Wiener Polarity Research Articles

Distance complexity measures versus the orbit-entropy measure of dendrimers

In this article, we compute several distance-based topological indices dendrimers. Indeed, based on the distances of related graphs, we investigate the distance-based complexity of these graphs. We also, determine an orbit entropy measure of these structures based on the size of orbits. The analysis results obtained by computing the correlations between given numerical data shows that the correlation between Winer complexity with GP-index, Wiener index, and Wiener polarity is quite low. As a result, we have inferred that the Wiener-complexity can be considered as new measures for quantitative structure-activity relationship/quantitative structure-property relationship (QSAR/QSPR) models of dendrimers. Hence, the W-complexity might be interesting for further investigations in predicting the physicochemical properties of molecules.

Prediction of the Normal Boiling Points and Enthalpy of Vaporizations of Alcohols and Phenols Using Topological Indices

Establishing quantitative correlations between various molecular properties and chemical structures is of great technological importance for environmental and medical aspects. These approaches are referred to as Quantitative Structure-Property Relationships (QSPR), which relate the physico-chemical or thermodynamic properties of compounds to their structures. The main goal of QSPR studies is to find a mathematical relationship between the property of interest and a number of molecular descriptors derived from the structure of the molecule. The current study presents the relationship between the Randic′ (1χ), Balaban (J),Wiener polarity (Wp), Hyper Wiener (WW), Szeged (Sz), Harary (H) and Wiener (W) indices to the normal boiling points (Tbp, K) and the standard enthalpies of vaporization (ΔH vap 0 , kJ/mol–1) of 227 alcohols and phenols. The multiple linear regression (MLR) and backward methods were employed to give the QSPR models. After MLR analysis, we studied the validation of linearity between the molecular descriptors in the best models for used properties. The results have shown that three descriptors (W, 1χ, J) could be efficiently used for estimating the normal boiling points, and two descriptors (1χ, J) could be used for modeling and predicting the standard enthalpies of vaporization of considered compounds.

Topological indices of the [formula omitted]-graph

Abstract This paper is devoted to the study of a new graph, called m k -graph and denoted by m k ( G ) , that arises from a simple graph G by k successive iterations of a special kind of construction. We provide some of its topological indices such as Wiener index, Hyper-Wiener index, Wiener polarity, Zagreb indices, Schultz and modified Schultz indices and Wiener-type invariant. Some Formulas concerning classical graphs are settled to show the scope of this study.

QSPR study on benzene derivatives to some physico-chemical properties by using topological indices

QSPR study on benzene derivatives have been made using recently introduced topological methodology. In this study the relationship between the Randic' (x'), Balaban (J), Szeged (Sz),Harary (H), Wiener (W), HyperWiener and Wiener Polarity (WP) to the thermal energy (Eth), heat capacity (CV) and entropy (S) of benzene derivatives is represented. Physicochemical properties are taken from the quantum mechanics methodology with HF level using the ab initio 6-31G basis sets. The multiple linear regressions (MLR) and back ward methods (with significant at the 0.05 level) were employed to give the QSPR models. The satisfactory obtained results show that combining the two descriptors (Sz, HW) are useful topological descriptors for predicted (CV) and (S) of the 45 benzene derivatives. The training set models established by MLR method have not good correlation of (Eth), which means QSPR models could not predict the thermal energy of compounds.

The prediction of thermal pressure coefficients for both normal and branched paraffins from molecular structure

An accurate correlation to predict the thermal pressure coefficients of normal paraffins, including polyethylene, is obtained. Only the number of carbon atoms is needed for the prediction of thermal pressure coefficients at densities from triple point up to critical point. The relationship between the thermal pressure coefficients of branched paraffins and their molecular structures is also discussed based on the graph theory. Two topological indexes, the Wiener index and polarity number, were used to develop a correlation which can predict the thermal pressure coefficients for branched paraffins satisfactorily.