University of Surrey

Test tubes in the lab Research in the ATI Dance Research

New donor-acceptor chromophores by formal [2+2] cycloaddition of donor-substituted alkynes to dicyanovinyl derivatives

Jarowski, PD, Wu, Y-L, Boudon, C, Gisselbrecht, J-P, Gross, M, Schweizer, WB and Diederich, F (2009) New donor-acceptor chromophores by formal [2+2] cycloaddition of donor-substituted alkynes to dicyanovinyl derivatives Org Biomol Chem, 7, 7. pp. 1312-1322.

[img] Text (Deleted)
CEJ_mechanism_FND.doc
Restricted to Repository staff only
Available under License : See the attached licence file.

Download (1MB)
[img]
Preview
Text (licence)
SRI_deposit_agreement.pdf
Available under License : See the attached licence file.

Download (33kB) | Preview
[img]
Preview
Text
new donor acceptor.pdf

Download (1MB) | Preview

Abstract

The efficient methodology of the cycloaddition between electron-rich alkynes and tetracyanoethylene (TCNE) or 7,7,8,8-tetracyanoquinodimethane (TCNQ), followed by retro-electrocyclisation, is extended to dicyanovinyl derivatives to produce new donor-acceptor push-pull 1,1-dicyanobutadienyl chromophores in excellent to quantitative yield (63-98%) that express strong charge-transfer (CT) absorptions from 300 to 600 nm. The scope of this reaction is established by both varying the nucleophilic and electrophilic components. Electrochemical studies show that the CT properties of these systems are readily tunable by substitution on the electrophile, which has the largest effect on the lowest unoccupied molecular orbital (LUMO). Non-reversible reduction potentials range from ca. -1.2 to -1.9 V in CH2Cl2, against the ferricinium/ferrocene couple (Fc(+)/Fc) according to cyclovoltammetry (CV) and rotating disk voltammetry (RDV). The chromophores show a significant non-planarity between the N,N-dimethylanilino donor and the 1,1-dicyanovinyl acceptor moieties, with torsional angles around 40 degrees from X-ray analysis, but retain strong quinoidal character. The mechanism of this reaction has been studied computational using density functional methods in the gas-phase and using the polarizable continuum model (PCM) for addressing solvent effects. The complete reaction free-energy profile has been determined for the reaction of 1,1-dicyanoethene and 4-ethynyl-N,N-dimethylaniline. The process proceeds through formal [2+2] cycloaddition followed by retro-electrocyclisation. The formation of a zwitterionic intermediate in the cycloaddition step is shown.

Item Type: Article
Divisions : Faculty of Engineering and Physical Sciences > Electronic Engineering > Advanced Technology Institute
Authors :
AuthorsEmailORCID
Jarowski, PDUNSPECIFIEDUNSPECIFIED
Wu, Y-LUNSPECIFIEDUNSPECIFIED
Boudon, CUNSPECIFIEDUNSPECIFIED
Gisselbrecht, J-PUNSPECIFIEDUNSPECIFIED
Gross, MUNSPECIFIEDUNSPECIFIED
Schweizer, WBUNSPECIFIEDUNSPECIFIED
Diederich, FUNSPECIFIEDUNSPECIFIED
Date : January 2009
Identification Number : 10.1039/b821230a
Related URLs :
Additional Information : Copyright 2009 Royal Society of Chemistry
Depositing User : Symplectic Elements
Date Deposited : 09 Jul 2014 10:35
Last Modified : 09 Jul 2014 13:33
URI: http://epubs.surrey.ac.uk/id/eprint/805653

Actions (login required)

View Item View Item

Downloads

Downloads per month over past year


Information about this web site

© The University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom.
+44 (0)1483 300800