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81.
Anthracene derivatives possessing pentafluorobenzoyloxy moieties at 9- and 10-positions showed polymorphism affording two types of fluorescent crystals with blue and bluish green fluorescence in their crystalline state, respectively. Their single crystal X-ray structures showed that the degree of overlap of anthracene moieties was responsible for the difference in fluorescence. Fluorescence in the crystalline state originated in the dimer emission deduced from their excitation spectra. 相似文献
82.
Xiushang Xu Gianluca Serra Andrea Villa Rafael Muoz-Mrmol Serhii Vasylevskyi Marcos Gadea Andrea Lucotti Zensen Lin Pedro G. Boj Ryota Kabe Matteo Tommasini María . Díaz-García Francesco Scotognella Giuseppe Maria Patern Akimitsu Narita 《Chemical science》2022,13(44):13040
We report the synthesis of a dibenzodinaphthocoronene (DBDNC) derivative as a novel nanographene with armchair, zigzag, and fjord edges, which was characterized by NMR and X-ray crystallography as well as infrared (IR) and Raman spectroscopies. Ultrafast transient absorption (TA) spectroscopy revealed the presence of stimulated emission signals at 655 nm and 710 nm with a relatively long lifetime, which resulted in dual amplified spontaneous emission (ASE) bands under ns-pulsed excitation, indicating the promise of DBNDC as a near-infrared (NIR) fluorophore for photonics. Our results provide new insight into the design of nanographene with intriguing optical properties by incorporating fjord edges.Dibenzo[a,m]dinaphtho[ef,hi]coronene with zigzag and fjord edges was synthesized and characterized, demonstrating a nonplanar structure with near-infrared stimulated emission with a relatively long lifetime and dual-amplified spontaneous emission. 相似文献
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Yongzhu J Hirose K Nakamura T Nishioka R Ueshige T Tobe Y 《Journal of chromatography. A》2006,1129(2):201-207
In order to develop a chiral stationary phase (CSP), which has even higher separation ability than the corresponding commercially available crown ether based CSP (OA-8000 having a pseudo-18-crown-6 ether with an OMe group as a selector), chemically bonded type CSP having a phenolic OH group on a crown ring was developed. Normal mobile phases with or without acid additive can be used with this OH type CSP in contrast to the conventional OMe type CSP which has a neutral chiral selector. Enantiomers of 25 out of 27 amino compounds, including 20 amino acids, 5 amino alcohols, and 2 lipophilic amines, were efficiently separated on a column with this CSP. Nine amino compounds out of 27 were separated with better separation factors than the corresponding OMe type CSP. It is noteworthy that the chromatography on this CSP exhibited excellent enantiomer-separations for amines and amino alcohols when triethyl amine was used as an additive in the mobile phase. Comparison of enantiomer separation ability on this OH type of CSP and on the OMe type of CSP and correlation between the enantioselectivity in chiral chromatography and that of the corresponding model compounds in solution imply that the chiral separation arose from chiral recognition in host guest interactions. 相似文献
86.
Sagawa T Sueyoshi R Kawaguchi M Kudo M Ihara H Ohkubo K 《Chemical communications (Cambridge, England)》2004,(7):814-815
A TiO(2)/polymer film on a quartz plate fabricated by a layer-by-layer method was employed for NADH production from NAD(+) with lipoamide dehydrogenase and methyl viologen in Tris-HCl buffer on irradiation with UV light, and the ultra thin film prevented from enzyme deactivating effectively. 相似文献
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A thin film of δ‐type MnO2 grown cathodically has been investigated with respect to the ability toward anodic decomposition of H2O2 and durability. With polarization at less positive potentials than +0.4 V vs. Ag/AgCl, the film was dissolved exclusively as a result of reduction of Mn4+ sites in the oxide by H2O2 to soluble Mn2+. At +0.9 V, MnO2 remained unchanged and decomposed H2O2 in solution. At +0.8 V, the film was once dissolved in the initial stage; however, it was self‐healed via reoxidation of the liberated Mn2+ ions. Amperometric flow‐injection analysis of H2O2 was carried out with the δ‐MnO2 film. 相似文献
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