schedule for research scholar day 2014schedule for research scholar day 2014 venue: 5104...
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SCHEDULE FOR RESEARCH SCHOLAR DAY 2014
VENUE: 5104
REGISTRATION : 8.30 AM – 8.55 AM WELCOME : 9.00 AM – 9.15 AM
Session I (9.15 AM – 10.45 AM) Speaker Title Time
Tridev Mishra Thermal Properties of a Particle Confined to a Parabolic Quantum Well in Two-Dimensional Space with Conical Disclination
9.15-9.30
C. Karthik Surface Studies on a Novel Discotic Liquid Crystalline Molecule 9.30-9.45 Sunita Joshi Fluorescence Quenching of Quinine Sulfate Dication: an indicator for sensing
Chloride ion in Ionic and Neutral Micellar Environments 9.45-10.00
Rituparna Bhattacharjee Variants of Hardness Potential: Development and Applications 10.00-10.15 Pankaj Nehra Synthesis, Characterization and Catalytic Applications of Palladium
Complex for C-C Coupling Reactions 10.15-10.30
Ravi Trivedi Density functional study of Hydrogen storage in small MgnCo clusters: A future energy solutions
10.30-10.45
TEA BREAK: 10.45 AM – 11.15 AM
Session II (11.15 AM – 12.45 PM)
Speaker Title Time Munesh Rathore Effect of Conditional Glass Former Variation on Electrical Transport in Li2O-
P2O5 Glassy and Glass-Ceramic Ionic System 11.15-11.30
Devnarayan VP Surface Plasmon Resonance Studies of Stearic Acid and Octadecanethiol Systems
11.30-11.45
Amar Singh DNA Unzipping due to Random Force 11.45-12.00 Keerti Choudhary Morphological and Electrical Characterization of Thin Film of TiO2
Nanoparticles 12.00-12.15
Monika Poonia Interaction of DNA and Langmuir Blodgett film of dioctadecyl ammonium bromide using QCM
12.15-12.30
Kapil Dhaka Shell Magnetism of Chromium Doped Germanium Superatom 12.30-12.45
LUNCH BREAK: 12.45 PM – 1.45 PM (INSTITUTE CAFETERIA )
Session III (2.00 – 2.45 PM) Speaker Title Time
Jitendra Kumar Effect of the Functionalized Carbon Nanotubes on the Physical Properties of Nematic Liquid Crystal
2.00-2.15
Amrit Sarmah A Density Functional Reactivity Theory Based Approach to Understand the Interaction between Aun (n = 3-6) Metal Clusters and Nucleobases
2.15-2.30
Pragati Fageria Synthesis of ZnO/Au and ZnO/Ag nanoparticles and their photocatalytic application using UV and visible light
2.30-2.45
POSTER SESSION & TEA: 2.45 PM – 4.15 PM
Session IV (3.30 – 4.15 PM)
Speaker Title Time Surendra Pratap Determination of Channel Electron Density of a Nano-MOSFET using
Quantum and Semi-classical Methods 3.30-3.45
Archana Choudhary Experimental and Theoretical studies of 'Ship-in-a-Bottle' Ni(II) Schiff base Complexes in Zeolite Y
3.45-4.00
Nisar Ahmad Mir Organocatalytic approach towards the synthesis five-membered nitrogen heterocycles
4.00-4.15
CONCLUDING REMARKS & VOTE OF THANKS: 4.15 PM – 4.30 PM
FOREWORDS
Research Scholar Day organized by the Department of Physics, BITS Pilani, Pilani campus is an
in-house symposium to facilitate sharing of research activities and exploring newer areas of
frontier research. The aim is to bring together the research scholars working in diverse areas of
science towards mutual appreciation and sharing of research aspirations.
We wish you all the best for your bright future.
Department of Physics
BITS, Pilani, Pilani Campus
Research Scholar Day 2014 Page 2
Table of Contents
ORAL PRESENTATIONS S.N. Title of the Presentation Presenter Page 1. Fluorescence Quenching of Quinine Sulfate Dication: an indicator for
sensing Chloride ion in Ionic and Neutral Micellar Environments Sunita Joshi 5
2. Variants of Hardness Potential: Development and Applications Rituparna Bhattacharjee
6
3. A Density Functional Reactivity Theory Based Approach to Understand the Interaction between Aun (n = 3-6) Metal Clusters and Nucleobases
Amrit Sarmah 7
4. Surface Plasmon Resonance Studies of Stearic Acid and Octadecanethiol Systems
Devanarayanan VP
8
5. Thermal Properties of a Particle Confined to a Parabolic Quantum Well in Two-Dimensional Space with Conical Disclination
Tridev Mishra 9
6. Shell Magnetism of Chromium Doped Germanium Superatom Kapil Dhaka 10 7. Effect of the Functionalized Carbon Nanotubes on the physical
properties of nematic liquid crystal Jitendra Kumar 11
8. Interaction of DNA and Langmuir Blodgett film of dioctadecyl ammonium bromide using QCM
Monika Poonia 12
9. Morphological and Electrical Characterization of Thin Film of TiO2 Nanoparticles
Keerti Choudhary
13
10. Effect of Conditional Glass Former Variation on Electrical Transport in Li 2O-P2O5 Glassy and Glass-Ceramic Ionic System
Munesh Rathore
14
11. Surface Studies on a Novel Discotic Liquid Crystalline Molecule C. Karthik 15 12. Synthesis of ZnO/Au and ZnO/Ag nanoparticles and their photocatalytic
application using UV and visible light Pragati Fageria
16
13. Experimental and Theoretical studies of 'Ship-in-a-Bottle' Ni(II) Schiff base Complexes in Zeolite Y
Archana Choudhary
17
14. Determination of Channel Electron Density of a Nano-MOSFET using Quantum and Semi-classical Methods
Surender Pratap
18
15. Synthesis, Characterization and Catalytic Applications of Palladium Complex for C-C Coupling Reactions
Pankaj Nehra 19
16. DNA Unzipping due to Random Force Amar Singh 20 17. Density functional study of Hydrogen storage in small MgnCo clusters:
A future energy solutions Ravi Trivedi 21
18. Organocatalytic approach towards the synthesis five-membered nitrogen heterocycles
Nisar Ahmad Mir
22
Research Scholar Day 2014 Page 3
POSTER PRESENTATIONS S.N. Title of the Presentation** Presenter Page 1. Photophysics of Quinine Sulphate Dication in Micellar Environments Sunita Joshi 24 2. Effect of Nanosize Micelles of Ionic and Neutral Surfactants on the
Photophysics of Protonated 6-Methoxyquinoline: Time-resolved Fluorescence Study
Tej Verma 25
3. Surface Plasmon Resonance studies of Langmuir-Blodgett Films of Stearic Acid
Devanarayanan VP
26
4. Magnetic behavior in Cr2@Gen (1≤n≤12) Clusters: A Density Functional Investigation
Kapil Dhaka 27
5. Temperature Dependent Electro-optic and Dielectric Properties of CdSe
QD’s Doped Nematic Liquid Crystal
Jitendra Kumar 28
6. Study on Detection of Contamination in Water using Quartz Crystal Microbalance
Monika Poonia 29
7. Langmuir- Blodgett films of Stearic acid - Aligning agent for Liquid
Crystal
Keerti Choudhary
30
8. Li 2SO4-Li 2O-P2O5 Ionic Glass Dispersed with [Bmim] [PF6] Ionic Liquid: Electrical Transport and Thermal Stability Investigations
Munesh Rathore
31
9. Thin Film studies on disc shaped tethered with rod like liquid crystal molecules
C. Karthik 32
10. Opening Profile of DNA Unzipping: Eye & Y-shape Phase Diagrams Amar Singh 33 11. One Dimensional Schrodinger-Poisson Solver Using Finite Difference
Method Surender Pratap
34
12. Magnetic superatom in MgnCo clusters (n=1-10): A first principle prediction
Ravi Trivedi 35
13. Landau-Fock-Darwin Confinement in two-Dimensional Space with Conical Disclination: A Thermodynamic Study
Tridev Mishra 36
** Serial number is the poster number also.
Research Scholar Day 2014 Page 4
ORAL
PRESENTATIONS
Research Scholar Day 2014 Page 5
Fluorescence Quenching of Quinine Sulfate Dication: an indicator for sensing Chloride ion
in Ionic and Neutral Micellar Environments
Sunita Joshi and D. D. Pant Department of Physics, Birla Institute of Technology & Science, Pilani (India)
Fluorescence quenching of Quinine sulfate dication (QSD) by chloride-ion (Cl-) in
micellar environments of anionic, sodium dodecyl sulfate (SDS), cationic,
cetyltrimethylammonium bromide (CTAB) and neutral, triton X-100 (TX-100) in aqueous phase
has been investigated by time-resolved and steady- state fluorescence measurements. The
quenching follows linear Stern-Volmer relation in micellar solutions and is dynamic in nature. A
significant reduction of quenching of fluorescence of QSD takes place in SDS micellar solution;
a moderate reduction takes place in CTAB and almost no change in TX-100 micelles when
compared with the quenching of QSD by Cl- in bulk water solution. In SDS micelles, the decay
becomes multi-exponential with an additional lifetime component and has been attributed to a
fraction of QSD molecules residing at the water-micelle interface. The probe molecules at
interface are protected from interaction with Cl-, consequently, a significant reduction in
fluorescence quenching of QSD in SDS micelles. The present study reveals that the chloride
sensing ability of QSD in biological media might get affected.
Research Scholar Day 2014 Page 6
Variants of Hardness Potential: Development and Applications
Rituparna Bhattacharjee and Ram Kinkar Roy Department of Chemistry, Birla Institute of Technology & Science, Pilani (India)
A simple method to obtain hardness potential (as defined by Parr and Gazquez, J. Phys.
Chem., 1993, 97, 3939) is presented. Use of hardness potential formally resolves the N-
dependence (N is no. of electrons of the system) problem of local hardness. It is shown that the
hardness potential has the ability to describe the intra- as well as intermolecular reactivity
sequence of a series of chemical systems. The corresponding electrophilic [)(kh ] and
nucleophilic [ )(kh ] variants of the hardness potential are also developed (Saha et al. J. Comp.
Chem. 2013, 34, 662). It is also shown that these two variants of the hardness potential leads to
the right and left derivatives of Fukui potential (as introduced by Berkowitz, J. Am. Chem. Soc.,
1987,109, 4823). The relative contribution of the sum of kinetic
3/2)(9
10rCF and exchange
energy
3/1)(9
4rCX terms to that of the electronic part of the molecular electrostatic potential
[ )(rVel ] in the variants of Hardness Potential is investigated to assess the proposed definition of
)]()([)( 1 kVkVkh Nel
Nel and )]()([)( 1 kVkVkh N
elN
el (Bhattacharjee et al. J. Phys.
Chem A, 2013, 117, 11528).
Research Scholar Day 2014 Page 7
A Density Functional Reactivity Theory Based Approach to Understand the Interaction between Aun (n = 3-6) Metal Clusters and Nucleobases
Amrit Sarmah and Ram Kinkar Roy Department of Chemistry, Birla Institute of Technology & Science, Pilani (India)
[email protected], [email protected]
It is important to understand the interaction of biological macromolecule such as DNA with a
particular metal surface because the restricted movement of nucleobases on the inorganic surface
modulates the characteristic electronic properties of the metal clusters to a considerable extent.
Various thermodynamic and kinetic aspects of the metal cluster-nucleobase interaction along
with the charge transfer process is investigated using Density Functional Reactivity Theory
(DFRT) based CDASE scheme. An extensive conventional ab-initio study is performed to
analyze more details about the other critical factors associated with the stable complex formation
between Aun cluster and nucleobases. It is expected that the tunable electronic properties of the
combined system (nucleobase-Aun cluster) is extremely useful for designing biological logic gate
on the next generation biosensors. The interaction trend of nucleobases with Aun clusters found
to follow the order G > A > C > T > U. It is also observed that Watson-Crick base pair GC
interaction with Aun cluster is both thermodynamically and kinetically more preferable in
comparison to that of the AT pair. We have obtained a precise correlation between the findings
of present study with earlier reported literature.
Research Scholar Day 2014 Page 8
Surface Plasmon Resonance Studies of Stearic Acid and Octadecanethiol Systems
Devanarayanan VP, Raj Kumar Gupta, V. Manjula Devi
Department of Physics, Birla Institute of Technology & Science, Pilani (India)
Surface Plasmons are the electronic oscillations at the metal-dielectric interface. Due to the role
of refractive index of dielectric layer in coupling condition of surface plasmons to the evanescent
waves of prism, the method is powerful to detect various chemical forms. We have developed a
surface plasmon resonance sensor in Kretschman geometry which is calibrated using the stearic
acid (common fatty acid) system. We have developed ultrathin films of stearic acid(C18H36O2) as
well as Octadecanethiol (C18H37SH;ODT) using various techniques and studied the SPR
characteristics. We found the surface plasmon resonance angular shift for stearic acid is less
than that of the ODT.
Research Scholar Day 2014 Page 9
Thermal Properties of a Particle Confined to a Parabolic Quantum Well in Two-
Dimensional Space with Conical Disclination
Tridev Mishra, Tapomoy Guha Sarkar, Jayendra Nath Bandyopadhyay
Department of Physics, Birla Institute of Technology & Science, Pilani (India)
The thermodynamic properties of a system, comprising of a spinless non-interacting charged
particle in the presence of an external magnetic field and confined in a parabolic quantum well
are studied. The focus has been on the effects of a topological defect, of the form of conical
disclination, with regard to the thermal properties of the system. We have obtained the
modifications to the traditional Landau-Fock-Darwin spectrum in the presence of conical
disclination. The effect of the conical kink on the degeneracy structure of the energy levels is
investigated. The canonical formalism is used to compute thermodynamic variables like entropy,
internal energy and specific heat. The study shows interplay between magnetic field, temperature
and the degree of conicity. The problem sets two scales for temperature corresponding to the
frequency of the confining potential and the cyclotron frequency of external magnetic field. The
kink parameter is found to affect the quantitative behaviour of the thermodynamic quantities. It
plays a crucial role in the competition between the external magnetic field and temperature in
fixing the values of the thermal response functions. This study provides an important motivation
for studying similar systems, however with non trivial interactions in the presence of topological
defects.
Research Scholar Day 2014 Page 10
Shell Magnetism of Chromium Doped Germanium Superatom
Kapil Dhaka and Debashis Bandyopadhyay
Department of Physics, Birla Institute of Technology & Science, Pilani (India)
It has been demonstrated that in a specific composition and size of a particular nanoclusters can
behavelike an elemental atom in the periodic table and hence can be chosen as superatoms [1-3].
According to the consequence of shell models some of the magic clusters can mimic chemical
properties of an elemental atoms. Following these, we have studied the structural, electronic and
magnetic properties for Cr@Gen (n=1 to 20) nanoclusters using density functional based first-
principles electronic structure calculations. From the study of the HOMO-LUMO gap, 2nd order
change in energy and adiabatic spin excitation energy in the complete range of the series of
Cr@Gen (n=1-20), the composition Cr@Ge10in quintet spin state is found most stable both
chemically as well as thermodynamically. The present study reports that the first and second
ionization potential (IP) of such superatom is 7.41eV and 10.93eV respectively. These values are
very close to the 1st and 2nd IPs of Ca and Sr, which are 6.11 eV and11.87 eV respectively.
References :-
1. Lin Zhu, Meichun Qian, and Shiv N. Khanna, J. Chem. Phys. 139, 064306 (2013)
2. Xinxing Zhang, Yi Wang, Haopeng Wang, Alane Lim, Gerd Gantefoer , Kit H. Bowen, J. Ulises
Reveles, and Shiv N. Khanna, J. Am. Chem. Soc.,135 (12), pp 4856–4861 (2013)
3. J.U. Reveles, P.A. Clayborne, A.C. Reber, S.N. Khanna, K. Pradhan, P. Sen, M.R. Pederson. Nature
Chemistry 1 310 (2009).
Research Scholar Day 2014 Page 11
Effect of the Functionalized Carbon Nanotubes on the Physical Properties of Nematic
Liquid Crystal
Jitendra Kumar and Manjuladevi. V
Department of Physics, Birla Institute of Technology & Science, Pilani (India)
We have investigated the effect of Functionalized carbon nanotube(FCNT) on the threshold
voltage and dielectric properties for pure nematic liquid crystal and CNT doped nematic liquid
crystal(NLC). The LCs were doped with two different FCNT (Octadecylamine functionalized
CNT (ODACNT) and acid functionalized CNT (AFCNT). It was found that doping the FCNT
into LC led to decrease in the threshold voltage compared to that of pure liquid crystal and
dielectric anisotropy is enhanced. The dielectric measurements reveal that relaxation frequency
for the doped sample has been shifted to the higher value compared to that of pure LC. The
conductance measurement using Atomic Force Microscopy (AFM) reveal the presence of FCNT
at the alignment layer.
Research Scholar Day 2014 Page 12
Interaction of DNA and Langmuir Blodgett film of dioctadecyl ammonium bromide using
QCM
Monika Poonia and Raj Kumar Gupta*
Department of Physics, Birla Institute of Technology & Science, Pilani (India)
We studied the interaction of DNA with a highly ordered functional ultrathin layer of cationic
surfactant, dioctadecyl ammonium bromide (DOAB). The ultrathin film of DOAB is fabricated
onto the pre-treated quartz crystal wafers using Langmuir Blodgett (LB) technique. The solution
of DNA in phosphate buffer saline (PBS) is injected through flow cell in a quartz crystal
microbalance (QCM) loaded with the functional ultrathin film. We also observed the aggregation
of DNA over the DOAB layer using atomic force microscope (AFM). The AFM image indicates
the trapping of DNA over the DOAB layer. Such trapping of DNA play an important role in the
field of genomics.
Research Scholar Day 2014 Page 13
Morphological and Electrical Characterization of Thin Film of TiO 2 Nanoparticles
Keerti Choudhary and Manjuladevi V.
Department of Physics, Birla Institute of Technology & Science, Pilani (India)
TiO2 nanoparticles can be employed in the fabrication of numerous photovoltaic devices. In the
present work, the thin film of TiO2 nanoparticles were deposited on gold deposited substrate by
spin coating method. The morphology of the TiO2 nanoparticles were characterized using atomic
force microscopy. We recorded the current-voltage (I-V) characteristic curve of the film
deposited onto gold electrodes. The change in band gap of the film was studied as a function of
temperature. The effect of visible light on the film was also studied.
Research Scholar Day 2014 Page 14
Effect of Conditional Glass Former Variation on Electrical Transport in Li2O-P2O5 Glassy and
Glass-Ceramic Ionic System
Munesh Rathore and Anshuman Dalvi
Department of Physics, Birla Institute of Technology & Science, Pilani (India)
Giving emphasis to electrical transport in the thermally unstable region, a conditional glass
former based system 50Li2O-(50-x)P2O5-xMoO3 is investigated. The glass forming region of this
system is found to be limited upto (x ≤ 15 mol %). However in this narrow region, the electrical
conductivity in case of glass as well as glass-ceramics exhibits significant increase with MoO3
content and found to be maximum for x = 15 mol %. The behavior of conductivity during
crystallization is nicely correlated with structural changes. It is revealed from conductivity
cycles, X-ray diffraction, scanning electron microscopy (SEM) and differential scanning
Calorimetry that addition of MoO3 suppresses the crystallization and improves the thermal
stability. Therefore, for samples with 15 mol % of MoO3, the conductivity of glass and glass-
ceramic is found to be comparable. SEM investigations suggest existence of tiny nano-
crystallites well separated by glass tissues for higher MoO3 content samples. Electronic
conductivity in these samples suggests phonon assisted polaron hopping. Further samples are
predominatly ionic in nature. The samples are found to be stable under battery conditions.
Research Scholar Day 2014 Page 15
Surface Studies on a Novel Discotic Liquid Crystalline Molecule C. Karthik and Raj Kumar Gupta
Department of Physics, Birla Institute of Technology & Science, Pilani (India)
In recent past, researchers have found immense interest in the disk shaped liquid crystals due to
their fascinating electro-optical properties. We have studied the surface manometry and surface
morphology of Langmuir-Blodgett films of Tricycloquinazoline (TCQ) based molecule tethered
with six ketone groups using Atomic Force Microscopy and spectroscopy. Using infrared
spectroscopy, it has been found that the transition dipole moment of TCQ molecule is planar to
the surface.
Research Scholar Day 2014 Page 16
Synthesis of ZnO/Au and ZnO/Ag nanoparticles and their photocatalytic application using UV and visible light
$Pragati Fageria, #Subhashis Gangopadhyay and $Surojit Pande $ Department of Chemistry, Birla Institute of Technology & Science, Pilani (India)
#Department of Physics, Birla Institute of Technology & Science, Pilani (India) [email protected]
Here, we report the low temperature gram level synthesis of ZnO/Au and ZnO/Ag nanoparticles
using cetyltrimethylammoniumbromide (CTAB) surfactant as a stabilizer. Initially, pure ZnO
nanoparticles were synthesized and then Au and Ag were deposited on ZnO surface using
hydrazine hydrate as reducing agent. The information about the sample crystallinity, structure
and surface morphology were assessed by UV-VIS spectroscopy, photoluminescence, X-ray
Diffraction, X-ray photoelectron spectroscopy, EDS, SEM, and TEM techniques. The influences
of the deposited metals (Au and Ag) on the surface of ZnO have been emphasized by applying
the as-synthesized nanoparticles in dye degradation under illumination of UV and visible light.
Photocatalytic performances of bare ZnO, ZnO/Ag, and ZnO/Au have been studied thoroughly.
The photocatalytic results reveal that the incorporation of noble metals not only enhance the
catalytic efficiency but also promotes the separation of photogenerated electron and hole pairs.
To investigate the charge carrier species, which involved in the degradation of dye we performed
scavenging experiment using different scavenger. It indicates that the holes in valence band play
major role when catalysis performed under visible light but the case is quite different under UV-
light, where, both the holes and hydroxyl radicals play important role in degradation of the dye
molecule.
Reference
1. Hui Zhang, Deren Yang, Yujie Ji, Xiangyang Ma, Jin Xu, and Duanlin Que, J. Phys. Chem. B, 2004,108, 3955-
3958.
2. Jun Geng, Guang-Hui Song, Xiang-Dong Jia, Fang-Fang Cheng, and Jun-Jie Zhu, J. Phys. Chem. C, 2012, 116,
4517-4525.
3. Nayane Udawatte, Myeongsoon Lee, Junhyung Kim, and Dongil Lee, ACS Appl. Mater. Interfaces, 2011, 3,
4531-4538.
4. Jian Xu, Yonggang Chang, Yunyan Zhang, Shiyu Ma, Yi Qu, Chengtian Xu, Applied Surface Science, 2008, 255,
1996- 1999.
5. Nan Zhang, Siqi Liu, Xianzhi Fu, and Yi-Jun Xu, J. Phys. Chem. C, 2011, 115, 9136–9145.
Research Scholar Day 2014 Page 17
Experimental and Theoretical studies of 'Ship-in-a-Bottle' Ni(II) Schiff base Complexes in
Zeolite Y
Archana Choudhary1, Saumi Ray1 and Bidisa Das2 1Department of Chemistry, Birla Institute of Technology & Science, Pilani (India)
2Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032.
It is observed that square planar Ni(II)–Schiff base complexes of general formula [Ni(L)2], (L:N,
Ń-bis(salicylidene)ethylenediamine, and N, Ń-bis(5-bromo salicylidene)ethylenediamine) when
encapsulated in a supercage of zeolite Y, the bulky guest complex adopt a non-planar geometry.
Detailed comparative characterization is carried out to understand the structural change of the
guest complex due to steric and electronic effects of the host framework while keeping the
integrity of framework intact after encapsulation. UV-Vis spectroscopic studies of encapsulated
and ‘neat’ complex show significant blue shift in d-d transition after encapsulation and the
diamagnetic 'neat' complex exhibits paramagnetism after encapsulation. DFT studies of Ni(II)–
Schiff base complexes have been carried out for neat and encapsulated form and the UV-Vis
spectra are simulated using TD-DFT to understand the observed spectra in full details.
Research Scholar Day 2014 Page 18
Determination of Channel Electron Density of a Nano-MOSFET using Quantum and Semi-
classical Methods
Surender Pratap and Niladri Sarkar
Department of Physics, Birla Institute of Technology & Science, Pilani (India)
Study of the electronic transport in Nano-Scale Devices is extremely important for understanding the working principles of futuristic devices. The variation of the electron density in the channel of a Nano-MOSFET will dictate its I-V characteristics. . For Nano-scale devices, the electron density can be calculated from diagonal elements of the density matrix. Another approach will be the semi-classical approach where the electron density, n, is given as
Tk
zUEF
h
kTmn
B
cnD
2/1
2/3
23
24
where 2/1F is the Fermi-Dirac integral. Effect of the size quantization is very well reflected when
we calculate the electron density using density matrix. However, when we increase the channel thickness, the result obtained by density matrix calculation matches with the semi-classical approach. The following figure shows the generic device(Dual Gate MOS Capacitor) which is used for our calculations.
Research Scholar Day 2014 Page 19
Synthesis, Characterization and Catalytic Applications of Palladium Complex for C-C Coupling Reactions
Pankaj Nehra, Vaishali Saini, S. C. Sivasubramanian*1 Bharti Khungar*2
Department of Chemistry, Birla Institute of Technology & Science, Pilani (India) *[email protected], *[email protected]
Transition metal complexes have been employed as catalyst for varied organic transformations.
The C-C bond forming reactions are very effective and important reactions in organic synthesis
[1]. Palladium-catalyzed cross-coupling reactions have significant contribution in organic
synthesis to build aryl−aryl bonds [2]. An intriguing aspect of palladium catalysis is its broad
synthetic applications that has played pivotal task in the synthesis of fine chemicals and
advanced functional materials [3, 4]. We have devised a novel route to synthesize an air stable,
water soluble and efficient Schiff base palladium complex. The complex was well characterized
by NMR, Mass, FT-IR, UV-visible spectroscopy, time resolved spectroscopy and powdered X-
ray diffraction and used as a catalyst for the C-C cross-coupling reactions in water. Good to
excellent yields with estimable turn over numbers and turn over frequencies were achieved using
modest mole percent of the catalyst. In addition, the catalyst can easily be reused and recycled
for more than six steps without much loss in reactivity, exhibiting an example of sustainable and
green methodology
References:
1. S. Wang Q. and Qian, H. Gong, Org. Lett. 14, 2012, 3352.
2. J. Ruan and J. Xiao, Acc. Chem. Res., 2011, 44, 614-626.
3. C.-H. Lu and F.-C. Chang, ACS Catal., 2011, 1, 48-488.
4. A. B. Dounay and L. E. Overman, Chem. Rev., 2003, 103, 2945-2963; Overman, L. E.; Rosen, M. D.
Angew. Chem., Int. Ed. 2000, 39, 4596.
Research Scholar Day 2014 Page 20
Figure: The figure in left shows the variation critical force vs chain length and figure in right shows the effect of random and equal force at different sites.
DNA Unzipping due to Random Force
Amar Singh and Navin Singh
Department of Physics, Birla Institute of Technology & Science, Pilani (India)
We investigate the mechanical unzipping of double-stranded DNA (dsDNA) by pulling two
strands in opposite directions in the constant force ensemble. The force is applied on randomly
selected sites along the chain and hence we calculate the force required to unzip the chain
(critical force, Fc). Using a two state model, we investigate the effect of the distribution of force
on the unzipping phenomenon and found that there is a critical region over which the force
applied at a point has no effect. The critical force is found to depend on the chain length as well
on the location of the applied force.
Research Scholar Day 2014 Page 21
Density functional study of Hydrogen storage in small MgnCo clusters: A future energy
solutions
Ravi Trivedi, Kapil Dhaka and Debashis Bandyopadhyay
Department of Physics, Birla Institute of Technology & Science, Pilani (India)
The present study reports the possibility of using Mg-Co hybrid nanoclusters as hydrogen
storage. It is well known that Magnesium and Magnesium based alloys are very much effective
as high hydrogen storage. Moreover, these alloys are light weight, cost effective and hence the
most promising candidates for hydrogen storage [1-2]. Because of the physical nature of
hydrogen, it is difficult to store it in a large quantity without taking up a significant amount of
space. Therefore search for the safe, reliable and cost effective hydrogen storage elements is one
of the main challenge in this field. But many metals and their alloys are capable of absorbing
large amounts of hydrogen to form metal hydride. So it is important to understand the interaction
of hydrogen with these materials. In general at the beginning metal hydride formation initiates by
dissociative chemisorptions of H2 on the metal surface and then H atom diffusion starts into the
crystal lattice in case of bulk systems [3-4]. On the other hand, it has been found that small sized
transition metal clusters improves the absorption process. Clusters are having high surface to
volume ratio which makes available surface for chemisorption of hydrogen more than the bulk.
Therefore in the present report structure, stability and reactivity of MgnCo (n=1-10) clusters with
or without hydrogen adsorption were studied using density functional theory. Binding energy,
chemisorptions, dissociation energies, reaction path, dipole moment and HOMO-LUMO gap
have been calculated and presented. The information gained can contribute to the design of novel
nanoclusters materials for hydrogen storage.
References
1. Hydrogen storage in magnesium based alloys, Waste-enviorment.vin.bg.ac.rs, J.Garbovic Novakovic, Tanja Brdaric, N. Novakovic, S. Mentus, pdf (2009)
2. Materials for hydrogen storage: current research trends and perspectives Annemieke W. C. van den Berg and Carlos Otero Area, ChemComm (2007)
3. Trends in hydride formation energies for magnesium-3d transition metal alloys, Journal of Alloys and Compound 386 (2005) 1–7
4. G walker, Solid state hydrogen storage: Materials and chemistry, Elsevier (2004)
Research Scholar Day 2014 Page 22
Organocatalytic approach towards the synthesis five-membered nitrogen heterocycles
Nisar Ahmad Mir, and Indresh Kumar
Department of Chemistry, Birla Institute of Technology & Science, Pilani 333031 (Rajasthan)
Pyrrolidines are the most important and versatile moiety found in natural products,
pharmaceuticals, agrochemicals and other synthetic compounds [1, 2]. In continuation of our
interest in organocatalyzed reactions [3], using linear dicarbonyl compounds as donor- acceptor
precursors, presently we developed an efficient organocatalytic method using succinaldehyde as
1, 3- carbon dipole and imines for the synthesis of 2,3- disubstituted pyrrolidines in high yields
(upto 78%) and excellent enantioselectivity (upto > 99%) [4]. The present idea of 1,3- carbon
dipole is very compatible and even more greener as compare to the only two methods known
earlier [4,5] and this method can be further utilized for the synthesis of some small molecule
natural products. Further after synthesizing the series of compounds we characterised these
compounds using various spectroscopic techniques such as 1H NMR, 13C NMR, mass
spectroscopy, optical rotation, HPLC and to assign relative and absolute configuration we
characterize one of the compound by X-ray crystallographic technique as shown in (figure 1).
Figure 1: 1H NMR and X-ray Structures of one of the compound
Details of this work will be presented here (scheme 1).
Scheme 1: Insitu generation of 1, 3- carbon dipole from succinaldehyde and application in pyrrolidine synthesis
Research Scholar Day 2014 Page 23
POSTER PRESENTATIONS
Research Scholar Day 2014 Page 24
Photophysics of Quinine Sulphate Dication in Micellar Environments
Sunita Joshi and D. D. Pant
Department of Physics, Birla Institute of Technology & Science, Pilani (India)
Steady state absorption and fluorescence spectral studies have been carried out for quinine
sulphate dication (QSD) in cationic cetyltrimethylammonium bromide (CTAB), anionic sodium
dodecylsulphate (SDS) and neutral triton X-100 (TX100) surfactants at concentrations above and
below critical micelle concentrations (c.m.c.) in aqueous phase. Edge excitation red shift (EERS)
in fluorescence maximum of QSD has been observed in all the surfactant solutions studied. The
magnitude of observed EERS is less in anionic SDS surfactant solution compared to the EERS in
CTAB and TX100 surfactants. The magnitude of EERS in CTAB and TX100 is almost the same
as in bulk water solution. The EERS has been ascribed in terms of solvent relaxation process. In
CTAB surfactant solution a continuous decrease in fluorescence intensity has been observed with
increase in surfactant concentration and is due to Stern –Volmer quenching. At premicellar
concentrations of SDS, the decrease in absorbance and appearance of an extra fluorescence band
at lower wavelengths are attributed to the ion-pair formation between QSD molecules and
surfactant monomers. At postmicellar concentrations the red shift in fluorescence spectrum and
increase in quantum yield are attributed to the incorporation of solute molecules to micelles.
Compared to the magnitude of edge excitation red shift (EERS) in bulk water solution of QSD,
the magnitude of EERS is less at higher concentrations of SDS due to heterogeneous restricted
motion of solvent molecules, whereas, at lower concentrations of SDS, a large shift in
fluorescence is observed on excitation at the red edge of absorption spectrum and this is
explained in terms of distribution of ion pairs of different energies in the ground state.
Research Scholar Day 2014 Page 25
Effect of Nanosize Micelles of Ionic and Neutral Surfactants on the Photophysics of
Protonated 6-Methoxyquinoline: Time-resolved Fluorescence Study
Tej Varma Y, Sunita Joshi and D. D. Pant
Department of Physics, Birla Institute of Technology & Science, Pilani (India)
The excited state dynamic studies have been carried out to investigate the effects of micellar
surface charge on the photophysics of protonated 6-methoxyquinoline (6MQ+) in anionic,
sodium dodecylsulphate (SDS), cationic, cetyltrimethylammonium bromide (CTAB) and neutral,
triton X-100 (TX100) surfactant at premicellar, micellar and postmicellar concentrations in
aqueous phase at room temperature. At premicellar concentration of SDS, there is a slight
decrease in emission intensity and at micellar and postmicellar concentrations increase in
emission intensity and blue shift of fluorescence spectrum and slight increase in quantum yield
are attributed to incorporation of solute molecule to micelles. Edge excitation red shift (EERS) in
fluorescence maximum of 6MQ+ has been observed in all the surfactant solutions studied. The
EERS has been ascribed in terms of solvent relaxation process. In SDS surfactant system, due to
heterogeneous restricted motion of solvent molecules, the solvent viscosity increases which
results in an increase in net magnitude of EERS and fluorescence decay components fit in multi
exponentials. The location of the probe molecule in micellar systems is justified by a variety of
spectral parameters such as refractive index, dielectric constant, ET(30), EERS, average
fluorescence decay time, radiative and non radiative rate constants, and rotational relaxation
time.
Research Scholar Day 2014 Page 26
Surface Plasmon Resonance studies of Langmuir-Blodgett Films of Stearic Acid
Devanarayanan VP, Raj Kumar Gupta, V. Manjula Devi
Department of Physics, Birla Institute of Technology & Science, Pilani (India)
Stearic acid is one of the commonly studied fatty acid. It exhibits interesting behavior on
surfaces. We have developed a surface plasmon resonance (SPR) instrument in the kretschman
configuration. Single layers of Langmuir-Blodgett (LB) films of stearic acid(SA) and films for
different concentrations of SA in chloroform were analyzed using our SPR setup. We find
interesting changes in SPR angle for the LB film and film deposited from solution.
Research Scholar Day 2014 Page 27
Magnetic behavior in Cr2@Gen (1≤n≤12) Clusters: A Density Functional Investigation
Kapil Dhaka and Debashis Bandyopadhyay
Department of Physics, Birla Institute of Technology & Science, Pilani (India)
With an aim to hold the magnetic moment of Cr in Cr2@Gennanoclusters,we have investigated
the structure and magnetic properties of pure Ge clusters doped with Cr dimer to produce
Cr2@Gen clusters. These kinds of nanoclusters have potential applications because of their high
magnetic moment. As the first step of calculation, geometrical optimizations of the nanoclusters
have been done. The optimized geometries have been used to calculate the average binding
energy per atom (BE), HOMO-LUMO gap and relative stability of the clusters. These
parameters have been demonstrated as structural and electronic properties of the clusters. Gap
between highest occupied molecular orbital and lowest unoccupied molecular orbital indicate
cluster to be a potential motif for generating magnetic cluster assembled materials. Based on
these values a comparative study on different sized clusters has been done in order to understand
the growth behaviour, electronic and magnetic properties of Cr2@Gen nanoclusters.
Research Scholar Day 2014 Page 28
Temperature Dependent Electro-optic and Dielectric Properties of CdSe QD’s Doped
Nematic Liquid Crystal
Jitendra Kumar and Manjuladevi. V
Department of Physics, Birla Institute of Technology & Science, Pilani (India)
We have studied the electro-optic and dielectric properties of cadmium selenide Quantum Dots
(CdSe QDs) doped nematic liquid crystal. The nematic liquid crystal was doped with different
concentrations of semiconducting quantum dots (QDs). The doped sample is found to have a
lower threshold voltage than that of pure NLC. The dielectric permittivity is estimated as a
function of temperature for both planar and homeotropic cells in order to find out dielectric
anisotropy. It was found that doping QDs led to increase in dielectric anisotropy in comparison
with that of pure liquid crystal. The result showed that the addition of QDs to NLC molecules
provide a way to improve the performance of LC based devices. The N-I transition temperature
for doped sample is comparable to that of pure LC.
Research Scholar Day 2014 Page 29
Study on Detection of Contamination in Water using Quartz Crystal Microbalance
Monika Poonia and Raj Kumar Gupta
Department of Physics, Birla Institute of Technology & Science, Pilani (India)
In recent years, there has been a rapid growth in the number of scientific reports in which the
quartz crystal microbalance (QCM) technique has played a key role for sensing applications. In
this work, we have detected the contaminations in water using QCM. The water with different
impurities is injected through a flow cell in a QCM. We found that resonance frequency of the
crystal decreases with increasing the impurity in water. We have investigated the temperature
dependent response of QCM for different water.
Research Scholar Day 2014 Page 30
Langmuir- Blodgett films of Stearic acid - Aligning agent for Liquid Crystal
Keerti Choudhary and Manjuladevi V.
Department of Physics, Birla Institute of Technology & Science, Pilani (India)
Stearic acid, because of its bifunctional character with a polar head group which can be attached
to metal ions and nonpolar chain, that is soluble in organic solvent finds use in many industrial
application. We formed the Langmuir monolayer of stearic acid at the air -water interface. We
have deposited single and multi layer of film on substrates at different pressures. We prepared
liquid crystal cell using such substrates. We found these cells exhibit tendency to align the
liquid crystal in planar orientation. We found that the liquid crystal alignment improves in cells
prepared with substrates deposited at higher pressures. We propose that stearic acid monolayer
can be used as an aligning agent for liquid crystals.
Research Scholar Day 2014 Page 31
Li 2SO4-Li 2O-P2O5 Ionic Glass Dispersed with [Bmim] [PF6] Ionic Liquid: Electrical Transport and Thermal Stability Investigations
Munesh Rathore1, Anshuman Dalvi1 and Anil Kumar2
1 Department of Physics, Birla Institute of Technology & Science, Pilani (India) 2 Department of Chemistry, Birla Institute of Technology & Science, Pilani (India)
Li+ ion conducting oxide glasses and glass-ceramics are the promising candidates for future solid
state ionic devices. However, their application is so far limited because of their low electrical
conductivity near room temperature. Recently, there has been interesting efforts of preparation of
ionic liquid-glass composites that exhibit high ionic conductivity at room temperature A fast
ionic composite is prepared by dispersion of Ionic liquid [Bmim][PF6] in Li2SO4-Li 2O-P2O5
glassy matrix by mixing through grinding. Amorphous/glassy nature of the samples is confirmed
by X-Ray diffraction (XRD). Surprisingly, the electrical conductivity of the samples is found to
be increasing by ~2 orders of magnitude and exhibits typical Arrhenius behavior with low
activation energy. DC polarization and impedance spectroscopy measurements suggest that
samples are essentially ionic in nature. The conductivity isotherms were also obtained at
different temperatures (T < 100 οC) and found to be appreciably stable at least for ~ 10 days.
Cyclic voltammograms on the systems are also obtained on cell of the type C|composite|C that
confirm an electrochemical stability window of at least 4 volts.
Research Scholar Day 2014 Page 32
Thin Film studies on disc shaped tethered with rod like liquid crystal molecules
C. Karthik and Raj Kumar Gupta
Department of Physics, Birla Institute of Technology & Science, Pilani (India)
Tricycloquinazoline (TCQ) acts as a potential core for designing interesting disk-shaped liquid crystals.
The liquid crystals composed of TCQ core exhibit interesting mesophases. We have studied the Langmuir
Blodgett (LB) films of such disk-shaped liquid crystals tethered with six cyano bi-phenyl groups
deposited at various target surface pressures using atomic force microscope. The LB films deposited at
various pressures revealed interesting topographical features.
Research Scholar Day 2014 Page 33
Opening Profile of DNA Unzipping: Eye & Y-shape Phase Diagrams
Amar Singh and Navin Singh
Department of Physics, Birla Institute of Technology & Science, Pilani (India)
We investigate the opening profile of a double stranded DNA (dsDNA) that is pulled from an
end or mid of the chain. We consider a homogeneous chain (all base pairs are of same kind) and
pulled the chain in constant extension ensemble (CEE). In CEE, the separation between the end
base pair of one of the ends in the dsDNA molecule is kept fixed. Average force needed to keep
this separation is measured by evaluating the change in free energy in displacing the base pair
from equilibrium position. We calculate the probability of opening of a pair and investigate the
opening of complete chain. The density plots clearly show the formation of Eye & Y-shape of
the transition from close to open state of DNA.
Figure: The figure in left shows Y-shape opening of DNA unzipping while figure in right shows Eye-shape opening when the chain pulled from the mid.
Research Scholar Day 2014 Page 34
One Dimensional Schrodinger-Poisson Solver Using Finite Difference Method
Surender Pratap and Niladri Sarkar
Department of Physics, Birla Institute of Technology & Science, Pilani (India)
We are modeling a dual gate MOS capacitor with channel thickness of the order of few
nanometers.The problem has quantum confinement along z-axes and we apply periodic boundary
condition in the x-y plane. Study of the electronic transport in Nano-Scale Devices is extremely
important for understanding the working principles of futuristic devices. The variation of the
electron density in the channel of a Nano-MOSFET will dictate its I-V characteristics.This is a
good approximation as the channel length and width dimensions are much larger than its
thickness.The Schrodinger equation and the Poisson equations are solved self consistently by
using Finite-Difference method.
Research Scholar Day 2014 Page 35
Magnetic superatom in MgnCo clusters (n=1-10): A first principle prediction
Ravi Trivedi and Debashis Bandyopadhyay
Department of Physics, Birla Institute of Technology & Science, Pilani (India)
The present study illustrates the formation of magnetic superatom in MgnCo (n= 1-10) cluster
based on a gradient corrected density functional approach. Co doped Mg8 cluster with 33 valence
electrons has filled 1S2,1P6,1D10,2S2….. Shells, making it highly stable and due to 4 unpaired
electrons breeding the magnetic moment. The newly discovered clusters, leading to the shell
model show enhanced stability. These stable clusters can mimic the chemical behavior of atoms
in the periodic table [1-4]. It has been investigated that group IIA elements (eg. Mgn, Can and
Srn) are the ideal elements and host for design super atom. Doping of transition metal into these
clusters induced exchange splitting energy of D orbital’s, due to the hybridization between the d
orbital’s of TM atom and D orbitals of the whole system. The ionization potential of such
superatom is 5.37e v, which is similar to Li and Lu atom group which have IP around of 5.39 and
5.42ev. As an application point of view we can say that these new clusters used to make
molecular electronic devices for computers with large memory storage.
References
1. Bergeron, D. E.; Castleman, A. W., Jr.; Morisato, T.; Khanna, S. N. Science 2004, 304, 84.
2. Bergeron, D. E.; Roach, P. J.; Castleman, A. W., Jr.; Jones, N. O.; Khanna, S. N. Science 2005, 307,
231.
3. Jones, N. O.; Reveles, J. U.; Khanna, S. N.; Bergeron, D. E.; Roach, P. J.; Castleman, A. W., Jr. J.
Chem. Phys. 2006, 124, 154311.
4. Bergeron, D. E.; Castleman, A. W.; Morisato, T.; Khanna, S. N. J. Chem. Phys. 2004, 121, 10456
Research Scholar Day 2014 Page 36
Landau-Fock-Darwin Confinement in two-Dimensional Space with Conical Disclination:
A Thermodynamic Study
Tridev Mishra, Tapomoy Guha Sarkar, and Jayendra Nath Bandyopadhyay
Department of Physics, Birla Institute of Technology & Science, Pilani (India)
The thermodynamic properties of a system, comprising of a spinless non-interacting charged
particle in the presence of an external magnetic field and confined in a parabolic quantum well
are studied. The focus has been on the effects of a topological defect, of the form of conical
disclination, with regard to the thermal properties of the system. We have obtained the
modifications to the traditional Landau-Fock-Darwin spectrum in the presence of conical
disclination. The canonical formalism is used to compute thermodynamic variables like entropy,
internal energy and specific heat. The study shows the interplay between magnetic field,
temperature and the degree of conicity. The kink parameter is found to affect the quantitative
behaviour of the thermodynamic quantities. It plays a crucial role in the competition between the
external magnetic field and temperature in fixing the values of the thermal response functions.