@article {46315, title = {Devising chemically robust and cationic Ni(II)-MOF with nitrogen-rich micropores for moisture-tolerant CO2 capture: highly regenerative and ultrafast colorimetric sensor for TNP and multiple Oxo-anions in water with theoretical revelation}, journal = {ACS Applied Materials \& Interfaces}, volume = {11}, year = {2019}, month = {OCT}, pages = {40134-40150}, type = {Article}, abstract = {

Metal-organic frameworks (MOFs) show distinctive superiority for carbon dioxide (CO2) capture and luminescent sensing of toxic pollutants over other materials where combination of both of these properties together with improvement of hydrolytic stability and pore functionality is critical to environmental remediation applications. The Ni(II) framework [Ni-2(mu 2OH)(azdc)(tpim)](NO3)center dot 6DMA center dot 6MeOH (CSMCRI-3) (tpim = 44{\textquoteright}4(2)-(1H-imidazole-245-triyl)tripyridine H(2)azdc = azobenzene-44{\textquoteright}-dicarboxylic acid DMA = dimethylacetamide CSMCRI = Central Salt \& Marine Chemicals Research Institute) encompassing cationic [Ni-2(mu(2)-OH)(CO2)(2)] SBUs is solvothermally synthesized from nitrogen-rich and highly fluorescent organic struts. The noninterpenetrated structure containing free nitrogen atom affixed microporous channels is stable in diverse organic solvents and weakly basic and acidic aqueous solutions. The activated MOF (3a) exhibits strong CO2-framework interaction and extremely selective CO2 adsorption over N-2 (292.5) and CH4 (11.7). Importantly water vapor exposure does not affect the surface area and/or multiple CO2 uptake-release cycles signifying potential of the porous structure for long-term use under humid conditions. Aqueous-phase sensing studies illustrate extremely specific and ultrafast detection of explosive 246-trinitrophenol (TNP) via remarkable fluorescence quenching (K-SV = 1.3 x 10 (5) M-1) with a 0.25 ppm limit of detection (LOD). Furthermore 3a serves as unique luminescent probe for highly discriminative and quick responsive detection of three noxious oxo-anions (Cr2O7 (2-) CrO4 (2-) MnO4-) in water via noteworthy turn-off responses and extreme low LODs (Cr2O7 (2-) 0.9; CrO4 (2-) 0.29; MnO4- 0.25 ppm). It is imperative to stress the outstanding reusability of the MOF toward multicyclic sensing of all four major water contaminants alongside visible colorimetric changes upon individual analyte detection. Mechanistic insights in light of the electron transfer route together with density functional theory calculations portray the influence of pore functionalization in framework-analyte interactions including alternation in energy levels where varying degrees of contribution of energy transfer explicitly authenticates high quenching of the material.

}, keywords = {chemically robust cationic MOF, DFT calculation, fast responsive detection, humid CO2 capture, TNP and oxo-anion sensing}, issn = {1944-8244}, doi = {10.1021/acsami.9b15179}, author = {Goswami, Ranadip and Seal, Nilanjan and Dash, Soumya Ranjan and Tyagi, Anshu and Neogi, Subhadip} } @article {46771, title = {Tweaking palladium electronic structure to attain oxygen reduction activity superior to platinum/C}, journal = {ACS Applied Energy Materials}, volume = {3}, year = {2020}, month = {JUL}, pages = {6127-6132}, type = {Article}, abstract = {

Enhancing oxygen reduction (ORR) activity through alloying is crucial to improve the performance of a fuel-cell catalysts. In this work, we have studied the alloying effects of 4f rare-earth (RE) metals with palladium. The modified catalyst exhibits better activity (E-onset = 1 V and E-1/2 = 0.88 V) and higher selectivity toward H2O (similar to 97\%) compared to the state-of-the-art catalysts due to complete dissociation of O-2. Hirshfeld charge analysis and 2D-electron localization function reveal improved adsorbate-adsorbent interaction on the catalyst surface. This work paves a strategy to design highly selective non-Pt-based catalysts for the ORR by controlling electronic structures and surface oxide formation.

}, keywords = {d-band center, DFT calculation, durability, EuPd, oxygen reduction reaction, YbPd}, issn = {2574-0962}, doi = {10.1021/acsaem.0c01241}, author = {Sarma, Saurav Ch. and Kaja, Sai Manoj and Mishra, Vidyanshu and Vinod, Chathakudath Prabhakaran and Peter, Sebastian C.} } @article {47646, title = {Gold-catalyzed complementary nitroalkyne internal redox process: a DFT study}, journal = {Frontiers in Chemistry}, volume = {9}, year = {2021}, month = {JUL}, pages = {689780}, type = {Article}, abstract = {Gold-catalysis, in this century, is one of the most emerging and promising new areas of research in organic synthesis. During the last two decades, a wide range of distinct synthetic methodologies have been unveiled employing homogeneous gold catalysis and aptly applied in the synthesis of numerous natural products and biologically active molecules. Among these, the reactions involving alpha-oxo gold carbene/alpha-imino gold carbene intermediates are of contemporary interest, in view of their synthetic potential and also due to the need to understand the bonding involved in these complexes. In this manuscript, we document the theoretical investigations on the regio-selectivity dependence of substitution on the gold-catalyzed cycloisomerization of o-nitroarylalkyne derivatives. We have also studied the relative stabilities of alpha-oxo gold carbene intermediates.}, keywords = {alpha-Oxo Gold Carbene, cycloisomerization, DFT calculation, Gold-catalysis, internal redox}, issn = {2296-2646}, doi = {10.3389/fchem.2021.689780}, author = {Vipin Raj, K. and Dhote, Pawan S. S. and Vanka, Kumar and Ramana, Chepuri V. V.} } @article {48811, title = {Origin of optoelectronic contradictions in 3,4-cycloalkyl[c]-chalcogenophenes: a computational study}, journal = {Polymers}, volume = {15}, year = {2023}, month = {NOV}, pages = {4240}, type = {Article}, abstract = {

The planar morphology of the backbone significantly contributes to the subtle optoelectronic features of pi-conjugated polymers. On the other hand, the atomistic tuning of an otherwise identical pi-backbone could also impact optoelectronic properties systematically. In this manuscript, we compare a series of 3,4-cycloalkylchalcogenophenes by tuning them atomistically using group-16 elements. Additionally, the effect of systematically extending these building blocks in the form of oligomers and polymers is studied. The size of the 3,4-substitution affected the morphology of the oligomers. In addition, the heteroatoms contributed to a further alteration in their geometry and resultant optoelectronic properties. The chalcogenophenes, containing smaller 3,4-cycloalkanes, resulted in lower bandgap oligomers or polymers compared to those with larger 3,4-cycloalkanes. Natural bonding orbital (NBO) calculations were performed to understand the disparity alongside the contour maps of frontier molecular orbitals (FMO).

}, keywords = {chalcogenophene, DFT calculation, Morphology, optoelectronic properties, steric effect}, doi = {10.3390/polym15214240}, author = {Masilamani, Ganesh and Krishna, Gamidi Rama and Debnath, Sashi and Bedi, Anjan} }