Preparation of a Mott insulator based on a BEDT-TTF charge transfer complex of hydrogen cyananilate: alpha '-(BEDT-TTF)(2)HCNAL

Citation
Mb. Zaman et al., Preparation of a Mott insulator based on a BEDT-TTF charge transfer complex of hydrogen cyananilate: alpha '-(BEDT-TTF)(2)HCNAL, J MAT CHEM, 11(9), 2001, pp. 2211-2215
Citations number
53
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science","Material Science & Engineering
Journal title
JOURNAL OF MATERIALS CHEMISTRY
ISSN journal
0959-9428 → ACNP
Volume
11
Issue
9
Year of publication
2001
Pages
2211 - 2215
Database
ISI
SICI code
0959-9428(2001)11:9<2211:POAMIB>2.0.ZU;2-5
Abstract
BEDT-TTF (ET) and cyananilic acid (H(2)CNAL) afforded charge transfer cryst als by a diffusion method. The chemical formula of the complex was deduced based on all the information concerning the elemental, structural, electric , magnetic and optical analyses. The ET molecules form one-dimensional colu mnar stacks composed of twisted dimers with a face-to-face overlap (alpha'- type stack). The acid works as an oxidant and is deprotonated to form the m onoanion, HCNAL(1-), which forms ribbon-like aggregation by means of hydrog en-bonds. The ribbons form anion layers that sandwich the ET layer. The cry stal is semiconductive with a room temperature conductivity of 0.20-0.83 Sc m(-1) and activation energy of 0.15 eV along the stacking direction, gy tho ugh the band calculation by the extended Huckel method suggests a metallic nature, indicating strong electron-correlation in this system. The complex is a Mott insulator and its magnetic susceptibility is described by the one -dimensional S = 1/2 antiferromagnetic Heisenberg chain model with J/k(B) = - 52 +/- 3 K.