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61.
We describe here a rapid process for the preparation of new 9-chloromethyl-12-aryl-10,12-dihydrobenzo[5,6]chromeno[2,3-d]pyrimidin-11-ones 5a-d and 10-chloromethyl-7-aryl-7,9-dihydrobenzo[7,8]chromeno[2,3-d]pyrimidin-8-ones 6a-d by two different methods utilizing microwave irradiation. This methodology provides better yields(72%–80%) and high purity of the title compounds. 相似文献
62.
Francisco Fraga López Eva C. Vázquez Barreiro Aida Jover Julio A. Seijas Francisco Meijide José Vázquez Tato 《Polymer Science Series B》2018,60(4):481-496
In this work we introduce the zinc 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphine (ZnTPyP) macrocycle as a crosslinking agent of the epoxy resin BADGE n = 0. NMR, TEM and FTIR confirm that both homopolymerization and heteropolymerization (resulting in the formation of a pyridone) are taken place. DSC evidences two exothermic signals at 170 and 290°C, with enthalpy values of 262.3 and–20.7 J/g, respectively. Crystal powder diffraction supports that the second one corresponds to a physical process. The introduction of the ZnTPyP into the epoxy network improves the thermal stability of the material, which, although very weakly, shows ferromagnetic properties. 相似文献
63.
Li WS Yamamoto Y Fukushima T Saeki A Seki S Tagawa S Masunaga H Sasaki S Takata M Aida T 《Journal of the American Chemical Society》2008,130(28):8886-8887
For tailoring solution-processable optoelectronic thin films, a rational strategy with amphiphilic molecular design is proposed. A donor-acceptor dyad consisting of an oligothiophene and C60, when modified with a hydrophilic wedge on one side and a paraffinic wedge on the other (1Amphi), forms over a wide temperature range a photoconducting smectic A liquid crystal having bicontinuous arrays of densely packed donor and acceptor units. In contrast, when modified with only paraffinic wedges (1Lipo), the dyad forms a smectic A liquid crystalline mesophase, which however is poorly conductive. As indicated by an absorption spectral feature along with a synchrotron radiation small-angle X-ray scattering profile, 1Lipo in the lamellar structure does not adopt a uniform head/tail orientation. Such defective donor and acceptor arrays likely contain a large number of trapping sites, leading to short-lived charge carriers, as observed by a flash photolysis time-resolved microwave conductivity study. 相似文献
64.
Sakurai T Shi K Sato H Tashiro K Osuka A Saeki A Seki S Tagawa S Sasaki S Masunaga H Osaka K Takata M Aida T 《Journal of the American Chemical Society》2008,130(42):13812-13813
A triply fused copper porphyrin dimer, when site-specifically modified on its periphery with hydrophobic and hydrophilic wedges (1C12/TEG), self-assembles into a columnar liquid crystalline (LC) mesophase over a wide-temperature range from -17 to 99 degrees C but gives rise to an amorphous solid when modified with only hydrophobic (1C12/C12) or hydrophilic wedges (1TEG/TEG). A LC film of 1C12/TEG displays at 16 degrees C a top-class one-dimensional electron mobility (0.27 cm2/V x s), as evaluated from its maximum flash-photolysis time-resolved microwave conductivity. 相似文献
65.
66.
Najmeh Edraki Aida Iraji Omidreza Firuzi Yousef Fattahi Mohammad Mahdavi Alireza Foroumadi Mehdi Khoshneviszadeh Abbas Shafiee Ramin Miri 《Journal of the Iranian Chemical Society》2016,13(12):2163-2171
The inhibition of AKR1B10 has been recognized as a potential therapeutic approach to the treatment of various types of cancers. A novel series of compounds with imino-2H-chromen and phenylimino-2H-chromen scaffolds were synthesized by Knoevenagel condensation reaction. The in vitro cytotoxic activity of synthesized compounds was evaluated against MOLT-4 and SK-OV-3 cells. Among the tested compounds, N-(3,4-dimethoxyphenyl)-2-(phenylimino)-2H-chromene-3-carboxamide (8g) demonstrated potent inhibitory activity against both examined cell lines. The results of the molecular docking study suggested that this compound is involved in critical hydrogen-bonding interactions with the Val301 and Lue302 of AKR1B10 catalytic site. 相似文献
67.
Magnetically Alignable Bicelles with Unprecedented Stability Using Tunable Surfactants Derived from Cholic Acid 下载免费PDF全文
Ryoichi Matsui Dr. Noriyuki Uchida Dr. Masataka Ohtani Kuniyo Yamada Arisu Shigeta Prof. Dr. Izuru Kawamura Prof. Dr. Takuzo Aida Dr. Yasuhiro Ishida 《Chemphyschem》2016,17(23):3916-3922
Five novel surfactants were prepared by modifying the three hydroxy groups of sodium cholate with triethylene glycol chains endcapped with an amide ( SC‐C1 , SC‐ n C4 , and SC‐ n C5 ) or a carbamoyl group ( SC‐O n C4 and SC‐O t C4 ). The phase behavior of aqueous mixtures of these surfactants with 1,2‐dimyristoyl‐sn‐glycero‐3‐phosphatidylcholine (DMPC) was systematically studied by 31P NMR spectroscopy. The surfactants endcapped with carbamate groups ( SC‐O n C4 and SC‐O t C4 ) formed magnetically alignable bicelles over unprecedentedly wide ranges of conditions, in terms of temperature (from 21–23 to >90 °C), lipid/surfactant ratio (from 5 to 8), total lipid content (5–20 wt %), and lipid type [DMPC, 1,2‐dilauroyl‐sn‐glycero‐3‐phosphatidylcholine (DLPC), or 1‐palmitoyl‐2‐oleoyl‐sn‐glycero‐3‐phosphatidylcholine (POPC)]. In conjunction with appropriate phospholipids, the carbamate‐endcapped surfactants afforded unique bicelles, characterized by exceptional thermal stabilities (from 0 to >90 °C), biomimetic lipid compositions (DMPC/POPC=25:75 to 50:50), and extremely large 2H quadrupole splittings (up to 71 Hz). 相似文献
68.
This paper is a tutorial review of the host-guest chemistry of fullerenes and metalloporphyrin. Among various host molecules for fullerenes, cyclic hosts composed of metalloporphyrin moieties possess one of the highest affinities toward fullerenes, which can be widely tuned simply by changing the central metal ions of the porphyrin moieties. Inclusion of fullerenes occurs not only by van der Waals interactions but also, in some cases, via pi-electronic charge-transfer from the host metalloporphyrin moieties to the guest fullerenes. Fullerenes such as C(120), upon inclusion with cyclic metalloporphyrin dimers, show an oscillatory motion within the host cavity, whose frequency reflects the solvation/desolvation dynamics of the fullerenes. A molecularly engineered metalloporphyrin host with a self-assembling capability allows a guest-directed formation of a supramolecular peapod, where included fullerenes, as peas, are aligned along the self-assembled metalloporphyrin nanotube, as a pod. Furthermore, certain metalloporphyrin hosts are applicable to the selective extraction of low-abundance higher fullerenes from an industrial production source and also allow spectroscopic discrimination of chiral fullerenes. 相似文献
69.
70.
Exchange of guest molecules into capsule shaped host molecules is the most fundamental process in host-guest chemistry. Several examples of quantitative measurements of guest exchange rates have been reported. However, there have been no reports on the activation energies of these processes. A molecule known as cavitand-porphyrin (H2CP) has been reported to have a flexible host structure capable of facilitating moderate guest exchange rates suitable for kinetic measurements of the guest exchange process with 1H NMR. In this article, various kinetic and thermodynamic parameters related to the process of encapsulation of small hydrocarbons into H2CP in CDCl3 solution were determined by 2D exchange spectroscopy (EXSY): association and dissociation rate constants (k(ass) = 320 M-1 s-1, k(diss) = 1.4 s-1 for methane at 25 degrees C), the corresponding activation energies (E(a,ass) = 27 kJ.mol-1, E(a,diss) = 58 kJ.mol-1), and thermodynamic parameters for each process (DeltaG++(ass) = 59 kJ.mol-1, DeltaG++(diss) = 72 kJ.mol-1, DeltaH++(ass) = 25 kJ.mol-1, DeltaH++(diss) = 55 kJ.mol-1, DeltaS++(ass) = -113 J.K-1.mol-1, and DeltaH++(diss) = 58 J.K-1.mol-1 for methane). The thermodynamic parameters (DeltaG degrees = -13 kJ.mol-1, DeltaH degrees = -31 kJ.mol-1, DeltaS degrees = -60 J.K-1.mol-1 for methane) for this encapsulation equilibrium determined by EXSY were comparable to those for methane determined by 1D 1H NMR titration (DeltaG degrees = -11 kJ.mol-1, DeltaH degrees = -33 kJ.mol-1, DeltaS degrees = -75 J.K-1.mol-1 for methane). In addition, the structure of the methane encapsulation process was revealed by ab initio MO calculations. The activation energies for methane association/dissociation were estimated from MP2 calculations (E(a,ass) = 58.3 kJ.mol-1, E(a,diss) = 89.1 kJ.mol-1, and DeltaH degrees = -30.8 kJ.mol-1). These values are in accord with the experimentally determined values. The observed guest exchange rates and energies are compared with the corresponding values of various reported capsule-shaped hosts. 相似文献