Authorship：Lead author   Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

Chiral electroactive materials have attracted attention for the effects of electrical magnetochiral anisotropy (eMChA) and chirality-induced spin selectivity (CISS). The combination of tetrathiafulvalene (TTF) with chiral moieties is one way to access chiral electroactive materials. In this paper, we have focused on the fused 2,3-dimethylcyclohexene (DMCh) ring as a substituent with chiral carbon atoms and without heteroatoms, which has not been used in the field of molecular conductors, and we synthesized a new TTF derivative (rac-DMCh-EDT-TTF). We have developed novel molecular conductors (rac-DMCh-EDT-TTF)2X (X− = PF6−, AsF6− and ClO4−), which have bilayer conducting sheets composed of the two crystallographically independent molecules. All salts exhibited semiconducting behavior from room temperature down to low temperatures, and a resistivity anomaly was observed at 180–250 K. X-ray structure analysis at 100 K and 263 K and molecular orbital calculations using the results of X-ray structure analysis indicated the emergence of a charge disproportionation between Layers 1 and 2 at the low-temperature phase.

DOI： 10.3390/chemistry6060091

Publishing type：Research paper (scientific journal)   Publisher：Oxford University Press (OUP)  

Abstract

Derivatives of a 1,3-dithiole[6]dendralene analog with two thiophene spacers inserted (2) have been successfully synthesized. Cyclic voltammetry and spectroelectrochemistry revealed that their redox behavior, based on the distribution of the positive charges, differed depending on the position and the electronic effect of substituents on the 1,3-dithiole rings.

DOI： 10.1093/chemle/upae104

Other Link： https://academic.oup.com/chemlett/article-pdf/53/6/upae104/58334564/upae104.pdf

Publishing type：Research paper (scientific journal)   Publisher：Oxford University Press (OUP)  

Abstract

Several derivatives of 1,3-dithiole[3]dendralene with one thiophene spacer (1) were newly prepared. X-ray structure analysis of the hexamethyl-1 (1Aa) revealed that 1Aa adopts a structure with significant distortion between the central 1,3-dithiole (DT) ring and the thiophene ring. Cyclic voltammograms of all the derivatives were composed of three pairs of one-electron redox waves in correspondence with the presence of three redox-active DT rings. The results of cyclic voltammetry and spectroelectrochemistry indicated that a positive charge in 1Aa•+ is mainly delocalized on the vinyl-extended tetrathiafulvalene (TTF) moiety, while two positive charges in 1Aa2+ are mainly distributed on the thiophene-inserted TTF moiety. X-ray structure analysis revealed that two-electron oxidation of 1Aa with (4-BrC6H4)3N•+SbCl6− gradually facilitated the formation of a dicationic species of its chlorinated product.

DOI： 10.1246/bcsj.20220191

Publishing type：Research paper (scientific journal)   Publisher：Oxford University Press (OUP)  

Abstract

Tetrathiafulvalene derivatives bridged by butylene units were successfully synthesized. X-ray structure analysis of the dimeric EBDT 1 revealed that C–C bonds have staggered arrangement and all substituents are arranged anti to each other in the butylene bridge. Cyclic voltammograms of the molecules 1 and the fused TTF analog 2 consisted of two-pairs of two-electron and four pairs of two-electron redox waves, respectively. X-ray structure analysis and calculation of overlap integrals of a dicationic salt of unsubstituted-1 (1Aa) indicated that the EBDT units are stacked with strong dimerization. Coin-type cells using the molecule 2 (2Ce) as a positive electrode material showed initial discharge capacity of 179 mAh g−1, initial energy density of 600 mWh g−1, and an average voltage of 3.35 V.

DOI： 10.1246/bcsj.20200357

Event date： 2025.3

Presentation type：Poster presentation  

Event date： 2025.3

Presentation type：Oral presentation (general)  

Event date： 2025.3

Presentation type：Oral presentation (invited, special)  

Event date： 2025.3

Presentation type：Oral presentation (general)  

Event date： 2025.3

Presentation type：Oral presentation (general)