Department of Chemistry

&ldquo;IIT Jodhpur is committed to impart quality education to facilitate the creation of qualified, competent and responsible human resources to meet the emerging technological challenges of the world. It is working towards creating an equitable learning platform that is positive, accessible and effective in the face of the modern societal and scientific advancements.

Flexibility in curriculum, in all its academic programs, encompassing elements of teaching, research, creativity, innovation and entrepreneurship is the most unique feature of IIT Jodhpur. The Department of Science and Technology (DST), under the National Mission on Cyber Physical Systems, has identified IIT Jodhpur as a Technology &amp; Innovation Hub in the area of Augmented Reality and Virtual Reality. The institute has also been nominated as the coordinator for the Jodhpur City and Knowledge Cluster by the Office of Principal Scientific Adviser, Government of India.

The sprawling 852-acre IIT Jodhpur campus is a majestic tribute to the deep-rooted diverse cultural heritage of the region. The campus is an architectural masterpiece, which is slated to become an international exemplar of sustainability with net-zero energy, and advanced water and waste management strategies.&rdquo;

IIT Jodhpur

A series of palladium nanoparticles (Pd NPs) intercalated montmorillonite clay catalysts is reported for hydrogenation of 3-diphenyl prop-2-en-1-imine under mild reaction conditions. Pd/clay catalyst was prepared by a simple wet-impregnation method, and the physicochemical properties were characterized extensively by various techniques including N-2 adsorption, XRD, TEM, XPS and TPR etc., which showed the intercalation of active Pd NPs between the clay layers. The effect of reaction conditions such as catalyst loading, reaction time, temperature and H-2 pressure is explored, and thereby a plausible mechanism is proposed. The optimum amount of 6 wt \% Pd/clay catalyst showed significant catalytic activity to yield 3-phenyl propyl aniline with 100 \% conversion and selectivity under 5 bar pressure and a shorter reaction period of 3.5 h at 100 degrees C. The developed catalytic system unveiled excellent reusability over five cycles and hence paved the way for industrial applications.

World University root node

CHEMPLUSCHEM

A Sustainable Palladium-Intercalated Montmorillonite Clay Catalytic System for Imine Hydrogenation under Mild Conditions

Fabrication protocols of transparent conducting electrodes (TCEs), including those which produce TCEs of high values of figure of merit, often fail to address issues of scalability, stability, and cost. When it comes to working with high-temperature stable electrodes, one is left with only one and that too, an expensive choice, namely, fluorine-doped SnO2 (FTO). It is rather difficult to replace FTO with a low-cost TCE due to stability issues. In the present work, we have shown that an Al nanomesh fabricated employing the crack template method exhibits extreme thermal stability in air even at 500 °C, compared with that of FTO. In order to fill in the non-conducting island regions present in between the mesh wires, a moderately conducting material SnO2 layer was found adequate. The innovative step employed in the present work relates to the SnO2 deposition without damaging the underneath Al, which is a challenge in itself, as the commonly used precursor, SnCl2 solution, is quite corrosive toward Al. Optimization of spray coating of the precursor while the Al mesh on a glass substrate held at an appropriate temperature was the key to form a stable hybrid electrode. The resulting Al/SnO2 electrode exhibited an excellent transparency of ∼83% at 550 nm and a low sheet resistance of 5.5 ω/. SnO2 coating additionally made the TCE scratch-proof and mechanically stable, as the adhesion tape test showed only 8% change in sheet resistance after 1000 cycles. Further, to give FTO-like surface finish, the SnO2 surface was fluorinated by treating with a Selectfluor solution. As a result, the Al/F-SnO2 hybrid film exhibited one order higher surface conductivity with negligible sensitivity toward humidity and volatile organics, while becoming robust toward neutral electrochemical environments. Finally, a custom-designed projection lithography technique was used to pixelate the Al/SnO2 hybrid film for optoelectronic device applications. © 2020 American Chemical Society

ACS Applied Materials and Interfaces

Scalable Fabrication of Scratch-Proof Transparent Al/F-SnO2Hybrid Electrodes with Unusual Thermal and Environmental Stability

Understanding intermolecular interactions among supramolecular self-assembled organization and identifying the molecular structure relevant to the self-assembly are crucial for designing materials with desired functionalities. Interactions of aromatic rings in a peptide–perylenediimide conjugate (P-1) are investigated using dispersion-corrected density functional theory. The binding energies of fully optimized dimeric P-1 are calculated to identify the most stable conformation of the dimer. We show that the dispersion correction terms have significant contributions to the total energies of the dimers. The combined results from electronic structure calculations and molecular dynamics simulations demonstrate that the stacked dimer with negative inter-planar angle with clock-wise rotation has stronger binding energy than the dimer with positive inter-planar angle. The excess stability of the dimer with clock-wise rotation is attributed to the intra- and inter-molecular π –π stacking of the side aromatic rings of the dimer facilitated by formation of less number of hydrogen bonds. The stacked P-1 dimer with negative inter-planar angle and stronger binding energy is identified as the building block of a super structure with left-handed helical arrangements. Our calculations will build the first step towards understanding the molecular origin of the stability of a specific super structure of P-1 over the other, as obtained in the experiment relevant to material science and technology. © 2020, Indian Academy of Sciences.

Department of Computer Science & Engineering

Bulletin of Materials Science

Molecular dynamics simulations of a stacked π -conjugated soft material: binding energy and preferential geometry for self-assembly

Quantum dots (QDs) are nanocrystals with bright fluorescence and long-term photostability, attributes particularly beneficial for single-molecule imaging and molecular counting in the life sciences. The size of a QD nanocrystal determines its physicochemical and photophysical properties, both of which dictate the success of imaging applications. Larger nanocrystals typically have better optical properties, with higher brightness, red-shifted emission, reduced blinking, and greater stability. However, larger nanocrystals introduce molecular-labeling biases due to steric hindrance and nonspecific binding. Here, we systematically analyze the impact of nanocrystal size on receptor labeling in live and fixed cells. We designed three (core)shell QDs with red emission (600-700 nm) and crystalline sizes of 3.2, 5.5, and 8.3 nm. After coating with the same multidentate polymer, hydrodynamic sizes were 9.2 nm (QD9.2), 13.3 nm (QD13.3), and 17.4 nm (QD17.4), respectively. The QDs were conjugated to streptavidin and applied as probes for biotinylated neurotransmitter receptors. QD9.2 exhibited the highest labeling specificity for receptors in the narrow synaptic cleft (∼20-30 nm) in living neurons. However, for dense receptor labeling for molecular counting in live and fixed HeLa cells, QD13.3 yielded the highest counts. Nonspecific binding rose sharply for hydrodynamic sizes larger than 13.3 nm, with QD17.4 exhibiting particularly diminished specificity. Our comparisons further highlight needs to continue engineering the smallest QDs to increase single-molecule intensity, suppress blinking frequency, and inhibit nonspecific labeling in fixed and permeabilized cells. These results lay a foundation for designing QD probes with further reduced sizes to achieve unbiased labeling for quantitative and single-molecule imaging. Copyright © 2020 American Chemical Society.

ACS Nano

Optimizing Quantum Dot Probe Size for Single-Receptor Imaging

Quantum dots (QDs) are a class of fluorescent nanocrystals in development as labels for molecular imaging in cells and tissues. Recently, coatings for quantum dots based on multidentate polymers have improved labeling performance in a range of bioanalytical applications, primarily due to reduced probe hydrodynamic size. Now, an ongoing challenge is to eliminate nonspecific binding between these small probes and cellular components that mask specifically labeled molecules. Here, we describe insights into controlling and minimizing intermolecular interactions governing nonspecific binding using multidentate polymers with tunable hydrophilic functional groups that are cationic, anionic, zwitterionic (ZW), or nonionic (oligoethylene glycol; OEG). By fixing surface-binding groups and polymer length, coated colloids have similar sizes but diverse physicochemical properties. We measure binding to globular proteins, fixed cells, and living cells and observe a substantial improvement in nonspecific binding resistance when surfaces are functionalized with a combination of ZW and OEG. The independent underlying effects of counterion adsorption and flexibility appear to synergistically resist adsorption when combined, particularly for fixed cells enriched in both charged and hydrophobic moieties. We further show that ZW-OEG QDs are stable under diverse conditions and can be self-assembled with antibodies to specifically label surface antigens on living cells and cytoplasmic proteins in fixed cells. This surface engineering strategy can be adopted across the diverse range of colloidal materials currently in use and in development for biomedical applications to optimize their molecular labeling specificity. © 2020 American Chemical Society.

Zwitterion and Oligo(ethylene glycol) Synergy Minimizes Nonspecific Binding of Compact Quantum Dots

This article involves microwave (MW) absorption characteristic investigation of surface fluorinated iron oxide, synthesized via the hydrothermal method and compared with pristine alpha -Fe2O3. The MW absorption characteristics are studied by measuring real and imaginary parts of both permittivity ( varepsilon ) and permeability ( mu ) for pristine alpha -Fe2O3 and surface fluorinated Fe2O3 in the frequency range of 5.85-18 GHz. The imaginary part of permeability ( {mu }{mathrm {r}}{''} ) and the magnetic loss tangent value ( {tan} {delta }{ {mu }} ) of surface fluorinated Fe2O3 are found to be superior to pristine alpha -Fe2O3. The maximum reflection loss (RL) in surface fluorinated Fe2O3 is observed at different frequencies as a function of sample's thickness, for example, RLs -18 dB at 7.5 GHz ( t = 3.5 mm) and -12 dB at 9 GHz ( t = 3 mm), respectively. These characteristics make this material a potential candidate as radar absorbing material (RAM) both in C -band and X -band. For the first time, the MW absorption characteristics of fluorinated alpha -Fe2O3 have been demonstrated, which are the novel study in itself. © 1965-2012 IEEE.

IEEE Transactions on Magnetics

On the Study of Surface Fluorinated α-Fe2O3for Microwave Absorption

Nonlocal correlations in a quantum mechanical system hold an indispensable place in understanding the foundational aspects of theory, and for exploring efficient theoretical and experimental proposals in the regime of quantum computation and information which are otherwise not possible using classical resources. One of the possible ways to understand the nuances of nonlocal correlations is to put it in the framework of game theory. For this purpose, we address the issue of decoherence and protection of nonlocal correlations from local noise from the perspective of a game, considering the two players as noise and weak measurement reversal operations, respectively. In order to effectively understand the moves of players, we study maximum payoff and Nash equilibrium strategies for different noisy channels. Our results compare two different situations where payoffs of players are defined using the Bell inequality and discord, respectively. The analysis shows a contrasting description of payoffs and strategies in two different cases. We believe that the results obtained here will help one to understand the intricacies involved in the process of entanglement distribution through noisy channels, evaluating optimal parameters to obtain maximum payoff in the designed game, and Nash equilibrium strategies of players to win the desired game. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.

Quantum Information Processing

Nonlocal correlations and noise in different settings of a two-player game

Nanometer and subnanometer particles and films are becoming an essential and integral part of new technologies and inventions in different areas. Some of the most common areas include the microelectronic industry, magnetic recordings, photovoltaic applications, and optical coatings. Because of the ultrasmall size at atomic levels, the effect of quantum size becomes prominent, and the sensitivity of size is defined even by a difference of a single atom. Additionally, the effect is of utmost importance as the single-atom catalysts are far more advantageous than conventional catalysts as they tend to anchor easily because of their low coordination. Also, the presence of a single-atom catalyst in reactions creates efficient charge transfer as it forms a strong interaction with the support. Furthermore, catalysts in the subnanometer regime exhibit different electronic states and adsorption capabilities compared to traditional catalysts. Therefore, to fully appreciate the subnanometer catalysis reactions, it is essential to study the means of characterizing the prepared subnano catalysts, in order to characterize the materials in their as-synthesized form, to obtain a precise and accurate analysis; these are some of the fundamental requirements for achieving an optimum performance. The physical properties of many interesting materials for advanced technological usage are highly governed by the distribution and placement of atoms. Superior techniques such as high-resolution transmission electron microscopy and high-angle annular dark-field scanning transmission electron microscopy and infrared and X-ray absorption spectroscopic techniques provide electronic and geometric configurations and also reveal the transformation of the subnano catalysts on the support material. Modeling methods such as density functional theory can successfully predict the electronic structure and geometric configuration of the catalyst, which in turn influence the selectivity and activity of the catalyst. Thus, understanding the characterization techniques gives the ability to understand, identify, and measure the local environment of individual atoms and the interaction with the surface support, which will give fundamental knowledge and insights in the realms of nanoscience and technology, materials science, chemistry, and physics. Therefore, detection and enhanced measurement of individual atoms is inherently challenging and is a prerequisite to the development of new technology and better performing materials. In this chapter, we have discussed various important methods of characterization for characterizing subnanometer and atomic catalysts. © 2020 American Chemical Society.

ACS Symposium Series

State of the Art in the Characterization of Nano- And Atomic-Scale Catalysts

RSnCl3 (R = 2-phenylazophenyl) on reaction with Na2S·9H2O in a 1:1 mixture of acetone and methanol afforded a tetranuclear monoorganotin sulfide cage [(RSnIV)4(μ-S)6]· 2CHCl3·4H2O (R = 2-phenylazophenyl) (1). Complex 1 crystallizes in the monoclinic space group P2/n. The molecular structure of 1 contains five-coordinate tin centers in distorted trigonal bipyramidal geometry. Complex 1 is monoorganotin sulfide derivative having a tetranuclear double-decker cage-like structure. In 1, four tin centers are bridged by a μ2-S unit affording a ubiquitous Sn−S−Sn motif among monoorganotin sulfide compounds. In addition, each tin also has intramolecular coordination to a nitrogen atom of a 2-phenylazophenyl substituent (N → Sn). The DFT calculation suggests that the complex 1 involves mainly ligand based transitions. The complex 1 based device was studied for its electrical behavior and was found to show stable, reproducible memristive behavior with an on−off ratio of 103, which suggests that the complex 1 is a promising material for memory device applications. © 2019 American Chemical Society

Department of Physics

ACS Applied Electronic Materials

Molecular Memory Switching Device Based on a Tetranuclear Organotin Sulfide Cage [(RSnIV)4(μ-S)6]·2CHCl3·4H2O (R = 2-(Phenylazo)phenyl): Synthesis, structure, DFT studies, and memristive behavior

An organophotoredox catalyzed efficient and robust approach for the synthesis of highly important 3-alkyl substituted chroman-4-one scaffold is developed using visible light induced radical cascade cyclization strategy. The reaction is initiated through the generation of alkyl radicals from N-(acyloxy)phthalimides under photoredox conditions, which subsequently undergo intermolecular cascade radical cyclization on 2-(allyloxy)arylaldehydes to afford chroman-4-one scaffolds. The presented strategy is attractive with regard to mild reaction conditions, operational simplicity, high functional group tolerance and broad substrate scope. © 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Chemistry - An Asian Journal

Organophotoredox-Catalyzed Cascade Radical Annulation of 2-(Allyloxy)arylaldehydes with N-(acyloxy)phthalimides: Towards Alkylated Chroman-4-one Derivatives