乐果和氧化乐果水解过程的衰减全反射-傅立叶变换红外光谱(ATR-FTIR)研究

Research on Hydrolysis of Dimethoate and Omethoate by Means of Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy(ATR-FTIR)

运用ATR-FTIR深入探讨了乐果和氧化乐果分子结构的特征振动及其酸、碱条件下水解历程对其特征结构振动的变化规律.由实验结果,ATR-FTIR能够显著地区分乐果和氧化乐果两分子的结构振动.氧化乐果在3302 cm-1νas(NH),3089 cm-1νas(CH2),1739 cm-1ν(C—O),1554 cm-1ν(O=C—N)II等峰位明显区别于乐果分子对应结构的振动峰位及其峰位强度.碱性水解条件下,乐果的ATR-FTIR特征表现在2108 cm-1平宽峰增强,氧化乐果则表现为ν(P=O)红移和νas(P—O—C)蓝移;酸性水解条件下,乐果ATR-FTIR中高波段的NH,CH3振动较强,氧化乐果则因其分子链被破坏,表现出无特征振动.以上ATR-FTIR获得的结果从另一角度,互补性地揭示了乐果和氧化乐果两分子内部的结构振动差别和酸、碱水解历程对其振动结构的影响变化.为便捷、高效地区分物质分子结构的差异,尤其是分子结构极为相似的细微结构的差异提供了较为完整的信息,同时也为研究物质结构及其形态变化提供了十分有益的参考.

The vibrations of dimethoate and omethoate＇s molecular structure,and their corresponding features of varying structures under acidic and basic conditions,were further explored by means of attenuated total reflection-Fourier transform infrared spectroscopy（ATR-FTIR）.According to the results,ATR-FTIR can significantly distinguish the different vibrational peaks of dimethoate and omethoate.These peaks at 3302 cm-1 νas（NH）,3089 cm-1 νas（CH2）,1739 cm-1 ν（C-O）,1554 cm-1 ν（O=C-N） II of omethoate were obviously different from corresponding structure vibrational peaks of dimethoate molecule.Under base condition,the vibrational peaks feature of dimethoate in ATR-FTIR at hydrolysis process was that the broad peak 2108 cm-1 became strong,while the vibrational peaks feature of omethoate showed ν（P=O） red shift and ν（P-O-C） blue shift.Under different acidic condition,vibrational peaks of NH and CH3 in dimethoate＇s ATR-FTIR at mid and high band spectra were strong,while all vibrations of omethoate＇s structure in ATR-FTIR were weak,owing to the whole of its molecule chain being destructed.These results were complementary to demonstrate the internal molecular structure differences between dimethoate and omethoate,and to demonstrate the influence changes of vibrational structures caused by hydrolysis process at acidic and basic conditions.The results could provide more information for distinguishing the similar molecular structures,especially having nice structure differences in different molecules,with convenient and efficient tools,and also the results could provide useful reference for studying molecular structures and morphological changes.