The catalytic efficiency of M-Htpda pincer complexes (M=Mn(I), Fe(II), Co(III)) in CO hydrogenation, emphasizing the role of transition metal variability have been discussed. The DFT analysis demonstrates that complexes with low αR values form weaker M-H bonds, enhancing catalyst reactivity with the elongation of M-H bond. The analysis further displays excellent catalytic performance for Mn-Htpda (ΔE=20.
View Article and Find Full Text PDFThe efficient removal of 99TcO4- from alkaline nuclear waste is vital for optimizing nuclear waste management and safeguarding the environment. However, current state-of-the-art sorbent materials are constrained by their inability to simultaneously achieve high alkali resistance, rapid adsorption kinetics, large adsorption capacity, and selectivity. In this study, we synthesized a urea-rich cationic porous organic polymer, IPM-403, which demonstrates exceptional chemical stability, ultrafast kinetics (~92% removal within 30 seconds), high adsorption capacity (664 mg/g), excellent selectivity, along with multiple-cycle recyclability (up to 7 cycles), making it highly promising for the removal of ReO4- (surrogate of 99TcO4-) from nuclear wastewater.
View Article and Find Full Text PDFSynthetically challenging spirolactams were developed in good yields and regio-selectivity through a step-up oxidative dearomatization of easily accessible arenols tethered to esters in the presence of quaternary ammonium tribromide as an economic oxidant and amines. The reaction mechanism associated with this unprecedented dearomative lactamisation has been forecasted with a series of controlled experiments and DFT studies.
View Article and Find Full Text PDFThe development of an efficient, selective, and durable catalysis system for the electrocatalytic N reduction reaction (ENRR) is a promising strategy for the sustainable production of ammonia. The high-performance ENRR is limited by two major challenges: poor adsorption of N over the catalyst surface and abysmal N solubility in aqueous electrolytes. Herein, with the help of our combined density functional theory (DFT) calculations and experimental electrocatalysis study, we demonstrate that concurrently induced electron-deficient Lewis acid sites in an electrocatalyst and in an electrolyte medium can significantly boost the ENRR performance.
View Article and Find Full Text PDFThere is no experimental evidence of whether such gold-catalyzed aminoauration reactions follow the - and/or -pathway, and hence, to understand the origin of the selectivity in Au(I)- and Au(III)-catalyzed reactions of alkynes, a thorough mechanistic study was performed using DFT methods. The NBO and ASM analyses provided significant information about the structure-stability-reactivity of the pathway-determining states (PDS). This study further reveals that the oxidation states and geometries of gold, the steric bulk, and the dihedral angles of the PDS direct the mechanistic pathways and control the turnover frequency.
View Article and Find Full Text PDFThis research showcases the machine learning (ML)-enabled homogeneous catalyst discovery to be employed in carbon dioxide hydrogenation. To achieve the desired turnover frequency (TOF), the electrophilicity of the central metal atom is a crucial factor in transition metal pincer complexes. The condensed Fukui function is a direct measure of the catalytic performance of these pincer complexes.
View Article and Find Full Text PDFAn inexpensive computational method is designed to demonstrate the efficacy of the complex COF toward CO capture. The interaction energy calculations of small repeating units of COF precisely demonstrate CO uptake capacity at high pressure and effective dual descriptors values of these repeating units of COFs accurately establish their structure-property relationships under ambient conditions. The computational findings are in consonance with experimental results reported by Yaghi and coworkers.
View Article and Find Full Text PDFA thorough DFT study was performed to unravel the true mechanism involved in the Pd(0)-catalyzed functional group transposition between aroyl chlorides and aryl iodides. Two different experimental groups proposed different mechanisms for the functional group transposition reaction. A careful assessment of experimental findings and thorough computational studies endorsed that the functional group transposition proceeds via phosphonium salt formation and ligand-enabled C-P bond metathesis, leading to the formation of the PhI and the intermediate .
View Article and Find Full Text PDFCarbon dioxide utilization is necessary to reduce carbon footprint and also to synthesize value-added chemicals. The transition metal pincer complexes are attractive catalysts for the hydrogenation of carbon dioxide to formic acid. There is a need to understand the factors affecting the catalytic performance of these pincer complexes through a structure-activity relationship study using computational methods.
View Article and Find Full Text PDFThe development of sustainable catalysts to get methanol from CO under milder conditions and without any additives is still considered an arduous task. In many instances, transition-metal-catalyzed carbon dioxide to formic acid formation is more facile than methanol formation. This article provides comprehensive density functional theoretic investigations of six new Mn(I)PNN complexes, which are designed to perform CO to methanol conversion under milder reaction conditions.
View Article and Find Full Text PDFDensity functional theory method in combination with a continuum solvation model is used to understand the role of hydrogen bonding in the interactions of tertiary nitrogen centers of guanine and adenine with monoaqua and diaqua NAMI-A. In the case of adenine, the interaction of N3 with monoaqua NAMI-A is preferred over that of N7 and N1 whereas, N7 site is the most preferred site over N3 and N1 in the diaqua ruthenium-adenine interaction. In the monoaqua and diaqua NAMI-A-guanine interactions, the N7 site is the most preferred site over the N3 site.
View Article and Find Full Text PDFTriose 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.
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