[3 + 2] versus [2 + 2] Addition: A Density Functional Theory Study on the Mechanistic Aspects of Transition Metal-Assisted Formation of 1,2-Dinitrosoalkanes

Journal of Chemistry. 2016;2016 DOI 10.1155/2016/4538696

 

Journal Homepage

Journal Title: Journal of Chemistry

ISSN: 2090-9063 (Print); 2090-9071 (Online)

Publisher: Hindawi Limited

LCC Subject Category: Science: Chemistry

Country of publisher: United Kingdom

Language of fulltext: English

Full-text formats available: PDF, HTML, ePUB, XML

 

AUTHORS

Ernest Opoku (Theoretical and Computational Chemistry Laboratory, Department of Chemistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana)
Richard Tia (Theoretical and Computational Chemistry Laboratory, Department of Chemistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana)
Evans Adei (Theoretical and Computational Chemistry Laboratory, Department of Chemistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana)

EDITORIAL INFORMATION

Blind peer review

Editorial Board

Instructions for authors

Time From Submission to Publication: 16 weeks

 

Abstract | Full Text

The pathways for the transition metal-assisted formation of 1,2-dinitrosoalkane complexes of cobalt and its congeners, have been studied using DFT/M06 with the LACVP* basis set. The activation barriers for the one-step [3 + 2] addition pathway for the formation of 1,2-dinitrosoalkanes, proposed by Bergman and Becker, are generally low compared to the activation barriers for the [2 + 2] addition to form an intermediate, which is the first of the two-step pathway proposed by Rappé and Upton, which are very high. The barriers of the rearrangement of the Rappé intermediates to the final products by reductive elimination involving the second metal-nitrogen π-bond are also very high. The reactions of the Co complexes have lower activation barriers than Rh and Ir complexes. The barriers of the reactions involving olefins with electron-donating groups are generally lower compared to the reactions of the parent (unsubstituted) ethylene while the activation barriers for reactions of olefins with electron-withdrawing groups are generally higher compared to the parent (unsubstituted) ethylene. The one-step [3 + 2] pathway remains the most favoured irrespective of the metal centre or the nature of the olefin. The mechanism of the reaction is therefore settled in favour of the [3 + 2] addition pathway.