Shinji Tarutani

New acceptors for highly conducting charge-transfer complexes and radical-anion salts: 1,2-Bis(p-benzoquino)-3-(dicyanomethyleneheteroquino)cyclopropane (BQDCNH-CP) derivatives

Abstract New acceptors, heterocycle-extended [3]radialene derivatives 2 and 3 have been synthesized by convenient methods. Single crystals of charge-transfer complexes of 2 with TTF and TTT showed a metallic behavior and N-methylquinolinium radicalanion salts showed a fairly high conductivity.

Novel electron acceptors for organic conductors: 1,2-bis(p-benzoquino)-3-[2-(dicyanomethylene)-2,5-thienoquino]cyclopropane derivatives

The title [3]radialene derivatives, having a hybrid structure of 2,5-bis(dicyanomethylene)-2,5-dihydrothiophene (thiophene–TCNQ) and tris(p-benzoquino)cyclopropane, and giving a stable radical anion and a dianion on two-step one-electron reductions, have been efficiently synthesised and the electrical properties of the conductive charge-transfer complexes with tetrathiafulvalene and related donors are described.

Low temperature X-ray study of purely one-dimensional electronic system Me4X(CPDT-TCNQ)2(X=As, N)

Abstract Isostructural anion radical salts Me 2 X(CPDT-TCNQ) 2 (X=N,P,As) have one-dimensional electronic structure, and show several type of metal-insulator transitions depending on X. The result of the polarized reflectance spectra shows that the compounds are probably purely one-dimensional electronic system. The results of X-ray photographs and crystal structure analyses indicate that the origins of the transitions are 4k F CDW accompanying a cation ordering in the Me 2 As, Me 4 P salts and by 2k F CDW in the Me 4 N salt.

Crystal structures and electrical conducting properties of the first molecular metals based on a novel electron acceptor, 4-oxo-2,6-bis(dicyanomethylene)-2,6-dihydrocyclopentadithiophene (CPDT)

A novel electron acceptor CPDT has been synthesized; the Fermi surfaces of the metallic anion radical salts of CPDT are purely one-dimensional, while the acceptor molecules form rigid and tight two-dimensional networks in the crystal structures of the salts.

Novel molecular metals composed of a [3]radialene type acceptor : 1,2-bis(p-benzoquino)-3-[2(dicyanomethylene)-2,5-selenoquino]cyclopropane derivative

Abstract A new acceptor, 1,2-bis(p-benzoquino)-3-[2-(dicyanomethylene)-2,5-selenoquino]cyclopropane derivative (DCNS-CP) has been efficiently synthesized by the reaction of a cyclopropenone derivative with selenienylmalononitle and subsequent oxidation. DCNS-CP proved to be a powerful acceptor and its anion radical and dianion are very thermodynamically stable. Single crystals of [TTF][DCNS-CP] and [TTT][DCNS-CP] complexes showed metallic temperature dependencies of the conductivities down to 182 and 80 K, recording σmax values of 500 and 760 Scm−1, respectively. These are a new class of metals based on a functionally different type of organic acceptor consisting of three electron-accepting groups in full conjugation.