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31.
Volker Böhmer Friedhelm Schneider Keiichi Fukuyama Shigeo Fujii 《Monatshefte für Chemie / Chemical Monthly》1985,116(12):1419-1432
Cyclic esters of adipic acid, suberic acid and sebacic acid were prepared by reaction of the acid dichlorides and pyrocatechol or hydroquinone in benzene under high dilution conditions. While only the cyclic dimers could be obtained from hydroquinone, pyrocatechol formed cyclic monomers as well as cyclic dimers (and also a cyclic dimer with succinic acid). The structure of all compounds was confirmed by1H-NMR- and mass spectra. The crystal structures of the pyrocatechol esters were determined by single crystal X-ray analysis.
Cyclische Ester aliphatischer Dicarbonsäuren mit Brenzcatechin und Hydrochinon
Zusammenfassung Es wurden cyclische Ester von Adipinsäure, Korksäure und Sebacinsäure durch Reaktion der entsprechenden Säure-Dichloride mit Brenzcatechin oder Hydrochinon bei hoher Verdünnung hergestellt. Während mit Hydrochinon lediglich die cyclischen Dimeren erhalten werden konnten, wurden mit Brenzcatechin sowohl cyclische Monomere als auch cyclische Dimere erhalten (ebenfalls das cyclische Dimer mit Bernsteinsäure). Die Strukturen wurden mittels1H-NMR und Massenspektren gesichert. Die Kristallstrukturen der Brenzcatechin-Ester wurden mittels Röntgenstrukturanalyse bestimmt.相似文献
32.
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
33.
Adachi K Sugiyama Y Yoneda K Yamada K Nozaki K Fuyuhiro A Kawata S 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(22):6616-6628
Novel triply hydrogen bonded suprastructures based on [M(tdpd)2(L)2]2- (H2tdpd=1,4,5,6-tetrahydro-5,6-dioxo-2,3-pyrazinedicarbonitrile, L=solvent) and melamine-analogous cations have been synthesized and characterized. The use of anions containing two AAA sets from [M(tdpd)2(L)2]2- together with cations containing one DDD set (A=hydrogen-bond acceptor, D=hydrogen-bond donor) leads to the formation of complementary triply hydrogen bonded modules in the solid state. In all cases, the building module is further extended via additional hydrogen-bonding interactions to produce a tape, and tapes are assembled into sheets. These results show that a hydrogen-bonded module consisting of different kinds of building blocks, one of which is a metal complex that includes hydrogen-bond acceptor sites and the other is a hydrogen-bond donor molecule, will be attractive for constructing metal-containing supramolecular systems by the self-assembly technique. 相似文献
34.
Ishiguro R Yokoyama Y Maeda H Shimamura A Kameyama K Hiramatsu K 《Journal of colloid and interface science》2005,290(1):91-101
Infrared spectra of hen egg white lysozyme and bovine serum albumin (BSA) adsorbed on a solid poly tris(trimethylsiloxy)silylstyrene (pTSS) surface in D2O solution were measured using attenuated total reflection (ATR) Fourier transform infrared spectroscopy. From the area and shape of the amide I' band of each spectrum, the adsorption amount and the secondary structure were determined simultaneously, as a function of adsorption time. We could show that the average conformation for all the adsorbed lysozyme molecules was solely determined by the adsorption time, and independent of the bulk concentration, while the adsorption amount increased with the bulk concentration as well as the adsorption time. These results suggest that lysozyme molecules form discrete assemblies on the surface, and that the surface assemblies grow over several hours to have a definite architecture independent of the adsorption amount. As for BSA, the extent of the conformational change was solely determined by the adsorption amount, regardless of the bulk concentration and the adsorption time. These differences in the adsorption properties of lysozyme and BSA may reflect differences in their conformational stabilities. 相似文献
35.
Irradiation of sodium 1-naphthoxide in MeOH gave selectively 1,4-dihydro-4',8-dihydroxy-1,1'-binaphthyl 2. A similar reaction in PhH afforded the regioisomer 5, along with 6, Structural proof is presented for these hitherto unknown dimers. The reaction is completely quenched in the presence of naphthalene, a good electron scavenger. This new type of photodimerization was proved to be initiated by intermolecular electron-transfer from the excited 1-naphthoxide anion to the ground state one to give the oxidation-reduction dimers. 相似文献
36.
37.
Kitamura M 《Journal of colloid and interface science》2001,236(2):318-327
The crystallization of calcium carbonate was carried out by mixing CaCl(2) and Na(2)CO(3) solutions. The morphology of precursor formed prior to the nucleation of the polymorphous crystals (calcite and vaterite) varies depending on the feed concentration. The faster nucleation rate of polymorphous crystals in 0.2 mol/L than in 0.05 mol/L solution results in the prompt disappearance of the precursor at 0.2 mol/L. In 0.05 mol/L solutions the lifetime of the precursor is relatively long. The crystallization fraction of vaterite increases with the feed concentration and decreases with the addition rate of Na(2)CO(2) solution. Vaterite takes on the various morphologies of the aggregates of the primary flocculation body (spherulite) depending on the crystallization conditions. Vaterite transforms to calcite by a direct solution-mediated mechanism. During crystallization the concentration attains a stationary value, which increases with the feed concentration and decreases with the addition rate of Na(2)CO(2) solution. This may be due to the crystal size decrease expected from the Gibbs-Kelvin equation. Magnesium ion suppresses the transformation of vaterite by inhibiting the growth of the calcite. Magnesium ion is selectively included in calcite and causes the increase of the attained concentration and the remarkable change in the morphology of calcite especially in 0.05 mol/L solution. Copyright 2001 Academic Press. 相似文献
38.
Keiichi Kimura Ryoko Mizutani Tatsuya Suzuki Masaaki Yokohama 《Journal of inclusion phenomena and macrocyclic chemistry》1998,32(2-3):295-310
Design of two types of ion-conducting systems using photochromic crown ethers as the photocontrol agents is described; one type is based on the phase transition of azobenzene derivatives induced by their photoisomerization and the other based on the molecular control of metal ion complexation by crowned spirobenzopyrans. The photoresponsive ion-conducting systems are applicable to electrostatic imaging and photorefractive materials. 相似文献
39.
40.
Yusuke Himei Tomohiro Nagakane Naoyuki Kitamura Akihiko Sakamoto 《Journal of Non》2008,354(27):3113-3119
Reduction in the temperature coefficient of the optical path length, dS/dT of Li2O-Al2O3-SiO2 glass-ceramics with near-zero thermal expansion coefficient was attempted using control of the temperature coefficient of electronic polarizability, ?, and the thermal expansion coefficient, α. The dS/dT value of 2.6 mol% B2O3-doped glass-ceramic was 12.5 × 10−6/°C, which was 0.9 × 10−6/°C smaller than that of B2O3-free glass-ceramic. On the other hand, reduction in dS/dT through B2O3 doping was not confirmed in precursor glasses. Results showed that reduction in dS/dT of the glass-ceramic through B2O3 doping is caused by the reduction in ?. The reduction in ? from B2O3 doping was probably attributable to numerical reduction in non-bridging oxide ions with larger ? value by the concentration of boron ions in the residual glass phase. In addition, application of hydrostatic pressure during crystallization was effective to inhibit precipitation of β-spodumene solid solution, which thereby decreases dS/dT. The dS/dT value of B2O3-doped glass-ceramic crystallized under 196 MPa was 11.7 × 10−6/°C. That value was slightly larger than that of silica glass. The α value of this glass-ceramic was smaller than that of silica glass. 相似文献