Variable connectivity index as a tool for solving the ‘anti-connectivity’ problem

Abstract A modified variable topological index was constructed to account for the combination of positive and negative contributions of atoms or bonds in structure–property–activity relationships. One such property is the response of the flame ionization detector, which increases with the number of carbon atoms in the molecule while the presence of oxygen atoms suppresses the signal. For a selection of organic compounds a single modified variable topological index, which offers important insight into the role of local structural components, produced a root-mean square error of 0.259 for the effective carbon number compared to 0.425 if no negative contributions are allowed.

[1]  S. Unger.  Molecular Connectivity in Structure–activity Analysis , 1987 .

[2]  Subhash C. Basak,et al.  On characterization of physical properties of amino acids , 2000 .

[3]  D. E. Willis,et al.  Calculation of Flame Ionization Detector Relative Response Factors Using the Effective Carbon Number Concept , 1985 .

[4]  Milan Randic,et al.  Variable Connectivity Index for Cycle-Containing Structures , 2001, J. Chem. Inf. Comput. Sci..

[5]  Milan Randic,et al.  On Use of the Variable Connectivity Index 1f in QSAR: Toxicity of Aliphatic Ethers , 2001, J. Chem. Inf. Comput. Sci..

[6]  M. Randic.  Novel graph theoretical approach to heteroatoms in quantitative structure—activity relationships , 1991 .

[7]  Milan Randic,et al.  Search for useful graph theoretical invariants of molecular structure , 1988, Journal of chemical information and computer sciences.

[8]  A. Balaban.  Highly discriminating distance-based topological index , 1982 .

[9]  A. Balaban,et al.  Topological Indices and Related Descriptors in QSAR and QSPR , 2003 .

[10]  Milan Randic,et al.  The Variable Connectivity Index 1f versus the Traditional Molecular Descriptors: A Comparative Study of 1f Against Descriptors of CODESSA , 2001, J. Chem. Inf. Comput. Sci..

[11]  Andrey A. Toropov,et al.  Improved molecular descriptors to calculate boiling points based on the optimization of correlation weights of local graph invariants , 2001 .

[12]  Yi-Zeng Liang,et al.  Structural Interpretation of a Topological Index. 1. External Factor Variable Connectivity Index (EFVCI) , 2004, J. Chem. Inf. Model..

[13]  Milan Randic,et al.  Construction of High-Quality Structure-Property-Activity Regressions: The Boiling Points of Sulfides , 2000, J. Chem. Inf. Comput. Sci..

[14]  M. Karelson,et al.  Quantum-Chemical Descriptors in QSAR/QSPR Studies. , 1996, Chemical reviews.

[15]  Milan Randić,et al.  High quality structure–property regressions. Boiling points of smaller alkanes , 2000 .

[16]  Ekaterina Gordeeva,et al.  Traditional topological indexes vs electronic, geometrical, and combined molecular descriptors in QSAR/QSPR research , 1993, J. Chem. Inf. Comput. Sci..

[17]  M. Randic,et al.  The connectivity index 25 years after. , 2001, Journal of molecular graphics & modelling.

[18]  Alexandru T Balaban,et al.  Using variable and fixed topological indices for the prediction of reaction rate constants of volatile unsaturated hydrocarbons with OH radicals. , 2004, Molecules.

[19]  Chongli Zhong,et al.  A QSAR study on inhibitory activities of 1-phenylbenzimidazoles against the platelet-derived growth factor receptor. , 2004, Bioorganic & medicinal chemistry.

[20]  Yi-Zeng Liang,et al.  External Factor Variable Connectivity Index , 2003, J. Chem. Inf. Comput. Sci..

[21]  Modeling of the Heat Capacity of Polymers with the Variable Connectivity Index , 2002 .

[22]  Computing the Variable Vertex-connectivity Index* , 2002 .

[23]  M. Randic,et al.  On Characterization of the CC Double Bond in Alkenes , 1999 .

[24]  Jan Cz. Dobrowolski,et al.  Optimal molecular connectivity descriptors for nitrogen-containing molecules , 1998 .

[25]  M. Randic.  On computation of optimal parameters for multivariate analysis of structure‐property relationship , 1991 .

[26]  S. Nikolic,et al.  On Variable Zagreb Indices , 2004 .

[27]  Milan Randic,et al.  The Variable Molecular Descriptors Based on Distance Related Matrices , 2001, J. Chem. Inf. Comput. Sci..

[28]  Nikolai S. Zefirov,et al.  QSAR for Boiling Points of "Small" Sulfides. Are the "High-Quality Structure-Property-Activity Regressions" the Real High Quality QSAR Models? , 2001, J. Chem. Inf. Comput. Sci..

[29]  M. Randic.  Characterization of molecular branching , 1975 .