Vanadia/ceria catalysts (2–10 wt% of V2O5) were prepared by wet impregnation of ammonium metavanadate in oxalic acid solution. Structural characterization was done with energy dispersive X-ray analysis (EDX), powder X-ray diffraction (XRD), BET surface area measurements, FT-IR spectroscopy and nuclear magnetic spectral analysis (51V MASNMR). XRD and 51V MASNMR results show highly dispersed vanadia species at lower loadings and the formation of CeVO4 phase at higher V2O5 loading. The catalytic activity of catalysts was conducted in liquid phase oxidation of ethylbenzene with H2O2 as oxidant. The oxidation activity is increased with loading up to 8 wt% V2O5 and then decreased with further increase in V2O5 content to 10 wt%. Different vanadia species evidenced by various techniques were found to be selective towards ethylbenzene oxidation. The CeVO4 formation associated with increased concentration of vanadia on ceria results the production of acetophenone along with 2-hydroxyacetophenone.
Prathapachandra Kurup, M R; Neema, Ani Mangalam(Elsevier, 2011)
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Abstract:
Six new copper complexes of di-2-pyridyl ketone nicotinoylhydrazone (HDKN) have been synthesized.
The complexes have been characterized by a variety of spectroscopic techniques and the structure of
[Cu(DKN)2]·H2O has been determined by single crystal X-ray diffraction. The compound [Cu(DKN)2]·H2O
crystallized in the monoclinic space group P21 and has a distorted octahedral geometry. The IR spectra
revealed the presence of variable modes of chelation for the investigated ligand. The EPR spectra
of compounds [Cu2(DKN)2( -N3)2] and [Cu2(DKN)2( -NCS)2] in polycrystalline state suggest a dimeric
structure as they exhibited a half field signal, which indicate the presence of a weak interaction between
two Cu(II) ions in these complexes
Prathapachandra Kurup, M R; Sheena Mary, Y; Raju, K; Yohannan Panicker, C; Neema, Ani Mangalam; Hema, Tresa Varghese; Sheeja, S R(Elsevier, March 16, 2010)
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Abstract:
FT-IR spectrum of quinoline-2-carbaldehyde benzoyl hydrazone (HQb H2O) was recorded and analyzed.
The synthesis and crystal structure data are also described. The vibrational wavenumbers were examined
theoretically using the Gaussian03 package of programs using HF/6-31G(d) and B3LYP/6-31G(d) levels of
theory. The data obtained from vibrational wavenumber calculations are used to assign vibrational bands
obtained in infrared spectroscopy of the studied molecule. The first hyperpolarizability, infrared intensities
and Raman activities are reported. The calculated first hyperpolarizability is comparable with the
reported values of similar derivatives and is an attractive object for future studies of non-linear optics.
The geometrical parameters of the title compound obtained from XRD studies are in agreement with
the calculated values. The changes in the CAN bond lengths suggest an extended p-electron delocalization
over quinoline and hydrazone moieties which is responsible for the non-linearity of the molecule
Description:
Journal of Molecular Structure 973 (2010) 36–46 http://dx.doi.org/10.1016/j.molstruc.2010.03.016
Manju, Kurian; Sugunan, S(Elsevier, January , 2006)
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Abstract:
Wet peroxide oxidation (WPO) of phenol is an effective means for the production of diphenols, which are of great industrial importance. An added advantage of this method is the removal of phenol from wastewater effluents. Hydroxylation of phenol occurs efficiently over mixed iron aluminium pillared montmorillonites. An initial induction period is noticed in all cases. A thorough study on the reaction variables suggests free radical mechanism for the reaction.
Mohammed Yusuff, K K; Varsha, Gopalakrishnan; Arun, Vasudevan; Manju, Sebastian; Leeju, P; Digna, Varghese(Crystallography Journals,Acta Crystallographica Section E ,Structure Reports, March 24, 2009)
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Abstract:
The asymmetric unit of the title compound, C11H8N4, contains
two independent molecules. In the crystal structure, intermolecular
N—H.....N hydrogen bonds link molecules into
ribbons extended in the [100] direction
Xavier, K O; Chacko, J; Mohammed Yusuff, K K(Elsevier, Applied Catalysis A :General, September 4, 2003)
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Abstract:
Co(II), Ni(II) and Cu(II) complexes of dimethylglyoxime and N,N-ethylenebis(7-methylsalicylideneamine) have been synthesized in situ
in Y zeolite by the reaction of ion-exchanged metal ions with the flexible ligand molecules that had diffused into the cavities. The hybrid
materials obtained have been characterized by elemental analysis, SEM, XRD, surface area, pore volume, magnetic moment, FTIR, UV-Vis
and EPR techniques. Analysis of data indicates the formation of complexes in the pores without affecting the zeolite framework structure, the
absence of any extraneous species and the geometry of encapsulated complexes. The catalytic activities for hydrogen peroxide decomposition
and oxidation of benzyl alcohol and ethylbenzene of zeolite complexes are reported. Zeolite Cu(II) complexes were found to be more active
than the corresponding Co(II) and Ni(II) complexes for oxidation reactions. The catalytic properties of the complexes are influenced by their
geometry and by the steric environment of the active sites. Zeolite complexes are stable enough to be reused and are suitable to be utilized as
partial oxidation catalysts.
Prathapachandra Kurup, M R; Sithambaresan, M; Jayakumar, K(October 31, 2011)
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Abstract:
The title compound, C15H16N4S, exists in the Z conformation
with the thionyl S atom lying cis to the azomethine N atom.
The shortening of the N—N distance [1.3697 (17) A ° ] is due to
extensive delocalization with the pyridine ring. The hydrazine–
carbothioamide unit is almost planar, with a maximum
deviation of 0.013 (2) A ° for the amide N atom. The stability of
this conformation is favoured by the formation of an
intramolecular N—H N hydrogen bond. The packing of
the molecules involves no classical intermolecular hydrogenbonding
interactions; however, a C—H interaction occurs