1), is calculable either by close formulas or by recursions.
A new approach, leading to a fragmental property index family, FPIF, is presented. Indices are calculated as local descriptors of some molecular fragments and the global values are then obtained by summing the fragmental contributions. The modeling ability of FPIF is demonstrated by modeling some physico-chemical properties and biological activities on… (More)
The paper presents a unitary approach of the use of a Molecular Descriptors Family in structure-property/activity relationships, particularly in modelling the chromatographic retention times of polychlorinated biphenyls. Starting from molecular structure, viewed as a graph, and considering the bonds and bond types, atom types and often the 3D geometry of… (More)