6 research outputs found
Studies on Piparwar Open Cast Mines of North Karanpura Coalfield
This paper deals with the study on coal deposits of Piperwar block of north Karanpura coalfield. A detailed geological map with its geological features in relation to the exposed rock has been prepared. The litholog of borehole up to a depth of 67 m is prepared to observe the geological characteristics and the decomposition of coal seams. The coal deposits with a view to find out its grade, quality and reserves have been studied and a general data about the environmental condition of desolation of sediments and deposition of coal has been presented. The structural units and where ever interesting features observed are photographed. The rank and grade of coal is interpreted based on the present study. However, more boreholes in the unexplored areas of the coalfield are required for the preparation of an elaborated geological map
Fenton’s Reagent Catalyzed Release of Carbon Monooxide from 1,3-Dihydroxy Acetone
Triose sugar, 1,3-dihydroxy
acetone (DHA) on treatment with Fenton’s
reagent releases CO under physiological conditions. The release of
CO has been demonstrated by myoglobin assay and quantum chemical studies.
The mechanistic study has been carried out using B3LYP/6-311++G(d,p),
M06-2X/6-311++G(d,p) and CCSD(T)//M06-2X/6-311++G(d,p) level of theories
in aqueous medium with dielectric constant of 78.39 by employing the
polarized continuum model (PCM). The theoretical investigation shows
that DHA breaks down completely into 2 equiv of CO, 1 equiv of CO<sub>2</sub>, and 6 equiv of H<sub>2</sub>O without formation of toxic
metabolites. The activation barriers of some steps are as high as
∼50 kcal mol<sup>–1</sup> along with barrierless intermediate
steps resulting from highly stabilized intermediates. The quantum
tunneling mechanism of proton transfer steps has been confirmed through
kinetic isotope effect study. The natural bond orbital analysis is
consistent with the proposed mechanism. The present protocol does
not require any photoactivation and thus it can serve as a promising
alternative to transition metal CO-releasing molecules. The present
work can initiate the study of carbohydrates as CO-releasing molecules
for therapeutic applications and it could also be useful in generation
of CO for laboratory applications
Theoretical Investigation of Photomagnetic Properties of Oxoverdazyl-Substituted Pyrenes
We
have investigated the ground state spin of 10 pairs of possible
photochromic diradical isomers by quantum chemical methods. Dihydrogen
pyrenes and dinitrile pyrenes have been chosen as spacers with radical
centers attached at (1,7) and (1,8) locations. Oxoverdazyl has served
as a radical center, and both C and N linkages have been investigated.
Triplet molecular geometries have been optimized at the UB3LYP/6-311G(d,p)
level. Single-point calculations on triplet and broken symmetry states
have been performed using the 6-311++G(d,p) basis set. Careful designs
have led to the prediction of strongly coupled dihydropyrene (DHP)
isomers, and the cyclophenadiene (CPD) isomers have always been found
as weakly coupled. The effect of the functional M06-2X has been investigated.
Calculated TDDFT spectra have been sufficient to guarantee photochromism
of the designed diradicals. It has been estimated that compounds of
diradicals with large coupling constants in the DHP form would show
a pronounced change in molar susceptibility on photoconversion. This
has led us to identify two molecules that can serve as a photomagnetic
switch at room temperature
Ligand Chirality Transfer from Solution State to the Crystalline Self‐Assemblies in Circularly Polarized Luminescence (CPL) Active Lanthanide Systems
The synthesis of a family of chiral and enantiomerically pure pyridyl‐diamide (pda) ligands that upon complexation with europium [Eu(CF3SO3)3] result in chiral complexes with metal centered luminescence is reported; the sets of enantiomers giving rise to both circular dichroism (CD) and circularly polarized luminescence (CPL) signatures. The solid‐state structures of these chiral metallosupramolecular systems are determined using X‐ray diffraction showing that the ligand chirality is transferred from solution to the solid state. This optically favorable helical packing arrangement is confirmed by recording the CPL spectra from the crystalline assembly by using steady state and enantioselective differential chiral contrast (EDCC) CPL Laser Scanning Confocal Microscopy (CPL‐LSCM) where the two enantiomers can be clearly distinguished