The synthesis and structure of a giant 102‐silver‐atom nanocluster (NC) 1 is presented. X‐ray structural analysis reveals that 1 features a multi‐shelled metallic core of Ag6@Ag24@Ag60@Ag12. An octahedral Ag6 core is encaged by a truncated octahedral Ag24 shell. The Ag24 shell is composed of a hitherto unknown sodalite‐type silver orthophosphate cluster (SOC) {(Ag3PO4)8}, reminiscent of the Ag3PO4 photocatalyst. The SOC is capped by six interstitial sulfur atoms, giving a unique anionic cluster [Ag6@{(Ag3PO4)8}S6]6−, which functions as an intricate polyhedral template with abundant surface O and S atoms guiding the formation of a rare rhombicosidodecahedral Ag60 shell. An array of 6 linear Ag2 staples further surround this Ag60 shell. [Ag6@{(Ag3PO4)8}S6]6− is an unusual Ag‐based templating anion to induce the assembly of a SOC within silver NC. This finding provides molecular models for bulk Ag3PO4, and offers a fresh template strategy for the synthesis of silver NCs with high symmetry.
ILs
with reversible construction of ionic networks, which mainly
consist of cooperative hydrogen bonds (CHBs) were designed for sigmoidal
ammonia (NH3) absorption isotherm, which leads to efficient
absorption, energy-saving desorption, and high reversibility. Combined
with NH3 absorption–desorption experiments, spectroscopic
investigations, NH3–TPD measurement, and quantum-chemical
calculations, NH3 absorption mechanism was proposed as
the hydrogen bond interaction with IL by overcoming the heat for disorganizing
ionic networks, including CHBs breakage and the phase change of IL
from solid to liquid. Reversely, the NH3 desorption would
be promoted by the heat release for the reformation of ionic networks.
Thereinto, [BzAm][Tf2N] with ionic networks showed NH3 absorption with threshold pressure at 0.28 bar and NH3 capacity of 2.8 mol NH3/mol IL at 1 bar as well
as be desorpted completely just through pressure swing, calorimetric
test indicated the exothermic reformation of ionic networks provided
31.8% of energy for NH3 desorption from [BzAm][Tf2N]. Furthermore, the ammonia capacity as well as the threshold pressure
would be changed by varying the CHBs interaction in IL, that [2PyH][Tf2N] with weaker interaction of CHBs indicating decreased threshold
pressure at 0.04 bar and enhanced NH3 capacity of 3.8 mol
NH3/mol IL at 1 bar. We believe this highly efficient and
reversible process by reversible construction of absorbents can provide
a potential alternative for NH3 as well as other gas absorption.
Recent advances in the all-abundant-element molecular devices for solar-driven H2generationviaintramolecular processes are overviewed including their assembly approaches, and structure–catalytic activity relationships.
Hyper-crosslinking polymers and its immobilized acid ionic liquid catalyst were prepared using cheap pitch, as a monomer, through hyper-crosslinking reactions and allyl chloride, as a chlorine source, for chloromethylation and further grafting with imidazole and functionalizing with sulfonic acid. The polymers were characterized by FE-SEM, FTIR, TG, and nitrogen sorption. The grafting ratios of the chloromethylated pitch-based hyper-crosslinked polymer (HCPpitch–CH2–Cl) and immobilized acid ionic liquid [HCPpitch–Im–Pros][Tos] were 3.5 mmol/g and 3.0 mmol/g, and the BET specific surface areas were 520 m2/g and 380 m2/g, respectively. This strategy provides an easy approach to preparing highly stable and acid functionalized mesoporous catalysts. The immobilized acidic ionic liquid was used as a catalyst for the esterification of oleic acid and methanol to synthesize biodiesel. The results demonstrated that under the optimal conditions of an alcohol to acid molar ratio of 7:1, ionic liquid to oleic acid molar ratio of 0.12, and a reaction time of 3 h at atmospheric pressure, the yield of methyl oleate can reach up to 93%. Moreover, the catalyst was reused five times without the yield decreasing significantly. This study shows that [HCPpitch–Im–Pros][Tos] is a robust catalyst for the synthesis of biodiesel.
Inspired by the metal active sites of [NiFeSe]-hydrogenases, a dppf-supported nickel(II) selenolate complex (dppf=1,1'-bis(diphenylphosphino)ferrocene) shows high catalytic activity for electrochemical proton reduction with a remarkable enzyme-like H evolution turnover frequency (TOF) of 7838 s under an Ar atmosphere, which markedly surpasses the activity of a dppf-supported nickel(II) thiolate analogue with a low TOF of 600 s . A combined study of electrochemical experiments and DFT calculations shed light on the catalytic process, suggesting that selenium atom as a bio-inspired proton relay plays a key role in proton exchange and enhancing catalytic activity of H production. For the first time, this type of Ni selenolate-containing electrocatalyst displays a high degree of O and H tolerance. Our results should encourage the development of the design of highly efficient oxygen-tolerant Ni selenolate molecular catalysts.
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