Synthesis, characterization, and physical properties of oligo(1-(N,N-dimethylamino)pyrrole)s and their doped forms, precursors of candidates for molecular flat-band ferromagnets
| العنوان: | Synthesis, characterization, and physical properties of oligo(1-(N,N-dimethylamino)pyrrole)s and their doped forms, precursors of candidates for molecular flat-band ferromagnets |
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| المؤلفون: | Kazuhiro Takahashi, Mariko Miyachi, Norikazu Ohshima, Tetsuro Kusamoto, Ryota Sakamoto, Yoshinori Yamanoi, Hiroshi Nishihara, Takeshi Hamada, Masashi Kurashina, Yohei Hattori |
| المصدر: | Journal of Materials Chemistry C. 3:4316-4320 |
| بيانات النشر: | Royal Society of Chemistry (RSC), 2015. |
| سنة النشر: | 2015 |
| مصطلحات موضوعية: | Chemistry, Stereochemistry, Dimer, General Chemistry, Crystal structure, Electrochemistry, law.invention, chemistry.chemical_compound, Crystallography, Paramagnetism, law, Materials Chemistry, Chemical stability, Electron paramagnetic resonance, Single crystal, Pyrrole |
| الوصف: | Fully oxidized poly(1-(N,N-dimethylamino)pyrrole)s (PDMAPyn+), which are synthesized through doping with anions with the same number of polymer units as the original pyrrole, have been proposed as candidates for molecular flat-band magnets from the theoretical calculations of Aoki and coworkers (Phys. Rev. B: Condens. Matter Mater. Phys., 2003, 68, 140403; Phys. Rev. B: Condens. Matter Mater. Phys., 2010, 82, 235127). Here we describe the synthesis of neutral forms of oligo(1-(N,N-dimethylamino)pyrrole)s (ODMAPys) from the dimer (2) to the dodecamer (12). The crystal structures of 2–6 (i.e., up to the hexamer) were determined by single crystal X-ray analysis. The chemical and electrochemical formation of their oxidized forms is also reported. Electrochemical measurements of the ODMAPys indicated that oligomers 4, 6, and 8 underwent 2e− oxidation, whereas 10 and 12 showed quasi-reversible 4e− oxidation. The oxidized forms maintained considerable chemical stability; 42+, 62+, 82+, 104+, and 124+ were isolated as SbCl6− salts. The neutral forms were colorless (λmax = 240–270 nm), whereas the oxidized forms exhibited strong blue color with λmax = 670–950 nm. EPR spectroscopy indicated that the dications 42+, 62+, and 82+ in the solid salts were intrinsically diamagnetic, but the tetracation of 104+ was paramagnetic at 4.4 K, which was supported by magnetic measurements. These physical properties of the ODMAPys are different from those common to polypyrroles, but consistent with their predicted unique electronic structures. |
| تدمد: | 2050-7534 2050-7526 |
| DOI: | 10.1039/c4tc02941k |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_________::3a3c51ec190be1dfee160521ad7bce3c https://doi.org/10.1039/c4tc02941k |
| رقم الانضمام: | edsair.doi...........3a3c51ec190be1dfee160521ad7bce3c |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 20507534 20507526 |
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| DOI: | 10.1039/c4tc02941k |