Spin–spin coupling between the two unpaired electrons in cross-conjugated tetrathiafulvalene dication radicals

✍ Scribed by Jun Yamauchi; Takuo Aoyama; Katsuichi Kanemoto; Shigeru Sasaki; Masahiko Iyoda

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 130 KB
• Volume: 13
• Category: Article
• ISSN: 0894-3230
• DOI: 10.1002/(sici)1099-1395(200004)13:4<197::aid-poc229>3.0.co;2-2

✦ Synopsis

Spin-spin interactions were examined for bis(tetrathiafulvalenyl) (TTF) derivatives bridged with a 1,1vinyl group (2,2-diphenyl, 1: 2,2-fluorenylidene, 2; and 2,2-dimethyl, 3). The chemical oxidation of these crossconjugated TTFs using AgClO 4 yielded characteristic seven-line ESR spectra, indicating the exchange interactions between the unpaired electrons on each TTF moiety. Compounds 2 and 3, in addition, exhibited fine structures and half-field resonances in the frozen solutions, which evidence the triplet interaction in the solid state, even with a twisted geometry of the molecular configuration. These findings substantiate the possibility of spin-spin interactions or triplet ground states predicted for some TTF oligomers.