Department of Chemistry

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In the present study, we have tried to characterize the inclusion complex of Hexaflumuron (HFM) with ß-cyclodextrin (ß-CD) using 1H &amp; 19F NMR experiments. HFM is a pesticide (anti-termite) belonging to benzoylphenylurea family that contains three classes of fluorine. Its' very low aqueous solubility can lead to facile accumulation in water or soil causing rapid poisoning of the environment. Therefore, elimination of HFM requires scavenging agents such as ß-CD that can encapsulate HFM resulting in better aqueous solubility. A significant change in 19F and 1H NMR chemical shift, 1H &amp; 19F longitudinal (T1) and 19F transverse relaxation (T2) time was observed for HFM in the presence of CD that confirms HFM-CD association. Jobs Plot demonstrated that ß-CD was found to form 2:1 inclusion complex with HFM. Association constant was determined from chemical shift titration method using modified Benesi-Hildebrand plot. The present study for the first time provides an insight in understanding formulation of HFM in ß-CD enhancingthe solubility giving rise to a possible soil remediation method. © 2019 American Institute of Physics Inc.. All rights reserved.

World University root node

AIP Conference Proceedings

Hexaflumuron_ß-cyclodextrin inclusion complex as improved pesticide formulation: A NMR case study

Purpose: Motility of spermatozoa helps not only in planning the type of infertility treatment but also directly reflects the success rate in assisted reproductive technology (ART). Previously, biotin, a water-soluble vitamin, has been shown to increase the motility and longevity of cryopreserved human spermatozoa. The present study was designed to understand the molecular basis of the beneficial effects of presence of biotin in sperm wash medium on early embryo development. Methods: The effect biotin supplementation to sperm wash medium on the sperm parameters were assessed in swim-up fraction of normozoospermic and asthenozoospermic ejaculates collected from infertile men. Fertilization and early embryo development was studied using Swiss albino mice. Results: Even though both biotin and pentoxifylline (PTX) enhanced the motility of spermatozoa from normozoospermic and asthenozoospermic samples, biotin group exhibited higher in vitro survival. Using mouse model, we observed that presence of biotin or PTX in sperm wash medium improved the fertilization rate and blastocyst rate compared to control. Blastocysts from these groups had significantly higher total cell number (P < 0.01) and lower apoptotic index. In silico target prediction revealed that GTPase HRas (HRas), tyrosine-protein phosphatase nonreceptor type 1 (PTP1B), and glucokinase are the probable targets for biotin. Solution-state Nuclear Magnetic Resonance (NMR) studies confirmed that biotin interacts both with human HRas and PTP1B. Conclusion: Our results indicate that presence of biotin in sperm wash medium can improve the fertilization potential and preimplantation embryo development and can be considered as a safe alternate to PTX. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.

Fulltext

Journal of Assisted Reproduction and Genetics

Supplementation of biotin to sperm preparation medium enhances fertilizing ability of spermatozoa and improves preimplantation embryo development

Hypervalent iodine(III) reagents have profound applications in a range of facile and novel synthetic methodologies primarily due to their remarkable oxidizing property, robust synthetic utility, environmentally benign nature and easy availability. This chapter emphasises mainly on the various transition metal-free reactions of hypervalent iodine(III) reagents for the construction of a diverse range of heterocyclic compounds. © 2020, Societa Chimica Italiana.

Targets in Heterocyclic Systems

Hypervalent iodine(III) reagents in the synthesis of heterocyclic compounds

The pyrene-decorated luminescent organotin compounds Ph3SnO2CPyr (1), [(Bz2Sn)2(μ3-O)(μ-OH)(O2CPyr)]2·2EtOH (2), and t-Bu2Sn[O2CPyr]2 (3) were synthesized from a one-pot reaction between pyrene-1-carboxylic acid (PyrCO2H) and the appropriate organotin precursors. The molecular and crystal structures of 1-3 were determined by single-crystal X-ray diffraction analyses, which reveal rich supramolecular architectures in their crystal structures. The luminescence properties of these compounds were studied in solution as well as in the solid state. While in the solid state all of the compounds reveal excimer bands, in solution, strong monomer emission is seen. Fluorescence lifetime measurements revealed (365 nm) that the average lifetimes of 1-3 in solution could be estimated as 4.97 ns (1), 4.69 ns (2), and 6.93 ns (3). © 2019 American Chemical Society.

Crystal Growth and Design

Luminescent Pyrene-Decorated Organotin Compounds: Observation of Monomer and Excimer Emission

We analyze the role of degree of entanglement for Vaidman’s game in a setting where the players share a set of partially entangled three-qubit states. Our results show that the entangled states combined with quantum strategies may not be always helpful in winning a game as opposed to the classical strategies. We further find the conditions under which quantum strategies are always helpful in achieving higher winning probability in the game in comparison to classical strategies. Moreover, we show that a special class of W states can always be used to win the game using quantum strategies irrespective of the degree of entanglement between the three qubits. Our analysis also helps us in comparing the Vaidman’s game with the secret sharing protocol. Furthermore, we propose a new Vaidman-type game where the rule maker itself is entangled with the other two players and acts as a facilitator to share a secret key with the two players. For practical purposes, the analysis is extended to study the proposed game under noisy conditions. In addition, the results obtained here are also generalized for multi-qubit games. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group.

International Journal of Computers and Applications

Analyzing the efficiency of partially entangled states in Vaidman’s-type games and its applications in Quantum Secret Sharing

The current work presents the effect of stirring hours and drying temperature on the quality of slurry, its surface morphology, and electrochemical performances of electrodes. Physical characterization studies, such as XRD, SEM, and SEM of slurry, and electrochemical characterization studies, namely, the investigation of charge-discharge capacities, rate performances, cyclability, and AC-impedance, were carried out. The cathode slurry was prepared at four different stirring intervals of 3 h, 4 h, 5 h, and 6 h and six different drying temperatures of 80, 90, 100, 110, 120, and 130 °C. The results showed that slurry obtained at a stirring time of 5 h and at a drying temperature of 120 °C exhibited best physical and electrochemical performances. SEM images showed that slurry obtained at a stirring time of 5 h has better surface uniformity and homogeneity compared to others. The electrodes prepared from this slurry also showed improved charge-discharge capacity and rate performance and low impedance. The initial discharge capacities of the electrodes, made from slurry with stirring times of 4 h, 5 h, and 6 h, were 54, 73, and 58 mA hg −1 , respectively at a current rate of C/10. The current study also provides clear-cut outline steps to prepare good quality cathode slurry. This study may provide guidelines for new researchers in the field of Li-ion battery technology to overcome these issues and get first hand good quality slurry for better results. © 2019 Author(s).

Journal of Renewable and Sustainable Energy

On the study of mixing and drying on electrochemical performance of spinel LiMn 2 O 4 cathodes

New efficient catalysts based on electrophilic N-fluoro quaternary ammonium salts are reported for catalytic allylation of (E)-N,1-diphenylmethanimine. The chiral version of the catalyst based on cinchonidine (F-CD-BF 4 ) shows high catalytic activity with approximately 94% ee and TOF (&gt;800 h −1 ). The F-CD-BF 4 is prepared from cinchonidine and Selectfluor by one-step transfer fluorination. © 2018 Wiley Periodicals, Inc.

Chirality

Electrophilic [N—F] + catalysed asymmetric allylation of (E)-N,1-diphenylmethanimine

Diazenes are an important family of organic compounds used widely in synthetic and materials chemistry. These molecules have a planar geometry and exhibit cis-trans isomerization. The simplest of all these molecules-diazene (N2H2)-has been subjected to several experimental and theoretical studies. Two mechanisms have been proposed for the cis-trans isomerization of diazene, which are an in-plane inversion and an out-of-plane torsion. The activation energies for these pathways are similar and the competition between these two mechanisms has been discussed in the literature based on electronic structure theory calculations. Three decades ago, a classical dynamics investigation of diazene isomerization was carried out using a model Hamiltonian and it was indicated that the in-plane inversion is forbidden classically because of a centrifugal barrier and the out-of-plane torsion is the only isomerization pathway. In the present work, we investigated the cis-trans isomerization dynamics of diazene using ab initio classical trajectory simulations at the CASSCF(2,2)/aug-cc-pVDZ level of electronic structure theory. The simulation results confirmed the presence of the aforementioned centrifugal barrier for the inversion and torsion was the only observed pathway. The calculations were repeated for a similar system (difluorodiazene, N2F2) and again the centrifugal barrier prevented the inversion pathway. © the Owner Societies.

Physical Chemistry Chemical Physics

Theoretical investigation of the isomerization pathways of diazenes: Torsion: Vs. inversion

A great deal of attention has been given to the decomposition chemistry of halons (halomethanes) due to their role in stratospheric ozone depletion. Knowledge of certain aspects of dissociation of halons such as the competition between radical and molecular pathways and their mechanistic details is limited. Halon molecules can isomerize to an iso form containing a halogen-halogen bond and such iso-halon forms have been identified as intermediates in condensed phase chemistry. Recently, a quantum chemistry study of role of iso-halons in the gas phase decomposition of halomethanes has been reported. In the present work, we have investigated the ground state dissociation chemistry of select halon molecules - CF2Cl2, CF2Br2, CHBr3, and CH2BrCl using electronic structure theory calculations and direct chemical dynamics simulations. Classical trajectories were generated on-the-fly using density functional PBE0/6-31G∗ level of theory at a fixed total energy. Simulation results showed that molecular products, in general, were dominant for all the four molecules at the chosen energy. A variety of mechanisms such as direct dissociation via multicenter transition states, decomposition via isomerization, radical recombinations, and roaming pathways contributed to the formation of molecular products. Atomic level mechanisms are presented, and the role of iso-halons in the gas phase chemistry of halomethanes is clearly established. © 2019 American Chemical Society.

Journal of Physical Chemistry A

Competing Molecular and Radical Pathways in the Dissociation of Halons via Direct Chemical Dynamics Simulations

A hydrated 1,2-dimyristoyl-sn-glycero-3-phosphorylcholine (DMPC) lipid membrane is investigated using an all atom molecular dynamics simulation at 308 K to determine the physical sources of universal slow relaxations of hydration layers and length-scale of the spatially heterogeneous dynamics. Continuously residing interface water (IW) molecules hydrogen bonded to different moieties of lipid heads in the membrane are identified. The non-Gaussian parameters of all classes of IW molecules show a cross-over from cage vibration to translational diffusion. A significant non-Gaussianity is observed for the IW molecules exhibiting large length correlations in translational van Hove functions. Two time-scales for the ballistic motions and hopping transitions are obtained from the self intermediate scattering functions of the IW molecules with an additional long relaxation, which disappears for bulk water. The long relaxation time-scales for the IW molecules obtained from the self intermediate scattering functions are in good accordance with the hydrogen bond relaxation time-scales irrespective of the nature of the chemical confinement and the confinement lifetime. Employing a block analysis approach, the length-scale of dynamical heterogeneities is captured from a transition from non-Gaussianity to Gaussianity in van Hove correlation functions of the IW molecules. The heterogeneity length-scale is comparable to the wave-length of the small and weak undulations of the membrane calculated by Fourier transforms of lipid tilts. This opens up a new avenue towards a possible correlation between heterogeneity length-scale and membrane curvature more significant for rippled membranes. Thus, our analyses provide a measure towards the spatio-temporal scale of dynamical heterogeneity of confined water near membranes. © 2019 The Royal Society of Chemistry.