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利用~1H-NMR中羰基的ASIS值在羰基周围不同的区域符号分布的经验规律,研究了一系列拟除虫菊酯化合物羰基酯键部分的构象,指出在具有α-氰基的菊酯分子中,其溶液态构象是α-氰基与酯羰基共平面的构象,而在个有α-甲基的菊酯分子中,溶液态构象是α-氢原子与酯羰基共平面的构象.本实验结果支持了Hopfinger等人用分子力学方法计算的结果,从而肯定了氰基取代的菊酯分子在溶液态下的构象与在晶体中构象的不同.
The conformations of a series of pyrethroid carbonyl bond moieties have been studied by using the rule of the ASIS value of carbonyl in ~ 1H-NMR spectra in different regions around the carbonyl. It is shown that among the pyrethroid molecules with α-cyano, The solution state conformation is the conformation of the α-cyano group and the carbonyl group of the ester, while in the α-methyl-pyrethrin molecule, the solution state conformation is the conformation of the α-hydrogen atom and the ester carbonyl coplanar. Supported the results calculated by the molecular mechanics method by Hopfinger et al., Thus confirming the difference between the conformation of cyano-substituted intron molecules in solution and the conformation in the crystal.