Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.


Issue 13, 2018
Previous Article Next Article

Probing semiconductivity in crystals of stable semiquinone radicals: organic salts of 5,6-dichloro-2,3-dicyanosemiquinone (DDQ) radical anions

Author affiliations

Abstract

The structural parameters and semiconductivity of crystals with stacked 5,6-dichloro-2,3-dicyanosemiquinone (DDQ) radicals were studied for a series of the first nine salts of DDQ with substituted N-ethyl- and N-methylpyridinium cations. Structures with stacks of equidistant radicals (interplanar separation <3.3 Å) are fairly good semiconductors (10−9 S cm−1), while those with Peierls-distorted stacks comprising diamagnetic dimers of radicals (interplanar separations are <3.1 Å within the dimers and >3.4 Å between the dimers) are insulators. DFT calculations indicate the covalent character (pancake bonding) of the interactions between the DDQ radical anions. The inductive effects of electronegative substituents (halogeno and cyano) on the quinoid ring stabilise the radicals, but also increase the HOMO–LUMO gap, resulting in lower electrical conductivity.

Graphical abstract: Probing semiconductivity in crystals of stable semiquinone radicals: organic salts of 5,6-dichloro-2,3-dicyanosemiquinone (DDQ) radical anions

Back to tab navigation

Supplementary files

Article information


Submitted
12 Dec 2017
Accepted
13 Feb 2018
First published
14 Feb 2018

CrystEngComm, 2018,20, 1862-1873
Article type
Paper

Probing semiconductivity in crystals of stable semiquinone radicals: organic salts of 5,6-dichloro-2,3-dicyanosemiquinone (DDQ) radical anions

K. Molčanov, D. Stalke, A. Šantić, S. Demeshko, V. Stilinović, Z. Mou, M. Kertesz and B. Kojić-Prodić, CrystEngComm, 2018, 20, 1862
DOI: 10.1039/C7CE02146A

Social activity

Search articles by author

Spotlight

Advertisements