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Electrofugalities of Acceptor‐Substituted Tritylium Ions
Author(s) -
Horn Markus,
Metz Christian,
Mayr Herbert
Publication year - 2011
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201100912
Subject(s) - chemistry , solvolysis , acetonitrile , reaction rate constant , ion , aqueous solution , ionization , piperidine , inorganic chemistry , medicinal chemistry , computational chemistry , organic chemistry , kinetics , hydrolysis , physics , quantum mechanics
Ionization rate constants of differently substituted tritylhalides and carboxylates have been determined by conductimetry at 25 °C in aqueous acetonitrile and in acetone. Common ion return was suppressed by the addition of piperidine, which traps the generated tritylium ions. The obtained rate constants were subjected to Winstein–Grunwald and Hammett analyses. The solvolysis rate constants of trityl chlorides and bromides were employed to derive electrofugality parameters ( E f ) of tritylium ions according to the linear free energy relationship log k ion = s f ( E f + N f ) (N. Streidl, B. Denegri, O. Kronja, H. Mayr, Acc. Chem. Res. 2010 , 43 , 1537–1549). A facile scheme for estimation of ionization rates of trityl derivatives is presented.