نتایج جستجو برای: tetrahedron substitution reaction
تعداد نتایج: 465599 فیلتر نتایج به سال:
Aluminum substituted yttrium iron garnet nano particles with compositional variation of Y(3.0-x) A1(x)Fe5O12, where x = 0.0, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 were prepared using sol gel technique. The X-ray diffraction results showed that the best garnet phase appeared when the sintering temperature was 800 degrees C. Nano-crystalline particles with high purity and sizes ranging from 20 to 100 n...
چکیده ندارد.
The reaction of 2-functionalized 1-halo-2,n-enynes (n = 7 or 8) with a divalent titanium reagent, Ti(O-i-Pr)4/2i-PrMgCl, proceeded in a domino fashion to afford bicyclic compounds in good yields. © 2011 Elsevier Science. All rights reserved ——— * Corresponding author. Tel.: +81-45-481-5661; fax: +81-45-413-9770; e-mail: [email protected] We have recently developed a divalent titanium re...
We study the pairing within the Peierls-HubbardModel for electronand hole-doped analogs of C60 accessible to exact diagonalization techniques (cube, truncated tetrahedron, etc.). We discuss how inclusion of electronphonon interactions can substantially modify the conclusions about pairing obtained when this coupling is neglected. We also discuss potential pitfalls in the extrapolation from thes...
Recent developments in the chemistry of η3-allylruthenium(IV) complexes are due to their straightforward synthesis resulting from oxidative addition of allylic substrates to a ruthenium(II) center. Subsequent reaction with a nucleophile is the basis of their involvement in the catalytic allylic substitution reaction. We focus here on ruthenium-catalyzed substitution of allylic substrates by C-,...
A green and efficient protocol for the synthesis of 3,3,6,6-tetramethyl-9-aryl-1,8-dioxooctahydroxanthene derivatives via cyclocondensation of 5,5-dimethyl-1,3-cyclohexanedione and aromatic aldehydes in the presence of catalytic amount of 10-molybdo-2-vanadophosphoric acid under solvent-free conditions has been described. The 10-molybdo-2-vanadophosphoric acid was prepared and characterized by ...
A green and efficient protocol for the synthesis of 3,3,6,6-tetramethyl-9-aryl-1,8-dioxooctahydroxanthene derivatives via cyclocondensation of 5,5-dimethyl-1,3-cyclohexanedione and aromatic aldehydes in the presence of catalytic amount of 10-molybdo-2-vanadophosphoric acid under solvent-free conditions has been described. The 10-molybdo-2-vanadophosphoric acid was prepared and characterized by ...
Experimental chemistry and atomic modelling studies were performed here to investigate a novel ionic co-substitution in hydroxyapatite (HA). Zinc, silicate co-substituted HA (ZnSiHA) remained phase pure after heating to 1100 °C with Zn and Si amounts of 0.6 wt% and 1.2 wt%, respectively. Unique lattice expansions in ZnSiHA, silicate Fourier transform infrared peaks and changes to the hydroxyl I...
The chemical structure of sodium aluminosilicate glasses is determined by high resolution x-ray photoelectron spectroscopy ~XPS! as silicon is gradually replaced by aluminum. A well-defined chemical state is found for silicon, aluminum, and sodium atoms, while three different environments are identified for oxygen atoms corresponding to Si–O–Si, Si–O–Al, and Si–O–Na bonds. The binding energy of...
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