Interfacial engineering through lead binding using crown ethers in perovskite solar cells

In the domain of perovskite solar cells(PSCs),the imperative to reconcile impressive photovoltaic performance with lead-related issue and environmental stability has driven innovative solutions.This study pioneers an approach that not only rectifies lead leakage but also places paramount importance on the attainment of rigorous interfacial passivation.Crown ethers,notably benzo-18-crown-6-ether(B18C6),were strategically integrated at the perovskite-hole transport material interface.Crown ethers exhibit a dual role:efficiently sequestering and immobilizing Pb^(2+)ions through host-guest complexation and simultaneously establishing a robust interfacial passivation layer.Selected crown ether candidates,guided by density functional theory(DFT)calculations,demonstrated proficiency in binding Pb2+ions and optimizing interfacial energetics.Photovoltaic devices incorporating these materials achieved exceptional power conversion efficiency(PCE),notably 21.7%for B18C6,underscoring their efficacy in lead binding and interfacial passivation.Analytical techniques,including time-of-flight secondary ion mass spectrometry(ToF-SIMS),ultraviolet photoelectron spectroscopy(UPS),time-resolved photoluminescence(TRPL),and transient absorption spectroscopy(TAS),unequivocally affirmed Pb^(2+)ion capture and suppression of non-radiative recombination.Notably,these PSCs maintained efficiency even after enduring 300 h of exposure to 85%relative humidity.This research underscores the transformative potential of crown ethers,simultaneously addressing lead binding and stringent interfacial passivation for sustainable PSCs poised to commercialize and advance renewable energy applications.

Li^(+)-ion bound crown ether functionalization enables dual promotion of dynamics and thermodynamics for ambient ammonia synthesis

Electrosynthesis of ammonia from the reduction of nitrogen is still confronted with the limited supply of gas reactant in dynamics as well as high activation barrier in thermodynamics.Unfortunately,despite tremendous efforts devoted to electrocatalysts themselves,they still fail to tackle the above two challenges simultaneously.Herein,we employ a heterogeneous catalyst adlayer-composed of crown ethers associated with Li^(+)ions-to achieve the dual promotion of dynamics and thermodynamics for ambient ammonia synthesis.Dynamically,the bound Li^(+)ions interact with the strong quadrupole moment of nitrogen,and trigger considerable reactant flux toward the catalyst.Thermodynamically,Li^(+)associated with the oxygen of crown ether achieves a higher density of states at the Fermi level for the catalyst,enabling effortless electron transfer from the catalysts to nitrogen and thus greatly reducing the activation barrier.As expected,the proof-of-concept system achieves an ammonia yield rate of 168.5μg h^(-1)mg^(-1)and a Faradaic efficiency of 75.3%at-0.3 V vs.RHE.This system-level approach opens up pathways for tackling the two key challenges that have limited the field of ammonia synthesis.

Cross-Linked Crown Ether-SE-54 as Stationary Phase for Open-Tubular Column Gas Chromatography

The cross-linking of crown ether-SE-54 in fused-silica capillary columns were initiated by dicumyl peroxide(DCUP),azo-bis-isobutyronitrile (AIBN)and ozone(O_3).Parameters of evaluation such as polarity,selectivity, phase transition temperature and thermal stability were studied and compared with those of poly(crown ether)stationary phase.

SILICA-BOUND CROWN ETHERS PLATINUM COMPLEX AS HYDROSILYLATION CATALYST

Silica-bound 15-Crown-5, 18-Crown-6 with a spacer of propyloxymethyl and their platinum complexes have been synthesized. It was found that they were efficient catalysts for the hydrosilylation of olefms with triethoxysilane in the temperature range of 60 to 130 ℃.

NETWORK CROWN ETHER POLYMERS WITH CENTRIC FUNCTIONAL GROUP (Ⅳ) SYNTHESIS OF NETWORK CROWN ETHER POLYMER WITH PENDANT DIETHYLAMINO THIAALKYL GROUP AND ITS PLATINUM COMPLEX

The title polymer was prepared from 5-diethylamino-3-thia-pentyl glycidyl ether anddiethylene glycol bisglycidyl ether via ring-opening copolymerization. It was found that thisreaction could be catalyzed by sodium, but not Lewis acid. The obtained polymer can coordinatewith platinum compound, and the platinum complex is a new kind of catalyst for thehydrosilylation of olefins with triethoxysilane.

STUDIES ON CROWN ETHER CYANINE DYES (X). THE SYNTHESIS OF BENZOXAZOLE CROWN ETHER CYANINE DYES

A simple method for synthesis of benoxazole crown ether cyanine dyes is described.

STUDIES ON CROWN ETHER CYANINE DYES(XI)THE SYNTHESIS OF BENZOTELLURAZOLE CROWN ETHER CYANINE DYES

Three methods for synthesis of benzotellurazole crown ether(6)are described.The cyanine dye(8)can be easily obtained by treating(6) with CH_3I and CH(OEt)_3.

Applications of Crown Ether Cross-Linked Chitosan for the Analysis of Lead and Cadmium in Environmental Water Samples

A new type of crown ether cross-linked chitosan was synthesized by the reaction of chitosan with 4,4′-dibromodibenzo-18-crown-6 (Br-DBC). Its token structure was analyzed with FT-IR and NMR and the adsorption behaviors for lead and cadmium in environmental water samples by FAAS were studied. In addition the best analysis conditions were discussed and the adsorption mechanism was explained. As the enrichment factor is above 100, both recoveries are 94%–106%, the detection limits of lead and cadmium are 0.5μg·L?1 and 0.04 μg·L?1 and the relatively standard deviations of lead and cadmium are 3.1% and 2.8% respectively, this new method was successfully applied to the determination of environmental water samples. This method is fast and simple and it greatly enhances the determination ability of FAAS for lead and cadmium.

Suppressing Li Dendrites via Electrolyte Engineering by Crown Ethers for Lithium Metal Batteries

Electrolyte engineering is considered as an effective strategy to establish stable solid electrolyte interface(SEI),and thus to suppress the growth of lithium dendrites.In a recent study reported in Advanced Functional Materials by Ma group,discovered that strong coordination force could be founded between 15-Crown-5 ether(15-C-5) and Li+,which facilitates the crown ether(15-C-1) to participate in the solvation structure of Li+ in the electrolyte for the same purpose.Such a novel strategy might impact the design of highperformance and safe lithium metal batteries(LMB s).

Preparation of Copolymer of Salen-crown Ether Complexes and its Catalytic Activation for Molecular Oxygen

A new stable salen Schiff base cobalt and crown ether sodium complex （SalCo-NaB18C6） was prepared through copolymerization. This copolymer complex was applied to catalytic oxidation of hydrocarbon compound with molecular oxygen without reductant, which was shown the higher activity and selectivity for ketone, and reused effectively.

SIDE CHAIN LIQUID CRYSTALLINE POLYSILOXANES CONTAINING CROWN ETHER AND BENZYL ETHER MOIETIES

Two kinds of side chain liquid crystalline polysiloxanes containing crown ether and benzyl ether were synthesized and characterized by optical polarization microscopy. Both the monomeric liquid crystals and polymeric liquid crystals show smectic phases.

Convenient synthesis of aryl-incorporated ditosylates and their application in preparation of crown ethers with higher yield

A convenient synthetic method with high yields for aryl-incorporated ditosylates by reaction of aryl-incorporated diols with TsCI in THF/NaOH/H2O solution was described. Some of these aryl-incorporated ditosylates reacted with diphenols to produce crown ethers in pleasant yield.

Microwave-assisted fast and efficient synthesis of some crown ethers

13-Crown-4, 16-crown-5, dibenzo-12-crown-4 and dibenzo-14-crown-4 were synthesized by a one-pot microwave-assisted procedure in good yields. Irradiation of diols and dichlorides in the presence of sodium hydroxide in DMSO gave title crown ethers presumably within a template effect. ？2009 Hossein Eshghi. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All fights reserved.

Synthesis of New Aza-crown Ethers Containing Pyridine Ring and their Liquid Membrane Transport of Alkali Cations

Five new aza-crown ethers have been prepared by the condensation of 2,6-bis[(2-formylphenyl)oxymethyl] pyridine with different diamino compounds in hot methanol, the bis-Schiff bases without isolation were reduced with NaBH4 to afford the corresponding aza-crown ethers. The liquid membrane transport or alkali cations using the five new macrocycles as the ion-carriers was also studied.

Study on the influence of crown ether on arsenic behavior during coal pyrolysis

The influence of crown ether on behaviors of arsenic at different temperatures and residence time was investigated during the pyrolysis of Tuanbo （TB） coal. The modes of occurrence of arsenic were determined by sequential chemical extraction, density fractionation and demineralization. The results indicated that at the same temperature and residence time, the arsenic removal adding dibenzo-18-crown-6 was higher than that adding 18-crown-6, and were all higher than that of TB coal during pyrolysis. When temperature was 850 ℃ and residence time was 30 min, the arsenic removal of TB coal was 30.63%; at the same condition, the arsenic removal while adding 18-crown-6 was 33.21%, higher than that of TB coal; and the arsenic removal while adding dibenzo-18-crown-6 was 67.41%, significantly higher than that of TB coal. From the results, we can see that adding crown ether can improve the arsenic removal during coal pyrolysis, and especially be conducive to the arsenic which is mainly associated with sulfates ＆ monosulfides and that in stable forms.

Studies on the Synthesis and Complexing Behavior of Crown Ethers with External Coordination Center

The synthesis, characterization of five ditopic or tritopic crown compounds were reported in this paper together with the preparation of the corresponding hetero-dinuclear and hetero-trinuclear complexes with different metal cations.

Density Functional Theory Study of Selectivity of Crown Ethers to Li^+ in Spent Lithium-Ion Batteries Leaching Solutions

It is a challenge to recover lithium from the leaching solution of spent lithium-ion batteries,and crown ethers are potential extractants due to their selectivity to alkali metal ions.The theoretical calculations for the selectivity of crown ethers with different structures to Li ions in aqueous solutions were carried out based on the density functional theory.The calculated results of geometries,binding energies,and thermodynamic parameters show that 15C5 has the strongest selectivity to Li ions in the three crown ethers of 12C4,15C5,and 18C6.B15C5 has a smaller binding energy but more negative free energy than 15C5 when combined with Li^+,leading to that the lithium ions in aqueous solutions will combine with B15C5 rather than 15C5.The exchange reactions between B15C5 and hydrated Li^+,Co^2+,and Ni^2+were analyzed and the results show that B15C5 is more likely to capture Li^+from the hydrated ions in an aqueous solution containing Li^+,Co^2+,and Ni^2+.This study indicates that it is feasible to extract Li ions selectively using B15C5 as an extractant from the leaching solution of spent lithium-ion batteries.

Spectral Properties of Extracted Complexes of MetalPicrates with Crown Ethers

The investigation on UV-visible spectra of species formed by extracting some metal picrates with benzo-15-crown-5(B15C5) and dibenzo-18-crown-6(DB18C6) verified that there are some interactions of picrate anion with K+, Na+ and rare earth ions in loaded organic phase. By the study of the charge transfer band and absorption spectra of picrate anion, it can be determined whether an ion pair has been formed and either a 1 : 1 contact ion pair or a 1 : 2 crown-separated ion pair involved in organic phase can be distinguished for an ion-pair extraction.

Synthesis, Characterization and Fluorescence of Rare earth Nitrate Complexes with Triaza-crown Ether Derivative

Four new complexes of rare earths with a triaza crown ether (L) derived from N 3O 2 macro cycle 1,12,15 triaza 3, 4: 9,10 dibenzo 5, 8 dioxacycloheptadecane were synthesized and characterized by elemental analysis, IR, molar conductance, TG DTA analysis and fluorescence spectra. The composition of the complexes determined as [RE(NO 3) 3L·3H 2O]·H 2O (RE=Sm, Eu, Tb and Dy). It is found that Sm 3+ , Eu 3+ , Tb 3+ and Dy 3+ complexes all show strong fluorescence emission in the solid state. Among these complexes, Tb 3+ complex has the strongest luminescence intensity. It shows that the ligand L triplet state energy matches 5D 4 energy level of Tb 3+ . In the Eu 3+ complex, η ( 5D 0→ 7F 2/ 5D 0→ 7F 1) is 2.6, which indicates that Eu 3+ locates at the asymmetric coordination field.

Synthesis and Selective Coloration of Monoaza Crown Ethers Bearing Picrylamino-type Side Arms for Alkali Metal Salts and Methylamine

N-pivot lariat ethers with picrylamino group as a chromophore (1, 2 and 3) have been prepared by reaction of N-(4-aminoaryl)monoaza crown ethers with picryl chrolide, and the selective coloration of 1, 2 and 3 for alkali metal salts and amines has been studied by UV-Vis spectra.