Calix[4]arene derivatives have been reported to possess high selectivity for metal ions.In order to analyze the extraction effect of substituents on Hg^(2+)and Pb^(2+),calix[4]arene derivatives containing hydroxyl,bro...Calix[4]arene derivatives have been reported to possess high selectivity for metal ions.In order to analyze the extraction effect of substituents on Hg^(2+)and Pb^(2+),calix[4]arene derivatives containing hydroxyl,bromoethoxy and 1,11-dioxa-4,8-dithiahendecene were successfully synthesized,with their extraction effectiveness towards Hg^(2+)and Pb^(2+)were evaluated respectively.The results indicated that the phenolic hydroxyl in calix[4]arene improved the extraction ability on Hg^(2+)by promoting the formation of the negative oxygen ions that could bind with Hg^(2+)by coordination and ionic bonds.The extraction ability of 5,17-dinitro-26,28-(1’,11’-dioxa-4’,8’-dithiahendecene)-calix[4]arene(calix[4]arene thia derivative)was improved slightly due to the better coordination capacity for metal ions after introduction of 1,11-dioxa-4,8-dithiahendecene,which was a chelate-binding centre.Regarding to Pb^(2+),only 1,11-dioxa-4,8-dithiahendecene on molecule contributed to extraction due to the coordination bond.Since the metal ion with higher charge-to-radius ratio could coordinate with one ligand more stably,Pb^(2+)with higher charge-to-radius ratio than Hg^(2+)was coordinated and extracted by the calix[4]arene thia derivative more easily.Furthermore,extraction rates of the calix[4]arene thia derivative on both ions(Hg^(2+)and Pb^(2+))increased with the increase of pH value in acidic aqueous system(pH<7).展开更多
Asymmetrically substituted phthalocyanines with sulfur-containing substituents for fabrication of self- assembled monolayers were synthesized. Phthalocyanine 7, bearing a disulfide group, was synthesized from phthaloc...Asymmetrically substituted phthalocyanines with sulfur-containing substituents for fabrication of self- assembled monolayers were synthesized. Phthalocyanine 7, bearing a disulfide group, was synthesized from phthalocyanine with a hydroxyl group, which was prepared via mixed condensation of the corresponding substituted phthalonitriles. Phthalocyanine 10, bearing an acetyl protected thiol group, was synthesized through the Pd-catalyzed coupling reaction of an iodophthalocyanine. Their self- assembling behavior on gold substrates was further studied by UV-vis spectroscopy.展开更多
Foldamers 1–4 incorporating different terminal substituents have been designed and synthesized for binding halide anions.~1H NMR titration experiments carried out in DMSO-d_6/CDCl_3（15/85, v/v）demonstrated that the...Foldamers 1–4 incorporating different terminal substituents have been designed and synthesized for binding halide anions.~1H NMR titration experiments carried out in DMSO-d_6/CDCl_3（15/85, v/v）demonstrated that the short oligo （aryltriazole）s backbone 1 could not bind halide anions unless that amide H-bond donors were incorporated at the termini of the oligomer. Terminal substituents on oligo（aryltriazoleamide）s foldamers 2–4 display a considerable influence on the binding affinities of the foldamers for halide anions. Large steric hindrance of the terminal substituents was found to be unfavorable for binding halide anions, but aromatic π-π interactions between two terminal substituents are capable of stabilizing the conformation of foldamers thus giving rise to an enhancement in the binding strengths. However, the terminal substituents were found to hardly affect the binding selectivity in the studied cases.展开更多
Based on the property that carboxymethylcellulose (CMC ) can be de-graded to anhydroglucose residues by cellulase, the rate constant (K) of enzymatic degra-dation of CMC synthesized in the benzene-ethanol medium has b...Based on the property that carboxymethylcellulose (CMC ) can be de-graded to anhydroglucose residues by cellulase, the rate constant (K) of enzymatic degra-dation of CMC synthesized in the benzene-ethanol medium has been determined. Further-morel experimental equation K = 2.71× 10^(-2)(DS)^(-1.2) reflecting the relationship betweenK and the degree of substitution (DS) is correlated and used to describe chemical mi-crostructure uniformity of the distribution of substituents along chains effectively. Chainstructure parameters of enzymatic degradation products of CMC-the number of chainbreaks and the percentage of glucose released have been also measured. Average length ofsubstituted and unsubstituted chain segments are calculated simultaneously. Through thestudy of static and dynamic procedures of enzymatic degradation, the method to charac-terize the distribution of substituents of CMC along the chain has been improved.展开更多
For the rational design of metal catalyst in olefin polymerization catalysis,various strategies were applied to suppress the chain transfer by bulking up the axial positions of the metal center,among which the"sa...For the rational design of metal catalyst in olefin polymerization catalysis,various strategies were applied to suppress the chain transfer by bulking up the axial positions of the metal center,among which the"sandwich"type turned out to be an eficient category in achieving high molecular weight polyolefin.In the a-dimine system,the"sandwich"type catalysts were built using the typical 8-aryl-naphthyI framework.In this contribution,by introducing the rotationally restrained benzosuberyl substituent into the ortho-position of N-aryl rings,a new class of "sandwich-like"a-diimine nickel catalysts was constructed and fully identified.The rotationally restrained benzosuberyl substituents played a"sandwich-like"function by capping the nickel center from two axial sites.Compared to the nickel catalyst Ni1 bearing freely rotated benzhydryl substituent,Ni2 featuring benzosubery|substituent enabled the increase(8 times)of polymer molecular weights from 8 kDa to 65 kDa in the polymerization of ethylene.By further increasing the steric bulk of another ortho-site of the N-aryl ring,the polymer molecular weight even reached an ultrahigh level of 833 kDa(Mw=1857 kDa)using the optimized Ni3.Notably,these nickel catalysts could also mediate the copolymerization of ethylene with methyl 10-undecenoate,with Ni3 giving the highest copolymer molecular weight(88 kDa)and the highest incorporation of comonmer(2.0 mol1%),along with high activity of up to 10^(5)g·mol^(-1)·h^(-1).展开更多
The synthesis and phosphorescence properties of two novel Ir(Ⅲ)complexes bearing tert-butyl substituents,bis(4-tert-butyl-2- phenylbenzothiozolato-N,C^(2′))iridium(Ⅲ)(acetylacetonate)[(tbt)_2Ir(acac)]and bis(4-tert...The synthesis and phosphorescence properties of two novel Ir(Ⅲ)complexes bearing tert-butyl substituents,bis(4-tert-butyl-2- phenylbenzothiozolato-N,C^(2′))iridium(Ⅲ)(acetylacetonate)[(tbt)_2Ir(acac)]and bis(4-tert-butyl-1-phenyl-1H-benzimidazolato- N,C^(2′))iridium(Ⅲ)(acetylacetonate)[(tpbi)_2Ir(acac)],are reported,their molecular structures are confirmed by^1H NMR,ESI-MS and elementary analysis.Photoluminescence(PL)studies revealed that they can emit strong green and orange phosphorescence in high quantum yields.Compared to their prototypes lacking of tert-butyl substituents,the two novel iridium(Ⅲ)complexes both have shorter lifetimes and improved or nearly similar PL quantum efficiencies,implying that the exciton quenching is inhibited effectively when molecular steric hindrance increases.The two chelates have great potential to be used as electrophosphorescent materials.展开更多
Understanding the degradation behavior of azo dyes in photocatalytic wastewater treatment is of fundamental and practical importance for their application in textile-processing and other coloration industries. In this...Understanding the degradation behavior of azo dyes in photocatalytic wastewater treatment is of fundamental and practical importance for their application in textile-processing and other coloration industries. In this study, quantum chemistry, as density functional theory, was used to elucidate different degradation pathways of azo pyridone dyes in a hydroxyl radical(HO ·)-initiated photocatalytic system. A series of substituted azo pyridone dyes were synthesized by changing the substituent group in the para position of the benzene moiety, ranging from strong electron-donating to strong electron-withdrawing groups. The effect of dye molecular structure on the photocatalytic degradation reaction mechanism was analyzed and quantification of substituent effects on the thermodynamic and kinetics parameters was performed. Potential energy surface analysis revealed the most susceptible reaction site for the HO ·attack. The calculated reaction barriers are found to be strongly affected by the nature of substituent group with a good correlation using Hammett σp constants and experimentally determined reaction rates. The stability of pre-reaction complexes and transition state complexes were analyzed applying the distortion-interaction model. The increased stability of the transition state complexes with the distancing from the substituent group has been established.展开更多
In order to better understand the specific substituent effects on the electrochemical oxidation process of β-O-4 bond, a series of methoxyphenyl type β-O-4 dimer model compounds with different localized methoxyl gro...In order to better understand the specific substituent effects on the electrochemical oxidation process of β-O-4 bond, a series of methoxyphenyl type β-O-4 dimer model compounds with different localized methoxyl groups, including 2-(2-methoxyphenoxy)-1-phenylethanone, 2-(2-methoxyphenoxy)-1-phenylethanol, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanol, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanol have been selected and their electrochemical properties have been studied experimentally by cyclic voltammetry, and FT-IR spectroelectrochemistry. Combining with electrolysis products distribution analysis and density functional theory calculations, oxidation mechanisms of all six model dimers have been explored. In particular, a total effect from substituents of both para-methoxy(on the aryl ring closing to Cα) and Cα-OH on the oxidation mechanisms has been clearly observed, showing a significant selectivity on the Cα-Cβbond cleavage induced by electrochemical oxidations.展开更多
Two new macrocyclic complexes with C-methyl substituents on the framework, namely, [CuL]（ClO4）2 （L = 5,12-dimethyl-1,8-dihydroxyethyl-1,3,6,8,10,13-hexaazacyclotetradecane） 1 and [NiL]（ClO4）2 2, have been synthe...Two new macrocyclic complexes with C-methyl substituents on the framework, namely, [CuL]（ClO4）2 （L = 5,12-dimethyl-1,8-dihydroxyethyl-1,3,6,8,10,13-hexaazacyclotetradecane） 1 and [NiL]（ClO4）2 2, have been synthesized and structurally characterized through X-ray diffraction analysis. Also, crystal structure of [CuL^1]（ClO4）2 （L^1 = 1,8-dimethyl- 1,3,6,8, [ 0,13- hexaazacyclotetradecane） 3 has been determined. Crystal data for 1： C14H32C12CuN6O10, Mr = 578.90, monoclinic, P2 1/n, α = 8.3529（11）, b = 10.8105（17）, c = 13.3709（17） ,A, β = 105.189（10）°, V= 1165.2（3） A3, Z = 2, Dc = 1.650 g/cm^3, F（000） = 602, λ（MoKct） = 0.71073 A,μ = 1.229 mm ^-1, R = 0.0474 and wR = 0.0895 for 2771 observed reflections （I 〉 2σ（Ⅰ））. Crystal data for 2： C14H32C12N6NiO10, Mr = 574.07, monoclinic, P2 1/c, a = 8.3636（12）, b = 12.997（2）, c = 10.764（2） A, β = 99.31（2）°, V = 1154.7（3） A^3, Z = 2, DC = 1.651 g/cm^3, F（000） = 600, λ（MoKa） = 0.71073 A,μ = 1. 134 mm^-1, R = 0.0380 and wR = 0.0796 for 2670 observed reflections （i 〉 2σ（Ⅰ））. Crystal data for 3： C 10H26Cl2CuN6O8, Mr = 492.81, monoclinic, P2 1/n, a = 8.4860（17）, b = 8.6320（17）, c = 12.662（3） ,A,β = 103.40（3）°, V = 902.2（3）A^3, Z = 2, Dc = 1.814 g/cm^3, F（000） = 510, λ（MoKa） = 0.71073A, μ = 1.562 mm^-1, R = 0.0505 and wR = 0.1061 for 1967 observed reflections （I〉 2σ（Ⅰ））. Complexes 1 and 2 are isostructural with the metal ions situated at the inversion center/Hydrogen bonds between O atoms of pendant and perchlorate anion give rise to a two-dimensional supramolecular layer. The Cu（Ⅱ） ions of compounds 1 and 3 adopt distorted axially-elongated octahedral coordinate geometry, and the nickel（Ⅱ） ion in complex 2 is four-coordinated with a square-planar configuration.展开更多
Molecular metallocycle electrocatalysts like metalloporphyrins and metallophthalocyanines were found to be effective for oxygen reduction reaction(ORR)due to their M-N_(4) active sites and large conjugated elec-tronic...Molecular metallocycle electrocatalysts like metalloporphyrins and metallophthalocyanines were found to be effective for oxygen reduction reaction(ORR)due to their M-N_(4) active sites and large conjugated elec-tronic molecular structures.Herein,the“substituents optimization”strategy combined with“push effect”modification was innovatively employed to target a single Co-N_(4) active site in three substituted phthalo-cyaninato cobalt complexes:tetranitrophthalocyaninato cobalt(CoTNPc),tetra(4-nitrophenoxy)phthalo-cyaninato cobalt(CoTPNPc),and tetraphenoxy phthalocyaninato cobalt(CoTPPc)electrocatalyst,also with 4-phenylpyridine axial coordination on Co-N_(4) unit.Through substituents screening,the half-wave poten-tial(E_(1/2))for ORR increases in the order of CoTPNPc(0.75 V)<CoTPPc(0.80 V)<CoTNPc(0.83 V)along with decreased electron-withdrawing ability of their substituents from-OC_(6) H_(4)-NO_(2),-OC_(6) H_(5) to-NO_(2) in the three cobalt phthalocyanine derivatives.CoTNPc with the weakest electron-withdrawing substituent exhibits the best ORR performance among the three compounds.This is attributed to its higher elec-tron delocalization and lifted HOMO energy level with the lower energy barrier in the rate-determining step relative to the other two compounds,which facilitate the electron transfer and reduction of oxy-gen as evidenced by XPS,UPS,and DRS analysis combined with DFT calculations.Further coordination of 4-phenylpyridine shifts the E_(1/2) up to 0.78,0.82,and 0.85 V for CoTPNPc,CoTPPc,and CoTNPc.DFT calcu-lations demonstrate that the introduction of the electron-donating phenylpyridine ligand into the cobalt phthalocyanines breaks the symmetry of the Co-N_(4) center and also raises the electron density of Co sites,which promotes O_(2) adsorption and improves ORR performance.After comparing the two strategies,the substituents on metallophthalocyanine are more determined by the electroactivity than the axial group,which directly regulates the coordination environment and then the activation barrier of the ORR pro-cess.This work provides theoretical and experimental guidance by two coupling strategies for the design of highly active molecular CoPc-based ORR electrocatalysts in the practical application.展开更多
Three series of polythiophenes containing fluoroalkoxy and fluoroether substituents were prepared by electrochemical polymerization. The effect of substituents with fluoroalkoxy or ether functional groups on the elect...Three series of polythiophenes containing fluoroalkoxy and fluoroether substituents were prepared by electrochemical polymerization. The effect of substituents with fluoroalkoxy or ether functional groups on the electrochemical polymerization of thiophene monomers and properties of the obtained polymers were analyzed. The introduction of a fluoroether functional group at the 3-position of the thiophene ring leads to an increase of the oxidation potential of the monomer and to a decrease of the conductivity of the resulting polymers, even with the use of a CH2 group as spacer. Conversely, the presence of an oxygen atom directly at the 3-position of the thiophene ring, which offsets the negative withdrawing effect of fluoroalkyl groups, facilitates the synthesis of highly conducting polythiophenes.展开更多
A series of binuclear lanthanide complexes with formulas[Dy_(2)(DMOMP)_(2)(TFNB)_(4)]·CH_(3)CH_(2)OCH_(2)CH_(3)(1),[Dy_(2)(DMOEP)_(2)(TFNB)_(4)](2),[Dy_(2)(DMOEP)_(2)(BTFA)_(4)](3),[Dy_(2)(DMOEP)_(2)(TTA)_(4)](4)...A series of binuclear lanthanide complexes with formulas[Dy_(2)(DMOMP)_(2)(TFNB)_(4)]·CH_(3)CH_(2)OCH_(2)CH_(3)(1),[Dy_(2)(DMOEP)_(2)(TFNB)_(4)](2),[Dy_(2)(DMOEP)_(2)(BTFA)_(4)](3),[Dy_(2)(DMOEP)_(2)(TTA)_(4)](4),and[Dy_(2)(DMOAP)_(2)(TFNB)_(4)](5),(DMOMP=2,6-dimethoxy-4-methylphenol,DMOEP=methyl 3,5-dimethoxy-4-hydroxybenzoate,DMOAP=3,5-dimethoxy-4-hydroxybenzaldehyde,TFNB=4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione,BTFA=benzoyltrifluoroacetone,TTA=2-thenoyltrifluoroacetone)were structurally and magnetically characterized.The core structures of these complexes consist of dinuclear lanthanide(Ⅲ)ions bridged firmly by phenoxyl O atoms from two nearly horizontal and isolated 2,6-dimethoxyphenol(DMOP)derivatives,which provide an ideal model to investigate the synergistic contribution of single-ion anisotropy and magnetic exchange interaction.展开更多
Four multinuclear Cd(Ⅱ)complexes,namely[Cd_(2)(L_(1))_(2)I_(2)·2DMSO](1),[Cd_(3)(L_(2))_(6)](2),[Cd_(4)(L_(3))_(6)Br_(2)](3)and[Cd_(4)(L_(4))_(6)Br_(2)·2DMF](4),were prepared by the solvothermal reactions o...Four multinuclear Cd(Ⅱ)complexes,namely[Cd_(2)(L_(1))_(2)I_(2)·2DMSO](1),[Cd_(3)(L_(2))_(6)](2),[Cd_(4)(L_(3))_(6)Br_(2)](3)and[Cd_(4)(L_(4))_(6)Br_(2)·2DMF](4),were prepared by the solvothermal reactions of Cd(II)salts with four 8-hydroxyquinoline ligands containing different substituent groups,respectively.The self-assembly behaviors of the cadmium salts and ligands were subsequently investigated using ultraviolet and fluorescence spectra.In the solid state,single-crystal X-ray diffraction analysis showed that complexes 1-4 exhibit an unprecedented structural diversification,and show one binuclear,one trinuclear and two tetranuclear Cd(Ⅱ)building units,which can be attributed to the different substituent groups in 8-quinolinate ligands.As a result,the four Cd(Ⅱ)complexes exhibit disparate photoluminescence properties(emission bands,fluorescence lifetimes and quantum yields).This unique capability may provide a useful strategy to tune the structures and optical properties of multinuclear materials,which could be exploited as important components for optoelectronic devices.展开更多
This work presents two square-planar Co(III)complexes within a N_(4) coordination sphere created by two related pyrrolecarboxamide ligands.Both complexes functioned as catalysts for the hydrazine-mediated reduction of...This work presents two square-planar Co(III)complexes within a N_(4) coordination sphere created by two related pyrrolecarboxamide ligands.Both complexes functioned as catalysts for the hydrazine-mediated reduction of aromatic,heterocyclic,as well as aliphatic nitro substrates.Binding studies provided evidence that the square-planar Co(III)complexes bind two equivalents of a substrate whereas mechanistic studies established the involvement of a Co^(3+)-Co^(2+)based redox cycle in the catalysis.The Co(III)complex having electron-withdrawing-Cl substituents on the ligand was noted to be a much better catalyst than the one with electron-donating-CH_(3) substituents.展开更多
The tripyrrin coordination motif,namely a conjugated tripyrrolic fragment of the porphyrin scaffold,is found in numerous metal complexes of oligopyrrolic macrocycles.Because of their typically limited stability,linear...The tripyrrin coordination motif,namely a conjugated tripyrrolic fragment of the porphyrin scaffold,is found in numerous metal complexes of oligopyrrolic macrocycles.Because of their typically limited stability,linear tripyrrins are underutilized in coordination chemistry;however,hexaalkyl-tripyrrindiones featuring the pyrrolinone termini characteristic of biopyrrin pigments have recently emerged as versatile redoxactive ligands.Herein,we report the synthesis of the first example of meso-di(pentafluorophenyl)tripyrrin-1,14-dione through the demethylation of a stable 1,14-dimethoxytripyrrin precursor.The two tripyrrin ligands coordinate palladium(II)in square planar geometries in completely distinct ways:the dimethoxytripyrrin forms a cyclopalladate following C(sp^(3))–H bond activation at one of the methoxy groups,whereas the tripyrrindione binds as a trianionic ligand engaging an adventitious aqua ligand in hydrogen-bonding interactions.When compared to the hexaalkyl substituents of previous tripyrrindiones,the meso-aryl groups significantly alter the electrochemical profile of the Pd(II)tripyrrindione complex,shifting anodically by∼500 mV the one-electron processes to attain the other redox states of the ligand.The formation of a ligand-based radical on the Pd(II)-bound meso-aryl tripyrrindione is confirmed by spectroelectrochemical and electron paramagnetic resonance(EPR)methods.展开更多
Over the past decade,considerable scientific attention has been given to adapting cobalt bis(dicarbollide)as innovative agent with various biomedical applications.Although the studied compounds show great potential in...Over the past decade,considerable scientific attention has been given to adapting cobalt bis(dicarbollide)as innovative agent with various biomedical applications.Although the studied compounds show great potential in this field,only a few reports have explored broad,well-thought-out libraries of derivatives to correlate their structure with biological activity.In this study,we investigate a panel of[CoSAN]^(−)derivatives substituted with fluorine,chlorine,bromine and iodine in order to elucidate the impact of the halogen presence on antimicrobial action and selectivity over mammalian cells.We present the first evidence that increasing the atomic mass of a substituent improves the biological activity of a derivative.Our results demonstrate that the addition of a single iodine atom to the[CoSAN]^(−)core results in the most selective antibacterial outcome,especially toward Staphylococcus aureus ATCC 6538.The described correlation between the lipophilicity and the activity of the compounds toward both bacteria and human cell lines highlights the importance of a conscious design method to obtain the most desirable[CoSAN]^(−)-based derivatives.展开更多
The synthesis and design of transition metal catalysts have attracted extensive attention in ethylene polymer-ization.In this work,a series of α-diimine nickel catalysts(Ni1-Ni4)bearing ether substituents were design...The synthesis and design of transition metal catalysts have attracted extensive attention in ethylene polymer-ization.In this work,a series of α-diimine nickel catalysts(Ni1-Ni4)bearing ether substituents were designed and synthesized.The steric hindrance of these catalysts was systematically modulated by varying the ether groups,which directly influenced their ethylene(co)polymerization performances.These catalysts showed exceptionally high activities(up to 10^(7) g·mol^(-1)·h^(-1)).The resulting polyethylene displayed a broad range of branching densities(22 to 92/1000C)and high polymer molecular weights(up to 59.8×10^(4) g·mol^(-1)).Polyethylene produced by Ni1 and Ni2 exhibited outstanding mechanical properties and elastic recovery performance.Furthermore,these catalysts efficiently catalyzed ethylene copolymerization with diverse polar monomers,yielding copolymers with incorporation ratios ranging from 0.24%to 1.43%.展开更多
The frontier orbital interactions of electron pushing and drawing substituents with ferrocenyl group were analyzed based on the electrochemical,UV visible spectral and spectroelectrochemical results of five ferrocene ...The frontier orbital interactions of electron pushing and drawing substituents with ferrocenyl group were analyzed based on the electrochemical,UV visible spectral and spectroelectrochemical results of five ferrocene derivatives,R-Fc-A1(PⅠ),A1-Fc-A1(PⅡ),D-Fc-R (PⅢ),D-Kc-A1(PIV) and D-Fc-A2(PV)(R,CH2OH;A1 CHO;A2,CH=C(CN)2 and D,(C18H37)2N-C6H4-CH=CH) It was found that there are strong interactions of the LUMO (πA) of electron drawing substituents with le2g(dxy,dx2 y2)and e2u of the ferroeenyl group because the energy levels of πA and e2g,C2U of (Cp )2 are close,which lower not only the energy levels of bonded orbits,πA+ and dx2-y2+[πA] of PⅠ,PⅡ,PⅣ and PⅤobviously,but also those of their non-bonded orbu dxy For PⅢ,PⅣ and PⅤ,there are strong interactions of HOMO(πD) of the electron pushing substituent with le of the ferrocenyl group because the levels of πD and e of (Cp)2 are close,which result in the formation of anti-bonded orbit,πD- and bonded orbit展开更多
The medium-bandgap polymerized small molecule acceptors(PSMAs)have broad application scenarios.However,the effort in the molecular design of the high-performance medium-bandgap PSMAs is limited.In this article,we intr...The medium-bandgap polymerized small molecule acceptors(PSMAs)have broad application scenarios.However,the effort in the molecular design of the high-performance medium-bandgap PSMAs is limited.In this article,we introduce alkoxy groups as outer side chains and as substituents of the thiopheneπ-bridges of the high-performance PSMA PY-IT to synthesize a mediumbandgap PSMA PO-TO.Due to the fact that the non-covalent interaction between the alkoxy groups and the terminal groups of the small molecule acceptor(SMA)unit can weaken the intramolecular charge transfer(ICT)effect,the bandgap of PO-TO is enlarged and its absorption is blue-shifted compared with PY-IT,while the absorbance of PO-TO solution and film is enhanced significantly compared with that of PY-IT.When blended PO-TO with the polymer donor PBQx-TF,the corresponding all-polymer solar cells(all-PSCs)exhibit an open-circuit voltage(V_(oc))exceeding 1.04 V with a power conversion efficiency(PCE)of 13.75%.Furthermore,PO-TO was used as the third component to fabricate ternary all-PSCs with PBQx-TF as the polymer donor and PY-IT as the main polymer acceptor,and the ternary all-PSCs based on PBQx-TF:PY-IT:PO-TO(1:1:0.2,w/w/w)demonstrated a high PCE of 17.71%with simultaneously improved V_(oc)of 0.940 V,short-circuit current density(J_(sc))of 24.60 m A cm^(-2)and fill factor(FF)of76.81%.In comparison,the binary all-PSCs based on PBQx-TF:PY-IT showed a PCE of 16.77%.This result indicates that introducing alkoxy groups is a promising strategy for synthesizing high-performance medium-bandgap PSMAs.展开更多
Side chain engineering with fluorine substitution is widely used to enhance photovoltaic performance of polymer donors in the research field of polymer solar cells(PSCs).However,fluorine substitution has disadvantages...Side chain engineering with fluorine substitution is widely used to enhance photovoltaic performance of polymer donors in the research field of polymer solar cells(PSCs).However,fluorine substitution has disadvantages of complicated synthesis and high cost.Herein,we synthesized a novel D-A copolymer donor PBQ9 based on difluoroquinoxaline A-unit with chlorine substitution on its alkyl-thiophene side chains instead of fluorine substitution in the polymer donor PBQ6,which greatly shortens the synthetic route and reduces the cost.Interestingly,the optimized binary PSC with PBQ9 as polymer donor and m-TEH as acceptor demonstrated a high power conversion efficiency(PCE)of 18.81%(certified PCE of 18.33%by National Institute of Metrology,China)with a high fill factor of 80.59%,and the photovoltaic performance of the PSCs is insensitive to the different batches of the polymer donor.The results indicate that PBQ9 is a high-performance polymer donor and that chlorine substitution is an effective strategy to improve photovoltaic performance and reduce the cost of polymer donors.展开更多
基金Natural Science Foundation of Education Department of Anhui Province,China(No.KJ2013B028)Textile Science and Technology Key Discipline in Anhui Polytechnic University,China
文摘Calix[4]arene derivatives have been reported to possess high selectivity for metal ions.In order to analyze the extraction effect of substituents on Hg^(2+)and Pb^(2+),calix[4]arene derivatives containing hydroxyl,bromoethoxy and 1,11-dioxa-4,8-dithiahendecene were successfully synthesized,with their extraction effectiveness towards Hg^(2+)and Pb^(2+)were evaluated respectively.The results indicated that the phenolic hydroxyl in calix[4]arene improved the extraction ability on Hg^(2+)by promoting the formation of the negative oxygen ions that could bind with Hg^(2+)by coordination and ionic bonds.The extraction ability of 5,17-dinitro-26,28-(1’,11’-dioxa-4’,8’-dithiahendecene)-calix[4]arene(calix[4]arene thia derivative)was improved slightly due to the better coordination capacity for metal ions after introduction of 1,11-dioxa-4,8-dithiahendecene,which was a chelate-binding centre.Regarding to Pb^(2+),only 1,11-dioxa-4,8-dithiahendecene on molecule contributed to extraction due to the coordination bond.Since the metal ion with higher charge-to-radius ratio could coordinate with one ligand more stably,Pb^(2+)with higher charge-to-radius ratio than Hg^(2+)was coordinated and extracted by the calix[4]arene thia derivative more easily.Furthermore,extraction rates of the calix[4]arene thia derivative on both ions(Hg^(2+)and Pb^(2+))increased with the increase of pH value in acidic aqueous system(pH<7).
基金supported by the NSFC(Nos.50973011 and 20702004)
文摘Asymmetrically substituted phthalocyanines with sulfur-containing substituents for fabrication of self- assembled monolayers were synthesized. Phthalocyanine 7, bearing a disulfide group, was synthesized from phthalocyanine with a hydroxyl group, which was prepared via mixed condensation of the corresponding substituted phthalonitriles. Phthalocyanine 10, bearing an acetyl protected thiol group, was synthesized through the Pd-catalyzed coupling reaction of an iodophthalocyanine. Their self- assembling behavior on gold substrates was further studied by UV-vis spectroscopy.
基金the National Natural Science Foundation of China(Nos.21332008 and 21472015)
文摘Foldamers 1–4 incorporating different terminal substituents have been designed and synthesized for binding halide anions.~1H NMR titration experiments carried out in DMSO-d_6/CDCl_3（15/85, v/v）demonstrated that the short oligo （aryltriazole）s backbone 1 could not bind halide anions unless that amide H-bond donors were incorporated at the termini of the oligomer. Terminal substituents on oligo（aryltriazoleamide）s foldamers 2–4 display a considerable influence on the binding affinities of the foldamers for halide anions. Large steric hindrance of the terminal substituents was found to be unfavorable for binding halide anions, but aromatic π-π interactions between two terminal substituents are capable of stabilizing the conformation of foldamers thus giving rise to an enhancement in the binding strengths. However, the terminal substituents were found to hardly affect the binding selectivity in the studied cases.
文摘Based on the property that carboxymethylcellulose (CMC ) can be de-graded to anhydroglucose residues by cellulase, the rate constant (K) of enzymatic degra-dation of CMC synthesized in the benzene-ethanol medium has been determined. Further-morel experimental equation K = 2.71× 10^(-2)(DS)^(-1.2) reflecting the relationship betweenK and the degree of substitution (DS) is correlated and used to describe chemical mi-crostructure uniformity of the distribution of substituents along chains effectively. Chainstructure parameters of enzymatic degradation products of CMC-the number of chainbreaks and the percentage of glucose released have been also measured. Average length ofsubstituted and unsubstituted chain segments are calculated simultaneously. Through thestudy of static and dynamic procedures of enzymatic degradation, the method to charac-terize the distribution of substituents of CMC along the chain has been improved.
基金the National Natural Science Foundation of China(Nos.21871250 and 22001244)the Jilin Provincial Science and Technology Department Program(No.20200801009GH).
文摘For the rational design of metal catalyst in olefin polymerization catalysis,various strategies were applied to suppress the chain transfer by bulking up the axial positions of the metal center,among which the"sandwich"type turned out to be an eficient category in achieving high molecular weight polyolefin.In the a-dimine system,the"sandwich"type catalysts were built using the typical 8-aryl-naphthyI framework.In this contribution,by introducing the rotationally restrained benzosuberyl substituent into the ortho-position of N-aryl rings,a new class of "sandwich-like"a-diimine nickel catalysts was constructed and fully identified.The rotationally restrained benzosuberyl substituents played a"sandwich-like"function by capping the nickel center from two axial sites.Compared to the nickel catalyst Ni1 bearing freely rotated benzhydryl substituent,Ni2 featuring benzosubery|substituent enabled the increase(8 times)of polymer molecular weights from 8 kDa to 65 kDa in the polymerization of ethylene.By further increasing the steric bulk of another ortho-site of the N-aryl ring,the polymer molecular weight even reached an ultrahigh level of 833 kDa(Mw=1857 kDa)using the optimized Ni3.Notably,these nickel catalysts could also mediate the copolymerization of ethylene with methyl 10-undecenoate,with Ni3 giving the highest copolymer molecular weight(88 kDa)and the highest incorporation of comonmer(2.0 mol1%),along with high activity of up to 10^(5)g·mol^(-1)·h^(-1).
文摘The synthesis and phosphorescence properties of two novel Ir(Ⅲ)complexes bearing tert-butyl substituents,bis(4-tert-butyl-2- phenylbenzothiozolato-N,C^(2′))iridium(Ⅲ)(acetylacetonate)[(tbt)_2Ir(acac)]and bis(4-tert-butyl-1-phenyl-1H-benzimidazolato- N,C^(2′))iridium(Ⅲ)(acetylacetonate)[(tpbi)_2Ir(acac)],are reported,their molecular structures are confirmed by^1H NMR,ESI-MS and elementary analysis.Photoluminescence(PL)studies revealed that they can emit strong green and orange phosphorescence in high quantum yields.Compared to their prototypes lacking of tert-butyl substituents,the two novel iridium(Ⅲ)complexes both have shorter lifetimes and improved or nearly similar PL quantum efficiencies,implying that the exciton quenching is inhibited effectively when molecular steric hindrance increases.The two chelates have great potential to be used as electrophosphorescent materials.
基金supported by the Ministry of Education,Science and Technological Development of the Republic of Serbia and the Slove-nian Research Agency (research core funding No. P2-0152)。
文摘Understanding the degradation behavior of azo dyes in photocatalytic wastewater treatment is of fundamental and practical importance for their application in textile-processing and other coloration industries. In this study, quantum chemistry, as density functional theory, was used to elucidate different degradation pathways of azo pyridone dyes in a hydroxyl radical(HO ·)-initiated photocatalytic system. A series of substituted azo pyridone dyes were synthesized by changing the substituent group in the para position of the benzene moiety, ranging from strong electron-donating to strong electron-withdrawing groups. The effect of dye molecular structure on the photocatalytic degradation reaction mechanism was analyzed and quantification of substituent effects on the thermodynamic and kinetics parameters was performed. Potential energy surface analysis revealed the most susceptible reaction site for the HO ·attack. The calculated reaction barriers are found to be strongly affected by the nature of substituent group with a good correlation using Hammett σp constants and experimentally determined reaction rates. The stability of pre-reaction complexes and transition state complexes were analyzed applying the distortion-interaction model. The increased stability of the transition state complexes with the distancing from the substituent group has been established.
基金The authors gratefully acknowledge the financial support of the Natural Science Foundation of China,China(Grant No.21975082 and 21736003)the Guangdong Basic and Applied Basic Research Foundation(Grant Number:2019A1515011472 and 2022A1515011341)the Science and Technology Program of Guangzhou(Grant Number:202102080479).
文摘In order to better understand the specific substituent effects on the electrochemical oxidation process of β-O-4 bond, a series of methoxyphenyl type β-O-4 dimer model compounds with different localized methoxyl groups, including 2-(2-methoxyphenoxy)-1-phenylethanone, 2-(2-methoxyphenoxy)-1-phenylethanol, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanol, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanol have been selected and their electrochemical properties have been studied experimentally by cyclic voltammetry, and FT-IR spectroelectrochemistry. Combining with electrolysis products distribution analysis and density functional theory calculations, oxidation mechanisms of all six model dimers have been explored. In particular, a total effect from substituents of both para-methoxy(on the aryl ring closing to Cα) and Cα-OH on the oxidation mechanisms has been clearly observed, showing a significant selectivity on the Cα-Cβbond cleavage induced by electrochemical oxidations.
基金Supported by the National Natural Science Foundation of China (20201008)
文摘Two new macrocyclic complexes with C-methyl substituents on the framework, namely, [CuL]（ClO4）2 （L = 5,12-dimethyl-1,8-dihydroxyethyl-1,3,6,8,10,13-hexaazacyclotetradecane） 1 and [NiL]（ClO4）2 2, have been synthesized and structurally characterized through X-ray diffraction analysis. Also, crystal structure of [CuL^1]（ClO4）2 （L^1 = 1,8-dimethyl- 1,3,6,8, [ 0,13- hexaazacyclotetradecane） 3 has been determined. Crystal data for 1： C14H32C12CuN6O10, Mr = 578.90, monoclinic, P2 1/n, α = 8.3529（11）, b = 10.8105（17）, c = 13.3709（17） ,A, β = 105.189（10）°, V= 1165.2（3） A3, Z = 2, Dc = 1.650 g/cm^3, F（000） = 602, λ（MoKct） = 0.71073 A,μ = 1.229 mm ^-1, R = 0.0474 and wR = 0.0895 for 2771 observed reflections （I 〉 2σ（Ⅰ））. Crystal data for 2： C14H32C12N6NiO10, Mr = 574.07, monoclinic, P2 1/c, a = 8.3636（12）, b = 12.997（2）, c = 10.764（2） A, β = 99.31（2）°, V = 1154.7（3） A^3, Z = 2, DC = 1.651 g/cm^3, F（000） = 600, λ（MoKa） = 0.71073 A,μ = 1. 134 mm^-1, R = 0.0380 and wR = 0.0796 for 2670 observed reflections （i 〉 2σ（Ⅰ））. Crystal data for 3： C 10H26Cl2CuN6O8, Mr = 492.81, monoclinic, P2 1/n, a = 8.4860（17）, b = 8.6320（17）, c = 12.662（3） ,A,β = 103.40（3）°, V = 902.2（3）A^3, Z = 2, Dc = 1.814 g/cm^3, F（000） = 510, λ（MoKa） = 0.71073A, μ = 1.562 mm^-1, R = 0.0505 and wR = 0.1061 for 1967 observed reflections （I〉 2σ（Ⅰ））. Complexes 1 and 2 are isostructural with the metal ions situated at the inversion center/Hydrogen bonds between O atoms of pendant and perchlorate anion give rise to a two-dimensional supramolecular layer. The Cu（Ⅱ） ions of compounds 1 and 3 adopt distorted axially-elongated octahedral coordinate geometry, and the nickel（Ⅱ） ion in complex 2 is four-coordinated with a square-planar configuration.
基金supported by the Key Program of the National Natural Science Foundation of China(No.22133006)National Nat-ural Science Foundation of China(No.21771192)+2 种基金Program for Tais-han Scholar of Shandong Province(No.ts201712019)NSF of Shan-dong Province(No.ZR2017ZB0315)Shandong Energy Group 2019 Science and Technology Program(Nos.YKKJ2019AJ11JG-R66 and YKKJ2019AJ05JG-R60).
文摘Molecular metallocycle electrocatalysts like metalloporphyrins and metallophthalocyanines were found to be effective for oxygen reduction reaction(ORR)due to their M-N_(4) active sites and large conjugated elec-tronic molecular structures.Herein,the“substituents optimization”strategy combined with“push effect”modification was innovatively employed to target a single Co-N_(4) active site in three substituted phthalo-cyaninato cobalt complexes:tetranitrophthalocyaninato cobalt(CoTNPc),tetra(4-nitrophenoxy)phthalo-cyaninato cobalt(CoTPNPc),and tetraphenoxy phthalocyaninato cobalt(CoTPPc)electrocatalyst,also with 4-phenylpyridine axial coordination on Co-N_(4) unit.Through substituents screening,the half-wave poten-tial(E_(1/2))for ORR increases in the order of CoTPNPc(0.75 V)<CoTPPc(0.80 V)<CoTNPc(0.83 V)along with decreased electron-withdrawing ability of their substituents from-OC_(6) H_(4)-NO_(2),-OC_(6) H_(5) to-NO_(2) in the three cobalt phthalocyanine derivatives.CoTNPc with the weakest electron-withdrawing substituent exhibits the best ORR performance among the three compounds.This is attributed to its higher elec-tron delocalization and lifted HOMO energy level with the lower energy barrier in the rate-determining step relative to the other two compounds,which facilitate the electron transfer and reduction of oxy-gen as evidenced by XPS,UPS,and DRS analysis combined with DFT calculations.Further coordination of 4-phenylpyridine shifts the E_(1/2) up to 0.78,0.82,and 0.85 V for CoTPNPc,CoTPPc,and CoTNPc.DFT calcu-lations demonstrate that the introduction of the electron-donating phenylpyridine ligand into the cobalt phthalocyanines breaks the symmetry of the Co-N_(4) center and also raises the electron density of Co sites,which promotes O_(2) adsorption and improves ORR performance.After comparing the two strategies,the substituents on metallophthalocyanine are more determined by the electroactivity than the axial group,which directly regulates the coordination environment and then the activation barrier of the ORR pro-cess.This work provides theoretical and experimental guidance by two coupling strategies for the design of highly active molecular CoPc-based ORR electrocatalysts in the practical application.
基金This work was supported by the National Natural Science Foundation of China.
文摘Three series of polythiophenes containing fluoroalkoxy and fluoroether substituents were prepared by electrochemical polymerization. The effect of substituents with fluoroalkoxy or ether functional groups on the electrochemical polymerization of thiophene monomers and properties of the obtained polymers were analyzed. The introduction of a fluoroether functional group at the 3-position of the thiophene ring leads to an increase of the oxidation potential of the monomer and to a decrease of the conductivity of the resulting polymers, even with the use of a CH2 group as spacer. Conversely, the presence of an oxygen atom directly at the 3-position of the thiophene ring, which offsets the negative withdrawing effect of fluoroalkyl groups, facilitates the synthesis of highly conducting polythiophenes.
基金supported by the NSFC(No.21572048,21102039)the Educational Commission of Heilongjiang Province(LH2019B016)the Heilongjiang University(JCL201605,2017230101001473).
文摘A series of binuclear lanthanide complexes with formulas[Dy_(2)(DMOMP)_(2)(TFNB)_(4)]·CH_(3)CH_(2)OCH_(2)CH_(3)(1),[Dy_(2)(DMOEP)_(2)(TFNB)_(4)](2),[Dy_(2)(DMOEP)_(2)(BTFA)_(4)](3),[Dy_(2)(DMOEP)_(2)(TTA)_(4)](4),and[Dy_(2)(DMOAP)_(2)(TFNB)_(4)](5),(DMOMP=2,6-dimethoxy-4-methylphenol,DMOEP=methyl 3,5-dimethoxy-4-hydroxybenzoate,DMOAP=3,5-dimethoxy-4-hydroxybenzaldehyde,TFNB=4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione,BTFA=benzoyltrifluoroacetone,TTA=2-thenoyltrifluoroacetone)were structurally and magnetically characterized.The core structures of these complexes consist of dinuclear lanthanide(Ⅲ)ions bridged firmly by phenoxyl O atoms from two nearly horizontal and isolated 2,6-dimethoxyphenol(DMOP)derivatives,which provide an ideal model to investigate the synergistic contribution of single-ion anisotropy and magnetic exchange interaction.
基金supported by the National Natural Science Foundation of China(No.21671002 and 21603001)the Anhui Provincial National Science Fund for Excellent Young Scholars and Training Programs of Innovation and Entrepreneurship for Undergraduates(201510360163 and 201610360160).
文摘Four multinuclear Cd(Ⅱ)complexes,namely[Cd_(2)(L_(1))_(2)I_(2)·2DMSO](1),[Cd_(3)(L_(2))_(6)](2),[Cd_(4)(L_(3))_(6)Br_(2)](3)and[Cd_(4)(L_(4))_(6)Br_(2)·2DMF](4),were prepared by the solvothermal reactions of Cd(II)salts with four 8-hydroxyquinoline ligands containing different substituent groups,respectively.The self-assembly behaviors of the cadmium salts and ligands were subsequently investigated using ultraviolet and fluorescence spectra.In the solid state,single-crystal X-ray diffraction analysis showed that complexes 1-4 exhibit an unprecedented structural diversification,and show one binuclear,one trinuclear and two tetranuclear Cd(Ⅱ)building units,which can be attributed to the different substituent groups in 8-quinolinate ligands.As a result,the four Cd(Ⅱ)complexes exhibit disparate photoluminescence properties(emission bands,fluorescence lifetimes and quantum yields).This unique capability may provide a useful strategy to tune the structures and optical properties of multinuclear materials,which could be exploited as important components for optoelectronic devices.
基金financial support from the Council of Scientific&Industrial Research(CSIR),New Delhi and the University of Delhi。
文摘This work presents two square-planar Co(III)complexes within a N_(4) coordination sphere created by two related pyrrolecarboxamide ligands.Both complexes functioned as catalysts for the hydrazine-mediated reduction of aromatic,heterocyclic,as well as aliphatic nitro substrates.Binding studies provided evidence that the square-planar Co(III)complexes bind two equivalents of a substrate whereas mechanistic studies established the involvement of a Co^(3+)-Co^(2+)based redox cycle in the catalysis.The Co(III)complex having electron-withdrawing-Cl substituents on the ligand was noted to be a much better catalyst than the one with electron-donating-CH_(3) substituents.
基金National Science Foundation(award CHE-2203361 to E.T.)。
文摘The tripyrrin coordination motif,namely a conjugated tripyrrolic fragment of the porphyrin scaffold,is found in numerous metal complexes of oligopyrrolic macrocycles.Because of their typically limited stability,linear tripyrrins are underutilized in coordination chemistry;however,hexaalkyl-tripyrrindiones featuring the pyrrolinone termini characteristic of biopyrrin pigments have recently emerged as versatile redoxactive ligands.Herein,we report the synthesis of the first example of meso-di(pentafluorophenyl)tripyrrin-1,14-dione through the demethylation of a stable 1,14-dimethoxytripyrrin precursor.The two tripyrrin ligands coordinate palladium(II)in square planar geometries in completely distinct ways:the dimethoxytripyrrin forms a cyclopalladate following C(sp^(3))–H bond activation at one of the methoxy groups,whereas the tripyrrindione binds as a trianionic ligand engaging an adventitious aqua ligand in hydrogen-bonding interactions.When compared to the hexaalkyl substituents of previous tripyrrindiones,the meso-aryl groups significantly alter the electrochemical profile of the Pd(II)tripyrrindione complex,shifting anodically by∼500 mV the one-electron processes to attain the other redox states of the ligand.The formation of a ligand-based radical on the Pd(II)-bound meso-aryl tripyrrindione is confirmed by spectroelectrochemical and electron paramagnetic resonance(EPR)methods.
文摘Over the past decade,considerable scientific attention has been given to adapting cobalt bis(dicarbollide)as innovative agent with various biomedical applications.Although the studied compounds show great potential in this field,only a few reports have explored broad,well-thought-out libraries of derivatives to correlate their structure with biological activity.In this study,we investigate a panel of[CoSAN]^(−)derivatives substituted with fluorine,chlorine,bromine and iodine in order to elucidate the impact of the halogen presence on antimicrobial action and selectivity over mammalian cells.We present the first evidence that increasing the atomic mass of a substituent improves the biological activity of a derivative.Our results demonstrate that the addition of a single iodine atom to the[CoSAN]^(−)core results in the most selective antibacterial outcome,especially toward Staphylococcus aureus ATCC 6538.The described correlation between the lipophilicity and the activity of the compounds toward both bacteria and human cell lines highlights the importance of a conscious design method to obtain the most desirable[CoSAN]^(−)-based derivatives.
基金supported by National Key R&D Program of China(No.2021YFA1501700)National Natural Science Foundation of China(No.52025031,22261142664,52403016)+1 种基金Fundamental Research Funds for the Central Universities(No.WK2060000074)CAS Project for Young Scientists in Basic Research(No.YSBR-094).
文摘The synthesis and design of transition metal catalysts have attracted extensive attention in ethylene polymer-ization.In this work,a series of α-diimine nickel catalysts(Ni1-Ni4)bearing ether substituents were designed and synthesized.The steric hindrance of these catalysts was systematically modulated by varying the ether groups,which directly influenced their ethylene(co)polymerization performances.These catalysts showed exceptionally high activities(up to 10^(7) g·mol^(-1)·h^(-1)).The resulting polyethylene displayed a broad range of branching densities(22 to 92/1000C)and high polymer molecular weights(up to 59.8×10^(4) g·mol^(-1)).Polyethylene produced by Ni1 and Ni2 exhibited outstanding mechanical properties and elastic recovery performance.Furthermore,these catalysts efficiently catalyzed ethylene copolymerization with diverse polar monomers,yielding copolymers with incorporation ratios ranging from 0.24%to 1.43%.
基金Project supported by the National Natural Science Foundation of China
文摘The frontier orbital interactions of electron pushing and drawing substituents with ferrocenyl group were analyzed based on the electrochemical,UV visible spectral and spectroelectrochemical results of five ferrocene derivatives,R-Fc-A1(PⅠ),A1-Fc-A1(PⅡ),D-Fc-R (PⅢ),D-Kc-A1(PIV) and D-Fc-A2(PV)(R,CH2OH;A1 CHO;A2,CH=C(CN)2 and D,(C18H37)2N-C6H4-CH=CH) It was found that there are strong interactions of the LUMO (πA) of electron drawing substituents with le2g(dxy,dx2 y2)and e2u of the ferroeenyl group because the energy levels of πA and e2g,C2U of (Cp )2 are close,which lower not only the energy levels of bonded orbits,πA+ and dx2-y2+[πA] of PⅠ,PⅡ,PⅣ and PⅤobviously,but also those of their non-bonded orbu dxy For PⅢ,PⅣ and PⅤ,there are strong interactions of HOMO(πD) of the electron pushing substituent with le of the ferrocenyl group because the levels of πD and e of (Cp)2 are close,which result in the formation of anti-bonded orbit,πD- and bonded orbit
基金supported by the National Key Research and Development Program of China(2019YFA0705900)the Ministry of Science and Technology,the National Natural Science Foundation of China(51820105003,21734008,52203248,61904181,52173188)+1 种基金the Key Research Program of the Chinese Academy of Sciences(XDPB13)the Basic and Applied Basic Research Major Program of Guangdong Province(2019B030302007)。
文摘The medium-bandgap polymerized small molecule acceptors(PSMAs)have broad application scenarios.However,the effort in the molecular design of the high-performance medium-bandgap PSMAs is limited.In this article,we introduce alkoxy groups as outer side chains and as substituents of the thiopheneπ-bridges of the high-performance PSMA PY-IT to synthesize a mediumbandgap PSMA PO-TO.Due to the fact that the non-covalent interaction between the alkoxy groups and the terminal groups of the small molecule acceptor(SMA)unit can weaken the intramolecular charge transfer(ICT)effect,the bandgap of PO-TO is enlarged and its absorption is blue-shifted compared with PY-IT,while the absorbance of PO-TO solution and film is enhanced significantly compared with that of PY-IT.When blended PO-TO with the polymer donor PBQx-TF,the corresponding all-polymer solar cells(all-PSCs)exhibit an open-circuit voltage(V_(oc))exceeding 1.04 V with a power conversion efficiency(PCE)of 13.75%.Furthermore,PO-TO was used as the third component to fabricate ternary all-PSCs with PBQx-TF as the polymer donor and PY-IT as the main polymer acceptor,and the ternary all-PSCs based on PBQx-TF:PY-IT:PO-TO(1:1:0.2,w/w/w)demonstrated a high PCE of 17.71%with simultaneously improved V_(oc)of 0.940 V,short-circuit current density(J_(sc))of 24.60 m A cm^(-2)and fill factor(FF)of76.81%.In comparison,the binary all-PSCs based on PBQx-TF:PY-IT showed a PCE of 16.77%.This result indicates that introducing alkoxy groups is a promising strategy for synthesizing high-performance medium-bandgap PSMAs.
基金supported by National Key Research and Development Program of China(grant no.2019YFA0705900)funded by MOST,the National Natural Science Foundation of China(grant nos.51820105003,21734008,61904181,and 52173188)the Key Research Program of the Chinese Academy of Sciences(grant no.XDPB13)+2 种基金the Basic and Applied Basic Research Major Program of Guangdong Province(grant no.2019B030302007)Y.W.acknowledges financial support from the Office of Naval Research(award no.N00014-19-1-2453)the use of the Stanford Synchrotron Radiation Light-source,SLAC National Accelerator Laboratory,which is supported by the U.S.Department of Energy,Office of Science,Office of Basic Energy Sciences(contract no.DE-AC02-76SF00515).
文摘Side chain engineering with fluorine substitution is widely used to enhance photovoltaic performance of polymer donors in the research field of polymer solar cells(PSCs).However,fluorine substitution has disadvantages of complicated synthesis and high cost.Herein,we synthesized a novel D-A copolymer donor PBQ9 based on difluoroquinoxaline A-unit with chlorine substitution on its alkyl-thiophene side chains instead of fluorine substitution in the polymer donor PBQ6,which greatly shortens the synthetic route and reduces the cost.Interestingly,the optimized binary PSC with PBQ9 as polymer donor and m-TEH as acceptor demonstrated a high power conversion efficiency(PCE)of 18.81%(certified PCE of 18.33%by National Institute of Metrology,China)with a high fill factor of 80.59%,and the photovoltaic performance of the PSCs is insensitive to the different batches of the polymer donor.The results indicate that PBQ9 is a high-performance polymer donor and that chlorine substitution is an effective strategy to improve photovoltaic performance and reduce the cost of polymer donors.
