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1. Influence of spin state and electron configuration on the active site and mechanism for catalytic hydrogenation on metal cation catalysts supported on NU-1000: insights from experiments and microkinetic modeling

   https://doi.org/10.1039/d0cy00394h  

   Shabbir, Hafeera ; Pellizzeri, Steven ; Ferrandon, Magali ; Kim, In Soo ; Vermeulen, Nicolaas A. ; Farha, Omar K. ; Delferro, Massimiliano ; Martinson, Alex B. ; Getman, Rachel B. ( June 2020 , Catalysis Science & Technology)

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   The mechanism of ethene hydrogenation to ethane on six dicationic 3d transition metal catalysts is investigated. Specifically, a combination of density functional theory (DFT), microkinetic modeling, and high throughput reactor experiments is used to interrogate the active sites and mechanisms for Mn@NU-1000, Fe@NU-1000, Co@NU-1000, Ni@NU-1000, Cu@NU-1000, and Zn@NU-1000 catalysts, where NU-1000 is a metal–organic framework (MOF) capable of supporting metal cation catalysts. The combination of experiments and simulations suggests that the reaction mechanism is influenced by the electron configuration and spin state of the metal cations as well as the amount of hydrogen that is adsorbed. Specifically, Ni@NU-1000, Cu@NU-1000, and Zn@NU-1000, which have more electrons in their d shells and operate in lower spin states, utilize a metal hydride active site and follow a mechanism where the metal cation binds with one or more species at all steps, whereas Mn@NU-1000, Fe@NU-1000, and Co@NU-1000, which have fewer electrons in their d shells and operate in higher spin states, utilize a bare metal cation active site and follow a mechanism where the number of species that bind to the metal cation is minimized. Instead of binding with the metal cation, catalytic species bind with oxo ligands from the NU-1000 support, as this enables more facile H 2 adsorption. The results reveal opportunities for tuning activity and selectivity for hydrogenation on metal cation catalysts by tuning the properties that influence hydrogen content and spin, including the metal cations themselves, the ligands, the binding environments and supports, and/or the gas phase partial pressures. 

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2. Light-Harvesting “Antenna” Behavior in NU-1000

   https://doi.org/10.1021/acsenergylett.0c02514  

   Goswami, Subhadip ; Yu, Jierui ; Patwardhan, Sameer ; Deria, Pravas ; Hupp, Joseph T. ( March 2021 , ACS Energy Letters)

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3. SO 2 capture enhancement in NU-1000 by the incorporation of a ruthenium gallate organometallic complex

   https://doi.org/10.1039/D1CE01076J  

   García Ponce, Jorge ; Díaz-Ramírez, Mariana L. ; Gorla, Saidulu ; Navarathna, Chanaka ; Sanchez-Lecuona, Gabriela ; Donnadieu, Bruno ; Ibarra, Ilich A. ; Montiel-Palma, Virginia ( November 2021 , CrystEngComm)

   The new material [RuGa]@NU-1000 incorporates Ru and Ga in 1.2 and 1.8 wt% respectively (molar ratio 1 : 2). It stems from the grafting of the heterobimetallic ruthenium gallate complex, [MeRu(η 6 -C 6 H 6 )(PPh 3 ) 2 ][GaMe 2 Cl 2 ] into the MOF material NU-1000. [RuGa]@NU-1000 shows enhanced adsorption of SO 2 , specially at low pressures (10 −3 bar) even when compared with other materials employing more expensive precious metals. Additionally, [RuGa]@NU-1000 samples need not be exposed to such harsh conditions for reactivation as they retain their adsorption properties after several cycles and preserve their porosity and structure. Thus, [RuGa]@NU-1000 is an excellent, selective material suitable for detection and precise quantification of SO 2 , with a lower cost compared to other MOFs incorporating precious metals. 

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4. Search for heavy resonances decaying into a pair of Z bosons in the $$\ell ^+\ell ^-\ell '^+\ell '^-$$ and $$\ell ^+\ell ^-\nu {{\bar{\nu }}}$$ final states using 139 $$\mathrm {fb}^{-1}$$ of proton–proton collisions at $$\sqrt{s} = 13\,$$TeV with the ATLAS detector

   https://doi.org/10.1140/epjc/s10052-021-09013-y  

   Aad, G. ; Abbott, B. ; Abbott, D. C. ; Abud, A. Abed ; Abeling, K. ; Abhayasinghe, D. K. ; Abidi, S. H. ; AbouZeid, O. S. ; Abraham, N. L. ; Abramowicz, H. ; et al ( April 2021 , The European Physical Journal C)

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   Abstract A search for heavy resonances decaying into a pair of Z bosons leading to $$\ell ^+\ell ^-\ell '^+\ell '^-$$ ℓ + ℓ - ℓ ′ + ℓ ′ - and $$\ell ^+\ell ^-\nu {{\bar{\nu }}}$$ ℓ + ℓ - ν ν ¯ final states, where $$\ell $$ ℓ stands for either an electron or a muon, is presented. The search uses proton–proton collision data at a centre-of-mass energy of 13 TeV collected from 2015 to 2018 that corresponds to the integrated luminosity of 139 $$\mathrm {fb}^{-1}$$ fb - 1 recorded by the ATLAS detector during Run 2 of the Large Hadron Collider. Different mass ranges spanning 200 GeV to 2000 GeV for the hypothetical resonances are considered, depending on the final state and model. In the absence of a significant observed excess, the results are interpreted as upper limits on the production cross section of a spin-0 or spin-2 resonance. The upper limits for the spin-0 resonance are translated to exclusion contours in the context of Type-I and Type-II two-Higgs-doublet models, and the limits for the spin-2 resonance are used to constrain the Randall–Sundrum model with an extra dimension giving rise to spin-2 graviton excitations. 

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5. Search for heavy ZZ resonances in the $$\ell ^+\ell ^-\ell ^+\ell ^-$$ℓ+ℓ-ℓ+ℓ- and $$\ell ^+\ell ^-\nu \bar{\nu }$$ℓ+ℓ-νν¯ final states using proton–proton collisions at $$\sqrt{s}= 13$$s=13 $$\text {TeV}$$TeV with the ATLAS detector

   https://doi.org/10.1140/epjc/s10052-018-5686-3  

   Aaboud, M. ; Aad, G. ; Abbott, B. ; Abdinov, O. ; Abeloos, B. ; Abidi, S. H. ; AbouZeid, O. S. ; Abraham, N. L. ; Abramowicz, H. ; Abreu, H. ; et al ( April 2018 , The European Physical Journal C)