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Borhade A.V.,HPT Arts and RYK Science College | Uphade B.K.,P.A. College
Journal of the Iranian Chemical Society

Abstract An efficient procedure has been reported for the synthesis of 4H-pyrano[2,3-c]pyrazoles in the presence of ZnS nanoparticles as a heterogeneous catalyst at the room temperature by grinding method. The ZnS nanoparticles were synthesized by hydrothermal method and characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and N2 adsorption-desorption isotherm analysis. The 4H-pyrano[2,3-c]pyrazoles were obtained with high yields (87-97 %) in a short reaction time (5-21 min) under solvent-free condition. This method has advantages such as it is solvent free, uses simple grinding method that can be carried out at room temperature, requires short reaction times and production of pure products without any by product. The nanocatalyst can be easily recovered and reused for five runs without appreciable loss of its catalytic activity. © 2014 Iranian Chemical Society. Source

Borhade A.V.,HPT Arts and RYK Science College | Uphade B.K.,University of Pune | Gadhave A.G.,University of Pune
Research on Chemical Intermediates

The calcinized eggshell as an efficient and green catalyst has been prepared from chicken eggshell waste and is characterized by different analytical techniques such as FT-IR, XRD, TGA, SEM, and EDAX. A series of substituted 2-arylbenzothiazoles have been synthesized by reaction of o-aminothiophenol and aromatic aldehydes under solvent free conditions using a grinding method at room temperature. The reaction proceeds smoothly in excellent yields (86–97 %), short reaction time (15–48 min), and with an easy work-up procedure. The reuse of catalyst and purification of products by non-chromatographic methods are some additional features of the present protocol. The calcinized eggshell is a safe, inexpensive, and a green catalyst with high catalytic efficiency obtained from renewable resources. © 2016 Springer Science+Business Media Dordrecht Source

Rahane A.B.,HPT Arts and RYK Science College | Rahane A.B.,University of Pune | Deshpande M.D.,HPT Arts and RYK Science College | Kumar V.,Dr. Vijay Kumar Foundation
Journal of Physical Chemistry C

Atomic structures and physical properties of Gd-doped alumina clusters-namely, GdAl 2n-1O 3n and Gd 2Al 2n-2O 3n with n = 1-10-have been studied within the framework of spin-polarized density functional theory and the projector augmented wave pseudopotential method. We find that the atomic structures of the host clusters (Al 2O 3) n are not changed significantly by the substitutional doping of a Gd atom on Al sites. Our results show that in the size range of the clusters we studied, a Gd atom prefers a maximum 4-fold-coordinated Al-site, except for n = 8, in which a 5-fold-coordinated Al site is favored. The substitution of Al with Gd atom is energetically favorable. This is in contrast to the substitutional doping of Gd in the bulk alumina corundum structure that is endothermic. There is a net magnetic moment of 7 μ B per Gd atom, which is mostly localized on the Gd atom. Further substitution of an Al atom with Gd in GdAl 2n-1O 3n clusters results in the lowest-energy configuration's being either ferromagnetic or antiferromagnetic, the difference between the two magnetic states being very small. The variation in the magnetic state is found to be associated with the variation in the coordination number of Gd atoms and the sites of the two Gd atoms. Our results suggest that Gd doping of nanoparticles offers an interesting way to prepare Gd-doped ceramic materials. © 2012 American Chemical Society. Source

Rahane A.B.,HPT Arts and RYK Science College | Rahane A.B.,University of Pune | Deshpande M.D.,HPT Arts and RYK Science College | Kumar V.,Dr. Vijay Kumar Foundation
Journal of Physical Chemistry C

The atomic structures, growth behavior, and electronic properties of (Al2O3)n, n = 1-10, clusters have been studied within the framework of density functional pseudopotential theory and generalized gradient approximation for the exchange-correlation energy. The lowest energy isomers of these clusters show preference for 4-membered Al 2O2 and 6-membered Al3O3 rings. There are 3-, 4-, and 5-fold coordinated Al atoms and 2-, 3-, and 4-fold coordinated oxygen atoms. The atomic structures have similarity with that of the γ-Al2O3 phase and the average coordinations of Al and O atoms in clusters are much lower from the values in the ground state of α-Al2O3 (corundum structure). In general, isomers with cage structures lie significantly higher in energy compared with the lowest energy structures we have obtained. The bonding characteristics for clusters of different sizes is studied using Bader charge analysis. It is found that with increasing size, the charge transfer from Al atoms to oxygen increases toward the value in bulk. Further, the infrared (IR) and Raman spectra have been calculated. For n = 4, a comparison of the calculated IR spectra for a few isomers with the available experimental results on cation shows the possibility of the occurrence of a mixture of isomers in experiments. The Raman spectra of these isomers are, however, quite different. Therefore, it is suggested that measurements on Raman spectra could give a clear indication of the isomer present in experiments. © 2011 American Chemical Society. Source

Pardeshi S.,HPT Arts and RYK Science College | Bobade V.D.,HPT Arts and RYK Science College
Bioorganic and Medicinal Chemistry Letters

A new series of triazol-3-one derivatives bearing 4-methyl-4H-thieno[30,20: 5,6]thiopyrano [4,3-d][1,3]thiazolyl or 4-(thiophene-3-yl) thiazolyl moiety at 4-position and alkyl substitution at 2-position are synthesized. All the synthesized compounds are characterized by elemental analysis, IR, 1H NMR, 13C NMR, and mass spectral data. The newly synthesized compounds are screened for antifungal and antibacterial activities © 2011 Elsevier Ltd. All rights reserved. Source

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