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How Does the Intrinsic Barrier of Intermolecular Proton Transfer Depend on Molecular Parameters?
Author(s) -
Goez Martin,
Heun Rainer
Publication year - 1998
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/(sici)1521-3773(19981116)37:21<3052::aid-anie3052>3.0.co;2-a
Subject(s) - valence bond theory , antibonding molecular orbital , intermolecular force , chemistry , proton , conjugated system , valence (chemistry) , thermodynamics , computational chemistry , molecule , chemical physics , molecular orbital , physics , quantum mechanics , organic chemistry , atomic orbital , polymer , electron
The question in the title is of fundamental importance , because the intrinsic barrier Δ G int ≠ is the key parameter connecting thermodynamics and kinetics. With a valence bond configuration mixing model for proton self‐exchange (see picture), it is shown that Δ G int ≠ is a linear function of I v − E ( σ NH * ), where I v is the ionization potential of the base and E ( σ NH * ) the energy of the antibonding orbital of the N−H bond in the conjugated acid. With para ‐substituted N , N ′‐dimethylanilines, this manifests itself by a linear relationship between Δ G int ≠ and the Hammett parameter σ + .