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.
