Nanoparticles of molecule-based conductors

Abstract

State of the art molecule-based conductors that have been isolated as nanoparticles are reviewed. Research efforts in this field is justified by their insolubility and low vapour pressure, making their integration into electronic devices difficult. Their availability as nanoparticles would allow researchers to study their properties at the nanoscale and as stable dispersions, offering new opportunities for processing. Molecular conductors and superconductors that have been isolated as nanoparticles are: TTFÁTCNQ, TTF[Ni(dmit) 2 ] 2 , TTFCl 0.77 and TTFBr 0.59 , (BEDT-TTF)Cl 0.66 and (BEDT-TTF) 2 Br, (TMTSF) 2 ClO 4 and (TMTSF) 2 PF 6 . Nanoparticle formation and shape depend on the stabilizing agent used for controlling the growth: ionic liquids, long-chain ammonium salts or neutral liquid polymers. The conductivities of the nanoparticle powders are reported.

Four Molecular Superconductors Isolated as Nanoparticles

“…[3] In particular, superconductivity was evi-bilizing agent and synthesis conditions. We report on the more recent conditions investigated (i) to produce nanoparticles of 35 nm for β-(BEDT-TTF) 2 I 3 , (ii) to reduce the particle size to 10-15 nm for TTF[Ni(dmit) 2 ] 2 and 3-5 nm for (TMTSF) 2 ClO 4 , and (iii) to improve the growth duration from days to one hour for (TMTSF) 2 PF 6 . Finally, we report evidence of superconductivity in (TMTSF) 2 ClO 4 particles.…”

“…We have explored the preparation of these compounds as thin films [1] and as nanoparticles (NPs). [2] (BEDT-TTF) 2 I 3 was also studied as a composite film. [3] In particular, superconductivity was evi-bilizing agent and synthesis conditions.…”

“…The four molecular superconductors (TMTSF) 2 PF 6 and (TMTSF) 2 ClO 4 Bechgaard salts, (BEDT-TTF) 2 I 3 , and TTF[Ni(dmit) 2 ] 2 [TMTSF = tetramethyltetraselenafulvalene; BEDT-TTF = bis(ethylenedithio)tetrathiafulvalene; dmit = 1,3-dithiole-2-thione-4,5-dithiolate] (Scheme 1) were first prepared in the 1980s and 1990s. [1] They are the parent compounds of a well-known series of superconductors and can be taken as models for studying the influence of morphology and size on physical properties, for instance, on the occurrence of superconductivity.…”

Spin density wave and superconducting properties of nanoparticle organic conductor assemblies

“…Recently dispersed nanoparticles of donor-acceptor (DA) organic conductors have been synthesized by either oxidation or electrocrystallization in the presence of stabilizing agents acting as growth inhibitors 9 . Additional refinements of the synthesis conditions have produced a number of DA organic superconductors where strong correlations between the spectroscopic and crystallographic properties of the bulk materials and the nanoparticles have been established 10 .…”

Molecular conductors as nanoparticles in the presence of long-chain alkyl imidazolium salts or amphiphilic molecules

“…2) are very good candidates to stabilize spherical metallic nanoparticles [8]. Observed mean diameters were in the 20−40 nm range [9][10][11][12]. In our case, the growth as spherical nano-objects in an ionic liquid/acetonitrile mixture could be explained by a self-organization of imidazolium salts as nano-domains in the solvent, i.e., CH 3 CN [13].…”