Correlation of the proton chemical shifts with the hammett-taft ? constants in 2-substituted pyridines and pyrazines

Autor:	G. P. Syrova, Yu. N. Sheinker
Rok vydání:	1972
Předmět:	Proton Chemical shift Organic Chemistry Substituent chemistry.chemical_element Resonance (chemistry) Nitrogen Meta chemistry.chemical_compound chemistry Nitrogen atom Computational chemistry Organic chemistry Inductive effect
Zdroj:	Chemistry of Heterocyclic Compounds. 8:313-317
ISSN:	1573-8353 0009-3122
Popis:	Good correlation between the relative chemical shifts of the ortho and para protons and σi and σ0cis observed in 2-substituted pyridines and pyrazines. An increase in the contribution of the inductive effect is observed for the relative chemical shifts of 4-H in 2-substituted pyridines as compared with monosubstituted benzenes. A considerable increase in the fraction of the conjugation effect is observed for the relative chemical shifts of 6-H in pyridines and pyrazines as compared with the meta position in benzenes. It is possible that this effect is associated with the fact that transfer of the effect is accomplished here through the nitrogen atom, while the interaction between the substituent and the nitrogen has resonance character.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::97b785baf99d1cdb983c233e1795bbe8 https://doi.org/10.1007/bf00475290 Zobrazit plný text záznamu Full text from SpringerLink