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81.
82.
A novel I2-catalyzed one-pot multicomponent protocol for the synthesis of a variety of elusive furo[2,3-b]pyrrole and thieno[2,3-b]pyrrole libraries has been established. To date, cyclization among alkanone, hydrazine and 2-bromobenzofuran or 2-bromobenzo[b]thiophene has not been explored in one-pot. Thus, the proposed single step protocol provides a versatile alternative to existing routes for accessing useful furo[2,3-b]pyrrole and thieno[2,3-b]pyrrole libraries. 相似文献
83.
P. Kuppusamy P. T. Manoharan C. Mahadevan M. Seshasayee 《Journal of chemical crystallography》1985,15(4):359-376
The crystal and molecular structure of the title compound, C21H11N6S4Ni, is reported. The crystals are triclinic:P¯1 (No. 2),Z=4,a=8.768(1),b=11.817(3),c=22.131(3) Å,=97.44(1),=91.90(1), and =94.04(1)°. The structure was solved by the heavy-atom method, and refined by full-matrix least squares toR=0.039 for 3213 unique reflections. The Ni atoms of both anions in the asymmetric unit have an approximately square-planar configuration. Anions and cations form segregated stacks alonga. The stacking of the anions along this direction is dimeric, with alternating Ni-Ni distances 4.111(2) and 7.593(2) Å for molecule I and 4.208(1) and 8.155(2) Å for molecule II. Static susceptibility measurements show strong antiferromagnetic coupling (2J=-241 cm–1) between the two anions of the dimers. 相似文献
84.
Results are reported of measurements of the glass transition temperature (Tg), conductivity and density (d) for glasses of the AsSbSe system, with compositions (As, Sb)40Se60 and AsxSb15Se85?x. The results are compared with glasses of similar compositions of the AsxSe100?x about compositions in the GexSb15Se85?x and AsxSe100?x glasses, in the case of AsxSb15Se85?x glasses, the As-rich compositions exhibit higher values of Tg and d compared to the stoichiometric composition As25Sb15Se60. These results are discussed in the light of a chemically ordered structural arrangement in these glasses. 相似文献
85.
S. Vishnu Priya J. Herbert Mabel S. Gopalakrishnan M. Palanichamy V. Murugesan 《Journal of molecular catalysis. A, Chemical》2008,290(1-2):60-66
Magnesium aluminophosphate-36 (MAPO-36) molecular sieve was synthesised hydrothermally and subjected to wet ion-exchange with Fe3+, Zn2+, La3+ or Ce3+. They were characterised by using XRD, SEM, temperature programmed desorption (TPD) of ammonia and thermogravimetric analysis (TGA). The XRD patterns of ion-exchanged MAPO-36 exhibit similar features to that of MAPO-36, which revealed no structural degradation during ion-exchange. TPD (ammonia) showed selective ion-exchange of strong acid sites for Fe3+, La3+ and Ce3+ but not for Zn2+. Based on the results of TGA the actual species involved in the ion-exchange is suggested to be M(OH)2+, which upon calcination converted to MO+ where M is Fe3+, La3+ or Ce3+. tert-Butylation of phenol was carried out in the vapour phase as a probe reaction to examine the catalytic activity of MAPO-36 and ion-exchanged MAPO-36 molecular sieves. The ion-exchanged catalysts were found to be more active than the parent MAPO-36 and also showed higher selectivity to 4-tert-butylphenol. 相似文献
86.
Sundaraganesan N Priya M Meganathan C Joshua BD Cornard JP 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2008,70(1):50-59
In this work, we will report a combined experimental and theoretical study on molecular and vibrational structure of 3,4-dimethoxyaniline (3,4-DMA). The Fourier transform infrared and Fourier transform Raman spectra of 3,4-DMA was recorded in the solid phase. The optimized geometry was calculated by HF and B3LYP methods using 6-31G(d,p) and 6-311++G(d,p) basis sets. The harmonic vibrational frequencies, infrared intensities, Raman scattering activities and the thermodynamic functions of the title compound were performed at and HF/B3LYP/6-311++G(d,p) level of theories. The scaled theoretical wavenumber showed very good agreement with the experimental values. A detailed interpretation of the infrared and Raman spectra of 3,4-DMA was reported. The theoretical spectrograms for IR and Raman spectra of the title molecule have been constructed. 相似文献
87.
G. Vijayakumar S. N. Karthick A. R. Sathiya Priya S. Ramalingam A. Subramania 《Journal of Solid State Electrochemistry》2008,12(9):1135-1141
New poly (vinylidenefluoride-co-hexafluoro propylene) (PVDF-HFP)/CeO2-based microcomposite porous polymer membranes (MCPPM) and nanocomposite porous polymer membranes (NCPPM) were prepared by
phase inversion technique using N-methyl 2-pyrrolidone (NMP) as a solvent and deionized water as a nonsolvent. Phase inversion occurred on the MCPPM/NCPPM
when it is treated by deionized water (nonsolvent). Microcomposite porous polymer electrolytes (MCPPE) and nanocomposite porous
polymer electrolytes (NCPPE) were obtained from their composite porous polymer membranes when immersed in 1.0 M LiClO4 in a mixture of ethylene carbonate/dimethyl carbonate (EC/DMC) (v/v = 1:1) electrolyte solution. The structure and porous morphology of both composite porous polymer membranes was examined
by scanning electron microscope (SEM) analysis. Thermal behavior of both MCPPM/NCPPM was investigated from DSC analysis. Optimized
filler (8 wt% CeO2) added to the NCPPM increases the porosity (72%) than MCPPM (59%). The results showed that the NCPPE has high electrolyte
solution uptake (150%) and maximum ionic conductivity value of 2.47 × 10−3 S cm−1 at room temperature. The NCPPE (8 wt% CeO2) between the lithium metal electrodes were found to have low interfacial resistance (760 Ω cm2) and wide electrochemical stability up to 4.7 V (vs Li/Li+) investigated by impedance spectra and linear sweep voltammetry (LSV), respectively. A prototype battery, which consists
of NCPPE between the graphite anode and LiCoO2 cathode, proves good cycling performance at a discharge rate of C/2 for Li-ion polymer batteries. 相似文献
88.
Aswathanarayana Srinivasa Kittappa Malavalli Mahadevan Kallappa Mahadevappa Hosamani Vijaykumar Hulikal 《Monatshefte für Chemie / Chemical Monthly》2008,139(2):141-145
Summary. 4-Nitrophthalic acid was found to be an effective catalyst for the imino Diels-Alder reaction of N-benzylideneanilines with 3,4-dihydro-2H-pyran and 2,3-dihydrofuran to afford pyrano- and furanoquinolines in good yields. It was also found that aryl amines react
smoothly with 3,4-dihydro-2H-pyran and 2,3-dihydrofuran under the same condition to afford the corresponding pyrano- and furanoquinolines in high yields.
This catalyst is inexpensive, easily available, water soluble, and stable to aqueous reaction conditions. 相似文献
89.
Aswathanarayana Srinivasa Kittappa M. Mahadevan Vijaykumar Hulikal 《Monatshefte für Chemie / Chemical Monthly》2008,10(1):255-259
Antimony(III) sulfate is found to catalyze the imino Diels-Alder reaction of Schiff’s bases with N-vinylpyrrolidin-2-one to afford 2-aryl-4-(2′-oxopyrrolidinyl-1′)-1,2,3,4-tetrahydroquinolines. One-pot synthesis of 1,2,3,4-tetrahydroquinolines
from 3-nitro benzaldehyde and aromatic amines with N-vinylpyrrolidin-2-one catalyzed by antimony(III) sulfate is also reported. This catalyst is inexpensive, easily available,
and it was also found that catalyst could be recovered quantitatively and reused without much loss of catalytic activity. 相似文献
90.
The matrix isolation technique has been combined with infrared spectroscopy and theoretical calculations to explore the reaction of (CH3)2Zn with O3 over a range of time scales. Upon twin jet deposition, an initial cage pair complex was observed, along with formation of the novel H3COZnCH3 species. Subsequent UV irradiation destroyed the complex and greatly increased the yield of H3COZnCH3. An extensive set of bands were seen for this molecule, and (18)O spectroscopic data were obtained as well. The identification of this species was supported by theoretical calculations at the B3LYP/6-311++g(d,2p) level. Merged jet deposition led to a very different set of products, including H2CO, CH3OH and C2H6, identifications that were confirmed by (18)O substitution. In addition, a new variable length concentric deposition technique was developed to permit study of the time scales between twin (relatively short) and merged (relatively longer) reaction times. Mechanistic inferences for this reaction are discussed. 相似文献