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AT Balaban

Publications and source records attributed to AT Balaban.

3 recordsLinked to original sources

Evaluation in quantitative structure--property relationship models of structural descriptors derived from information-theory operators

During the search for new structural descriptors we have defined the information-theory operators U(M), V(M), X(M), and Y(M), that are computed from atomic invariants and measure the information content of the elements of molecular matrices. Structural descriptors computed with these four information-theory operators are used to develop structure-property models for the boiling temperature, molar heat capacity, standard Gibbs energy of formation, vaporization enthalpy, refractive index, and density of alkanes. The information-theory operators were applied to six molecular matrices, namely, the distance D, the reciprocal distance RD, the distance-path Dp, the reciprocal distance-path RDp, the path Szeged Sz(p), and the reciprocal path Szeged RSz(p) matrices. In combination with other topological indices, the information-theory indices offer good structure-property models for all six alkane properties investigated in this study.

Journal Article↗

Topological indices: their nature and mutual relatedness

We calculated 202 molecular descriptors (topological indices, TIs) for two chemical databases (a set of 139 hydrocarbons and another set of 1037 diverse chemicals). Variable cluster analysis of these TIs grouped these structures into 14 clusters for the first set and 18 clusters for the second set. Correspondences between the same TIs in the two sets reveal how and why the various classes of TIs are mutually related and provide insight into what aspects of chemical structure they are expressing.

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Comparison of weighting schemes for molecular graph descriptors: application in quantitative structure-retention relationship models for alkylphenols in gas-liquid chromatography

Organic compounds containing heteroatoms or multiple bonds can be conveniently represented as vertex- and edge-weighted molecular graphs. These atom and bond parameters can be computed for any organic compound with two parameter sets that we have recently defined, namely, the relative electronegativity X and the relative covalent radius Y weighting schemes. Structural descriptors computed with these two weighting schemes and the previously defined atomic number Z parameter set are used to develop quantitative structure-retention relationship (QSRR) models for alkylphenols in gas-liquid chromatography. The QSRR models are generated with structural descriptors computed with several newly introduced graph operators, namely, the Wiener, hyper-Wiener, minimum eigenvalue, maximum eigenvalue, Ivanciuc-Balaban, and information on distance operators. These molecular graph operators were applied to the distance D and the reciprocal distance RD matrixes.

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