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11.
Hayami S Hashiguchi K Juhász G Ohba M Okawa H Maeda Y Kato K Osaka K Takata M Inoue K 《Inorganic chemistry》2004,43(14):4124-4126
Cobalt(II) compounds [Co(pyterpy)Cl(2)].MeOH (1.(MeOH)) and [Co(pyterpy)Cl(2)].2H(2)O (1.(2H(2)O)) were synthesized. The compound 1.(MeOH) forms the quasi 3-D networks by making pi-pi stacking between the 1-D chains. The methanol molecules from 1.(MeOH) can be removed by heating, and substituted by absorption of water molecules. The MeOH molecules in 1.(MeOH) are removed by heating at 410 K, and they are substituted by water molecules to form 1.(2H(2)O). 1.(2H(2)O) exhibits a S = (3)/(2) (HS) left arrow over right arrow S = (1)/(2) (LS) spin transition with a thermal hysteresis. We have succeeded in constructing a guest dependent 1-D spin-crossover cobalt(II) compound. 相似文献
12.
Chromal blue G in the presence of cetyltrimethylammonium chloride is proposed for the spectrophotometric determination of microgram amounts of beryllium. The sensitivity of color reaction between beryllium and chromai blue G has been greatly increased by the sensitizing action of cetyltrimethylammonium chloride (626nm = 93,000). Beer's law is obeyed over the range 0.012–0.12 ppm of beryllium. Full color development occurs in 20 min at pH 5.5 and at 626 nm. The mole ratio of beryllium and chromai blue G in the complex is estimated to be 1:2. The proposed method is very sensitive and selective for determination of beryllium when EDTA is used as a masking agent. 相似文献
13.
Yamada K Yagishita S Tanaka H Tohyama K Adachi K Kaizaki S Kumagai H Inoue K Kitaura R Chang HC Kitagawa S Kawata S 《Chemistry (Weinheim an der Bergstrasse, Germany)》2004,10(11):2647-2660
Novel metal-complex assemblies constructed from the flexible hinge-like ligand H(2)bhnq (H(2)bhnq=2,2'-bi(3-hydroxy-1,4-naphthoquinone)) have been synthesized. The X-ray crystal structures of these compounds reveal that four types of architectures are accessible by variation of the metal ions. In copper(II) compounds 1-3, the chelating bhnq(2-) ions bridge copper(II) centers to form one-dimensional zigzag chains. The chains of 1-3 are arranged by hydrogen-bonding interactions and stacking interactions to produce porous structures. Cobalt(II) and zinc(II) compounds 4 and 5 form one-dimensional helical chains. In 4 and 5, the crystal packing induces spontaneous resolution of the helical chains with chiral cavities formed perpendicular to the helices. Nickel(II) compounds 6 and 7 form cyclic tetramers. The fourth architecture, a dimer (compound 8), is obtained by the reaction of zinc(II) and bhnq(2-) in MeOH. In these compounds, changes of the dihedral angles and the metal-coordination mode of the bhnq(2-) ion induce the structural versatility. The assemblies of the zigzag chains of the copper(II) compounds exhibit reversible vapochromic behavior. UV/Vis, powder X-ray diffraction, EPR, and adsorption isotherm measurements indicate that this vapochromic behavior is based on the hinge-like flexibility of the bhnq(2-) ion. 相似文献
14.
Mukai C Inagaki F Yoshida T Yoshitani K Hara Y Kitagaki S 《The Journal of organic chemistry》2005,70(18):7159-7171
[reaction: see text] Rhodium(I)-catalyzed PKR of allenynes was found to be applicable for constructing azabicyclo[5.3.0]decadienone as well as oxabicyclo[5.3.0]decadienone frameworks. In addition, a reliable procedure for constructing a 10-monosubstituted bicyclo[5.3.0]deca-1,7-dien-9-one ring system by the rhodium(I)-catalyzed PKR of allenynes was developed under the condition of 10 atm of CO. Investigation of the rhodium(I)-catalyzed cycloisomerization of 4-phenylsulfonylnona-2,3-dien-8-ynes under nitrogen atmosphere gave the corresponding cyclohexene derivatives, whereas the C1-homologated allenynes produced cycloheptene derivatives and/or bicyclo[5.2.0]nonene skeletons depending on the substitution pattern at the allenic terminus. Thus, proper choice of the starting allenynes and reaction conditions led to the selective formation of 2-phenylsulfonylbicyclo[5.3.0]deca-1,7-dien-9-ones (Pauson-Khand-type product), 3-alkylidene-1-phenylsulfonyl-2-vinylcycloheptene derivatives, and bicyclo[5.2.0]nonene frameworks. 相似文献
15.
Shuichi Hirata Kouichi Tanaka Katsuya Matsui Fernando Arteaga Arteaga Yasushi Yoshida Shinobu Takizawa Hiroaki Sasai 《Tetrahedron: Asymmetry》2013,24(19):1189-1192
The introduction of a 1,3-propanediamine unit at the 3-position of (S)-BINOL using a methylene spacer led to the formation of a chiral bifunctional organocatalyst for the aza-Morita–Baylis–Hillman (aza-MBH) reaction. The organocatalyst 1k mediated aza-MBH transformations with high chemical yields and with up to 82% ee. 相似文献
16.
Transition Metal Chemistry - The crystal structures and magnetic properties of three coordination compounds constructed from various nitroxide radicals L and MII(hfac)2(H2O)2 building blocks... 相似文献
17.
Yanting Song Katsuya Takatsuki Muneki Isokawa Tetsushi Sekiguchi Jun Mizuno Takashi Funatsu Shuichi Shoji Makoto Tsunoda 《Analytical and bioanalytical chemistry》2013,405(25):7993-7999
In this study, a fast and quantitative determination method for branched-chain amino acids (BCAAs), namely leucine, isoleucine, and valine, was developed using a pillar array column. A pillar array column with low-dispersion turns was fabricated on a 20?×?20-mm2 microchip using multistep ultraviolet photolithography and deep reactive ion etching. The BCAAs were fluorescently labeled with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F), followed by reversed-phase separation on the pillar array column. The NBD derivatives of the three BCAAs and an internal standard (6-aminocaproic acid) were separated in 100 s. The calibration curves for the NBD-BCAAs had good linearity in the range of 0.4–20 μM, using an internal standard. The intra- and interday precisions were found to be in the ranges of 1.42–3.80 and 2.74–6.97 %, respectively. The accuracies for the NBD-BCAA were from 90.2 to 99.1 %. The method was used for the analysis of sports drink and human plasma samples. The concentrations of BCAAs determined by the developed method showed good agreements with those determined using a conventional high-performance liquid chromatography system. As BCAAs are important biomarkers of some diseases, these results showed that the developed method could be a potential diagnostic tool in clinical research. 相似文献
18.
Katsuya Maeyama Kenji Yamashita Shugo Maeda Noriyuki Yonezawa Shunichi Aikawa Yasuhiko Yoshida 《合成通讯》2013,43(23):4158-4170
Optically active aromatic ether ketone macrocycles containing 2,2′-dimethoxy-1,1′-binaphthyl-6,6′-diyl moieties were synthesized through electrophilic aromatic substitution reaction and stepwise nucleophilic aromatic substitution reactions. Structures of the resulting macrocycles were confirmed by NMR and matrix assisted laser desorption/ionization time of flight (MALDI-TOF) mass measurements. 相似文献
19.
20.
Katsuya Oji Asako Igashira‐Kamiyama Nobuto Yoshinari Takumi Konno 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(7):2023-2027
A novel AuICoIII coordination system that is derived from the newly prepared [Co(D ‐nmp)2]− ( 1 −; D ‐nmp=N‐methyl‐D ‐penicillaminate) and a gold(I) precursor AuI is reported. Complex 1 − acts as a sulfur‐donating metallaligand and reacts with the gold(I) precursor to give [Au2Co2(D ‐nmp)4] ( 2 ), which has an eight‐membered AuI2CoIII2 metallaring. Treatment of 2 with [Au2(dppe)2]2+ (dppe=1,2‐bis(diphenylphosphino)ethane) leads to the formation of [Au4Co2(dppe)2(D ‐nmp)4]2+ ( 3 2+), which consists of an 18‐membered AuI4CoIII2 metallaring that accommodates a tetrahedral anion (BF4−, ClO4−, ReO4−). In solution, the metallaring structure of 3 2+ is readily interconvertible with the nine‐membered AuI2CoIII metallaring structure of [Au2Co(dppe)(D ‐nmp)2]+ ( 4 +); this process depends on external factors, such as solvent, concentration, and nature of the counteranion. These results reveal the lability of the Au S and Au P bonds, which is essential for metallaring expansion and contraction. 相似文献