Login Register Cart 0
Generic placeholder image

Current Physical Chemistry

Editor-in-Chief

ISSN (Print): 1877-9468
ISSN (Online): 1877-9476

Back
Journal Home About Journal Editorial Board Journal Insight Current Issue Volumes/Issues
Subscribe
Mini-Review Article

Application of LFER to the N(1)-H Acidities of Five-Membered Nitrogen Heterocyclic Ring Systems: A Review on Graduate Chemical Education Exercise

Author(s): Sanjeev Rachuru and Jagannadham Vandanapu*

Volume 12, Issue 2, 2022

Published on: 19 September, 2022

Page: [117 - 127] Pages: 11

DOI: 10.2174/1877946812666220624125226

Price: $65

Abstract

An attempt is made for the first time in our laboratory to apply the Hammett and Taft equations to the five-membered heterocyclic ring systems pyrroles, pyrazoles, imidazole, and triazoles. It is shown that the pKa values of N(1)-H acidities of 3-X-pyrroles, 3-Xpyrazole, 4-X-pyrazole, 4-X-imidazole, 3-X-1,2,4-triazole and 4-X-1,2,3-triazole correlated well with Hammett σ values.

Keywords: Hammett equation, N(1)-H acidities, nitrogen heterocycles, pKa values, LFER, heterocyclic ring.

Next »
Graphical Abstract

[1]
Hammett, L.P. The effect of structure upon the reactions of organic compounds. Benzene derivatives. J. Am. Chem. Soc., 1937, 59(1), 96-103.
[http://dx.doi.org/10.1021/ja01280a022]
[2]
Hammett, L.P. Physical Organic Chemistry; McGraw Hill Book Co., Inc.: New York, 1940.
[3]
Jaffe, H. A reëxamination of the Hammett equation. Chem. Rev., 1953, 53(2), 191-261.
[http://dx.doi.org/10.1021/cr60165a003]
[4]
Wells, P.R. Linear free energy relationships. Chem. Rev., 1963, 63(2), 171-219.
[http://dx.doi.org/10.1021/cr60222a005]
[5]
Sanjeev, R.; Jagannadham, V. Comparison of substituent effects in Benzenes (XC5H5C), Pyridines (XC5H4N) and Phosphorines (XC5H4P) and their protonated species, world. J. Chem. Educ., 2020, 8(4), 155-162.
[http://dx.doi.org/10.12691/wjce-8-4-3]
[6]
Freeman, F. Linear free energy relationships in the furan and thiophene ring systems. J. Chem. Educ., 1970, 47(2), 140-142.
[http://dx.doi.org/10.1021/ed047p140]
[7]
Sanjeev, R.; Jagannadham, V. A deep insight into the application of Linear Free Energy Relationships (LFER) to five membered heterocyclic ring systems: A review. Mini Rev. Org. Chem., 2021.
[8]
Sanjeev, R.; Jagannadham, V.; Adam, A. Skelton The pKa of pentazole (HN5). Aust. J. Chem., 2021, 74(8), 584-590.
[http://dx.doi.org/10.1071/CH21014]

Rights & Permissions Print Cite
Article Metrics
3
© 2025 Bentham Science Publishers | Privacy Policy