Derivatization Enhanced Raman Characteristic Vibration Spectrum of PAEs Based on Pharmacophore Model

In this paper, 3D QSAR pharmacophore models of PAEs Raman characteristic vibration spectrum were established by Discovery Studio software for 17 phthalic acid esters were used as training set and 5phthalic acid esters used as test set. The substitution reaction of PAEs (take environmental priority controlled pollutants DMP, DBP and DNOP for example) used the optimal pharmacophore model built by Hypo 1 and 9 kinds of common hydrophobic groups. At the same time, the Raman characteristic vibration spectrum of PAEs and derivatives in gaseous environment were calculated by using density functional theory at B3LYP/6-31g(d) level, which was to screen derivative reaction of PAEs Raman characteristic vibration spectrum enhanced significantly. The results showed that the pharmacophore model (Hypo 1) was significant and had good predictive abilities with the greatest correlation coefficient (R-2) of 0. 83, the smallest value of root mean square (RMS) of 0. 182 and the total cost of 71. 865, the configuration value of 12. 68 (< 17). There were 23PAEs derivatives based on Hypo 1, including 9 DMP derivatives, 9 DBP derivatives, 5 DNOP derivatives, and the positive frequencies of derivative molecules were greater than 0, which illustrate the structure of PAEs derivatives were stable. The Raman characteristic vibration spectrum intensity of DMP-CH2CH3, DBP-Cl, DNOP-C6H5 increased comparing with DMP, DBP, DNOP by 6.25 times, 2.05 times and 1.56 times respectively, which indicated that PAEs derivatization had significantly enhanced effect on Raman characteristic vibration spectrum intensity. In addition, the substitution reaction energy barriers of PAEs derivatives were calculated by using density functional theory at B3LYP/6-31g(d) level, ( take DNOP for example), and the substitution reaction order of the substituent -C-6 H-5 -CH2CH2CH3, -SH, -Cl, -NO2 and DNOP molecule was -CH2CH2CH3 > -C6H5, -NO2 > - SH > -C1, which can be uesd as the basis of screening PAEs molecular derivatization enhanced Raman spectrum reaction and provide theoretical support for the enhanced Raman spectrum detection technology.