کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
9770087 1501939 2005 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effect of substituents on the 13C chemical shifts of the azomethine carbon atom of N-(substituted phenylmethylene)-3- and -4-aminobenzoic acids
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Effect of substituents on the 13C chemical shifts of the azomethine carbon atom of N-(substituted phenylmethylene)-3- and -4-aminobenzoic acids
چکیده انگلیسی
13C chemical shifts of the azomethine carbon atom for N-(substituted phenylmethylene)-3- and -4-aminobenzoic acids having a wide range of substituent effects, were determined in deuterated DMSO solution. Good Hammett correlations of the 13C NMR chemical shifts of azomethine carbons with electrophilic substituent constants σp+ for electron-donor substituents for both series of acids indicate an important resonance interaction of the substituents on the benzylidene ring with the azomethine carbon atom. On the other hand, good correlations of the 13C NMR chemical shifts of azomethine carbon atom of both series of acids with inductive substituent constants for electron-acceptor substituents in benzylidene ring indicates that the chemical shifts are influenced only by inductive effect of the substituents. The demand for electrons by the azomethine carbon atom in both investigated series have been compared, discussing the mode of transmission of substituent effects, both inductive and resonance, in relation to the geometry of investigated imines.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Structure - Volumes 744–747, 3 June 2005, Pages 411-416
نویسندگان
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