Journal of the Chilean Chemical Society
On-line version ISSN 0717-9707
NIE, CHANGMING; WU, YAXIN; WU, RONGYAN and WEN, SONGNIAN. AN IMPROVED TOPOLOGICAL DESCRIPTOR EDm AND ITS APPLICATION. J. Chil. Chem. Soc. [online]. 2012, vol.57, n.1, pp. 955-963. ISSN 0717-9707. http://dx.doi.org/10.4067/S0717-97072012000100001.
In this paper, on the basis of the topological index EDm derived from ionicity index matrix, improved distance matrix and branching degree matrix, we proposed the new topological descriptor EDm' by introducing the bond angle into hidden hydrogen graph of molecules and using the geometric distance instead of the sum of bond length between two vertexes. The EDm describes the molecular structure more accurately, and realizes unique characterization to cis-trans isomers. The quantitative structure-property relationship (QSPR) models, with correlation coefficients (R) in the range of 0.984-1.000 for the boiling point (b.p.), the standard enthalpy of formation ( DfHmθ), the molar refraction (Rm) and the molar volume (Vm) of some cis-trans isomers for alkenes, are subsequently developed by index EDm'. Moreover, the good stability and predictive ability of the models were demonstrated by LOO (leave-one-out) method and RSP (random sampling prediction) method, which further manifests the index EDm has high potential of wide applications in QSPR study.
Keywords : cis/trans isomers; ionicity index matrix; improved distance matrix; branching degree matrix.