Quantum chemical investigations of the thermal and photoinduced proton-transfer reactions of 2-(2′,4′-dinitrobenzyl)pyridine

authored by: Irmgard Frank, Stefan Grimme, Sigrid D. Peyerimhoff
Abstract: Quantum chemical calculations of the proton-transfer system 2-(2′,4′-dinitrobenzyl)pyridine (DNBP) and of derivatives with larger aromatic bases are presented. These systems undergo photochemical isomerizations from a stable form to two different photoisomers. Ab initio methods are employed to investigate the isomerization of methylimine to vinylamine as a model system for the proton-transfer reaction of DNBP. The ground and excited states of both isomers and of the transition state for the isomerization are studied with Hartree-Fock and MRD-CI (multireference singles and doubles CI) methods. The isomerizations of the larger system DNBP and its derivatives are investigated with semiempirical PM3-SCF and PM3-MRD-CI methods. The intrinsic reaction coordinate formalism is used for calculating the reaction pathways from the optimized transition states. The relative stabilities of the various isomers and the mechanism of the intramolecular proton-transfer reaction are discussed. The ortho-nitro group assists the proton transfer from the methylene group to the pyridine ring. The experimentally observed reaction barriers are reproduced by taking crystal effects into account.
External Organisation(s): University of Bonn
Max Planck Institute for Solid State Research (MPI-FKF)
Type: Article
Journal: Journal of Physical Chemistry
Volume: 100
Pages: 16187-16194
No. of pages: 8
ISSN: 0022-3654
Publication date: 03.10.1996
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: General Engineering, Physical and Theoretical Chemistry
Electronic version(s): https://doi.org/10.1021/jp960923+ (Access: Closed)

BibTeX

@article{e8d59b056d5444f9ad1bfb9a3d3cb557,
title = "Quantum chemical investigations of the thermal and photoinduced proton-transfer reactions of 2-(2′,4′-dinitrobenzyl)pyridine",
abstract = "Quantum chemical calculations of the proton-transfer system 2-(2′,4′-dinitrobenzyl)pyridine (DNBP) and of derivatives with larger aromatic bases are presented. These systems undergo photochemical isomerizations from a stable form to two different photoisomers. Ab initio methods are employed to investigate the isomerization of methylimine to vinylamine as a model system for the proton-transfer reaction of DNBP. The ground and excited states of both isomers and of the transition state for the isomerization are studied with Hartree-Fock and MRD-CI (multireference singles and doubles CI) methods. The isomerizations of the larger system DNBP and its derivatives are investigated with semiempirical PM3-SCF and PM3-MRD-CI methods. The intrinsic reaction coordinate formalism is used for calculating the reaction pathways from the optimized transition states. The relative stabilities of the various isomers and the mechanism of the intramolecular proton-transfer reaction are discussed. The ortho-nitro group assists the proton transfer from the methylene group to the pyridine ring. The experimentally observed reaction barriers are reproduced by taking crystal effects into account.",
author = "Irmgard Frank and Stefan Grimme and Peyerimhoff, {Sigrid D.}",
year = "1996",
month = oct,
day = "3",
doi = "10.1021/jp960923+",
language = "English",
volume = "100",
pages = "16187--16194",
journal = "Journal of Physical Chemistry",
issn = "0022-3654",
publisher = "American Chemical Society",
number = "40",
}