Imidacloprid and related compounds: Structure and water solubility of N-alkyl derivatives of imidacloprid

被引:30
作者
Kagabu, S [1 ]
Yokoyama, K [1 ]
Iwaya, K [1 ]
Tanaka, R [1 ]
机构
[1] Gifu Univ, Fac Educ, Dept Chem, Gifu 5011193, Japan
关键词
imidacloprid; log P; water solubility; molecular surface area; hydrogen bonding;
D O I
10.1271/bbb.62.1216
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
An intramolecular hydrogen bond between NH ... O2N in insecticide, imidacloprid (1), and its nitromethylene. analog 15 mas proved by NMR and IR spectra. That electron delocalization over their planar moieties was disrupted by alkylation at the imidazolidine nitrogen atom is demonstrated by the hypsochromic shifts in UV and deshielding effect in NMR spectra. interestingly, the N-alkyl derivatives (C1-5) had greater water solubility than 1, although increasing alkyl chain length decreased the solubility. The hydrophilicity of the alkyl derivatives mould result from remote charge heads being formed as a result of the conjugation disruption by alkylation, while the hydrophobicity of 1 could be. ascribed to the charge distribution over the conjugated system coupled with the intramolecular H-bonding. The greater water solubility of 15 than 1 and contrastively small solubility of the cyanoimine analogue are discussed based on the difference in their steric crowding.
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页码:1216 / 1224
页数:9
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