吡唑和1-甲胺酰基吡唑类化合物的紫外吸收光谱及其应用

The Ultraviolet Absorption Spectra of Pyrazoles and 1-Carboxamidepyrazoles and Their Application

研究了吡唑类化合物和1-甲胺酰基吡唑类化合物的紫外吸收光谱。结果表明，3位和5位的取代使吡唑的最大吸收波长红移3～4nm，而4位的取代能够引起较大的红移（〉10nm）。甲胺酰基的引入可使吡唑类化合物的最大吸收波长红移20-26nm，最大消光系数提高2～3倍。基于此，建立了快速测定吡唑类化合物含量的紫外分光光度法，并测定了长效尿素中3，4-二甲基吡唑磷酸盐（DMPP）的含量为尿素-N的1．15％，1-甲胺酰基-3-甲基吡唑（CMP）在水溶液中水解的半减期在20，25和30℃下分别为48，30和16h，应用不同提取剂对三种土壤中硝化抑制剂3-甲基吡唑磷酸盐（MPP）的提取率为63．2％～89．2％。

The ultraviolet absorption spectra of pyrazoles and 1-carboxamidepyrazoles were studied. The results indicated that substitution in the 3 or the 5 position it leads to a bathochromic shift of the position of the maximum absorption by about 3-4 run, whereas in the 4 position leads to a much larger bathochromic shift （〉10 nm）. The introduction of carboxamide causes a bathochromic shift of the position of the maximum absorption by about 20-26 nm. Its also leads to an increase in molar extinction coef- ficient by about 2-3 times. So UV methods were established for determining the contents of pyrazoles and their derivations. Using these methods, the content of 3,4-dimethylpyrazole phosphate （DMPP） in stabilized urea was determined to be 1.15% of urea-N, the hydrolytic half lives of 1-carboxamide-3-methylpyrazole （CMP） in water solution at 20, 25 and 30℃ were 48, 30 and 16 h, respectively, and the extraction percentage of nitrification inhibitor 3-methylpyrazole phosphate （MPP） in 3 soils by 3 different extractants were ranged from 63. 2% to 89. 2%.