Department of Chemistry

Indian Institute of Technology Palakkad&nbsp;(IIT Palakkad or IIT PKD) is a public autonomous&nbsp;engineering&nbsp;and&nbsp;research&nbsp;institute located in&nbsp;Palakkad,&nbsp;Kerala. It was&nbsp;one of the five new&nbsp;IITs&nbsp;proposed in the&nbsp;2014 Union budget of India. The campus was inaugurated on 3 August 2015. The institute has 94 faculty, 978 students, and 63 non-teaching staffs.

IT Palakkad currently offers four-year Bachelor of Technology (B.Tech) and two years MS programmes in 8 different engineering disciplines including&nbsp;Computer Science, Electrical, Mechanical, Civil among others.

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IIT Palakkad

Factors that govern inclusion of organic molecules within octa acid (OA), a synthetic deep cavity cavitand, have been delineated by examining the complexation behavior of a number of organic molecules with varying dimensions and functionalities with OA. The formation of two types of complexes has been noted: the one which we call cavitandplex is a partially open complex in which a part of the guest molecule remains exposed to water, and the other termed capsuleplex is formed through assembly of two OA molecules. In capsuleplex, the guest is protected from water. Generally, guest molecules that possess ionic head groups form cavitandplex, and all others form capsuleplex. Capsuleplex may contain one or two guest molecules within the capsule. Small organic molecules (&lt;10 Å in length) may form both 2:1 and 2:2 capsuleplex, while longer ones (&gt;12 Å) preferentially form 2:1 capsuleplex. Extensive 1H NMR experiments have been carried out to characterize host-guest complexes. In the absence of the guest,OAtends to aggregate in water. The extent of aggregation depends on the concentration of OA and the presence of salts in solution. We expect the information obtained from this study to be of great value in predicting the nature of complexes with a given guest and facilitating appropriate guest chosen by researchers. © 2009 American Chemical Society.

World University root node

Langmuir

Nature of supramolecular complexes controlled by the structure of the guest molecules: Formation of octa acid based capsuleplex and cavitandplex

Tetrahedron

The syntheses and applications of β-benzylmercaptoethylamine derivatives

The application of FT-IR to the study of the structure and interactions of the major plant-cell wall polysaccharide pectin has been reported for many decades. Nevertheless, here we show that the generally reported methodology for one of its most commonly utilised applications, the measurement of the degree of methylesterification (DM), requires careful interpretation and sample handling; including consideration of the moisture content and ionisation state. We propose instead a different methodology based on the assessment of the magnitude of C-H stretches in the methyl groups relative to those in the backbone and demonstrate experimentally the advantage of this method. In addition, we add a theoretical dimension to our work, performing full quantum chemical (DFT) calculations of monomeric-, dimeric-, and trimeric-pectic compounds, in various states of partial methylesterification. These extensive calculations not only confirm the identity of the proposed methyl-band and illustrate its scaling with DM; but also demonstrate the success of the theoretical approach. Thus, DFT calculations are expected to be a valuable tool in the interpretation of IR spectra obtained from more complex systems such as polysaccharide conjugates. © 2009 Elsevier Ltd. All rights reserved.

Carbohydrate Polymers

Determining the degree of methylesterification of pectin by ATR/FT-IR: Methodology optimisation and comparison with theoretical calculations

4-Hydroxyacids are products of ubiquitously occurring lipid peroxidation (C9, C6) or drugs of abuse (C4, C5). We investigated the catabolism of these compounds using a combination of metabolomics and mass isotopomer analysis. Livers were perfused with various concentrations of unlabeled and labeled saturated 4-hydroxyacids (C4 to C11) or 4-hydroxynonenal. All the compounds tested form a new class of acyl-CoA esters, 4-hydroxy-4-phosphoacyl-CoAs, characterized by liquid chromatography-tandem mass spectrometry, accurate mass spectrometry, and 31P-NMR. All 4-hydroxyacids with five or more carbons are metabolized by two new pathways. The first and major pathway, which involves 4-hydroxy-4-phosphoacyl-CoAs, leads in six steps to the isomerization of 4-hydroxyacyl-CoA to 3-hydroxyacyl-CoAs. The latter are intermediates of physiological β-oxidation. The second and minor pathway involves a sequence of β-oxidation, β-oxidation, and β-oxidation steps. In mice deficient in succinic semialdehyde dehydrogenase, high plasma concentrations of 4-hydroxybutyrate result in high concentrations of 4-hydroxy-4-phospho-butyryl-CoA in brain and liver. The high concentration of 4-hydroxy-4-phospho-butyryl-CoA may be related to the cerebral dysfunction of subjects ingesting 4-hydroxybutyrate and to the mental retardation of patients with 4-hydroxybutyric aciduria. Our data illustrate the potential of the combination of metabolomics and mass isotopomer analysis for pathway discovery. © 2009 by The American Society for Biochemistry and Molecular Biology, Inc.

Fulltext

Journal of Biological Chemistry

Catabolism of 4-hydroxyacids and 4-hydroxynonenal via 4-hydroxy-4-phosphoacyl-CoAs

Inorganic carbonates, which occur abundantly on earth, constitute an inexpensive natural source of carbon. Therefore, the direct conversion of these carbonates into methane is of considerable importance. Thermal decomposition of transition metal carbonates with the composition MCa(CO3)2 (where M=Co, Ni, or Fe, and M/Ca is 1:1) and M1M2Ca(CO3)3 (where M1M2=CoNi, NiFe, or FeCo, and M1/M2/Ca is 1:1:2) shows that the reduced transition metals in combination with metal oxide nanoparticles (e.g., Co/CoO/CaO) act as catalysts for the conversion of CO2 (produced from the carbonates) into methane. The favorable decomposition conditions include heating at 5508 Cin an H2 atmosphere for 5-6 h. These catalysts are found to be excellent for the methanation of CaCO3, exhibiting high efficiency in the utilization of H2 with 100% conversion and 100% selectivity. The best catalyst for conversion of CaCO3 into CH4 is Co/CoO/CaO. There are also indications that similar catalysts based on Fe may yield higher hydrocarbons. © 2009 Wiley-VCH Verlag GmbH &amp; Co. KGaA, Weinheim.

ChemSusChem

Investigations of the conversion of inorganic carbonates to methane

We have been exploring the use of a deep cavity cavitand known by the trivial name 'octa acid' as a photochemical reaction, cavity for manipulating photochemical and photophysical properties of organic molecules. In the current study, we have monitored the micropolarity of the interior of the cavitand by recording the fluorescence of five different organic probes. They all indicate that the interior of octa acid capsuleplex (2:1, H/G complex) is nonpolar and does not contain water molecules in spite of the complex being present in water. The nature of the octa acid-probe complex in each case has been characterized by 1H NMR data to be a 2:1 capsuleplex. Photophysical and 1H NMR experiments were employed to probe the factors that control the structure of the complex, 2:2, 2:1, and 1:1. The data we have on hand suggest that the structure of the host/guest complex depends on the size and hydrophobicity of the guest molecule. © 2009 American Chemical Society.

Cavitand octa acid forms a nonpolar capsuleplex dependent on the molecular size and hydrophobicity of the guest

A recent theoretical model developed by Imparato of the experimentally measured heat and work effects produced by the thermal fluctuations of single micron-sized polystyrene beads in stationary and moving optical traps has proved to be quite successful in rationalizing the observed experimental data. The model, based on the overdamped Brownian dynamics of a particle in a harmonic potential that moves at a constant speed under a time-dependent force, is used to obtain an approximate expression for the distribution of the heat dissipated by the particle at long times. In this paper, we generalize the above model to consider particle dynamics in the presence of colored noise, without passing to the overdamped limit, as a way of modeling experimental situations in which the fluctuations of the medium exhibit long-lived temporal correlations, of the kind characteristic of polymeric solutions, for instance, or of similar viscoelastic fluids. Although we have not been able to find an expression for the heat distribution itself, we do obtain exact expressions for its mean and variance, both for the static and for the moving trap cases. These moments are valid for arbitrary times and they also hold in the inertial regime, but they reduce exactly to the results of Imparato in appropriate limits. © 2009 The American Physical Society.

Physical Review E - Statistical, Nonlinear, and Soft Matter Physics

Brownian particles in stationary and moving traps: The mean and variance of the heat distribution function

BCN nanotube brushes have been obtained by the high temperature reaction of amorphous carbon nanotube (a-CNT) brushes with a mixture of boric acid and urea. The a-CNT brushes themselves were obtained by the pyrolysis of glucose in a polycarbonate membrane. The BCN nanotubes have been characterized by EELS, XPS, electron microscopy, Raman spectroscopy and other techniques. The composition of these nanotubes is found to be BC4N. The nanotubes, which are stable up to 900 °C, are insulating and nonmagnetic. They exhibit a selective uptake of CO2 up to 23.5 wt%. In order to understand the structure and properties, we have carried out first-principles density functional theory based calculations on (6, 0), (6, 6) and (8, 0) nanotubes with the composition BC4N. While (8, 0) BC4N nanotubes exhibit a semiconducting gap, the (6, 0) BC4N nanotube remains metallic if ordered BN bonds are present in all the six-membered rings. The (6, 6) BC4N nanotubes, however, exhibit a small semiconducting gap unlike the carbon nanotubes. The most stable structure is predicted to be the one where BN3 and NB3 units connected by a B-N bond are present in the graphite matrix, the structure with ordered B-N bonds in the six-membered rings of graphite being less stable. In the former structure, (6, 0) nanotubes also exhibit a gap. The calculations predict BC4N nanotubes to be overall nonmagnetic, as is indeed observed. © 2008 by World Scientific Publishing Co. Pte. Ltd.

Trends In Chemistry Of Materials: Selected Research Papers Of C N R Rao

Synthesis, structure and properties of homogeneous BC4N nanotubes

A bottom-up approach has been used to tune the morphology of single-crystalline hematite from hollow spheres to nanocups. The mechanism involves the formation of nanocups through buckling of the spheres, similar to a deflated ball (see picture). As the shape changes, there is a drastic change in magnetic properties. © 2008 Wiley-VCH Verlag GmbH & Co. KGaA.

Angewandte Chemie - International Edition

Hollow spheres to nanocups: Tuning the morphology and magnetic properties of single-crystalline α-Fe2O3 nanostructures

A hierarchically porous bioactive glass of composition 80 mol % SiO 2 and 15 mol % CaO (MBGH) was synthesized using pluoronic P123 and glucose-derived amorphous carbon spheres as templates. While the carbon spheres leave behind pores of 300 nm to a few micrometers after calcination, the walls of these pores contain orderly arranged mesopores of 3-5 nm orchestrated by the pluoronic polymer. The role of carbon spheres is not only to create pores but also to aid in increased growth rate of hydroxycarbonate apatite in simulated body fluid (SBF). The negatively charged carbon spheres favor the local enrichment of calcium ions and facilitate the formation of amorphous calcium phosphate around the surface. On calcination, the walls of the macropores contain crystalline hydroxycarbonate apatite nuclei. MBGH also exhibits an accelerated growth of monoclinic-like apatite in SBF. The in vitro activity has been studied by XRD, FT-IR, FESEM, and TEM. © 2008 American Chemical Society.

Journal of Physical Chemistry C

Carbon spheres assisted synthesis of porous bioactive glass containing hydroxycarbonate apatite nanocrystals: A material with high in vitro bioactivity