In this paper,based on distance matrix and adjacent matrix,a new topological index has been developed to be used in research on physical and chemical properties of alkanes.It is concluded that the index bears good str...In this paper,based on distance matrix and adjacent matrix,a new topological index has been developed to be used in research on physical and chemical properties of alkanes.It is concluded that the index bears good structural selectivity and relativity.展开更多
Polychlorinated diphenyl ethers(PCDEs) are listed as the so-called persistent pollutants.Atomic characteristic values of all 209 possible molecular structure patterns of PCDEs were calculated,then a new connectivity i...Polychlorinated diphenyl ethers(PCDEs) are listed as the so-called persistent pollutants.Atomic characteristic values of all 209 possible molecular structure patterns of PCDEs were calculated,then a new connectivity index,orientating corresponding index was calculated with the technique of molecule graphics.The orientating corresponding index was combined with five observed thermodynamic properties of PCDEs,i.e.molecular mean polarizability,standard enthalpy,free energy,heat capacity at constant volume and standard entropy,and fifteen quantitative structure-property relationship(QSPR) models(r>0.99)were obtained with the unitary linear regression method,and the relative mean deviations were 1.02%,0.48%,0.48%,0.22% and 0.90%,respectively.In order to test the stability and prediction ability of each model,the jackknifed cross validation was performed and good results(r>0.99)were obtained.These models can better elucidate the change of the thermodynamic properties for the PCDEs,and the QSPR models have satisfactory stability and good predictability.展开更多
文摘In this paper,based on distance matrix and adjacent matrix,a new topological index has been developed to be used in research on physical and chemical properties of alkanes.It is concluded that the index bears good structural selectivity and relativity.
文摘Polychlorinated diphenyl ethers(PCDEs) are listed as the so-called persistent pollutants.Atomic characteristic values of all 209 possible molecular structure patterns of PCDEs were calculated,then a new connectivity index,orientating corresponding index was calculated with the technique of molecule graphics.The orientating corresponding index was combined with five observed thermodynamic properties of PCDEs,i.e.molecular mean polarizability,standard enthalpy,free energy,heat capacity at constant volume and standard entropy,and fifteen quantitative structure-property relationship(QSPR) models(r>0.99)were obtained with the unitary linear regression method,and the relative mean deviations were 1.02%,0.48%,0.48%,0.22% and 0.90%,respectively.In order to test the stability and prediction ability of each model,the jackknifed cross validation was performed and good results(r>0.99)were obtained.These models can better elucidate the change of the thermodynamic properties for the PCDEs,and the QSPR models have satisfactory stability and good predictability.
