02813nas a2200229 4500008004100000022001400041245013100055210006900186260000800255300001600263490000700279520198000286100002302266700002202289700001802311700002202329700001702351700002602368700002802394700003002422856013102452 2022 eng d a2050-748800aCovalent organic framework with electrodeposited copper nanoparticles - a desirable catalyst for the Ullmann coupling reaction0 aCovalent organic framework with electrodeposited copper nanopart cJUL a15647-156560 v103 a

A covalent organic framework is a porous covalently-linked polymeric assembly built from molecular lego blocks, the monomers. A COF's high surface area, ordered pores, and intrinsic low density makes it a perfect heterogeneous catalyst component. Dispersing catalytic metal nanoparticles into the porous COF matrix in a `capping-agent-free' manner can aid the maximal utilization of the active sites. To generate single-site catalysts, metals have been anchored to dense supports, or metal ions have been coordinated to the porous organic framework. The latter has superior atom efficiency and a substrate diffusion advantage. Stably nestling neutral metallic clusters into open-framework supports with no specifically strong binding groups requires a different approach. If infused from extremely dilute electrolytes, metal clusters can be nanoconfined into electrically activated COFs. At low-loadings, it can resemble a single-site catalyst with high atom efficiency. Herein, we report the larger scale synthesis of IISERP-COF15 and electrochemical loading of copper nanoparticles into its pores at loadings as low as 3.34 wt%. We employed classical Ullmann reactions to adjudge its activity. Typical turnover numbers for the catalysts reported in the literature are approximately 50-100. A Cu@COF shows high activity with a very low catalyst loading of 0.25 mol% (TON around similar to 300-350 vs. 4 for neat CuCl2 center dot 2H(2)O (homogeneous catalyst) and turnover frequency (similar to 15-17 h(-1))). We recycled it for up to 3 cycles. Furthermore, we report a multi-fold Ullmann reaction producing an unreported hexaaldehyde to demonstrate the latitude of the catalyst. Our work points to the potential of a dilutely loaded metal@COF as a mimic of the single-site catalyst for synthesizing valuable C-O linked molecules. Our findings from computational modeling shed light on the role of the COF as an active nanoporous support for Ullmann C-O coupling.

1 aChandran, Chandana1 aSingh, Himan, Dev1 aLeo, Liya, S.1 aShekhar, Pragalbh1 aRase, Deepak1 aChakraborty, Debanjan1 aVinod, Chathakudath, P.1 aVaidhyanathan, Ramanathan uhttps://library.ncl.res.in/content/covalent-organic-framework-electrodeposited-copper-nanoparticles-desirable-catalyst-ullmann02525nas a2200301 4500008004100000022001400041245011100055210006900166260000800235300001200243490000700255520151500262653002701777653002801804653001701832653002701849653002701876100002101903700001701924700002201941700001801963700003601981700001402017700002302031700001902054700003002073856012002103 2022 eng d a1614-683200aIncorporating conducting polypyrrole into a polyimide COF for carbon-free ultra-high energy supercapacitor0 aIncorporating conducting polypyrrole into a polyimide COF for ca cSEP a22007540 v123 a

Redox-active covalent organic frameworks (COFs) store charges but possess inadequate electronic conductivity. Their capacitive action works by storing H+ ions in an acidic electrolyte and is typically confined to a small voltage window (0-1 V). Increasing this window means higher energy and power density, but this risks COF stability. Advantageously, COF's large pores allow the storage of polarizable bulky ions under a wider voltage thus reaching higher energy density. Here, a COF-electrode-electrolyte system operating at a high voltage regime without any conducting carbon or redox active oxides is presented. Conducting polypyrrole (Ppy) chains are synthesized within a polyimide COF to gain electronic conductivity (approximate to 10 000-fold). A carbon-free quasi-solid-state capacitor assembled using this composite showcases high pseudo-capacitance (358 mF cm(-2)@1 mA cm(-2)) in an aqueous gel electrolyte. The synergy among the redox-active polyimide COF, polypyrrole and organic electrolytes allows a wide-voltage window (0-2.5 V) leading to high energy (145 mu Wh cm(-2)) and power densities (4509 mu W cm(-2)). Amalgamating the polyimide-COF and the polypyrrole as one material minimizes the charge and mass transport resistances. Computation and experiments reveal that even a partial translation of the modules/monomers intrinsic electronics to the COF imparts excellent electrochemical activity. The findings unveil COF-confined polymers as carbon-free energy storage materials.

10acarbon free capacitors10acation-anion co-storage10aconductivity10ahigh energy capacitors10apolypyrrole doped COFs1 aHaldar, Sattwick1 aRase, Deepak1 aShekhar, Pragalbh1 aJain, Chitvan1 aVinod, Chathakudath, Prabhakara1 aZhang, En1 aShupletsov, Leonid1 aKaskel, Stefan1 aVaidhyanathan, Ramanathan uhttps://library.ncl.res.in/content/incorporating-conducting-polypyrrole-polyimide-cof-carbon-free-ultra-high-energy03138nas a2200253 4500008004100000022001400041245012100055210006900176260000900245300001200254490000600266520224700272100001702519700002702536700002202563700002202585700001802607700002602625700002102651700001902672700003202691700003002723856013102753 2023 eng d a2055-675600aHydroxide ion-conducting viologen-bakelite organic frameworks for flexible solid-state zinc-air battery applications0 aHydroxide ionconducting viologenbakelite organic frameworks for  cJAN  a224-2340 v83 a

Adaptable polymer-based solid-state electrolytes can be a game-changer toward safe, lightweight flexible batteries. We present a robust Bakelite-type organic polymer covalently decked with viologen, triazine, and phenolic moieties. Its flexible structure with cationic viologen centers incorporates counter-balancing free hydroxide ions into the polymeric framework. By design, the aromatic groups and heteroatoms in the framework can be activated under an applied potential to prompt a push-pull drive, setting off the towing of hydroxide ions via weak electrostatic, van der Waals, and hydrogen-bond interactions. The frontier orbitals from a DFT-modeled structure certify this. The hydroxyl-polymer requires minimal KOH wetting to maintain a humid environment for Grotthuss-type transport. The hydroxide ion conductivity reaches a value of 1.4 x 10(-2) S cm(-1) at 80 degrees C and 95% RH, which is retained for over 15 h. We enhanced its practical utility by coating it as a thin solid-state separator-cum-electrolyte on readily available filter paper. The composite exhibits a conductivity of 4.5 x 10(-3) S cm(-1) at 80 degrees C and 95% RH. A zinc-air battery (ZAB) constructed using this polymer-coated paper as electrolyte yields a maximum power density of 115 mW cm(-2) and high specific capacitance of 435 mA h g(-1). The power density recorded for our ZAB is among the best reported for polymer electrolyte-based batteries. Subsequently, the flexible battery fabricated with IISERP-POF11_OH@FilterPaper exhibits an OCV of 1.44 V, and three batteries in series power a demo traffic signal. To underscore the efficiency of hydroxide ion transport through the complex multifunctional backbone of the polymer, we calculated the diffusion coefficient for OH- (Exp: 2.9 x 10(-5) cm(2) s(-1); Comp. 5.2 x 10(-6) cm(2) s(-1)) using electrochemical methods and MD simulations. Climbing-edge NEB calculations reveal a large energy barrier of 2.11 eV for Zn2+ to penetrate the polymer and identify hydroxide ions within the polymer, suggesting no undesirable Zn2+ crossover. Our findings assert the readily accessible C-C-linked cationic polymer's capacity as a solid-state electrolyte for ZABs and any anion-conducting membrane.

1 aRase, Deepak1 aIllathvalappil, Rajith1 aSingh, Himan, Dev1 aShekhar, Pragalbh1 aLeo, Liya, S.1 aChakraborty, Debanjan1 aHaldar, Sattwick1 aShelke, Ankita1 aAjithkumar, Thalasseril, G.1 aVaidhyanathan, Ramanathan uhttps://library.ncl.res.in/content/hydroxide-ion-conducting-viologen-bakelite-organic-frameworks-flexible-solid-state-zinc-air02409nas a2200289 4500008004100000022001400041245011300055210006900168260000800237490000700245520141200252653003201664653002301696653001501719653002301734653002101757100002001778700001801798700002201816700001701838700002701855700001601882700002301898700003601921700003001957856013201987 2023 eng d a1614-683200aMade to measure squaramide COF cathode for zinc dual-ion battery with enriched storage via redox electrolyte0 aMade to measure squaramide COF cathode for zinc dualion battery  cSEP0 v133 a

Aqueous rechargeable batteries are promising grid-scale energy storage devices because of their affordability, operational safety, and environmental benignity. Among these, Zn-ion batteries (ZIBs) have unfolded new horizons. Designing superior cathodes for ZIBs is crucial. Covalent organic frameworks (COFs) can be made redox active with a high storage surface. Here, for the first time, a chelating COF with redox-active ZnI2 in a ZnSO4(aq) electrolyte is combined. Including iodide harvests an approximately threefold enhancement in capacity from 208 to 690 mAh g(-1) at 1.5 A g(-1), the highest among all the COF-derived ZIBs. Remarkably, a charge-discharge curve at 1.3 V exhibits very limited dropout voltage and super-flat platform, with a remarkable capacity of 600 mAh g(-1) at 5 A g(-1) stable up to 6000 cycles, confirming that the polyiodide generation and storage are sustainable. The COF's dual-ion storage (Zn2+ and polyidode) delivers a ZIB with the highest energy density. Spectro-electrochemical measurements coupled with X-ray photoelectron spectroscopy unambiguously unveil the existence of multiple polyiodide species, with I-3(-) and IO3- ions as the prominent species. The latter gets reduced at the COF electrode under an applied potential, leaving I-3(-) as the major species stored on the COF. The prospect of COF-polyiodide((aq)) is a windfall for metal-ion batteries.

10acovalent organic frameworks10aflexible batteries10apolyiodide10aredox electrolytes10aZn ion batteries1 aKushwaha, Rinku1 aJain, Chitvan1 aShekhar, Pragalbh1 aRase, Deepak1 aIllathvalappil, Rajith1 aMekan, Deep1 aCamellus, Augastus1 aVinod, Chathakudath, Prabhakara1 aVaidhyanathan, Ramanathan uhttps://library.ncl.res.in/content/made-measure-squaramide-cof-cathode-zinc-dual-ion-battery-enriched-storage-redox-electrolyte02348nas a2200265 4500008004100000022001400041245014300055210006900198260000800267300001200275490000800287520138500295653003201680653002801712100001801740700002001758700001701778700002201795700001901817700001901836700003201855700003601887700003001923856012901953 2023 eng d a0002-786300aTailoring COFs: transforming nonconducting 2D layered COF into a conducting quasi-3D architecture via interlayer knitting with polypyrrole0 aTailoring COFs transforming nonconducting 2D layered COF into a  cDEC a487-4990 v1463 a

Improving the electronic conductivity and the structural robustness of covalent organic frameworks (COFs) is paramount. Here, we covalently cross-link a 2D COF with polypyrrole (Ppy) chains to form a quasi-3D COF. The 3D COF shows well-defined reflections in the SAED patterns distinctly indexed to its modeled crystal structure. This knitting of 2D COF layers with conjugated polypyrrole units improves electronic conductivity from 10(-9) to 10(-2 )S m(-1). This conductivity boost is affirmed by the presence of density of states near the Fermi level in the 3D COF, and this elevates the COF's valence band maximum by 0.52 eV with respect to the parent 2D pyrrole-functionalized COF, which agrees well with the opto-electro band gaps. The extent of HOMO elevation suggests the predominant existence of a polaron state (radical cation), giving rise to a strong EPR signal, most likely sourced from the cross-linking polypyrrole chains. A supercapacitor devised with COF20-Ppy records a high areal capacitance of 377.6 mF cm(-2), higher than that of the COF loaded with noncovalently linked polypyrrole chains. Thus, the polypyrrole acts as a ``conjugation bridge'' across the layers, lowering the band gap and providing polarons and additional conduction pathways. This marks a far-reaching approach to converting many 2D COFs into highly ordered and conducting 3D ones.

10acovalent organic frameworks10aElectrical conductivity1 aJain, Chitvan1 aKushwaha, Rinku1 aRase, Deepak1 aShekhar, Pragalbh1 aShelke, Ankita1 aSonwani, Disha1 aAjithkumar, Thalasseril, G.1 aVinod, Chathakudath, Prabhakara1 aVaidhyanathan, Ramanathan uhttps://library.ncl.res.in/content/tailoring-cofs-transforming-nonconducting-2d-layered-cof-conducting-quasi-3d-architecture01101nas a2200325 4500008004100000022001400041245015200055210006900207260000800276300001400284490000700298653001500305653001300320653002000333653001400353100002200367700001800389700002200407700002000429700001700449700002200466700001800488700001800506700001900524700003600543700001500579700002300594700003000617856012800647 2024 eng d a0897-475600aResorcinol-Azodianiline Covalent Organic Framework Supported FeOOH Quantum Dot-Catalyzed Electrochemical Ammonia Synthesis under Ambient Conditions0 aResorcinolAzodianiline Covalent Organic Framework Supported FeOO cAUG a8229-82380 v3610aconversion10anitrogen10aRecent Progress10areduction1 aShekhar, Pragalbh1 aKosugi, Kento1 aSingh, Himan, Dev1 aKushwaha, Rinku1 aRase, Deepak1 aMatsuzaki, Takumi1 aJain, Chitvan1 aSingh, Piyush1 aSingh, Yashraj1 aVinod, Chathakudath, Prabhakara1 aKondo, Mio1 aMasaoka, Shigeyuki1 aVaidhyanathan, Ramanathan uhttps://library.ncl.res.in/content/resorcinol-azodianiline-covalent-organic-framework-supported-feooh-quantum-dot-catalyzed