Syntheses, structure and properties of vinylogous EDO-TTFs

• Published in: Physica. B, Condensed matter Condensed matter, 2010-06, Vol.405 (11), p.S61-S64
• Main Authors: Shirahata, T., Morikawa, T., Miyamoto, H., Nakano, Y., Yamochi, H., Misaki, Y.
• Format: Article
• Language: English
• Subjects: Condensed matter; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Conductivity of specific materials; Crystal structure; CT complexes; Electrical resistivity; Electronic transport in condensed matter; Exact sciences and technology; Hydrogen atoms; Hydrogen bonds; Molecular conductors; Organic compounds; Physics; Polymers; organic compounds (including organic semiconductors); Redox properties; Resistivity; Stacking; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; X-ray crystal structure analyses; X-rays; π-Extended donors
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2009.12.024

We synthesized vinylogous 4,5-ethylenedioxy-tetrathiafulvalenes (EDO-TTFs), 4,5-ethylenedioxy-2,2′-ethanediylidenebis(1,3-dithiole) (EDO-EBDT), 4,5-dimethyl-4′,5′-ethylenedioxy-2,2′-ethanediylidenebis(1,3-dithiole) (DMEDO-EBDT), 4,5-bis(thiomethyl)-4′,5′-ethylenedioxy-2,2′-ethanediylidenebis(1,3-dithiole) (BTMEDO-EBDT), and 4,5-bis(methoxycarbonyl)-4′,5′-ethylenedioxy-2,2′-ethanediylidenebis(1,3-dithiole) (BMCEDO-EBDT). The cyclic voltammograms of the vinylogous EDO-TTFs show two pairs of single-electron redox waves. The first oxidation potentials ( E 1) of vinylogous EDO-TTFs are lower than those of the related TTFs, indicating that the electron donating abilities of new donors are stronger than those of the corresponding TTFs. The smaller E 2− E 1 values of new donors compared with those of the related TTFs suggest a decrease in the on-site Coulombic repulsion in the dication state. X-ray crystal structure analysis of BMCEDO-EBDT reveals that the inter-molecular C-H⋯O type hydrogen bond is constructed between the hydrogen atom and the oxygen atom of the ethylenedioxy group. Single crystalline TCNQ complexes of DMEDO-EBDT and BTMEDO-EBDT have been prepared and their conducting properties and crystal structure have been investigated. The TCNQ complexes of DMEDO-EBDT and BTMEDO-EBDT show low electrical conductivities ( σ rt