Atish Maldhure | Amravati University (original) (raw)

Papers by Atish Maldhure

Unsymmetrical tetradentate Schiff base N-(2-hydroxy-5-methylacetophenone)-N'-(2-hydroxy acetophen... more Unsymmetrical tetradentate Schiff base N-(2-hydroxy-5-methylacetophenone)-N'-(2-hydroxy acetophenone) ethylene
diamine (H2L) and its complexes with Cr(III), Mn(II), Fe(III), Co(II), Ni(II) and Cu(II) have been synthesized and characterized by elemental
analyses, magnetic susceptibility measurements, IR, electronic spectra and thermogravimetric analyses. 1H, 13C-NMR and
FAB Mass spectra of ligand clearly indicate the presence of OH and azomethine groups. Elemental analyses of the complexes indicate
that the metal to ligand ratio is 1:1 in all complexes. Infrared spectra of complexes indicate a dibasic quadridentate nature
of the ligand and its coordination to metal ions through phenolic oxygen and azomethine nitrogen atoms. The thermal behavior
of these complexes showed the loss of lattice water in the first step followed by decomposition of the ligand in subsequent
steps. The thermal data have also been analyzed for the kinetic parameters by using Horowitz-Metzger method. The dependence
of the electrical conductivity on the temperature has been studied over the temperature range 313−403 K and the complexes
are found to show semiconducting behavior. XRD and SEM images of some representative complexes have been recorded. The antimicrobial
activity of the ligand and its complexes has been screened against various microorganisms and all of them were found
to be active against the test organisms. The Fe(III) and Ni(II) complex have been tested for the catalytic oxidation of styrene.

The synthesized 3-bromo-5-chloro-2-hydroxyacetophenone on condensation with anisaldehyde and benz... more The synthesized 3-bromo-5-chloro-2-hydroxyacetophenone on condensation with anisaldehyde and benzaldehyde)
gives corresponding 2-hydroxy substituted chalcone. On bromination, 2-hydroxy substituted chalcone gives 5-
chloro-2-hydroxy chalcone dibromide, 5-chloro-2-hydroxy -4-methoxy chalcone dibromide, 3-bromo-5-chloro-2-
hydroxy chalcone dibromide and 3-bromo-5-chloro-2-hydroxy-4-methoxy chalcone dibromide respectively. The
structure of ligands was elucidated on the basis of molecular weight, elemental analysis and spectral data.

In this study N-(salicylidene)-N’-(2-hydroxy acetophenone)ethylenediamine (H2L1) and N-(2-hydroxy... more In this study N-(salicylidene)-N’-(2-hydroxy acetophenone)ethylenediamine (H2L1) and
N-(2-hydroxy-5-methyl acetophenone)-N’-(2-hydroxy acetophenone)ethylenediamine
(H2L2) Schiff bases have been subjected to spectroscopic investigation at different pH and
theoretical studies by using Semi-empirical AM1 method. The molecular geometry,
HOMO-LUMO energy gap, molecular hardness (η), ionization energy (IE) and electron
affinity (EA) were analyzed.

Nature has been a source of medicinal agents for thousands of years and an impressive numbers of ... more Nature has been a source of medicinal agents for thousands of years and an impressive
numbers of modern drugs have been isolated from natural resources. Tridax
procumbens Linn (Family –Asteraceae common name- Dhaman grass) is a common
herb found in India. Tridax procumbens is well known Ayurvedic, ethino-botanical and
unani medicinal plant. Pharmacological studies have shown that Tridax procumbens
possess properties like anti-inflammatory, hepatoprotective, wound heal, antimicrobial,
antiseptic, hypotensive and bradycardiac effects. The whole plant was reported to treat
various elements, such as dysentery, diarrhea and preventing hair loss. These
properties are mainly due to many active phytochemicals including the presence of
carbohydrates, proteins, tannins, steroids, alkaloids, dexamethasone, luteoline,
glucolureolin, β--silosterol, flaone, glycoside and quercetin in this plant.

The interaction of Co(II), Ni(II) and Cu(II) metal ions with N-(5-methyl-2-hydroxyacetophenone)-N... more The interaction of Co(II), Ni(II) and Cu(II) metal ions with N-(5-methyl-2-hydroxyacetophenone)-N’-(2-
hydroxyacetophenone) ethylenediamine have been studied at 0.1M ionic strength in 70% Dioxane-water mixture by
Bjerrum method as adopted by Calvin and Wilson. It is observed that Co(II), Ni(II) and Cu(II) metal ions form 1:1
complexes with ligand (L). The data obtained were used to estimate and compare the values of proton-ligand
stability constant (pK) and metal-ligand stability constant (logK), from estimated data (pK and log K),

PVA gel electrolyte with different concentration of PVA (0.5, 1 ,1.5, 2 ,2.5 by weight) in KSCN+D... more PVA gel electrolyte with different concentration of PVA (0.5, 1 ,1.5, 2 ,2.5 by weight) in KSCN+DMSO
electrolyte has been prepared by simple technique and characterized by X-RD and measuring d.c. conductivity
electrical conductivity as a function of temperature in the range 00to 1000c . Variation of conductivity of gel electrolyte
with loading concentration of PVA has also been studied .It has been observed that all gel sample are amorphous in
nature with shifting a broad peak. As loading of PVA in 0.2 M electrolyte of KSCN+DMSO increases conductivity
decreases. But conductivity is found to be increases with increases in temperature for all sample consisting VTF and
Arrhenius behavior.

A new series of Mn(II), Co(II), Ni(II), Cu(II), Cr(III) and Fe(III) complexes with tetradentate u... more A new series of Mn(II), Co(II), Ni(II), Cu(II), Cr(III) and Fe(III) complexes with tetradentate
unsymmetrical Schiff base ligand derived from o-hydroxyacetophenone, 5-chloro-2-
hydroxyacetophenone and ethylenediamine have been reported. The complexes have been
characterized by elemental analyses, magnetic susceptibility measurements, electronic and
infrared spectra and thermogravimetric analyses. The ligand and its complexes were screened for
their antimicrobial activities against the bacteria Staphalococcus aureus, Bacillus Subtilis,
Salmonella typhimurium and Escherichia coli and fungi Aspergillus oryzae and Fusarium
species. The results indicated that the complexes exhibited good antimicrobial activities.

The electrical conductivity of the solid Ni(II), Co(II), Mn(II), Cu(II), Fe(III) and Cr(III) comp... more The electrical conductivity of the solid Ni(II), Co(II), Mn(II), Cu(II), Fe(III) and Cr(III) complexes of unsymmetrical tetradentate Schiff base ligand derived from salicyladehyde, o-hydroxy acetophenone and ethylene diamine were measured and the activation energy of complexes were also calculated from Arrehenius plots. Ligand and its complexes were tested against various microorganisms and all of them found to be active against the organisms.

The solid complexes of Mn(III), VO(IV), MoO 2 (VI) and UO 2 (VI) with unsymmetrical dibasic tetra... more The solid complexes of Mn(III), VO(IV), MoO 2 (VI) and UO 2 (VI) with unsymmetrical dibasic tetradentate ONNO donor Schiff base derived from the condensation of salicylaldenyde, o-hydroxy acetophenone and ethylene diamine have been synthesized and characterized by elemental analysis, magnetic susceptibility measurements, IR and reflectance spectra. The thermal dehydration and decomposition of these complexes were studied kinetically using the Horowitz-Metzger method. The solid state electrical conductivity of complexes has been measured in the temperature range 313 K≤ T ≥403 K and the complexes exhibited semiconducting behavior. Scanning electron micrograph has also been reported and suggested homogeneous phase material. Complexes were used for the catalytic oxidation of styrene.