02343nas a2200229 4500008004100000022001400041245011800055210006900173260000800242490000700250520149600257653002801753653001901781653002801800653002101828653003201849100002501881700002901906700002701935700002601962856012501988 2023 eng d a1439-423500aCan Li atoms anchored on boron- and nitrogen-doped graphene catalyze dinitrogen molecules to ammonia? a DFT study0 aCan Li atoms anchored on boron and nitrogendoped graphene cataly cJUN0 v243 a

The most successful electrochemical conversion of ammonia from dinitrogen molecule reported to date is through a Li mediated mechanism. In the framework of the above fact and that Li anchored graphene is an experimentally feasible system, the present work is a computational experiment to identify the potential of Li anchored graphene as a catalyst for N-2 to NH3 conversion as a function of (a) minimum number of Li atoms needed for anchoring on graphene sheets and (b) the role of chemical modification of graphene surfaces. The studies bring forth an understanding that Li anchored graphene sheets are potential catalysts for ammonia conversion with preferential adsorption of N-2 through end-on configuration on Li atoms anchored on doped and pristine graphene surfaces. This mode of adsorption being characteristic of Nitrogen Reduction Reaction (NRR) through enzymatic pathway, examination of the same followed by analysis of electronic properties demonstrates that tri-Li atoms (Tri Atom Catalysts, TACs) are more efficient as catalysts for NRR as compared to two Li atoms (Di Atom Catalysts, DACs). Either way, the rate determining step was found to be *NH2 ->*NH3 step (mixed pathway) with Delta G(max)=1.02 eV and *NH2-*NH3 ->*NH2 step (enzymatic pathway) with Delta G(max)=1.11 eV for 1B doped TAC and DAC on graphene sheet, respectively. Consequently, this work identifies the viability of Li anchored graphene based 2-D sheets as hetero-atom catalyst for NRR.

10acomputational chemistry10aGraphene Sheet10aheterogeneous catalysis10aLi Nanoparticles10aNitrogen Reduction Reaction1 aVerma, Tushar, Singh1 aSamal, Pragnya, Paramita1 aSelvaraj, Kaliaperumal1 aKrishnamurty, Sailaja uhttps://library.ncl.res.in/content/can-li-atoms-anchored-boron-and-nitrogen-doped-graphene-catalyze-dinitrogen-molecules01682nas a2200205 4500008004100000022001400041245011900055210006900174260000800243300001400251490000700265520092200272100002101194700002901215700002501244700002301269700002601292700002801318856013001346 2023 eng d a0022-326300aCatalyst-assisted selective vinylation and methylallylation of a quaternary carbon center using tert-butyl acetate0 aCatalystassisted selective vinylation and methylallylation of a  cJUL a9686-97030 v883 a

The In-(OTf)(3)-catalyzed & alpha;-vinylationof varioushydroxy-functionalized quaternary carbon centers using in situ generatedisobutylene from tert-butyl acetate is presentedas a novel synthetic methodology. Moreover, tert-butylacetate is a nonflammable feed stock and is a readily available sourcefor the in situ production of vinyl substituents, as demonstratedby the vinylation reaction with quaternary hydroxy/methoxy compounds.Moreover, an excellent selectivity for methylallylation over vinylationwas obtained with Ni-(OTf)(2) as a catalyst. In the case ofperoxyoxindole, methylallyl-functionalized 1,4-benzoxazin-3-one derivativeswere formed through the sequential rearrangement of peroxyoxindolefollowed by the nucleophilic attack by isobutylene. The detailed mechanismfor this reaction and rationalization for the selectivity are providedusing kinetics and density functional theory studies.

1 aMohanta, Nirmala1 aSamal, Pragnya, Paramita1 aPandey, Akanksha, M.1 aMondal, Shankhajit1 aKrishnamurty, Sailaja1 aGnanaprakasam, Boopathy uhttps://library.ncl.res.in/content/catalyst-assisted-selective-vinylation-and-methylallylation-quaternary-carbon-center-using01955nas a2200181 4500008004100000022001400041245008700055210006900142260000800211300001400219490000700233520132300240100002901563700001901592700002601611700001901637856011701656 2026 eng d a1463-907600aCO2, N2 and H2 adsorption in Zn2+-containing zeolites and metal-organic frameworks0 aCO2 N2 and H2 adsorption in Zn2containing zeolites and metalorga cFEB a5161-51740 v283 a

We employ a chemically accurate (+/- 4 kJ mol-1) embedding approach to calculate enthalpies for CO2, N2, and H2 adsorption in the Zn2+-containing zeolites FAU and CHA, and for CO2 and H2 in the metal-organic frameworks (MOFs) Zn-MOF-74 and CALF-20. Using MP2 as the high-level method and PBE+D4 as the periodic low-level method (MP2:PBE+D4), we obtain CO2 adsorption enthalpies of -46, -34, and -36 kJ mol-1 for Zn-CHA, Zn-MOF-74, and CALF-20, respectively, all within chemical accuracy limits of the experimental values of -42, -30, and -39 kJ mol-1. For CO2 in Zn-FAU, where no experimental data exist, we provide an MP2:PBE+D4 prediction of -49 kJ mol-1. For N2, we predict MP2:PBE+D4 adsorption enthalpies of -41 and -39 kJ mol-1 in Zn-CHA and Zn-FAU, respectively. CO2 adsorption is stronger in the zeolites than in the studied MOFs. Across all systems, CO2 adsorption tends to be stronger than N2 adsorption and both are largely favoured over H2. We observe inconsistent accuracy of PBE+D4 for the two MOFs, despite their similar characteristics, underscoring the need for high-level approaches in predictive screening. Additionally, we conclude that Zn2+ cations with open coordination sites act as the primary binding sites and that these cations preferentially occupy 6-membered rings in zeolites.

1 aSamal, Pragnya, Paramita1 aBerger, Fabian1 aKrishnamurty, Sailaja1 aSauer, Joachim uhttps://library.ncl.res.in/content/co2-n2-and-h2-adsorption-zn2-containing-zeolites-and-metal-organic-frameworks