A New Organic Conductor and a Novel Structural Phase Transition in the BEDT-TTF Trihalide Family

Abstract

A new quasi‐2D molecular conductorbased on BEDT‐TTF with an assembly of the trihalide anions I2Br–, IBr2–, and BrICl– is presented here. This set of anions promotes the formation of α′‐ and α‴‐type conducting layers (see Figure, top) along with a low‐temperature α‴→β″ transition seen for the first time in BEDT‐TTF salts.

Polymorphism of a New Bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) Based Molecular Conductor; Novel Transformations in Metallic BEDT-TTF Layers

“…For example, the use of the Bu 4 NBr 0.6 I 1.4 Cl salt generates crystals of BEDT-TTF-based organic conductor with another contribution of halides: (BEDT-TTF) 2 Br 1.3 I 1.1 Cl 0.6 . 9 Below we will focus on X-ray crystal data. Because of geometrical and symmetrical requirements, the relative contribution of the three trihalide species cannot be derived on the basis of the structural data obtained.…”

“…These features make them very attractive as model molecular conductors of reduced dimensionality. [5][6][7][8][9][10] It should be stressed that BEDT-TTF trihalide salts can be successfully generated as a continuous well-oriented nanocrystalline layer at the surface of a polymeric film that allows one to combine the transport and magnetic properties of molecular conductors with the advantageous properties of commercial polymers. 11,12 Recently we reported some new and important examples of BEDT-TTF-based organic conductors that can contain different sets of various trihalide anions.…”

Polyhalogen and Polyinterhalogen Anions from Fluorine to Iodine

“…It was reported for the first time in 1938 as [NH 4 ][BrICl] . Other examples of this anion have only been obtained in low‐dimensional organic conductors of bis(ethylenedithio)tetrathiofulvalene (BEDT‐TTF) salts with trihalide counterions and are therefore disordered, or rather a combination of different anions . The anion [ICl 2 ⋅IBr] − was obtained by reacting both [NMe 4 ][IClBr] with ICl and [NMe 4 ][ICl 2 ] with IBr.…”

Polyhalogen‐ und Polyinterhalogen‐Anionen von Fluor bis Iod

“…Es wurde erstmals 1938 in [NH 4 ][BrICl] beobachtet . Andere Beispiele dieses Ions sind nur bekannt von niederdimensionalen, organischen Leitern aus Bis(ethylendithio)tetrathiofulvalen (BEDT‐TTF)‐Salzen mit Trihalogenid‐Gegenionen, die fehlgeordnet sind oder eigentlich aus mehreren Anionen bestehen . Das Anion [ICl 2 ⋅IBr] − ging aus den Reaktionen von entweder [NMe 4 ][IClBr] mit ICl oder [NMe 4 ][ICl 2 ] mit IBr hervor.…”