Bulletin of the Chemical Society of Japan · 1988 · 26 citations · 16 references
Natural SciencesChemistryPhysical ChemistryStructure-activity RelationshipsThermodynamicsAb Initio MethodsMolecular StructureMolecular SymmetryMolecular ThermodynamicsSize-dependent PropertiesStructure-property RelationshipsChemical Structure-activity RelationshipsCorrelationThermodynamic AnalysisTopological DescriptorsTopological Indices
Abstract Correlation coefficients between twelve thermodynamic properties (ΔS, ΔHf, ΔGf, bp, d, nD, Rm, Vm, pc, Tc, Vc, dc) of 624 isomers of nonane through dodecane and five different topological indices (Z, p3, w, p2, A3) were calculated, where the new index A3 is proposed to be defined as the half sum of the off-diagonal elements of the cube of the adjacency matrix A. These properties can be classified into several types, according to the behavior of the two correlation coefficients, ρ(Z) and ρ(p3), against the change of the size of molecules. ΔS and bp depend largely on Z, while d and nD on p3, irrespective of the size change of molecules. On the other hand, ΔHf of smaller alkanes is largely dependent on Z, but for larger alkanes it turns out to be a p3-dependent property. Various interesting behaviors of the structure-activity relationships including the “pentane effect” were observed and discussed.
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