Fumio Ogura

Synthesis, structure, and polymerization of 2,2'-bitellurophene

Abstract 2-2′-Bitellurophene was prepared in one-pot from tellurophene. Its molecular and crystal structures were elucidated by an X-ray crystal analysis. Its electrochemical polymerization gave poly(bitellurophene) as a black film or powder, which had an electrical conductivity in the range of 10−6−10−9 Scm−1.

2,2′-Bitellurophene and 2,2′:5′,2″-tertellurophene as novel high homologues of tellurophene☆

Abstract The title heterocycles were prepared from tellurophene, and their spectroscopic and electrochemical properties were systematically compared together with those of other chalcogenophene congeners. Their electropolymerizations gave poly(bitellurophene) and poly(tertellurophene) as black films, which both had higher electrical conductivities than poly(tellurophene) similarly obtained.

Design of Novel Chalcogen-Containing Organic Metals: Extensively Conjugated Electron Donors and Acceptors With Reduced On-Site Coulomb Repulsion

Abstract This review describes the design of extensively conjugated electron donors and acceptors based on structural modifications of tetrathiafulvalene (TTF) and tetracyanoquinodimethane (TCNQ), respectively. These molecules have the advantage of reduced on-site Coulomb repulsion which is one of the prerequisites for components of organic metals. The construction of such large compounds is currently accomplished by insertion of an extensively π-conjugated system between two 1,3-dithiolylidene or dicyanomethylene groups. The usefulness of a heteroquinoid system as such a building block is demonstrated by examples of heteroatom-incorporating TCNQ acceptors (hetero-TCNQs), which form a variety of highly conductive charge-transfer complexes. In addition, recent advances concerning quino-2,2′-bis(1,3-dithioles) and TTF vinylogs as novel electron donors are introduced.

Naphtho[1,8-bc : 5,4-b′c′]dithiophene: a new heteroarene isoelectronic with pyrene

The title compound is prepared as a new heteroarene isoelectronic with pyrene, having a stronger electron donating ability than pyrene and isomeric naphtho[1,8-bc : 4,5-b′c′]dithiophene.

Phenanthro[1,10-cd:8,9-c′d′]bis[1,2]-dithiole and -diselenole as novel electron donors

The preparation of the title compounds is reported along with their formation of electrically highly conductive charge-transfer complexes with the common electron acceptors TCNQ, TCNQF4, and DDQ.

2,6-Bis(dicyanomethylene)-2,6-dihydrobenzo[1,2-b;4,5-b']dithiophene as a novel electron acceptor

Abstract The title-TCNQ involving the the 2,6-quinoid skeleton of benzo[1,2-b:4,5b′]dithiophene has been prepared in order to design a superior electron acceptor with both a strong electron-accepting ability and a strong heteroatomic interaction. The cyclic voltammetry demonstrated that it corresponds to a potential electron acceptor comparable to TCNQ. It thus formed highly conductive complexes with the following electron donors: TTT, 4,5 Scm−1; HMTTeF, 25 Scm−1; DMTTeA, 0.07 Scm−1; TPBP, 0.54 Scm−1.

11,11,12,12-Tetracyano-2,6-anthraquinodimethane (TANT) as a novel extensive electron acceptor

The title compound is prepared as a higher homologue in an extensively conjugated series of TCNQ (7,7,8,8-tetracyanoquinodimethane) and TNAP (9,9,10,10-tetracyano-2,6-naphthoquinodimethane); its complexes with TTT (tetrathiatetracene) and HMTTeF (hexamethylenetetratellurafulvalene) are electrically highly conductive.

2,5-bis(dicyanomethylene)-2,5-dihydrofuran and its conjugated homologues as novel oxygen-containing electron acceptors

Abstract The title furanoquinonoid compounds have been prepared in order to design new oxygen-containing organic metals, but most of them behaved as week electron acceptors to form low-conductive molecular complexes. An X-ray crystallographic analysis of the TTF complex of 5,5′-bis(dicyanomethylene)-5,5′-dihydro-δ 2,2′ -bifuran revealed that the bifuranoquinonoid conjugation takes a planar trans form and the embedded oxygens do not take part in any intermolecular interaction. On the other hand, 3,3′-dibromo-5,5′-bis(dicyanomethylene)-5,5′-dihydro-δ 2,2′ -bifuran as a modified acceptor gave a high-conductive TTT complex of 2.4 Scm −1 .