Crystal and electronic structures and electrical, magnetic, and optical properties of two copper tetrahalide salts of bis(ethylenedithio)-tetrathiafulvalene

Magnetic Molecular Conductors

“…Fitting the data to the Bleaney-Bowers 67 model indicates a ferromagnetic exchange constant of 4 K. Since the shortest Cu-Cu distance is 8.5 Å, the direct exchange interaction between the Cu moments should 47 By contrast, in (BEDT-TTF) 3 [CuBr 2 Cl 2 ] the interaction between the two sublattices is strong, and structural phase transitions transform the electrical and magnetic properties. 68 The crystal structures of the [CuBr 4 ] 2and [CuCl 2 Br 2 ] 2salts are very different from the [CuCl 4 ] 2salt, and their electronic properties are unrelated. Whereas the [CuCl 4 ] 2form a flattened tetrahedron, as expected for Jahn-Teller d 9 ions, the anions in the bromo salts are squareplanar.…”

“…While the interaction between the BEDT-TTF and the metal ion spins is weak yet observable in (BEDT-TTF) 3 [CuCl 4 ]·H 2 O, it is negligible in semiconducting (BEDT-TTF) 2 [FeCl 4 ] and insulating (BEDT-TTF)[FeBr 4 ] . By contrast, in (BEDT-TTF) 3 [CuBr 2 Cl 2 ] the interaction between the two sublattices is strong, and structural phase transitions transform the electrical and magnetic properties . The crystal structures of the [CuBr 4 ] 2- and [CuCl 2 Br 2 ] 2- salts are very different from the [CuCl 4 ] 2- salt, and their electronic properties are unrelated.…”

Crystal structures, and electrical conduction and magnetic properties in CuCl4 salts of dimethylthio- and ethylenedithio-tetrathiafulvalenothioquinone-1,3-dithiolemethides

“…1 Several p/d-cooperative molecular systems are so far known, but are limited to copper-2 and cobalt-phthalocyanines, 3 copper dimethyldicyanoquinodiimine (DMe-DCNQI), 4 and bis(ethylenedithio)-tetrathiafulvalene (BEDT-TTF) and -tetraselenafulvalene (BEDT-TSF) radical cation salts with copper or iron counter-anions. 5±8 Furthermore, the degree of p/d interaction is very weak for almost all the molecular systems, except for (DMe-DCNQI) 2 ?Cu, 9 (BEDT-TTF) 3 ?CuBr 4 , 10 (BEDT-TTF) 3 ?CuCl 2 Br 2 , 10 l-(BEDT-TSF) 2 ?FeCl 4 , 11 and k-(BEDT-TSF) 2 ?FeBr 4 , 12 which exhibit signi®cant p/d interaction and novel electrical conduction/magnetic properties. In order to understand more fully the p/d interaction and also to create unprecedented molecularbased organic metal magnets, much attention is being directed towards new p/d-cooperative molecular systems, especially those based on new donor molecules.…”

Synthesis and Solid State Chemistry of CH3BiI2: A Structure with an Extended One-Dimensional Organometallic Framework

“…Hybrid organic−inorganic compounds, which combine an extended inorganic framework with organic species, are involved in various fundamental as well as more applied studies related to their transport, − optical, − magnetic, ,, thermochromic, or structural ,− properties. It is expected that these properties can be enhanced or fine tuned through the coupling between the organic and inorganic components of the structure.…”