A series of 2,4,5,7,9,10-hexaethynylpyrenes was synthesized using 2,7,9,10tetrabromopyrene-4,5-dione as the key intermediate. The effects of the position and number of the ethynyl groups on the physicochemical properties of the corresponding pyrenes were clarified by comparison with 4,5,9,10-tetraethynylpyrene and 2,7-diethynylpyrene derivatives. The prepared hexaethynylpyrenes that bear benzene moieties self-assemble via π−π stacking in solution and/or the condensed phase.
Japanese native chiken population is newly found in southern region of Ehime Prefecture in Shikoku. The measurments of external traits and the collecting of blood samples from 121 birds were performed. Size of the chickens was small, weighing 1,091 g for adult males and 796g for adult females. The population varied in plumage and skin colors more than the Tosajidori, one of the oldest Japanese native chicken breed, and originating in Kochi Prefecture, Shikoku. High frequencies of C, e+, s, Mo, w and ld were always ovserved in the five polymorphic loci of the population, whereas these loci were monomorphic in the Tosajidori. Blood samples were analyzed for protein polymorphisms by starch gel or polyacrylamid gel electrophoresis. Polymorphisms were observed in nine loci, that is Tf, Alb, PasA, Akp, Akp-2, Es-1, Amy-1, Ct and 6-PGD. A dendrogram based on genetic distances was drawn to elucidate phylogenetic relationships of 44 breeds or populations of the chickens. Relative close relations were ovserved among the Ehime native chicken population, the Tosajidori, the Ohiki (the Minohikichabo) and the Koshamo. The Tosajidoris in ealier days were much more polymorphic in plumage, skin and ear lobe colors, and were similar to the Ehime native population. The present feature of the population may reflect a prototype of the Tosajidori. It is suggested that the Ehime native chicken population (which we propose to name the Ehimejidori) and Tosajidori deriverd from a commom ancester..
Optically active fullerenes, including C60 and C70 derivatives carrying organic substituents, are used in a range of applications because of their unique spectroscopic, catalytic, and chiral recognition properties. However, their inherent photoexcited chirality is yet to be elucidated because of their very poor fluorescence quantum yield (Φf). We synthesised a new chiral C70 derivative, X70A, with 20% yield, by reacting bis-borylated xanthene with C70 in a one-step double addition reaction, followed by a successful optical resolution. The isolation of two separate X70A enantiomers was confirmed by mirror-image circular dichroism spectroscopy in the range of 300–750 nm. In toluene, the enantiomeric pair of X70A clearly revealed mirror-image circularly polarised luminescence (CPL) spectra with a high |glum| value of 7.0 × 10−3 at 690 nm. The first fullerene-based deep-red CPL of X70A should provide a new guideline for the design of chiral nanocarbon materials.
The preparation of large rylenes often needs the use of solubilizing groups along the rylene backbone, and all the substituents of the terrylenes and quaterrylenes were introduced before creating the rylene skeleton. In this work, we successfully synthesized 2,5,10,13-tetrakis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)terrylene (TB4) by using an iridium-catalyzed direct borylation of C–H bonds in terrylene in 56% yield. The product is soluble in common organic solvents and could be purified without column chromatography. Single crystal X-ray diffraction analysis revealed that the terrylene core is not disturbed by the substituents and is perfectly flat. The photophysical properties of TB4 are also unchanged by the substituents because the carbon atoms at 2,5,10,13-positions have less coefficients on its HOMO and LUMO, estimated by theoretical calculations. Finally, the same borylation reaction was applied for quaterrylene, resulting in the formation of soluble tetra-borylated quaterrylene despite a low yield. The post modification of rylenes enables us to prepare their borylated products as versatile units after creating the rylene skeletons.
We successfully achieved the synthesis of C 60 -xanthlium, X60_ NTf 2 , where fullerene is an electron donor and xanthlium is an electron acceptor. When the precursor compound X60-OH was excited at 550 nm, the C 60 emission was observed at 715 nm. On the other hand, the fluorescence of X60_NTf 2 was completely quenched under the same conditions, suggesting that photo-induced intramolecular electron transfer (ET) occurred from the singlet excited state of C 60 . The electrochemical measurement proved that the X60_NTf 2 is exothermically possible of ET reaction from 1 C 60 * to xanthylium to form C 60 * + . Density functional theory (DFT) calculations support the acceptor ability of the xanthylium by showing that the coefficients of the lowest unoccupied molecular orbital (LUMO) were on xanthene moiety. This is a well-arranged model compound to investigate the properties of transiently generated fullerene radical cations.
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