New Development in the Preparation of Micro/Nano-Wires of Molecular (Magnetic) Conductors

Abstract

A lot of molecular (magnetic) conductors are prepared largely using charge-transfer (CT) salts of donor molecules with acceptor molecules or nonmagnetic or magnetic anions such as metal halides and oxides; their CT salts are usually obtained as bulk crystals, which are used to elucidate the electrical conducting (magnetic) properties. In contrast, a small number of micro/nano-crystals of the molecular (magnetic) conductors, especially micro/nano-wires, are known, of which highly conducting nanowires are necessary as a key component in the development of the next generation of nano-size transistors and spin-transistors. Very recently, we succeeded in preparing highly conductive micro/nano-wires of CT salts between bent donor molecules developed by one of the author’s group and magnetic FeX4– (X = Cl, Br) ions: (1) by electrochemical oxidation of the bent donor molecules with a silicon wafer electrode coated with a phospholipid multi-lamellar structure as well as, (ii) by electrochemical oxidation of the bent donor molecules with a large arc structure, in the presence of NBu4FeX4 supporting electrolytes. This article reviews template-free and template-assisted methods developed so far for the preparation of micro/nano-wires of molecular (magnetic) conductors along with our new methods. The conducting properties of these micro/nano-wires are compared with those of the corresponding bulk crystals.

New Nanobiocomposite Materials for Bioelectronic Devices

“…The TCNQ (1 μL) and TTF (2 μL) solutions were mixed on the surface of the PEDOT/GR composite; the excess unreacted TTF was washed away with ACN after the CTC crystallization process had been completed. The resulting CTC crystals had a characteristic needle-like shape, which is in accordance with the data in [ 5 ], but were rather unevenly distributed over the electrode surface, forming islands corresponding to the crystallization centers ( Fig. 1B ).…”

Colloidal Solutions of Organic Conductive Nanoparticles

“…These materials are obtained as crystals exhibiting needle-like morphology because of their intrinsic one-dimensional (1D) structural arrangement. Films, nanowires or gels, were successfully grown. − Films, grown on various substrates, − show room-temperature conductivities in the 1–70 S cm –1 range. Metallic behavior and superconductivity were evidenced in electrodeposited films of Ni(tmdt) 2 and TTF[Ni(dmit) 2 ] 2 , respectively .…”

“…Reaction of TTF and TCNQ in solution leads to needle-like microcrystalline TTF–TCNQ powders. Indeed, in the presence of an ionic liquid or a quaternary ammonium salt as stabilizing agent, the reaction affords nanoparticles, , but they are insoluble and rapidly decant. We report here that, by using long chain aliphatic amines as stabilizing agent, soluble TTF–TCNQ nanoparticles are prepared and afford colloidal solutions that can be directly used for film processing or line drawing.…”