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1تقرير
المؤلفون: Suenaga Yusaku, lnomata Masataka, Yabumoto Shiomi, Yamaguchi Ryotaro, Okubo Takashi, Maekawa Masahiko, Takayoshi Kuroda-Sowa
مصطلحات موضوعية: Tri-nuclear Co complex, Hexahydroxy triphenylene, Valence tautomeric behavior, Electrochemical behavior, Magnetic property
الوصف: [Abstract] Three tri-nuclear cobalt complexes ([Co3(tpa)3(L)](BF4)4 (1) (tpa=tris(2-pyridylmethyl)amine),[Co3(Metpa)3(L)](BF4)4 (2) (Metpa=(6-methyl-2-pyridylmethyl)bis(2-pyridylmethyl)amine) and [Co3(Me2tpa)3(L)](BF4)3 (3) (Me2tpa=bis(6-methyl-2-pyridylmethyl)(2-pyridylmethyl)amine)) with 2,3,6,7,10,11hexahydroxytriphenylene (H6L) and three spieces ancillary ligands have been prepared. Tri-nuclear mixed-valence Co complex (3) is prepared from methanol solution. Complex (3) has consist in that the valence of two cobalt ions have +III,one cobalt ion has +II and the tris-dioxolene bridging ligand is formally in the -5 [cat,cat,sq] oxidation state. Complex (3) shows evidence of temperature dependence of the charge distribution, displaying thermally induced valence tautomeric transition from {(ls-CoIII)2(hs-CoII)}-L(cat,cat,sq) to {(ls-CoIII)(hs-CoII)2}-L(cat,sq,sq) in both solid and solution states. On the other hand, complex (1) and complex (2) are stable in the entire temperature range investigated.Various-temperature magnetic susceptibility data for the compound displayed little variation in the range 2-380 K, and the reason caused the distinct charge distribution on Co-L (L: bridging ligand) by the natural rigidity of the tripodal ligands. These results appeared methylation of the 6-position of the pyridine rings in ancillary ligand effect on redox state in the complex, occuring the distribution of electrons between the cobalt centers and the bridging ligand.
وصف الملف: application/pdf
العلاقة: https://kindai.repo.nii.ac.jp/?action=repository_uri&item_id=19947Test; http://id.nii.ac.jp/1391/00019928Test/; 理工学総合研究所研究報告 = Annual reports by Science and Technology Research Institute, (30), 1-10(2018-02-28); https://kindai.repo.nii.ac.jp/?action=repository_action_common_download&item_id=19947&item_no=1&attribute_id=40&file_no=1Test
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2تقرير
المؤلفون: Suenaga Yusaku, Hirano Yasuhiro, Umehata Yukiko, Kamei Kuniaki, Maekawa Masahiko, 前川, 雅彦
مصطلحات موضوعية: bis(catechol), acetylene group, rod like structure, electrochemical behavior
الوصف: [Abstract] Three bis(catechol) compounds 5,5'-(buta-1,3-diyne-1,4-diyl) bis(3-tert-butylcatechol) (Biscat 1), 5,5'-(2,5-dimethoxy-1,4-phenylene)bis(ethyne-2,1-diyl)bis(3-tert-butyl-catechol) (Biscat 2) and 5,5'-(1,3-phenylene)bis(ethyne-2,1-diyl)bis(3-tert-butylcatechol) (Biscat 3) were obtained from cross-coupling reactions. Biscat 1 and Biscat 2 were characterized by X-ray crystal analysis and cyclic voltammetry (CV). The results from Xray crystal analysis shows that Biscat 1 and 2 possess a rod like structure with molecular lengths 14.7Å for Biscat 1 and 19.3Å for Biscat 2. In Biscat 1, the two catechol rings are not in the same plane and the dihedral angle of terminal catechol rings is about 25°. CVs for Biscat 1 and 2 were measured under alkaline conditions. An oxidation wave was observed corresponding to Sq-Sq (Sq: semiquinone)→Bq-Bq (Bq: benzoquinone) at around -300 mV. However, the redox waves disappeared when the CV scan was repeated. In contrast, Biscat 3 showed stable redox waves in the range from -1 V to ＋1.5 V even in alkaline conditions. These results suggest that Biscat 1 and 2 were converted into polymer or oligomer compounds (insoluble materials) through the Bq-Bq structures during repeat of the CV scans.
وصف الملف: application/pdf
العلاقة: https://kindai.repo.nii.ac.jp/?action=repository_uri&item_id=11144Test; http://id.nii.ac.jp/1391/00011138Test/; 理工学総合研究所研究報告 = Annual reports by Research Institute for Science and Technology, (23), 23-33(2011-02-01); https://kindai.repo.nii.ac.jp/?action=repository_action_common_download&item_id=11144&item_no=1&attribute_id=40&file_no=1Test
