Cross Conjugation in Polyenes and Related Hydrocarbons

What Can Be Learned from Valence Bond Theory about Single-Molecule Conductance?

Junjing Gu, Wei Wu, Thijs Stuyver, David Danovich, Roald Hoffmann, Yuta Tsuji, Sason Shaik

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

This study examined the nature of the electronic structure of representative cross-conjugated polyenes from a valence bond (VB) perspective. Our VBSCF calculations on a prototypical dendralene model reveal a remarkable inhibition of the delocalization compared to linear polyenes. Especially along the C-C backbone, the delocalization is virtually quenched so that these compounds can essentially be considered as sets of isolated butadiene units. In direct contrast to the dendralene chains, quinodimethane compounds exhibit an enhancement in their delocalization compared to linear polyenes. We demonstrate that this quenching/enhancement of the delocalization is inherently connected to the relative weights of specific types of long-bond VB structures. From our ab initio treatment, many localization/delocalization-related concepts and phenomena, central to both organic chemistry and single-molecule electronics, emerge. Not only do we find direct insight into the relation between topology and the occurrence of quantum interference (QI), but we also find a phenomenological justification of the recently proposed diradical character-based rule for the estimation of the magnitude of molecular conductance. Generally, our results can be conceptualized using the "arrow-pushing" concept, originating from resonance theory.

Original languageEnglish
Pages (from-to)6030-6047
Number of pages18
JournalJournal of the American Chemical Society
Volume141
Issue number14
DOIs
Publication statusPublished - Apr 10 2019

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Polyenes
Hydrocarbons
Molecules
Organic Chemistry
Butadiene
Electronic structure
Quenching
Electronic equipment
Topology
Weights and Measures
3,4,5-trimethylenehepta-1,6-diene

All Science Journal Classification (ASJC) codes

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

Cite this

Cross Conjugation in Polyenes and Related Hydrocarbons : What Can Be Learned from Valence Bond Theory about Single-Molecule Conductance? / Gu, Junjing; Wu, Wei; Stuyver, Thijs; Danovich, David; Hoffmann, Roald; Tsuji, Yuta; Shaik, Sason.

In: Journal of the American Chemical Society, Vol. 141, No. 14, 10.04.2019, p. 6030-6047.

Research output: Contribution to journalArticle

Gu, Junjing ; Wu, Wei ; Stuyver, Thijs ; Danovich, David ; Hoffmann, Roald ; Tsuji, Yuta ; Shaik, Sason. / Cross Conjugation in Polyenes and Related Hydrocarbons : What Can Be Learned from Valence Bond Theory about Single-Molecule Conductance?. In: Journal of the American Chemical Society. 2019 ; Vol. 141, No. 14. pp. 6030-6047.
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