【摘要】 采用傅里叶转换红外光谱方法测定了三种1,2-二-[β-(α-甲基-α′对位取代基苯基)噻吩]六氟环戊烯化合物I、Ⅱ、Ⅲ的红外光谱。在确认主要红外吸收峰归属并对图谱进行解析的基础上观测到环戊烯环上的碳氟键吸收频率依化合物Ⅰ,Ⅱ,Ⅲ次序逐一相应增高,发生规律性变化。化合物Ⅰ:νasC—F=1332.21cm-1,νsC—F=1231.91cm-1,δC—F=1159.99cm-1;化合物Ⅱ:νasC—F=1338.18cm-1,νsC—F=1254.31cm-1,δC—F=1179.22cm-1;化合物Ⅲ:νasC—F=1360.99cm-1,νsC—F=1263.29cm-1,δC—F=1194.00cm-1。对此不仅从红外光谱吸收原理进行了定性讨论,而且采用核磁共振谱测定化合物氢谱的方法给出了定量描述:化合物Ⅰ,Ⅱ,Ⅲ的H-1,H-2化学位移δ值,均为Ⅰ>Ⅱ>Ⅲ,反映出取代基引起苯环质子周围的电子云密度增加。因此可确认红外吸收的诱导效应与共轭效应共同作用是导致化合物环戊烯环上的碳氟键伸缩振动频率发生规律性变化的原因。这说明核磁共振氢谱是红外光谱解析的有力工具。更多还原

【Abstract】 FTIR spectroscopy and 1H NMR method were used to investigate three organic compounds—1,2-di[-β-(α-methyl-α′-p-substitutephenyl) thiophene]hexafluorocyclo pentene. After assigning all main infrared spectrum peaks, it was observed that the stretching vibration frequency(ν) of C—F band in cyclopentene is rised gradually, and it was found that for compound Ⅰ: νas C—F=1 332.21 cm-1, νs C—F=1 231.91 cm-1 and δC—F=1 159.9 cm-1; for compound Ⅱ: νas C—F=1 338.18 cm-1, νs C—F=1 254.31 cm-1 and δC—F=1 179.22 cm-1; and for compound Ⅲ: νas C—F=1 360.99 cm-1, νs C—F=1 263.29 cm-1 and δC—F=1 194.00 cm-1. The reason for ν change is discussed not only using infrared absorption theory qualitatively but also using 1H NMR method quantitatively. It was also found that for compound Ⅰ H-1=7.503, H-2=7.484; for compound Ⅱ H-1=6.896, H-2=7.465; and for compound Ⅲ: H-1=6.728, H-2=7.413, proveing that the substitution group —F, —OCH2CH3, —N(CH3)2 influences the C—F stretching vibration by the conjugative effect and the inductive effect. The result is satisfactory and it shows that 1H NMR is a powerful tool for infrared spectrum analysis.更多还原