Campus Units

Chemistry

Document Type

Article

Publication Version

Published Version

Publication Date

2015

Journal or Book Title

Journal of the American Chemical Society

Volume

137

Issue

9

First Page

3402

Last Page

3410

DOI

10.1021/jacs.5b00707

Abstract

Carbocations are traditionally thought to be closed-shell electrophiles featuring an empty orbital rich in p character. Here, density functional theory computations indicate that when strong π donors are not placed in direct conjugation with benzylic-type cations, alternative diradical configurations that resemble non-Kekulé diradicals are possible. For certain donor–acceptor frameworks, an open-shell singlet configuration is the computed ground state for the cation, whereas for coumarin and xanthenyl cations substituted with strong donors, a triplet diradical configuration is the computed ground state. Changing the substituent nature and attachment location substantially alters the energy gaps between the different electronic configurations and can manipulate the computed ground-state electronic configuration. There are few known examples of ground-state triplet carbocations, and, to our knowledge, no other examples of open-shell singlet carbocations. The open-shell singlet and triplet “carbocations” described here may have reactivity distinct from that of typical closed-shell singlet carbocations and, if appropriately stabilized, lead to organic materials with interesting electronic and magnetic properties.

Comments

Reprinted (adapted) with permission from J. Am. Chem. Soc., 2015, 137 (9), pp 3402–3410. Copyright (YEAR) American Chemical Society.

Copyright Owner

American Chemical Society

Language

en

File Format

application/pdf

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