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1.
2.
The cyclophanes derived from 2,6-bis(chloromethyl)benzoquinone and suitable dithiols were reduced with sodium dithionate and then further coupled with various dibromides to give intra annularly linked bicyclic cyclophanes, which forms charge transfer complexes with TCNQ and TCNE. 相似文献
3.
Fluorenophanes derived from 2,7-bis-(bromomethyl)-9,9′-diheptyl-9H-fluorene and various diols exhibit excellent photoluminescence properties. 相似文献
4.
Antimony telluride thin films were prepared on the well-cleaned glass substrates under a pressure of 10 – 5 torr by thermal
evaporation method. The thicknesses of the films were measured using Multiple Beam Interferometer (MBI) technique. The structure
of the sample was analyzed by X-ray diffraction technique. The film attains crystalline structure as the temperature of the
substrate is increased to 373 K. The d spacing and the lattice parameters of the sample were calculated. Optical behavior
of the film samples with the various thicknesses was analyzed by obtaining their transmittance spectra in the wavelength range
of 400 – 800 nm. The transmittance is found to decrease with increase in film thickness and also it falls steeply with decreasing
wavelength. The optical constants were estimated and the results are discussed. The optical band gap energy decreases with
increase in the film thickness. The optical transition in these films is found to be indirect and allowed.
Paper presented at the 2nd International Conference on Ionic Devices, Anna University, Chennai, India, Nov. 28–30, 2003. 相似文献
5.
6.
3-Chloro-1H-indole-2-carboxaldehydes are obtained in moderate yields by the one-pot reaction of various substituted 2-[(carboxymethyl)amino]benzoic acids (1a-d) using Vilsmeier reagent (DMF/POCl(3)). The benzfused acyclic diacids analogous to 1a in which nitrogen was replaced by oxygen and sulfur also underwent the reaction smoothly. 3-Chloro-1H-pyrrole-2,4-dicarboxaldehyde was obtained as the only product by the reaction of N-carboxymethyl beta-alanine. 相似文献
7.
The compound [PPh(4)](2)[NEt(4)][CuTe(7)] has been synthesized from the reaction of CuCl with a polytelluride solution in dimethylformamide at room temperature. The compound crystallizes with two formula units in the triclinic space group P(-)1 in a cell with dimensions a = 8.9507(18) A, b = 14.714(3) A, and c = 23.277(5) A and alpha= 86.32(3) degrees, beta= 80.17(3) degrees, and gamma= 75.63(3) degrees (T = -120 degrees C). Ab initio calculations indicate that the nonclassical [CuTe(7)](3)(-) anion is the result of joining Te(3)(2-) and [CuTe(4)](1-) fragments through donor-acceptor interactions. 相似文献
8.
Treatment of 2 equiv of indole-3-aldehyde with o, m, p-xylyl, 2,5-dimethoxy-p-xylyl dibromides and 4,4′-bis(bromomethyl)-1,1′-biphenyl gave the bisalkylated products, which underwent McMurry coupling with low valent titanium to give indolophanes. Various cis-stilbenophanes with m-terphenyl building blocks were also synthesized by application of the McMurry coupling technique. 相似文献
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10.
T. Balakrishnan S. Hari Babu A. Perumal 《Journal of polymer science. Part A, Polymer chemistry》1990,28(6):1421-1434
The alkylation and cycloalkylation of phenylacetonitrile (PAN) with excess of 1-bromobutane and 1,4-dibromobutane respectively catalyzed by aqueous NaOH and insoluble polystyrene-bound benzyltriethylammonium chloride were studied and the rates depend upon several experimental parameters. The rate of cycloalkylation of PAN is five times faster than the alkylation and the former proceeds even in the absence of the solid catalyst. Both alkylation and cycloalkylation gave higher rates in reverse addition method than in direct addition. Deprotonation of PAN by hydroxide ion takes place without participation of the polymeric catalyst. The electrostatic force between the positive charge on the nitrogen atom of catalyst and carbanion is responsible for alkylation of active nitrile with polystyrene-bound phase-transfer catalyst. The rates of both the reactions increase with increased stirring speed, ring substitution, hydroxide ion concentration and catalyst amount and decrease with increased particle size and the degree of cross-linking of the polymer. Apparent activation energies for the reactions were calculated. The kinetic results are discussed in terms of mass transfer and a combination of intraparticle diffusion and intrinsic reactivity limitations of the rates. 相似文献