Highly Efficient Carbon Monoxide Capture by Carbanion‐Functionalized Ionic Liquids through C‐Site Interactions

A novel method for the highly efficient and reversible capture of CO in carbanion‐functionalized ionic liquids (ILs) by a C‐site interaction is reported. Because of its supernucleophilicity, the carbanion in ILs could absorb CO efficiently. As a result, a relatively high absorption capacity for CO (up to 0.046 mol mol⁻¹) was achieved under ambient conditions, compared with CO solubility in a commonly used IL [Bmim][Tf₂N] (2×10⁻³ mol mol⁻¹). The results of quantum mechanical calculations and spectroscopic investigation confirmed that the chemical interaction between the C‐site in the carbanion and CO resulted in the superior CO absorption capacities. Furthermore, the subsequent conversion of captured CO into valuable chemicals with good reactivity was also realized through the alkoxycarbonylation reaction under mild conditions. Highly efficient CO absorption by carbanion‐functionalized ILs provides a new way of separating and converting CO.     

Highly Efficient Carbon Monoxide Capture by Carbanion-Functionalized Ionic Liquids through C-Site Interactions

A novel method for the highly efficient and reversible capture of CO in carbanion-functionalized ionic liquids (ILs) by a C-site interaction is reported. Because of its supernucleophilicity, the carbanion in ILs could absorb CO efficiently. As a result, a relatively high absorption capacity for CO (up to 0.046 mol mol⁻¹) was achieved under ambient conditions, compared with CO solubility in a commonly used IL [Bmim][Tf₂N] (2×10⁻³ mol mol⁻¹). The results of quantum mechanical calculations and spectroscopic investigation confirmed that the chemical interaction between the C-site in the carbanion and CO resulted in the superior CO absorption capacities. Furthermore, the subsequent conversion of captured CO into valuable chemicals with good reactivity was also realized through the alkoxycarbonylation reaction under mild conditions. Highly efficient CO absorption by carbanion-functionalized ILs provides a new way of separating and converting CO.     

Multi‐Molar Absorption of CO2 by the Activation of Carboxylate Groups in Amino Acid Ionic Liquids

A new strategy for multi‐molar absorption of CO₂ is reported based on activating a carboxylate group in amino acid ionic liquids. It was illustrated that introducing an electron‐withdrawing site to amino acid anions could reduce the negative inductive effect of the amino group while simultaneously activating the carboxylate group to interact with CO₂ very efficiently. An extremely high absorption capacity of CO₂ (up to 1.69 mol mol^?1) in aminopolycarboxylate‐based amino acid ionic liquids was thus achieved. The evidence of spectroscopic investigations and quantum‐chemical calculations confirmed the interactions between two kinds of sites in the anion and CO₂ that resulted in superior CO₂ capacities.     

Preorganization and Cooperation for Highly Efficient and Reversible Capture of Low‐Concentration CO2 by Ionic Liquids

A novel strategy based on the concept of preorganization and cooperation has been designed for a superior capacity to capture low‐concentration CO₂ by imide‐based ionic liquids. By using this strategy, for the first time, an extremely high gravimetric CO₂ capacity of up to 22 wt % (1.65 mol mol⁻¹) and excellent reversibility (16 cycles) have been achieved from 10 vol. % of CO₂ in N₂ when using an ionic liquid having a preorganized anion. Through a combination of quantum‐chemical calculations and spectroscopic investigations, it is suggested that cooperative interactions between CO₂ and multiple active sites in the preorganized anion are the driving force for the superior CO₂ capacity and excellent reversibility.     

N‐Boc‐Protected 1,2‐Diphenylethylenediamine‐Based Dendritic Organogels with Multiple‐Stimulus‐Responsive Properties

A new class of poly(benzyl ether) dendrimers, decorated in their cores with N‐Boc‐protected 1,2‐diphenylethylenediamine groups, were synthesized and fully characterized. It was found that the gelation capability of these dendrimers was highly dependent on dendrimer generation, and the second‐generation dendrimer (R,R)‐G₂DPENBoc proved to be a highly efficient organogelator. A number of experiments (SEM, TEM, FTIR spectroscopy, ¹H NMR spectroscopy, rheological measurements, UV/Vis absorption spectroscopy, CD, and XRD) revealed that these dendritic molecules self‐assembled into elastically interpenetrating one‐dimensional nanostructures in organogels. The hydrogen bonding, π–π, and solvophobic interactions were found to be the main driving forces for formation of the gels. Most interestingly, these dendritic organogels exhibited smart multiple‐stimulus‐responsive behavior upon exposure to environmental stimuli such as temperature, anions, and mechanical stress.     

Ultrathin 2D Graphitic Carbon Nitride on Metal Films: Underpotential Sodium Deposition in Adlayers for Sodium‐Ion Batteries

Efficient and low‐cost anode materials for the sodium‐ion battery are highly desired to enable more economic energy storage. Effects on an ultrathin carbon nitride film deposited on a copper metal electrode are presented. The combination of effects show an unusually high capacity to store sodium metal. The g‐C₃N₄ film is as thin as 10 nm and can be fabricated by an efficient, facile, and general chemical‐vapor deposition method. A high reversible capacity of formally up to 51 Ah g^?1 indicates that the Na is not only stored in the carbon nitride as such, but that carbon nitride activates also the metal for reversible Na‐deposition, while forming at the same time an solid electrolyte interface layer avoiding direct contact of the metallic phase with the liquid electrolyte.     

The Studies of Structure of 2N‐(3‐phenyl‐allyl‐)(5‐phenyl‐[1,3,4] Thiadiazol‐2‐yl) Amine in Solution

2N‐(3‐phenyl‐allyl‐)(5‐phenyl‐[1,3,4] thiadiazol‐2‐yl) amine was studied by means of the ¹H, ¹³C, ¹⁵N NMR spectroscopy and DFT calculations. On the basis of the one‐dimensional ¹H, ¹³C, ¹⁵N‐NMR and two‐dimensional ¹H‐¹³C HMQC, ¹H‐¹³C HMBC, ¹H‐¹⁵N HMQC, ¹H¹H NOESY, ¹H¹H COSY correlation spectra the amine‐type and the imine‐type tautomers have been determined in the solution. Variety of structural forms including: biradical, ionic–biradical, and ionic structures of the amine‐type a and of the imine‐type b , c tautomers exist in the solution. According to the DFT computations the differences in the total energy between a and b , a and c , and b and c tautomers are equal to 1.5 kJ/mol, 1.2 kJ/mol, and 0.3 kJ/mol, respectively.     

A Multiple Structure‐Design Strategy towards Ultrathin Niobate Perovskite Nanosheets with Thickness‐Dependent Photocatalytic Hydrogen‐Evolution Performance

Hydrogen production by catalytic water splitting using sunlight holds great promise for clean and sustainable energy source. Despite the efforts made in the past decades, challenges still exist in pursuing solid catalysts with light‐harvesting capacity, large surface areas and efficient utilities of the photogenerated carrier, at the same time. Here, a multiple structure design strategy leading to highly enhanced photocatalytic performance on hydrogen production from water splitting in Dion–Jacobson perovskites KCa₂Na_{n ‐3}Nb_n O_{3n +1} is described. Specifically, chemical doping (N/Nb⁴⁺) of the parent oxides via ammoniation improved the ability of sunlight harvesting efficiently; subsequent liquid exfoliation of the doped perovskites yielded ultrathin [Ca₂Na_{n ‐3}Nb_n O_{3n +1}]⁻ nanosheets with greatly increased surface areas. Significantly, the maximum hydrogen evolution appears in the n =4 nanosheets, which suggests the most favorable thickness for charge separation in such perovskite‐type catalysts. The optimized black N/Nb⁴⁺‐[Ca₂NaNb₄O₁₃]⁻ nanosheets show greatly enhanced photocatalytic performance, as high as 973 μmol h⁻¹ with Pt loading, on hydrogen evolution from water splitting. As a proof‐of‐concept, this work highlights the feasibility of combining various chemical strategies towards better catalysts and precise thickness control of two‐dimensional materials.     

Ferrocene‐tagged ionic liquid stabilized on silica‐coated magnetic nanoparticles: Efficient catalyst for the synthesis of 2‐amino‐3‐cyano‐4H‐pyran derivatives under solvent‐free conditions

An advanced novel magnetic ionic liquid based on imidazolium tagged with ferrocene, a supported ionic liquid, is introduced as a recyclable heterogeneous catalyst. Catalytic activity of the novel nanocatalyst was investigated in one‐pot three‐component reactions of various aldehydes, malononitrile and 2‐naphthol for the facile synthesis of 2‐amino‐3‐cyano‐4H‐pyran derivatives under solvent‐free conditions without additional co‐catalyst or additive in air. For this purpose, we firstly synthesized and investigated 1‐(4‐ferrocenylbutyl)‐3‐methylimidazolium acetate, [FcBuMeIm][OAc], as a novel basic ferrocene‐tagged ionic liquid. This ferrocene‐tagged ionic liquid was then linked to silica‐coated nano‐Fe₃O₄ to afford a novel heterogeneous magnetic nanocatalyst, namely [Fe₃O₄@SiO₂@Im‐Fc][OAc]. The synthesized novel catalyst was characterized using ¹H NMR, ¹³C NMR, Fourier transform infrared and energy‐dispersive X‐ray spectroscopies, X‐ray diffraction, and transmission and field emission scanning electron microscopies. Combination of some unique characteristics of ferrocene and the supported ionic liquid developed the catalytic activity in a simple, efficient, green and eco‐friendly protocol. The catalyst could be reused several times without loss of activity.     

Ionic Liquids as Precursors for Efficient Mesoporous Iron‐Nitrogen‐Doped Oxygen Reduction Electrocatalysts

A ferrocene‐based ionic liquid (Fe‐IL) is used as a metal‐containing feedstock with a nitrogen‐enriched ionic liquid (N‐IL) as a compatible nitrogen content modulator to prepare a novel type of non‐precious‐metal–nitrogen–carbon (M‐N‐C) catalysts, which feature ordered mesoporous structure consisting of uniform iron oxide nanoparticles embedded into N‐enriched carbons. The catalyst Fe¹⁰@NOMC exhibits comparable catalytic activity but superior long‐term stability to 20 wt % Pt/C for ORR with four‐electron transfer pathway under alkaline conditions. Such outstanding catalytic performance is ascribed to the populated Fe (Fe₃O₄) and N (N2) active sites with synergetic chemical coupling as well as the ordered mesoporous structure and high surface area endowed by both the versatile precursors and the synthetic strategy, which also open new avenues for the development of M‐N‐C catalytic materials.     

Encapsulated Ionic Liquids for CO2 Capture: Using 1‐Butyl‐methylimidazolium Acetate for Quick and Reversible CO2 Chemical Absorption.

The potential advantages of applying encapsulated ionic liquid (ENIL) to CO₂ capture by chemical absorption with 1‐butyl‐3‐methylimidazolium acetate [bmim][acetate] are evaluated. The [bmim][acetate]‐ENIL is a particle material with solid appearance and 70 % w/w in ionic liquid (IL). The performance of this material as CO₂ sorbent was evaluated by gravimetric and fixed‐bed sorption experiments at different temperatures and CO₂ partial pressures. ENIL maintains the favourable thermodynamic properties of the neat IL regarding CO₂ absorption. Remarkably, a drastic increase of CO₂ sorption rates was achieved using ENIL, related to much higher contact area after discretization. In addition, experiments demonstrate reversibility of the chemical reaction and the efficient ENIL regeneration, mainly hindered by the unfavourable transport properties. The common drawback of ILs as CO₂ chemical absorbents (low absorption rate and difficulties in solvent regeneration) are overcome by using ENIL systems.     

In‐vitro Aluminum Determination and Preconcentration in Blood of Dialysis Patients Based on Ionic Liquid Dispersive Liquid‐Liquid Biomicroextraction by 2‐Amino‐3‐(1H‐imidazol‐4‐yl)propanoic Acid

In this study, trace amounts of aluminum in serum of dialysis patients were chelated with 2‐Amino‐3‐(1H‐imidazol‐4‐yl)propanoic acid (Histidine) and determined by electro‐thermal atomic absorption spectrometry (ETAAS). A fast and efficient method based on ionic liquid dispersive liquid‐liquid bio‐micro‐extraction (IL‐DLLBME) was developed for the determination of Al cation in human blood serum samples. In this work, a small amount of 1‐Hexyl‐3‐methylimmidazolum hexafluorophosphate ([HMIM] [PF₆]) as an extractant solvent was dissolved in acetone as a dispersant solvent and then the binary solution was rapidly injected by a syringe into the serum containing Al³⁺,Which have already in‐vitro chelated by Histidine amino acid (Al‐His) at pH = 6.5. After separation, the settled IL‐phase was dissolved in ethanol up to 200 μL and 20 μL of samples injected into the ET‐AAS by auto‐sampler. Various parameters have been studied and optimized for 10 mL of sample. Under the optimum conditions, the enrichment factor (EF), limit of detection (LOD) and working range (peak area mode) were obtained 53, 15 ng L^?1 and 0.05‐4.1 μg L^?1 respectively. In vitro Al chelation showed that His can significantly decrease aluminum concentration in serum of dialysis patients. Validation of methodology was confirmed by standard reference material (SRM).     

Synthesis and Characterization of Secondary Nitrosamines from Secondary Amines Using Sodium Nitrite and p‐Toluenesulfonic Acid

We synthesized nitrosamines (R₂N? NO) with R=iPr ( 1 ), nPr ( 2 ), nBu ( 3 ), and hydroxyethyl ( 4 ) from the amine using sodium nitrite/p‐toluenesulfonic acid in CH₂Cl₂. The rate of formation of 1 – 4 increases in the direction iPr<nPr<nBu2CH₂OH. Compounds 1 – 3 were obtained as colorless solids, whereas 4 is a bright yellow liquid. Compounds 1 – 4 were characterized by elemental analysis, MS, IR, and multinuclear NMR (¹H, ¹³C, and ¹⁵N) spectroscopies. Additionally, we measured the UV/Vis spectra of all compounds, which show maxima of absorption at approximately 221 nm and molar extinction coefficients between 3043 and 4859 L mol^?1 cm^?1. We calculated the optimized structures of 1 – 4 (B3LYP/6‐311+G(d,p)) and computed the NMR spectroscopic chemical shifts and infrared frequencies. Furthermore, we carried out a natural bond orbital (NBO) analysis of the nitrosamine moiety. Lastly, the compounds described in this work are valuable starting materials for the synthesis of 2‐tetrazenes with potential interest to replace highly toxic hydrazines in rocket propulsion.     

Tuning the Adsorption Energy of Methanol Molecules Along Ni‐N‐Doped Carbon Phase Boundaries by the Mott–Schottky Effect for Gas‐Phase Methanol Dehydrogenation

Engineering the adsorption of molecules on active sites is an integral and challenging part for the design of highly efficient transition‐metal‐based catalysts for methanol dehydrogenation. A Mott–Schottky catalyst composed of Ni nanoparticles and tailorable nitrogen‐doped carbon‐foam (Ni/NCF) and thus tunable adsorption energy is presented for highly efficient and selective dehydrogenation of gas‐phase methanol to hydrogen and CO even under relatively high weight hourly space velocities (WHSV). Both theoretical and experimental results reveal the key role of the rectifying contact at the Ni/NCF boundaries in tailoring the electron density of Ni species and enhancing the absorption energies of methanol molecules, which leads to a remarkably high turnover frequency (TOF) value (356 mol methanol mol^?1 Ni h^?1 at 350 °C), outpacing previously reported bench‐marked transition‐metal catalysts 10‐fold.     

Red to Blue High Electrochromic Contrast and Rapid Switching Poly(3,4‐ethylenedioxypyrrole)–Au/Ag Nanocomposite Devices for Smart Windows

Poly(3,4‐ethylenedioxypyrrole) (PEDOP)–Ag and PEDOP–Au nanocomposite films have been synthesized for the first time by electropolymerization of the conducting‐polymer precursor in a waterproof ionic liquid, 1‐butyl‐1‐methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, followed by Ag/Au nanoparticle incorporation. That the Ag/Au nanoparticles are not adventitious entities in the film is confirmed by a) X‐ray photoelectron spectroscopy, which provides evidence of Ag/Au–PEDOP interactions through chemical shifts of the Ag/Au core levels and new signals due to Ag–N(H) and Au–N(H) components, and b) electron microscopy, which reveals Au nanoparticles with a face‐centered‐cubic crystalline structure associated with the amorphous polymer. Spectroelectrochemistry of electrochromic devices based on PEDOP–Au show a large coloring efficiency (η_max=270 cm² C^?1, λ=458 nm) in the visible region, for an orange/red to blue reversible transition, followed by a second, remarkably high η_max of 490 cm² C^?1 (λ=1000 nm) in the near‐infrared region as compared to the much lower values achieved for the neat PEDOP analogue. Electrochemical impedance spectroscopy studies reveal that the metal nanoparticles lower charge‐transfer resistance and facilitate ion intercalation–deintercalation, which manifests in enhanced performance characteristics. In addition, significantly faster color–bleach kinetics (five times of that of neat PEDOP!) and a larger electrochemical ion insertion capacity unambiguously demonstrate the potential such conducting‐polymer nanocomposites have for smart window applications.     

Hydrogenation of Imines Catalyzed by Trisphosphine‐Substituted Molybdenum and Tungsten Nitrosyl Hydrides and Co‐Catalytic Acid

Hydride complexes Mo,W(CO)(NO)H(mer‐etpⁱp) (iPr₂PCH₂CH₂)₂PPh=etpⁱp) ( 2 a,b(syn) , syn and anti of NO and Ph(etpⁱp) orientions) were prepared and probed in imine hydrogenations together with co‐catalytic [H(Et₂O)₂][B(C₆F₅)₄] (140 °C, 60 bar H₂). 2 a,b(syn) were obtained via reduction of syn/anti‐Mo,W(NO)Cl₃(mer‐etpⁱp) and syn,anti‐Mo,W(NO)(CO)Cl(mer‐etpⁱp). [H(Et₂O)₂][B(C₆F₅)₄] in THF converted the hydrides into THF complexes syn‐[Mo,W(NO)(CO)(etpⁱp)(THF)][B(C₆F₅)₄]. Combinations of the p‐substituents of aryl imines p‐R¹C₆H₄CH=N‐p‐C₆H₄R² (R¹,R²=H,F,Cl,OMe,α‐Np) were hydrogenated to amines (maximum initial TOFs of 1960 h^?1 ( 2 a(syn) ) and 740 h^?1 ( 2 b(syn) ) for N‐(4‐methoxybenzylidene)aniline). An ‘ionic hydrogenation’ mechanism based on linear Hammett plots (ρ=?10.5, p‐substitution on the C‐side and ρ=0.86, p‐substitution on the N‐side), iminium intermediates, linear P(H₂) dependence, and DKIE=1.38 is proposed. Heterolytic splitting of H₂ followed by ‘proton before hydride’ transfers are the steps in the ionic mechanism where H₂ ligand addition is rate limiting.     

A Stable Quasi‐Solid‐State Sodium–Sulfur Battery

Ambient‐temperature sodium–sulfur (Na–S) batteries are considered a promising energy storage system due to their high theoretical energy density and low costs. However, great challenges remain in achieving a high rechargeable capacity and long cycle life. Herein we report a stable quasi‐solid‐state Na‐S battery enabled by a poly(S‐pentaerythritol tetraacrylate (PETEA))‐based cathode and a (PETEA‐tris[2‐(acryloyloxy)ethyl] isocyanurate (THEICTA))‐based gel polymer electrolyte. The polymeric sulfur electrode strongly anchors sulfur through chemical binding and inhibits the shuttle effect. Meanwhile, the in situ formed polymer electrolyte with high ionic conductivity and enhanced safety successfully stabilizes the Na anode/electrolyte interface, and simultaneously immobilizes soluble Na polysulfides. The as‐developed quasi‐solid‐state Na‐S cells exhibit a high reversible capacity of 877 mA h g^?1 at 0.1 C and an extended cycling stability.     

High Performance Fe Porphyrin/Ionic Liquid Co‐catalyst for Electrochemical CO2 Reduction

The efficient and selective catalytic reduction of CO₂ is a highly promising process for both of the storage of renewable energy as well as the production of valuable chemical feedstocks. In this work, we show that the addition of an ionic liquid, 1‐butyl‐3‐methylimidazolium tetrafluoroborate, in an aprotic electrolyte containing a proton source and FeTPP, promotes the in situ formation of the [Fe⁰TPP]^2? homogeneous catalyst at a less negative potential, resulting in lower overpotentials for the CO₂ reduction (670 mV) and increased kinetics of electron transfer. This co‐catalysis exhibits high Faradaic efficiency for CO production (93 %) and turnover number (2 740 000 after 4 hour electrolysis), with a four‐fold increase in turnover frequency (TOF) when compared with the standard system without the ionic liquid.     

Noncovalent Assembly of Picket‐Fence Porphyrins on Nitrogen‐Doped Carbon Nanotubes for Highly Efficient Catalysis and Biosensing

A water‐insoluble picket‐fence porphyrin was first assembled on nitrogen‐doped multiwalled carbon nanotubes (CN_x MWNTs) through Fe? N coordination for highly efficient catalysis and biosensing. Scanning electron micrographs, Raman spectra, X‐ray photoelectron spectra, UV/Vis absorption spectra, and electrochemical impedance spectra were employed to characterize this novel nanocomposite. By using electrochemical methods on the porphyrin at low potential in neutral aqueous solution, the presence of CN_x MWNTs led to the direct formation of a high‐valent iron(IV)–porphyrin unit, which produced excellent catalytic activity toward the oxidation of sulfite ions. By using sulfite ions, a widely used versatile additive and preservative in the food and beverage industries, as a model, a highly sensitive amperometric biosensor was proposed. The biosensor showed a linear range of four orders of magnitude from 8.0×10^?7 to 4.9×10^?3 mol L^?1 and a detection limit of 3.5×10^?7 mol L^?1 due to the highly efficient catalysis of the nanocomposite. The designed platform and method had good analytical performance and could be successfully applied in the determination of sulfite ions in beverages. The direct noncovalent assembly of porphyrin on CN_x MWNTs provided a facile way to design novel biofunctional materials for biosensing and photovoltaic devices.     

1‐(2‐Cyclohex‐2‐enylpropionyl)‐3‐methylurea, 2‐ethyl‐5‐methylhexanamide and 2‐ethylpentanamide: three products of barbiturate decomposition

The three title compounds were obtained by reactions which mimic, with more extreme conditions, the in vivo metabolism of barbiturates. 1‐(2‐Cyclohex‐2‐enylpropionyl)‐3‐methylurea, C₁₁H₁₈N₂O₂, (I), and 2‐ethylpentanamide, C₈H₁₇NO, (III), both crystallize with two unique molecules in the asymmetric unit; in the case of (III), one unique molecule exhibits whole‐molecule disorder. 2‐Ethyl‐5‐methylhexanamide, C₉H₁₉NO, (II), crystallizes as a fully ordered molecule with Z′ = 1. In the crystal structures, three different hydrogen‐bonding motifs are observed: in (I) a combination of R₂²(4) and R₂²(8) motifs, and in (II) and (III) a combination of R₄²(8) and R₂²(8) motifs. In all three structures, one‐dimensional ribbons are formed by N—H...O hydrogen‐bonding interactions.