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81.
Misaki Ueda Zi Lang Goo Katsue Minami Nobuto Yoshinari Takumi Konno 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(41):14815-14820
A 60‐nuclear silver sulfide nanocluster with a highly positive charge ( 1 ) has been synthesized by mixing an octahedral RhIII complex with 2‐aminoethanethiolate ligands, silver(I) nitrate, and d ‐penicillamine in water under mild conditions. The spherical surface of 1 is protected by the chiral octahedral RhIII complex, with cleavage of the C?S bond of the d ‐penicillamine supplying the sulfide ions. Although 1 does not contain d ‐penicillamine, it is optically active because of the enantiomeric excess of the RhIII molecules induced by chiral transfer from d ‐penicillamine. 1 can accommodate/release external Ag+ ions and replace inner Ag+ ions by Cu+ ions. The study demonstrates that a thiolato metal complex and sulfur‐containing amino acid can be used as cluster‐surface‐protecting and sulfide‐supplying regents, respectively, for creating chiral, water‐soluble, structurally precise silver sulfide nanoclusters, the properties of which are tunable through the addition/removal/exchange of Ag+ ions. 相似文献
82.
Lianhua Jin Nobuto Miyatsu Eiichi Kondoh Bernard Gelloz Naobumi Kanazawa Toru Yoshizawa 《Optical Review》2018,25(6):656-662
The diameter of cylindrical openings is conventionally measured with the mechanical and contact method. In this paper, we propose a contactless optical approach to measure dimensions of inner profile by a disk beam probe. The measurement is carried out illuminating the inner cylindrical opening with a light sheet generated by the disk beam probe, acquiring the light-section image of the object with an image sensor through a widefield lens, then numerically extracting the diameter. During measurement, the probe is aligned inside the openings with high freedom, which causes the optical section to manifest a variety of ellipses besides a circle accordingly. The measurement method copes with extracting the diameter of openings from various ellipse optical sections. The high freedom of probe alignment allows optical diameter measurement to be flexible and simple. The dimensions of cylindrical openings of manufactured parts were practically measured with the disk beam probe, and the results were confirmed with those measured with the vernier caliper. 相似文献
83.
Dr. Nobuto Yoshinari Dr. Natthaya Meundaeng Dr. Hiroyasu Tabe Prof. Yusuke Yamada Dr. Satoshi Yamashita Prof. Yasuhiro Nakazawa Prof. Takumi Konno 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(41):18204-18209
Postsynthetic installation of lanthanide cubanes into a metallosupramolecular framework via a single-crystal-to-single-crystal (SCSC) transformation is presented. Soaking single crystals of K6[Rh4Zn4O(l -cys)12] (K6[ 1 ]; l -H2cys=l -cysteine) in a water/ethanol solution containing Ln(OAc)3 (Ln3+=lanthanide ion) results in the exchange of K+ by Ln3+ with retention of the single crystallinity, producing Ln2[ 1 ] ( 2Ln ) and Ln0.33[Ln4(OH)4(OAc)3(H2O)7][ 1 ] ( 3Ln ) for early and late lanthanides, respectively. While the Ln3+ ions in 2Ln exist as disordered aqua species, those in 3Ln form ordered hydroxide-bridged cubane clusters that connect [ 1 ]6− anions in a 3D metal-organic framework through coordination bonds with carboxylate groups. This study shows the utility of an anionic metallosupramolecular framework with carboxylate groups for the creation of a series of metal cubanes that have great potential for various applications, such as magnetic materials and heterogeneous catalysts. 相似文献
84.
Counter‐Anion‐Regulated Mixed‐Valency of Cobalt(II/III) Centers in a Metallosupramolecular Framework
A diamagnetic AuI4CoIII2 hexanuclear complex, [Au4Co2(dppe)2(l ‐nmc)4]2+ ([ 1L ‐ nmc ]2+; dppe=1,2‐bis(diphenylphosphino)ethane, l ‐H2nmc=N‐methyl‐l ‐cysteine), was newly synthesized by the reaction of [Co(l ‐nmc)2]? with [Au2Cl2(dppe)] and crystallized with different inorganic anions (X=ClO4?, NO3?, Cl?, SO42?) to produce ionic solids ([ 1L ‐ nmc ]Xn). Single‐crystal X‐ray analysis revealed that all the solids crystallize in the chiral space group F432 with a face‐centered‐cubic lattice structure consisting of supramolecular octahedra of complex cations. The paramagnetic nature of all the solids was evidenced by magnetic susceptibility measurements, showing the variation of the oxidation states of two cobalt centers in [ 1L ‐ nmc ]n+ from CoII1.00CoIII1.00 for X=ClO4? or NO3? to CoII0.67CoIII1.33 for X=Cl?, via CoII0.83CoIII1.17 for X=SO42?. The difference in the CoII/III mixed‐valences was explained by the difference in sizes and charges of counter anions accommodated in lattice interstices with a fixed volume. 相似文献
85.
Shin Ando Yoshinari Okamoto Masami Otsuka Kazuo Umezawa 《Journal of heterocyclic chemistry》2008,45(6):1803-1808
Conophylline is a bisindole alkaloid of unique structure that shows anti‐cancer and anti‐diabetic activities. Two indole core structures of conophylline, namely 6,7‐dimethoxy‐5‐methoxymethoxy‐1H‐indole ( 1 ), and N‐benzoyl‐N‐[2‐(6‐methoxymethoxy‐2‐vinyl‐1H‐indol‐3‐yl)ethyl]amine ( 2 ) has been synthesized starting with substituted benzene derivatives. 相似文献
86.
Mingdeng Wei Yoshinari Konishi Hideki Sugihara Hironori Arakawa 《Solid State Communications》2005,133(8):493-497
Nanotubes TiO2 were synthesized from layered titanate Na2Ti3O7 particles by a soft chemical process. These nanotubes have a hollow structure with an opening end. The wall of nanotubes is very well crystallized multi-wall structure. The inner diameters of nanotubes are ca. 30-40 nm and the length up to several hundreds nanometers. XRD results show that TiO2 phase was formed during the procedure of exfoliating Na2Ti3O7 particles into nanosheets. Based on our experimental results, an exfoliating-rolling model was proposed for formation of nanotube structure. 相似文献
87.
88.
89.
M Ono Y Takaki M Takatsuji K Akiyama M Okawa J Kinjo H Miyashita H Yoshimitsu T Nohara 《Chemical & pharmaceutical bulletin》2012,60(8):1083-1087
Three new resin glycosides, quamoclins V (1), VI (2), and VII (3) and a new tetrahydropyran derivative, quamopyran (4), were isolated from the seeds of Quamoclit pennata BOJER (Convolvulaceae). The chemical structures of these compounds were determined primarily on the basis of spectroscopic data. The carboxyl group of the aglycone, 11S-convolvulinolic acid, of 1 and 2 was linked intermoleculary with a hydroxy group of the sugar moiety to form a macrocyclic ester structure, as in already known jalapins, and 3 was an acylated glycosidic acid methyl ester. All of the sugar moieties of 1-3 were acylated by one 2S-methylbutyric acid. Compound 4 was a diketone having a tetrahydropyran ring. 相似文献
90.
Inoue K Ikemura A Tsuruta Y Tsutsumiuchi K Hino T Oka H 《Biomedical chromatography : BMC》2012,26(2):137-141
We developed a high-throughput method based on on-line solid-phase extraction liquid chromatography tandem mass spectrometry (SPE-LC-MS/MS) to determine N-terminal thymosin-β fragment peptide (N-acetyl-seryl-aspartyl-lysyl-proline, Ac-SDKP) in human plasma samples. Quantification of Ac-SDKP was performed using direct injection for on-line SPE based on C(18), reversed-phase LC separation and stable isotope dilution electrospray ionization-MS/MS in multiple reaction-monitoring (MRM) mode. The Ac-SDKP-(13)C(6), (15)N(2) (m/z 496 → 137) was synthesized for the internal standard. The MRM ion for Ac-SDKP was m/z 488 → 129 (quantitative ion)/226. The limit of detection and lower limit of quantitation were 0.05 and 0.1 ng/mL in standard solution, respectively. Recovery values were 98.3-100.4% with inter-day (relative standard deviation, RSD, 0.4-14.1%) and intra-day (RSD, 0.8-19.7%) assays. This method was applied to the measurement of Ac-SDKP levels in plasma from hemodialyzed subjects. Concentrations were 0.59 ± 0.23 ng/mL (pre-hemodialyzed subjects, n = 9) and 0.44 ± 0.19 ng/mL (post-hemodialyzed subjects, n = 9). All plasma Ac-SDKP levels were decreased by dialysis. Thus, plasma Ac-SDKP was decreased through dialysis in chronic kidney disease. The findings in this study will be useful for the treatment of anemia in chronic kidney disease with dialysis. 相似文献