Indian Institute of Technology Ropar

About: Indian Institute of Technology Ropar is a education organization based out in Ropar, India. It is known for research contribution in the topics: Catalysis & Computer science. The organization has 1014 authors who have published 2878 publications receiving 35715 citations.

Reactivity of Donor-Acceptor Cyclopropanes with Saturated and Unsaturated Heterocyclic Compounds

Abstract: Strain in the ring engenders versatile reactivity that can be utilized for the synthesis of complex molecules by the assimilation of suitable substituents. In this context, vicinal donor-acceptor cyclopropanes (DACs) serve as three-carbon synthetic equivalents in organic synthesis from the last few decades. Owing to their zwitterionic nature, they have been frequently utilized in [3+n]-annulation reactions with different dipolarophiles like aldehydes, imines, oximes, epoxides, aziridines, etc. This review highlights developed synthetic tools for annulation reactions of vicinal donor-acceptor cyclopropanes with saturated and unsaturated heterocyclic compounds.

Quasinormal modes, shadow, and greybody factors of 5D electrically charged Bardeen black holes

Abstract: We study quasinormal modes (QNMs) in a five-dimensional electrically charged Bardeen black hole spacetime by considering the scalar and electromagnetic field perturbations. The black hole spacetime is an exact solution of Einstein gravity coupled to nonlinear electrodynamics in five dimensions, which has nonsingular behavior. To calculate QNMs, we use the WKB approximation method up to sixth order. Due to the presence of electric charge ${q}_{e}g0$, both the scalar and electromagnetic field perturbations decay more slowly when compared to the Schwarzschild-Tangherlini black holes. We discover that the scalar field perturbations oscillate more rapidly compared to the electromagnetic field perturbations. In terms of damping, the scalar field perturbations damp more rapidly. We graphically show that the transmission (reflection) coefficients decrease (increase) with an increase in the magnitude of the electric charge ${q}_{e}$. The emission of gravitational waves allows the spacetime to undergo damped oscillations due to the nonzero value of the imaginary part, which is always negative. The imaginary part of the QNM frequencies continuously decreases with an increase in the magnitude of the electric charge ${q}_{e}$ for a given mode ($l$, $n$). A connection between the QNM frequencies and the black hole shadow, as well as the geometric cross section in the eikonal limit, is also described.

Activation and Utilization of CO2 Using Ionic Liquid or Amine-Functionalized Basic Nanocrystalline Zeolites for the Synthesis of Cyclic Carbonates and Quinazoline-2,4(1H,3H)-dione

Abstract: CO2 was activated and used as a reactant for the preparation of cyclic carbonates and quinazoline-2,4(1H,3H)-dione using functionalized basic nanocrystalline zeolite Nano-ZSM-5 as catalysts. Nano-ZSM-5 was treated with aqueous NH3 solution to prepare basic Nano-ZSM-5. The surface basicity of the basic Nano-ZSM-5 was systematically varied by the surface modification with various amines and basic ionic liquids. Powder X-ray diffraction, N2 adsorption–desorption, scanning/transmission electron microscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, 29Si and 13C cross polarized-magic angle spin NMR, elemental analysis, and temperature-programmed desorption techniques were used to characterize the materials. Kinetic (rate constant, activation energy) and thermodynamic parameters (change in enthalpy, free energy, and entropy) were calculated for the cycloaddition reaction of CO2 to epichlorohydrin and 2-aminobenzonitrile by varying the reaction parameters. Basic Nano-ZSM-5 functionalize...