IR@NEIST - North East Institute of Science and Technology (CSIR)
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Microwave Assisted Dihydroxylation of Olefins, Proceeding of the Nineth CRSI National Symposium
Get PDFUncatalyzed Michael addition of indoles: synthesis of some novel 3-alkylated indoles via a three-component reaction in solvent-free conditions
Get PDF—Synthesis of some novel 3-alkylated indoles via an uncatalyzed Michael addition of indoles using three components in
one-pot solvent-free conditions is reported. The mechanism was established by performing the reaction in two steps. The reaction
was also studied in different solvents and an important solvent effect was noticed
FT-IR spectroscopic investigation of high sulphur assam coals and their solvent-extracts
Get PDFThe FT-IR spectroscopic techniques were used to
understand the structural feature of four samples of high
sulphur Assam coals and their extracts in polar solvents.
Pyridine, N, N-Dimethyl Acetamide and Ethyl Acetate
were used for extraction of the coals at their reflux
temperatures in a Soxhlet apparatus. The
difference-FT-IR spectroscopic technique was used to
characterize the compositions of extracts. The extracts
were found to contain characteristic absorption bands of
original coals. Both aromatic and aliphatic C-H stretching
bands were observed in the spectra of extracts. The
spectral interpretations of the extracts closely resembled
the parent coal structures. The relative transmittances of
characteristic bands in extract spectrum suggest that the
distribution of functional groups in coals were somewhat
effected due to the interaction with the solvents. The
spectra show some depletion of bands along with
increase in some regions. The information regarding the
structure of coal and extracts obtained by this method
are qualitative in nature but very much useful in coal
utilizations. © Geol. Soc. India
A novel method for the synthesis of chiral epoxides from styrene derivatives using chiral acids in presence of Pseudomonas lipase G6 [PSL G6] and hydrogen peroxide
Get PDFhiralepoxidationofstyreneanditsderivativeswascarriedoutusingseriesofchiralacidsandureahydrogenperoxide(UHP)or
aqueoushydrogenperoxide(50%)intwophasesunderthecatalyticinfluenceofimmobilizedPseudomonaslipaseG6[PSLG6]at25–55 C.
A moderate to good yield and enantioselectivities of chiral epoxides were obtained
Influence of anions on the adsorption kinetics of salicylate onto alpha aluminium in aqueous medium
Get PDFKinetics of adsorption of p-hydroxy benzoate and phthalate on hematite–electrolyte interface were investigated at a constant ionic strength,
I
=5×10−4 moldm−3,pH5andatthreedifferenttemperatures.Thestateofequilibriumfortheadsorptionofp-hydroxybenzoateontohematite
surfaces was attained at 70 h, whereas it was 30 h for phthalate–hematite system. None of the three kinetics models (Bajpai, pseudo first order
and pseudo second order) is applicable in the entire experimental time period; however, the pseudo second order kinetics model is considered
to be better than the pseudo first order kinetics model in estimating the equilibrium concentration both the p-hydroxy benzoate–hematite and
phthalate–hematite systems. The variation of adsorption density of p-hydroxy benzoate and phthalate onto hematite surfaces as a function of
concentration of adsorbate was studied over pH range 5–9 at a constant ionic strength, I
= 5×10−4 moldm−3 and at constant temperature.
The adsorption isotherms for both the systems were Langmuir in nature and the maximum adsorption density (Γmax)ofp-hydroxy benzoate is
∼1.5timesmorethanthatofphthalateonhematiteatpH5and30◦Cinspiteofanadditionalcarboxylicgroupatorthopositioninphthalate.This
is due to the more surface area coverage by phthalate than that ofp-hydroxy benzoate on hematite surface. The activation energy was calculated
using Arrhenius equation and the activation energy for adsorption of p-hydroxy benzoate at hematite–electrolyte interface is∼1.8 times more
than that of phthalate–hematite system. The negative Gibbs free energy indicates that the adsorption of p-hydroxy benzoate and phthalate on
hematite surfaces is favourable. The FTIR spectra of p-hydroxy benzoate and phthalate after adsorption on hematite surfaces were recorded for
obtaining the bonding properties of adsorbates. The phenolic νC–O appears at∼1271 cm−1 after adsorption of p-hydroxy benzoate on hematite
surfaces, which shifted by 10 cm−1 to higher frequency region. The phenolic group is not deprotonated and is not participating in the surface
complexation. The shifting of theνas(–COO−)andνs(–COO−) bands and non-dissolution of hematite suggest that thep-hydroxy benzoate and
phthalate form outer-sphere surface complexwith hematite surfaces in the pH range of 5–7
KF/Al2O3 mediated 1,3-dipolar cycloaddition of azomethine ylides: a novel and convenient procedure for the synthesis of highly substituted pyrrolidines
Get PDF—The regio- and diastereoselective synthesis of pyrrolidine derivatives through 1,3-dipolar cycloaddition of an azomethine
ylide and dipolarophile mediated by KF/Al 2O 3, a versatile solid supported reagent, is reported. KF/Al 2O 3 is sufficiently basic such
thatitcandeprotonatea-iminoesterstogenerateazomethineylidesanditalsofunctionsasasolidsupportedcatalystleadingtothe
cycloadduct rather than the Michael adduct.
2007 Elsevier Ltd. All rights reserved
XRD and FT-IR investigations of sub-bituminous Assam coals
Get PDFTwo coal samples collected from Makum coal field,
Assam, India were studied by XRD and FT-IR techniques.
The X-ray diffractogram shows the existence of some
crystalline carbons in Assam coals as proven by the
appearance of peaks. The radial distribution functional
(RDF) method was applied for the determination of
structural aspects of the coals. The study indicates that
the coals are lignite in type and there is no evidence of
graphite-like structures. The maximum in the G(r) plots
of function of radial distribution of atoms (FRDA) relates
to different distances between carbon atoms of aliphatic
chains. The first significant maximum relates to the C-C
bond (type C-CH=CH-C), the second maximum relates
to the distance between carbon atoms of aliphatic chains
that are located across one carbon atom. The curve
intensity profiles obtained from FRDA show quite regular
molecular packets for this coal. The coals were found to
be lignite in nature. FT-IR study shows the presence of
aliphatic carbon, C=O and C-O stretching associated with
-OH and -NH stretching vibrations. Kaolinite and quartz
were also found to be major minerals in Assam coals by
FTIR spectroscopy. The difference in intensities of
carbonyl groups of the coal samples is likely to relate
with the rank. © Indian Academy of Sciences