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.

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).

STUDIES ON COMPLEXES OF RARE EARTHS WITH CROWN ETHERS(V)-SYNTHESIS AND CHARACTERIZATION OF THE COMPLEXES OF RARE EARTH NITRATES WITH 2,2'-DINITRO-4,5,4',5'-BIS-(15-CROWN-5)-DIBENZO DISULFIDE

Three new solid complexes of macrocyclic polyether ligand 2, 2'-dinitro-4, 5, 4', 5'bis-(15- crown-5)-dihenzo disulfide(L) with trivalent rare earth nitrates having composition of RE(NO_3)_3·L ·6H_2O(RE=Ce, Pr, Nd) have been synthesized in acetonitrile. All the isolated complexes have been characterized by elementary analysis, IR and UV spectra, differential thermal and thermogravimetric analysis, X-ray powder diffraction analysis, molar conductance and measurements of solubility in some general solvents.

STUDIES ON RARE EARTH COMPLEXES WITH CROWN ETHERS ⅩⅧ——Synthesis,Characterization and Crystal Structure of[Sc(NO_3)_3(H_2O)_2]·(15-Crown-5)

The single crystal of the complex [Sc(NO_3)_3(H_2O)_2]·(15C5) has been prepared in acetonitrile.The new complex has been characterized by elemental analysis,IR spectra,solubility and molar conductance measurements.The structure of the complex is determined by single crystal X-ray diffraction analysis.

ELECTRONIC STRUCTURE AND BOND CHARACTER OF COMPLEXES OF RARE EARTH CHLORIDES WITH CROWN ETHERS

A series of lanthanide complexes LnCl_3·L(Ln=La,Pr,Nd;L=15-C-5 or 18-C-6)have been synthesized and their molecular configuration,electronic structure and bond character have been studied by XPS and quantum chemical calculation.The calculated results are in good agreement with that obtained in the experiments.Three Cl atoms are on the same side of Ln in LnCl_3·15-C-5 and the crown ring on the other side.forming a complex molecule with coordination number 8.LnCl_3·15-C-5 is easily hygroscopic in air because of its unsaturated coordination,which differs sharply from the stable Ln(NO_3)_3·15-C-5 com- plex of coordination number 11.The HOMO and neighboring occupied MOs are composed of Cl 3p and O2p, and the LUMO and neighboring unoccupied MOs are composed of Ln orbitals.The level structure easily pro- duces Ln3d satellite in XPS caused by L→Ln charge transfer transition.Due to the coordination,the absolute values of the charge are decreased at Ln and O atoms,but increased at Cl atoms,which is in agreement with XPS results.

STUDIES ON COMPLEXES OF RARE EARTHS WITH CROWN ETHERS(Ⅳ)SYNTHESIS AND CHARACTERIZATION OF THE COMPLEXES OF RARE EARTH NITRATES WITH 4'-BROMO-5'-NITROBENZO-15-CROWN-5

Six new solid complexes of macrocyclic polyether ligand 4′-bromo-5′-nitrobenzo-15-crown-5(L)with Uivalent rare earth nitrates having composition of RE(NO_3)_3·L·mCH_3CN·nH_2O(RE=L_a--Nd,m=n=0, RE=Sm,Bu,m=0.1,n=1,4)have been synthesized in acetonitrile or acetone.All the isolated complexes have been char- acterized by elementary analysis,IR and UV spectra,differential thermal and thermogravimetric analysis,X-ray powder diffraction analysis,molar conductance and measurementa of solubility in some general solventa.It shows that coordination number of the rare earth cation in the complexes of La,Ce,Pr and Nd nitrate is eleven.

ENUMERATION OF ISOMERS OF SUBSTITUTED CROWN ETHERS

The graphtheory method is used to enumerate the numbers of constitutions, configurations,chiral and achiral configurations of substituted crown ethers.The numerical results are tabulated.

A CONVENIENT SYNTHESIS OF PERFLUOROALRYLBENZO CROWN ETHERS

Perfluoroalkylbenzo crown ethers were readily prepared from the reaction of benzo crown ethers with sodium perfluoroalkanesulfinates in the presence of an oxidizing agent such as Ce(SO_4)_2 or Mn(OAC)_3.2H_2O in good yields through a radical process.

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.

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 ℃.

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 and Properties of New-type Troponoid Dithio-Crown Ethers

Condensation of 3,7-dichloromethyl-5-isopropyl-2-methoxytropane 4 with bis (mercaptoethyl) ether 5a and mono, di, and tri-ethylene glycol bis(mercaptoethyl) ethers 5b-5d gave troponoid-annexed dithiocrown ethers 6a-6d. Compounds 6a-6d have selective and reversible mercury salt capturing ability.

Liquid Membrane Transport Behavior of Functional Substituted Crown Ethers for Amino Acids

Three functional substituted crown ethers were synthesized as liquid membrane transport carriers for amino acids. The result obtained shows that this kind of ditopic ligands can transport sodium salt of amino acids in good rate value especially the one with two pyridinyl groups as binding site outside the macrocycle.

Bis Crown Ethers( Ⅸ)——Caesium Selective PVC Membrane Electrodes Based on Schif f Base Type of Bis Crown Ethers

Recently, much attention has been focused on the use of neutral carrier species as membrane components to extract ions from aqueous solution into a hydrophobic membrane phase. Some potassium-or caesium-selective electrodes based on bis-benzo-15-crown-5 or bis-benzo-18-crown-6 containing ester or other linkage were prepared by K. Kimura and K. W. Fung. The selective coefficients K;, K;,or K;, K were 2.6×10;, 1.9×10;and 1.7×10;, respectively.

SYNTHESIS OF CHIRAL BINAPHTHYL CROWN ETHERS AND THEIR USE IN ANIONIC POLYMERIZATION OF METHYL METHACRYLATE AS INITIATOR LIGANDS

Some chiral binaphthyl crown ethers were synthesized. The anionic polymerization of methyl methacrylate (MMA) was carried out in the presence of t-BuOK, Ph2CHK or Ph2CHNa (RM), and RM coordination initiator by using chiral binaphthyl crown ethers as ligands, respectively. The results showed that in the former case the PMMA obtained has mainly isotactic structure but without optical activity, while in the later case the PMMA produced predominately has syndiotactic structure also without optical activity.

Molecular design of crown ethers .18.~1 Cationextractability and selectivities of selena-13- to 14-crown-4

Three selena-crown-4 derivatives have been prepared and their cation hinting abilities and selectivities with alkali and heavy metal ions have been evaluated by solvent extraction of aqueous metal picrates to show the highest Ag+ extractability for novel benzo-selena-14-crown-4 (2,3-benzo-7, 12-diselena-1, 4-dioxacyclotetradecane-2-ene) over any other crown ethers.

Studies on the syntheses and properties of Schiff base type crown ethers

Eight bis-,two tris-and two mono-crown ethers of Schiff base type have been pre- parcd by the reaction of 4'-formylbenzo-15-crown-5 with diamincs.Conductivity measurements show that the bis-crown ethers form 1:1 complexes(crown cther unit:metal ion)with sodium ion and 2:1 complexes with potassium,rubidium and ammonium ion,respectively.

Study on Molecular Recognition of Crown Ethers to Aniline and Monosaccharides

Theoretical study on coordinates between crown ethers and aniline as well as monosaccharides is performed by AM1, MNDO and PM3 methods. It is indicated that crown ethers possess ability to recognize polar guests especially ionic guests and monosaccharides. Electronic spectra of coordinates are computed by the INDO/SCI method. The reason of the blue-shift for UV absorption of complexes relative to that of hosts is discussed and electronic transition is theoretic- cally assigned.

Synthesis of Schiff Base-type Liquid Crystalline Crown Ethers Containing Dibenzo-18-Crown-6 Unit

The synthesis and characterization of novel Schiff base liquid crystalline crown ethers prepared from the inter-mediates 4-(4-alkoxylbiphenyl-4-carbonyl)benzaldehyde, cis- and trans-4,4-diaminodibenzo-18-crown-6 are de-scribed. The structure of these compounds have been well characterized by elemental analysis, IR, 1H NMR and MS spectroscopy. The liquid-crystalline behavior of these compounds was also inverstigated by differential scanning calorimetry (DSC), polarizing optical microscopy (POM) with a heating stage and polarimetric analysis.