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Thallation of fluorenes: A kinetic and mechanistic study
Author(s) -
Narasimhan S.,
Ramani P. V.,
Venkatasubramanian N.
Publication year - 1978
Publication title -
international journal of chemical kinetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.341
H-Index - 68
eISSN - 1097-4601
pISSN - 0538-8066
DOI - 10.1002/kin.550100605
Subject(s) - chemistry , fluorene , kinetics , thallium , electrophilic substitution , solvent polarity , electrophilic aromatic substitution , electrophile , medicinal chemistry , solvent , halogenation , photochemistry , organic chemistry , catalysis , physics , quantum mechanics , polymer
The kinetics of thallation of fluorene with thallium triacetate (TTA) in HOAc‐H 2 SO 4 solutions led to the rate expression\documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm rate = [TTA]}^{\rm 2} [{\rm fluorene}] $$\end{document}The rate of thallation is found to increase with increasing acid concentration, and a sixth‐order dependence on [H 2 SO 4 ] is observed. Decrease in solvent polarity increases the rate of thallation. The effect of substituents is in accord with the electrophilic substitution at an aromatic system. Thallation occurs at 4‐position. A mechanism similar to aromatic bromination is proposed for the thallation of fluorene.