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Australian Journal of Chemistry Australian Journal of Chemistry Society
An international journal for chemical science
RESEARCH ARTICLE

Simultaneous conformity and non-conformity to Hammett’s linear free energy relationship (LFER): a rarity

Sanjeev Rachuru https://orcid.org/0000-0002-6117-7112 A * , Jagannadham Vandanapu https://orcid.org/0000-0001-9152-7729 B * and Adam A Skelton C
+ Author Affiliations
- Author Affiliations

A Department of Chemistry, St Ann’s College for Women, Mehdipatnam, Hyderabad, 500 028, Telangana, India.

B Department of Chemistry, Osmania University, Hyderabad, 500007, India.

C Department of Pharmacy, School of Health Science, University of KwaZulu–Natal, Durban 4000, South Africa.


Handling Editor: Amir Karton

Australian Journal of Chemistry 77, CH24110 https://doi.org/10.1071/CH24110
Submitted: 2 August 2024  Accepted: 4 November 2024  Published online: 22 November 2024

© 2024 The Author(s) (or their employer(s)). Published by CSIRO Publishing.

Abstract

Linear free energy relationships (LFERs) are an important topic in physical-organic chemistry. When one browses the literature, one encounters innumerable instances wherein the series in question conforms to LFER; one also encounters appreciable numbers of examples of non-conformity to LFER. It is extremely rare or maybe we are the first to report simultaneous conformity and non-conformity of Hammett’s relationship (LFER) in the same series, the para-substituted phenyl pentazoles. This rarity and a plausible reason are discussed.

Keywords: bond length alternation, BLA, electron donating, electron withdrawing, Hammett LFER, harmonic oscillator model aromaticity, HOMA index, linear free energy relationship, para-substituted phenyl pentazoles.

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