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321.
Raj Pal Sharma Rajni Sharma Ritu Bala Juan M. Salas Miguel Quiros 《Journal of chemical crystallography》2005,35(10):769-775
Dark red crystals of bis[trans-dinitrobis(ethylenediamine)cobalt(III)] dichromate, [trans-Co(en)2(NO2)2]2(Cr2O7) have been obtained by slowly allowing to mix the solutions of potassium dichromate and trans-dinitrobis(ethylenediamine)cobalt(III)
nitrate in 1:2 molar ratio in aqueous medium. Elemental analyses and spectroscopic techniques (IR, UV/visible, 1H and 13C NMR) were used for characterizing the complex salt. The complex salt crystallizes in the orthorhombic space group Fdd2 with
unit cell dimensions a = 24.778(2) ?, b = 30.457(2) ?, c = 6.5364(5) ?, Z = 8, V = 4932.8(7) ?3, R1 = 0.0617 and wR2 = 0.1518. X-ray structure determination revealed an ionic structure consisting of cationic cobaltammine [trans-Co(en)2(NO2)2]NO3 and dichromate anion. It is the first crystal structure of this cation with a dianion. 相似文献
322.
Potassium carbonate mediated unusual transformation of 2,3-dihydroquinazolinone via cascade reaction
An unusual potassium carbonate mediated transformation of 2,3-dihydroquinazolinone by a one-pot operation is reported under mild conditions. In addition, it is interesting to report the regioselective transformation of 3-(2-bromophenyl)-2-isopropyl-2,3-dihydroquinazolin-4(1H)-one from compound 16. 相似文献
323.
Ravi Kant G. Amresh K. Chandrashekar Sanjeev K. Shukla 《Phosphorus, sulfur, and silicon and the related elements》2013,188(9):2453-2464
Perfluoroorganoantimony(III) (Rf)nSbCl3? n and -antimony(V) (Rf)nSbCl5? n (n = 1,2,3, Rf = C6F5) compounds are screened for the first time for biological activity. The compounds exhibited significant in vitro antitumor activity against MCF-7 (human breast cancer) cell line and antibacterial activity against three pathogenic bacteria: Pseudomonas aeruginosa, Staphylococcus aureus, and Klebsiella pneumoniae. They also showed antifungal activity against Aspergillus flavus and Aspergillus niger as well as insecticidal activity against cockroach (Periplanata americana), housefly (Musca domestica), Tobacco caterpillar (Spodoptera litura), and spider mite (Tetranychus urticae). These studies suggest a better biocidal activity for the pentafluorophenyl antimony halides compared to the corresponding phenyl analogues. 相似文献
324.
325.
V. Tsurkan J. Deisenhofer A. Günther Ch. Kant M. Klemm H.-A. Krug von Nidda F. Schrettle A. Loidl 《The European Physical Journal B - Condensed Matter and Complex Systems》2011,79(3):289-299
We report on structural, magnetic, conductivity, and thermodynamic studies of FeSe0.5Te0.5 single crystals grown by self-flux and Bridgman methods. The lowest values of the susceptibility in thenormal state, the highest transition temperature T c of 14.4 K, and the largest heat-capacity anomaly at T c were obtained for pure (oxygen-free) samples. The criticalcurrent density j c of 8.6 × 104A/cm2 (at 2 K) achieved in pure samples is attributed to intrinsic inhomogeneity due to disorder at the anion sites. The samples containing an impurity phase of Fe3O4 show increased j c up to2.3 × 105A/cm2 due to additional pinning centers. The upper critical field\(H_{c2}\)of ~500 kOe is estimated from the resistivity studyin magnetic fields parallel to the c-axis using a criterion of a 50%drop of the normal state resistivity R n . The anisotropy ofthe upper critical fieldγ H c2 =H ab c2/H c2 c reaches a value ~6 at\(T\longrightarrow T_c\). Extremely low values of the residualSommerfeld coefficient \(\gamma_r\) of about 1 mJ/mol K2,compared to the normal state Sommerfeld coefficient γ n = 25mJ/mol K2 for pure samples indicate a high volume fraction of thesuperconducting phase (up to 97%). The electronic contribution to the specific heat in thesuperconducting state is well described within a single-band BCS model with a temperature dependent gapΔ(0 K) = 27(1) K. A broad cusp-like anomaly in the electronic specific heat observed at low temperatures in samples with suppressed bulk superconductivity is ascribed to a splitting of the ground state of the Fe2+ ions at the 2c sites. This contribution is fully suppressed in the ordered state in samples with bulk superconductivity. 相似文献
326.
Palladium‐Catalyzed Synthesis of Phenanthridine/Benzoxazine‐Fused Quinazolinones by Intramolecular CH Bond Activation 下载免费PDF全文
Puneet K. Gupta Nisha Yadav Subodh Jaiswal Mohd. Asad Dr. Ruchir Kant Dr. Kanchan Hajela 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(38):13210-13215
A highly efficient synthesis of phenanthridine/benzoxazine‐fused quinazolinones by ligand‐free palladium‐catalyzed intramolecular C?H bond activation under mild conditions has been developed. The C?C coupling provides the corresponding N‐fused polycyclic heterocycles in good to excellent yields and with wide functional group tolerance. 相似文献
327.
A common problem during recovery of bioproducts by adsorption from particulate broths is fouling of the adsorbent material as a result of the interaction of cells and cell debris, which present negative charges, with the positively charged anion exchangers commonly used in bioprocesses. The effect of shielding an adsorbent with a layer of agarose on reducing the binding of cells while still allowing the low-molecular-mass bioproducts to be adsorbed was studied. Coating the anion-exchange resin Amberlite IRA-400 with agarose followed by cross-linking the agarose layer effectively prevented the binding of Escherichia coli, Saccharomyces cerevisiae, and Lactobacillus casei cells but allowed binding of lactic acid to the adsorbent. The cross-linked agarose layer was stable during recycling of the adsorbent. 相似文献
328.
Nonlinear Dynamics - Juggling a devil-stick can be described as a problem of non-prehensile manipulation. Assuming that the devil-stick remains confined to the vertical plane, the problem of... 相似文献
329.
Acta Mathematicae Applicatae Sinica, English Series - In this paper, based on fourth order Ostrowski method, we derive an optimal eighth order iteration scheme for obtaining simple roots of... 相似文献
330.
M. Schmidt Ch. Kant T. Rudolf F. Mayr A. A. Mukhin A. M. Balbashov J. Deisenhofer A. Loidl 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,71(3):411-418
We provide a detailed study of the reflectivity of multiferroic TbMnO3 for wave numbers from
40 cm-1 to 1000 cm-1 and temperatures 5 K < T < 300 K. Excitations are studied for
polarization directions E || a, the polarization where electromagnons are observed,
and for E || c, the direction of the spontaneous polarization in this material. The
temperature dependencies of eigenfrequencies, damping constants and polar strengths of all modes are studied and
analyzed. For E || a and below the spiral ordering temperature of about 27 K we
observe a transfer of optical weight from phonon excitations to electromagnons, which mainly involves
low-frequency phonons. For E || c an unusual increase of the total polar strength and
hence of the dielectric constant is observed indicating significant transfer of dynamic charge probably within
manganese-oxygen bonds on decreasing temperatures. 相似文献