Under the condition of solvothermal synthesis,the viologen ligand 1,1′-bis(3-carboxyphenyl)-(4,4′-bipyri-dine)dichloride(H_(2)bcbpy·2Cl)and KI are coordinated with the metal cadmium ions.A case of thermochromic...Under the condition of solvothermal synthesis,the viologen ligand 1,1′-bis(3-carboxyphenyl)-(4,4′-bipyri-dine)dichloride(H_(2)bcbpy·2Cl)and KI are coordinated with the metal cadmium ions.A case of thermochromic coor-dination polymer[Cd(bcbpy)I_(2)]·2H_(2)O(1)was constructed.Complex 1 displays a 1D chain structure and exhibits thermochromic behavior.Under different temperature stimulation,the complex(ground)slowly changed from green to yellow-green,and with the increase of temperature,the color of complex 1 gradually deepened,and finally became orange-yellow.Therefore,complex 1 was prepared as a thermochromic film.In addition,we also performed electrochemical tests on complex 1,which showed that the complex is a semiconductor material.CCDC:2391802.展开更多
π-Conjugated donor-acceptor-donor-acceptor-donor(D-A-D-A-D)type pyrenoviologens(PyV^(2+)),with the 2,7 positions of pyrene serving as connection bridges,were synthesized through SN2 reactions.Specifically,pyrenoviolo...π-Conjugated donor-acceptor-donor-acceptor-donor(D-A-D-A-D)type pyrenoviologens(PyV^(2+)),with the 2,7 positions of pyrene serving as connection bridges,were synthesized through SN2 reactions.Specifically,pyrenoviologen 3c was modified with a methylnaphthalene group,while 3a and 3b were modified with methyl and benzyl groups,respectively,for comparison.These pyrenoviologens exhibit reversible redox properties and strong fluorescence emission.Electrochromic devices(ECDs)were prepared using pyrenoviologens as the active materials.Notably,naphthalene-containing pyrenoviologen 3c,with its DA-D-A-D conjugated structure,possesses more stable free radicals,enabling it to maintain the radical color for a longer duration after power loss.A series of color-changing devices were successfully assembled.Due to the strong fluorescence of pyrenoviologens and the unique electron transfer effect between them and picric acid(PA),a sensor film with good selectivity and high sensitivity for PA in aqueous solution was prepared using pyrenoviologens as the fluorescent probe.Specifically,3c exhibited the highest sensitivity to PA due to its lowest energy gap.The introduction of the D-A-D-A-D structure is a strategic approach to enhancing photoelectric performance and broadening the application of viologens.展开更多
The design and synthesis of catalysts for the oxidation desulfurization and production of hydrogen are extremely important for solving environmental pollution and energy shortage.Herein,a novel bifunctional [α-Mo_(8)...The design and synthesis of catalysts for the oxidation desulfurization and production of hydrogen are extremely important for solving environmental pollution and energy shortage.Herein,a novel bifunctional [α-Mo_(8)O_(26)]^(4-)/[β-Mo_(8)O_(26)]^(4-)-based Cu-viologen complex H_(4)[Cu_(2)~ⅠCl_(2)(Hbcbpy)_(4)] [α-Mo_(8)O_(26)] [β-Mo8O_(26)]·H_(2)O(BHU-2,Hbcbpy=1-(4-carboxybenzyl)-4,4'-bipyridinium) was synthesized and characterized by single-crystal X-ray diffraction(XRD),infrared radiation spectra,powder X-ray diffraction(PXRD) and X-ray photoelectron spectroscopy(XPS) spectra.The structural characteristic of BHU-2 is the presence of two types of octamolybdate clusters [α-Mo_(8)O_(26)]^(4-)/[β-Mo_(8)O_(26)]^(4-)and a new binuclear Cu~Ⅰ-Hbcbpy complex linked by Cl-bridges[Cu_(2)ⅠCl_(2)(Hbcbpy)_(4)]^(4+).BHU-2 as a heterogeneous catalyst exhibits excellent activities to the oxidation desulfurization and photocatalytic hydrogen production.At room temperature,BHU-2 can catalyze 96% conversion of methyl phenyl sulfide with 98% selectivity,and the process obeys the pseudo-first-order reaction kinetic with the half-life of9.6 min.The notorious 2-chloroethyl ethyl sulfide can achieve 99% conversion with 98% selectivity within only1 min at the presence of BHU-2,and the turnover frequency(TOF) is up to 7400 h^(-1).BHU-2 also exhibits high catalytic activity for the oxidation of other aromatic and aliphatic thioethers within short time at room temperature.Furthermore,BHU-2 shows a high catalytic activity for visible-light-driven hydrogen evolution with an H_(2) evolution rate of 1677.85 μmol·g^(-1)·h^(-1) within 10 h.Moreover,the catalytic activities do not decrease evidently after three cycles,revealing the prominent structural stability and recyclability.展开更多
Direct X-ray detectors,which directly convert X-rays into electrical signals through semiconductors,have higher space solution than scintillator-mediated indirect X-ray ones and are high desirable for early cancer det...Direct X-ray detectors,which directly convert X-rays into electrical signals through semiconductors,have higher space solution than scintillator-mediated indirect X-ray ones and are high desirable for early cancer detection and other applications,but the mainstream commercialα-Se detector is still largely limited by high production costs,large leakage current and low stability.This article reports an easily prepared,stable radiochromic semiconductive metal–organic framework(MOF),(MV)[Cd_(3)(tdc)_(4)]·2H_(2)O(RCS-1,H_(2)tdc=2,5-thiophenedicarboxylic acid;MV^(2+)=methyl viologen cation)with direct X-ray detecting ability.With a large bulk resistivity of 8.40×10^(9)Ωcm,this material ensures minimal dark current and low noise for X-ray detection.Additionally,it exhibits higher sensitivity to W KαX-rays(98.58μC Gy^(-1)cm^(-2))thanα-Se(~20μC Gy^(-1)cm^(-2)).Meanwhile,unlike most reported direct X-ray detecting semiconductors,compound RCS-1 shows remarkable color change upon X-ray irradiation owing to the presence of photochromism-active viologen cations.This feature offers an appealing visual detecting ability to direct X-ray detectors that provide only the electrical signals.展开更多
Viologens known as a kind of promising negolyte materials for aqueous organic redox flow batteries,face a critical stability challenge due to the S_N2 nucleophilic attack by hydroxide ions(OH-)during the battery cycli...Viologens known as a kind of promising negolyte materials for aqueous organic redox flow batteries,face a critical stability challenge due to the S_N2 nucleophilic attack by hydroxide ions(OH-)during the battery cycling.In this work,a N-cyclic quaternary ammonium-grafted viologen molecule,viz.1,1'-bis(4,4'-dime thylpiperidiniumyl)-4,4'-bipyridinium tetrachloride((DBPPy)Cl_(4)),is developed by the molecular engineering strategy.The obtained(DBPPy)Cl_(4) molecule shows a decent solubility of 1.84 M and a redox potential of-0.52 V vs.Ag/AgCl,Experimental and theoretical results reveal that the grafted N-cyclic quaternary ammonium groups act as the steric hindrance to prevent nucleophilic attack by OH~-,increasing the alkali resistance of the electroactive molecule.The symmetrical battery with 0.50 M(DBPPy)Cl4shows negligible decay during the 13-day cycling test.As demonstration,the flow battery utilizing 1.0 M(DBPPy)Cl_(4) as the negolyte and 1-(1-oxyl-2,2',6,6'-tetramethylpiperidin-4-yl)-1'-(3-(trimethylammonio)propyl)-4,4'-bipyridinium trichloride as the posolyte exhibits a high capacity retention rate of 99.99%per cycle at 60 mA cm^(-2).展开更多
Electrochromic technology has gained significant attention in various fields such as displays,smart windows,biomedical monitoring,military camouflage,human-machine interaction,and electronic skin due to its ability to...Electrochromic technology has gained significant attention in various fields such as displays,smart windows,biomedical monitoring,military camouflage,human-machine interaction,and electronic skin due to its ability to provide reversible and fast color changes under applied voltage.With the rapid development and increasing demand for flexible electronics,flexible electrochromic devices(FECDs)that offer smarter and more controllable light modulation hold great promise for practical applications.The electrochromic material(ECM)undergoing color changes during the electrochemical reactions is one of the key components in electrochromic devices.Among the ECMs,viologens,a family of organic small molecules with 1,1'-disubstituted-4,4'-dipyridinium salts,have garnered extensive research interest,due to their well-reversible redox reactions,excellent electron acceptance ability,and the ability to produce multiple colors.Notably,viologen-based FECDs demonstrate color changes in the liquid or semisolid electrolyte layer,eliminating the need for two solid electrodes and thus simplifying the device structure.Consequently,viologens offer significant potential for the development of FECDs with high optical contrast,fast response speed,and excellent stability.This review aims to provide a comprehensive overview of the progress and perspectives of viologen-based FECDs.It begins by summarizing the typical structure and recent exciting developments in viologen-based FECDs,along with their advantages and disadvantages.Furthermore,the review discusses recent advancements in FECDs with additional functionalities such as sensing,photochromism,and energy storage.Finally,the remaining challenges and potential research directions for the future of viologen-based FECDs are addressed.展开更多
A new iodiplumbate/organic hybrid constructed from asymmetric viologen and polyiodides,（PBPY-H2）2[PbI4（I3）2]（1, PBPY = N-（propionate）-4,4？-bipyridinium）, has been synthesized via solvothermal reaction and str...A new iodiplumbate/organic hybrid constructed from asymmetric viologen and polyiodides,（PBPY-H2）2[PbI4（I3）2]（1, PBPY = N-（propionate）-4,4？-bipyridinium）, has been synthesized via solvothermal reaction and structurally determined by X-ray diffraction method. Compound 1 crystallizes in monoclinic system, space group P21/c with Mr = 1936.72, a = 11.622（2）, b = 14.839（3）, c = 13.372（2）A^°, β = 109.447（3）°, V = 2174.6（7）A^°^3, Z = 2, Dc = 2.958 g/cm^3, F（000） = 1712, μ（Mo Kα） = 11.011 mm^–1, the final R = 0.0389 and wR = 0.0854 for 3866 observed reflections with I 〉 2σ（I）. [Pb I4（I3）2]^4-mononuclear cluster of 1 features a seldom example of coordinated I-3 donors for the lead center. Intermolecular hydrogen bonds between [Pb I4＋4（I3）2]^4-clusters and（PBPY-H）2^4＋ dimmers contribute to the formation of a 2-D layer. Its absorption spectrum was investigated, and lower energy band gap of 1.42 eV was explained by DFT calculation. Interestingly, 1 exhibits photocatalytic activity for the degradation of rhodamine B.展开更多
Recently,increasing atte ntion has been paid on extending theπ-conjugation structures ofviologens(1,1’-disubstituted-4,4’-bipyridylium salts)by incorporating planar aromatic units into the bipyridinium backbones.Va...Recently,increasing atte ntion has been paid on extending theπ-conjugation structures ofviologens(1,1’-disubstituted-4,4’-bipyridylium salts)by incorporating planar aromatic units into the bipyridinium backbones.Various viologen derivative s with extendedπ-conjugation structures have been synthesized,including the N-termini aromatic substituted viologens,the extendedπ-conjugated viologens(denoted as ECVs)as well as theπ-conjugated oligomeric viologens(denoted as COVs).These compounds typically exhibit interesting properties distinguished from those of an isolated viologen unit,which make them as new class of electron deficient supra-/molecular building blocks in supramolecular chemistry and materials science.In this review,we would like to highlight the recent advances of viologen derivatives with extendedπ-conjugation structures in versatile applications ranging from electrochromic and energy storage materials,the ECV/COV-based supramolecular self-assembly systems including the linear supramolecular polymers and 2D/3D supramolecular organic frameworks(SOFs),to the viologen-based covalent organic frameworks(COFs)/networks.We hope this review will serve as an in-time summary worthy of referring,more importantly,to provide inspiration in the rational design of novel molecules with unexplored properties and functions.展开更多
Compound 1 bearing urea and viologen groups has been designed and synthesized.It could be used as a colorimetric receptor for dicarboxylate anions due to the significant color changes of the solution upon the addition...Compound 1 bearing urea and viologen groups has been designed and synthesized.It could be used as a colorimetric receptor for dicarboxylate anions due to the significant color changes of the solution upon the addition of dicarboxylates.More importantly,the color changes were related to the chain lengths of the dicarboxylates tested.UV-vis,＇H NMR and HRMS studies demonstrated that receptor 1 utilized hydrogen bonds and electrostatic interactions to form 1：1 stoichiometry complexes with these anions.In addition,the generation of cation radical 1＇ during the complexation process was also detected by EPR.展开更多
Viologens (<i>N,N'</i>-dimethyl-4,4-bipyridinium) are advanced functional materials, found important applications in electrochromic devices, molecular machines, organic batteries, and carbohydrate oxid...Viologens (<i>N,N'</i>-dimethyl-4,4-bipyridinium) are advanced functional materials, found important applications in electrochromic devices, molecular machines, organic batteries, and carbohydrate oxidation catalysts in alkaline fuel. In this article, we investigated the design, synthesis and photophysical properties of <i>N,N'</i>-dimethyl-2,5-Bis(pyridinium)oxadiazole <b>4</b> and its precursor 2,5- Bis(pyridine)oxadiazole<b> 2</b>. The crystal structure and photophysical properties of viologen <b>4</b> and precursor <b>2</b> have been determined. The viologen molecule <b>4</b> crystallized in monoclinic form, space group <i>P</i>2<sub>1</sub>/<i>n</i> with four molecules in unit cell. Precursor molecule <b>2</b> also crystalized in monoclinic form, space group <i>C</i>2/<i>c</i> with four molecules in unit cell. From X-rd data, we found three cations in the molecular structure of viologen molecule <b>4</b>, which is unusual in viologens. In the three-dimensional molecular packing diagram of molecule <b>4</b>, the three cations and iodate anions are stabilized by C···C, C···I, N···I, N···H, H···I, N—H···I and C—H···I. The dihedral angle between planes having oxadiazole and two benzene rings are 5°and 8°, suggesting the molecule <b>4</b> is a slightly strained one. The molecular structure of precursor molecule <b>2</b> stabilized by C···C and N···H short contacts between the molecules. The molecule <b>4</b> displayed strong absorbance at 315 nm and emissions between 390 - 410 nm.展开更多
In order to achieve monodisperse particles with high content of antibacterial groups covalently bonded on surface, a bicationie viologen, N-hexyl-N-（4-vinylbenzyl）-4,4＇-bipyridinium bromide chloride （HVV） was dev...In order to achieve monodisperse particles with high content of antibacterial groups covalently bonded on surface, a bicationie viologen, N-hexyl-N-（4-vinylbenzyl）-4,4＇-bipyridinium bromide chloride （HVV） was devised as a surfrner in dispersion polymerization of styrene （St） using a mixture of methanol （or ethylene glycol） and water as media. Effects of content of HVV, its addition profile and composition of reaction media on particles size and incorporation of HVV moieties were mainly investigated. The attachment of silver and gold nanoparticles on particle surface under UV irradiation ascertained the surface-bonded HVV segments. SEM, TEM observations and XPS, zata potential measurements indicated that increase of initial HVV contents and addition of HVV （when polymerization had been performed for 3 h） led to grown particles and enhanced immobilization of HVV moieties. Using a mixture of ethylene glycol and water as reaction media, small particles （520-142 nm） with highly attached HVV moieties were prepared. Furthermore, antibacterial efficacy of the resultant particles against S. aureus was assayed, and particles with more HVV moieties anchored on surface demonstrated greater efficiency of antibacterial activity.展开更多
Two highly emissive pyrenoviologen derivatives were synthesized and used to fabricate fluorescent sensors for detection of picric acid(PA)with good sensitivity and selectivity.The sensitivity of the sensor was attribu...Two highly emissive pyrenoviologen derivatives were synthesized and used to fabricate fluorescent sensors for detection of picric acid(PA)with good sensitivity and selectivity.The sensitivity of the sensor was attributed to the specific electrostatic association effect of the cationic pyrenoviologens to the picrate anions,which also gave the sensor special selectivity among other compounds with similar structure.The electron transfer between them was attributed to the fluorescence response.Fluorescence lifetime measurements revealed that the quenching is static in nature.The novel and efficient pyrenoviologen derivatives-based sensors offered a strategy to fabricate real-life PA sensor.展开更多
A series of acrylic ester copolymers with viologen group as pendant were synthesizedthrough the reaction of MMA-EBA (Ethenyl bromoacetate) copolymer with 4-(4'-pyridyl)-N-alkyl (or arylalkyl) pyridiniums. These vi...A series of acrylic ester copolymers with viologen group as pendant were synthesizedthrough the reaction of MMA-EBA (Ethenyl bromoacetate) copolymer with 4-(4'-pyridyl)-N-alkyl (or arylalkyl) pyridiniums. These viologen copolymers can exchange their anionwith NH_4PF_6 in methanol to improve their solubility in organic solvents such as DMFand acetone. Compared with the corresponding low molecular viologens, these viologencopolymers have relatively lower color development rate under UV light and fade fasterin air due to less affinity to photo-reductant and deficiency of association between theircation radicals. Their photofatigue resistant ability is also slightly better than that of lowmolecular vinlogens.展开更多
Methyl viologen （MV） as a bench-mark anolyte material has been frequently applied in aqueous organic redox flow batteries （AORFBs） towards large-scale renewable energy storage. However, only the first re- duction ...Methyl viologen （MV） as a bench-mark anolyte material has been frequently applied in aqueous organic redox flow batteries （AORFBs） towards large-scale renewable energy storage. However, only the first re- duction of MV was utilized in aqueous electrolytes because of the insoluble MV0generated from the second reduction of MV. Herein, we report that methyl viologen with bis（trifluoromethane）sulfonamide counter anion, MVTFSI, can achieve two reversible reductions in a nonaqueous supporting elec- trolyte. Paired with （Ferrocenylmethyl）trimethylammonium bis（trifluoromethanesulfonyl）imide, FcNFFSI, as catholyte, the MVTFS/FcNTFSI nonaqueous organic redox flow battery （NOARFB） can take advantage of either one electron or two electron storage of the methyl viologen moiety and provide theoretical energy density of 24.9Wh/L and a cell voltage of up to 1.5V. Using a highly conductive LiTFSI/CH_3CN supporting electrolyte and a porous Daramic separator, the NOARFB displayed excellent cycling performance, includ- ing up to a 68.3g energy efficiency at 40 mA/cm2, and more than 88g total capacity retention after 100 cycles.展开更多
Abstract: : The substituted nitroarenes were reduced effectively to the corresponding aniline deriva tives by an insoluble resin with viologen structure as an electron-transfer catalyst(ETC) in dichloromethane-resin...Abstract: : The substituted nitroarenes were reduced effectively to the corresponding aniline deriva tives by an insoluble resin with viologen structure as an electron-transfer catalyst(ETC) in dichloromethane-resin-water -three-phase system.展开更多
A new copper iodide/organic hybrid incorporated with methyl viologen, [（MV）（Cu2I4）·H2O]n（1, MV = methyl viologen）, has been solvothermally synthesized and structurally determined by X-ray diffraction method...A new copper iodide/organic hybrid incorporated with methyl viologen, [（MV）（Cu2I4）·H2O]n（1, MV = methyl viologen）, has been solvothermally synthesized and structurally determined by X-ray diffraction method. 1 crystallizes in tetragonal system, space group P42212 with Mr = 838.95, a = 12.4721（18）, c = 6.5892（13A, V = 1025.0（3） A3, Z = 2, Dc = 2.7125 g/cm3, F（000） = 756, μ（Mo Kα） = 8.097 mm–1, the final R = 0.0273 and wR = 0.0665 for 1062 observed reflections with I 〉 2σ（I）. In 1, the（Cu2I4）n2n- chain was constructed from edge-sharing of distorted Cu I4 tetrahedra. Its absorption spectrum and photoluminescence were investigated, and energy band gap of 1.76 e V indicates its semiconductor nature. Interestingly, 1 exhibits photocatalytic activity for the degradation of rhodamine B.展开更多
Porphyrins and methyl viologen(MV;) are widely used as a photosensitizer and an electron acceptor respectively in photoinduced electron transfer systems. Literatures covered numerous examples of photochemical studies ...Porphyrins and methyl viologen(MV;) are widely used as a photosensitizer and an electron acceptor respectively in photoinduced electron transfer systems. Literatures covered numerous examples of photochemical studies of porphyrins covalently linked to various electron acceptor units, such as viologen, which functioned as both a photosensitizer and an electron acceptor in the same molecule. However, the length of the linked chain between porphyrin and viologen is very important. To improve the rate of photoin-展开更多
Developing efficient photosensitizers for C-P bond construction is highly important and remains a challenge due to the urgently needed for the synthesis of modified nucleosides,nucleotides,and other phosphine-containi...Developing efficient photosensitizers for C-P bond construction is highly important and remains a challenge due to the urgently needed for the synthesis of modified nucleosides,nucleotides,and other phosphine-containing ligands.Herein,two pyrene-tethered bismoviologen derivatives(Py-BiV^(2+))were designed and synthesized for visible-light-induced C-P bonds formation.The photochemical and electrochemical properties of Py-BiV^(2+)were studied systemically,certifying fine-tunable opto-electronic properties through the number of pyrene groups(4,n=1;6,n=2).The prepared Py-BiV^(2+)showed strong light absorption,while retaining good redox features and chromic response features that were inherent to viologens.4 exhibited accelerated photoinduced electron transfer in the presence of the electron donor(pyrene)and the generated 4(radical cation)showed higher stability.Accordingly,Py-BiV^(2+)directly served as photosensitizers for the first time in the visible-light-induced C(sp^(3))-P and C(sp^(2))-P bonds formation.As expected,these novel viologen derivatives exhibited good catalytic performance and good substrate expansibility under ambient conditions.展开更多
By introducing a host molecule cucurbit[8]uril(CB[8]) into a charge transfer system containing an amphiphile 1-[11-(naphthalene-2-ylmethoxy)-11-oxoundecyl]pyridinium(NP) and an electron-deficient molecule methyl violo...By introducing a host molecule cucurbit[8]uril(CB[8]) into a charge transfer system containing an amphiphile 1-[11-(naphthalene-2-ylmethoxy)-11-oxoundecyl]pyridinium(NP) and an electron-deficient molecule methyl viologen(MV), a novel and anisotropic ternary building block was constructed by hostvip interactions, thereby leading to the morphology transformation of the final assemblies from thinfilms(NP/MV complexes) into diamond-like structures(NP/MV/CB[8] complexes). These intriguing assemblies were firstly discovered and were similar with the shape of well-known metal organic frameworks(MOFs), but just comprised three small organic molecules without metal ions. This finding can enrich the shape of current supramolecular assemblies and thus contributing to more potential applications in material science.展开更多
Redox-flow batteries(RFBs)are a promising energy storage technology with remarkable scalability and safety for storing vast amounts of renewable energy and mitigating outputfluctuations of renewable power grids.We demon...Redox-flow batteries(RFBs)are a promising energy storage technology with remarkable scalability and safety for storing vast amounts of renewable energy and mitigating outputfluctuations of renewable power grids.We demonstrate a neutral pH aqueous RFB using a custom-designed 1’,1’’’,1’’’’’-(benzene-1,3,5-triyltris(methylene))tris(1-(3-(trimethyl ammonio)propyl)-[4’’,4’’’-bipyridine]-1,1’-diium)nonachloride(BTTMPB)as a 3 e-storage anolyte.The custom design with the high polarization in charge density has led to the excellent water solubility of 4.0 M in H_(2)O(321.6 A h L^(-1))and 2.4 M in 2.0 M NaCl(192.9 A h L^(-1)).The density functional theory(DFT)calculations and electrochemical experiments have shown 3 e-storage response of BTTMPB with a diffusion coefficient of 3.1×10^(-6)cm^(2) s^(-1)and rate con-stant of 1.6×10^(-2)cm s^(-1) for thefirst reduction process.The synthesized anolyte was paired with(Ferrocenylmethyl)trimethylammonium chloride(FcNCl)as catholyte enabling a 0.92 V aqueous RFB with 125.9 W h L^(-1)theoretical energy density.The aqueous RFB has an excellent cycling performance from 10-30 m A cm^(-2),energy efficiency up to 80%,capacity retention of 99.96%per cycle at 20 m A cm^(-2),and a high demonstrated energy density of 29.1 W h L^(-1).展开更多
文摘Under the condition of solvothermal synthesis,the viologen ligand 1,1′-bis(3-carboxyphenyl)-(4,4′-bipyri-dine)dichloride(H_(2)bcbpy·2Cl)and KI are coordinated with the metal cadmium ions.A case of thermochromic coor-dination polymer[Cd(bcbpy)I_(2)]·2H_(2)O(1)was constructed.Complex 1 displays a 1D chain structure and exhibits thermochromic behavior.Under different temperature stimulation,the complex(ground)slowly changed from green to yellow-green,and with the increase of temperature,the color of complex 1 gradually deepened,and finally became orange-yellow.Therefore,complex 1 was prepared as a thermochromic film.In addition,we also performed electrochemical tests on complex 1,which showed that the complex is a semiconductor material.CCDC:2391802.
基金supported by the Shaanxi Province Technological Innovation Guidance Special(No.2022QFY08-01)the National Key Research and Development Program of China(No.2021YFB3200702)+5 种基金Natural Science Foundation of China(Nos.22201228,22205172,52203240 and 22175138)China Postdoctoral Science Foundation(Nos.2022M712530,2023T160506,and 2022M712497)Fundamental Research Funds for the Central Universities(No.xzy012022017)Young Talent Fund of Association for Science and Technology in Shaanxi(No.20230624)Shaanxi Province Postdoctoral Science Foundation(No.2023b SHTBZZ04)the Youth Innovation Team of Shaanxi Universities。
文摘π-Conjugated donor-acceptor-donor-acceptor-donor(D-A-D-A-D)type pyrenoviologens(PyV^(2+)),with the 2,7 positions of pyrene serving as connection bridges,were synthesized through SN2 reactions.Specifically,pyrenoviologen 3c was modified with a methylnaphthalene group,while 3a and 3b were modified with methyl and benzyl groups,respectively,for comparison.These pyrenoviologens exhibit reversible redox properties and strong fluorescence emission.Electrochromic devices(ECDs)were prepared using pyrenoviologens as the active materials.Notably,naphthalene-containing pyrenoviologen 3c,with its DA-D-A-D conjugated structure,possesses more stable free radicals,enabling it to maintain the radical color for a longer duration after power loss.A series of color-changing devices were successfully assembled.Due to the strong fluorescence of pyrenoviologens and the unique electron transfer effect between them and picric acid(PA),a sensor film with good selectivity and high sensitivity for PA in aqueous solution was prepared using pyrenoviologens as the fluorescent probe.Specifically,3c exhibited the highest sensitivity to PA due to its lowest energy gap.The introduction of the D-A-D-A-D structure is a strategic approach to enhancing photoelectric performance and broadening the application of viologens.
基金financially supported by the National Natural Science Foundation of China (Nos.22271021,21901018 and 21971024)the Natural Science Foundation of Liaoning Province (No.2022-MS-373)Liaoning Revitalization Talents Program (No.XLYC1902011)。
文摘The design and synthesis of catalysts for the oxidation desulfurization and production of hydrogen are extremely important for solving environmental pollution and energy shortage.Herein,a novel bifunctional [α-Mo_(8)O_(26)]^(4-)/[β-Mo_(8)O_(26)]^(4-)-based Cu-viologen complex H_(4)[Cu_(2)~ⅠCl_(2)(Hbcbpy)_(4)] [α-Mo_(8)O_(26)] [β-Mo8O_(26)]·H_(2)O(BHU-2,Hbcbpy=1-(4-carboxybenzyl)-4,4'-bipyridinium) was synthesized and characterized by single-crystal X-ray diffraction(XRD),infrared radiation spectra,powder X-ray diffraction(PXRD) and X-ray photoelectron spectroscopy(XPS) spectra.The structural characteristic of BHU-2 is the presence of two types of octamolybdate clusters [α-Mo_(8)O_(26)]^(4-)/[β-Mo_(8)O_(26)]^(4-)and a new binuclear Cu~Ⅰ-Hbcbpy complex linked by Cl-bridges[Cu_(2)ⅠCl_(2)(Hbcbpy)_(4)]^(4+).BHU-2 as a heterogeneous catalyst exhibits excellent activities to the oxidation desulfurization and photocatalytic hydrogen production.At room temperature,BHU-2 can catalyze 96% conversion of methyl phenyl sulfide with 98% selectivity,and the process obeys the pseudo-first-order reaction kinetic with the half-life of9.6 min.The notorious 2-chloroethyl ethyl sulfide can achieve 99% conversion with 98% selectivity within only1 min at the presence of BHU-2,and the turnover frequency(TOF) is up to 7400 h^(-1).BHU-2 also exhibits high catalytic activity for the oxidation of other aromatic and aliphatic thioethers within short time at room temperature.Furthermore,BHU-2 shows a high catalytic activity for visible-light-driven hydrogen evolution with an H_(2) evolution rate of 1677.85 μmol·g^(-1)·h^(-1) within 10 h.Moreover,the catalytic activities do not decrease evidently after three cycles,revealing the prominent structural stability and recyclability.
基金financial support by the National Key Research and Development Program of Ministry of Science and Technology(No.2021YFB3801604)the National Natural Science Foundation(Nos.22073102,21827813,21921001)of China。
文摘Direct X-ray detectors,which directly convert X-rays into electrical signals through semiconductors,have higher space solution than scintillator-mediated indirect X-ray ones and are high desirable for early cancer detection and other applications,but the mainstream commercialα-Se detector is still largely limited by high production costs,large leakage current and low stability.This article reports an easily prepared,stable radiochromic semiconductive metal–organic framework(MOF),(MV)[Cd_(3)(tdc)_(4)]·2H_(2)O(RCS-1,H_(2)tdc=2,5-thiophenedicarboxylic acid;MV^(2+)=methyl viologen cation)with direct X-ray detecting ability.With a large bulk resistivity of 8.40×10^(9)Ωcm,this material ensures minimal dark current and low noise for X-ray detection.Additionally,it exhibits higher sensitivity to W KαX-rays(98.58μC Gy^(-1)cm^(-2))thanα-Se(~20μC Gy^(-1)cm^(-2)).Meanwhile,unlike most reported direct X-ray detecting semiconductors,compound RCS-1 shows remarkable color change upon X-ray irradiation owing to the presence of photochromism-active viologen cations.This feature offers an appealing visual detecting ability to direct X-ray detectors that provide only the electrical signals.
基金jointly supported by the Guangdong Major Project of Basic and Applied Basic Research (2023B0303000002)National Natural Science Foundation of China (22178126,22325802,U22A20417,22208110)+3 种基金Guangdong Basic and Applied Basic Research Foundation (2023B1515120005)Science and Technology Program of Guangzhou (2023B03J1281,2023A04J1357)China Postdoctoral Science Foundation (2023T160223)the State Key Laboratory of Pulp and Paper Engineering (2023ZD03)。
文摘Viologens known as a kind of promising negolyte materials for aqueous organic redox flow batteries,face a critical stability challenge due to the S_N2 nucleophilic attack by hydroxide ions(OH-)during the battery cycling.In this work,a N-cyclic quaternary ammonium-grafted viologen molecule,viz.1,1'-bis(4,4'-dime thylpiperidiniumyl)-4,4'-bipyridinium tetrachloride((DBPPy)Cl_(4)),is developed by the molecular engineering strategy.The obtained(DBPPy)Cl_(4) molecule shows a decent solubility of 1.84 M and a redox potential of-0.52 V vs.Ag/AgCl,Experimental and theoretical results reveal that the grafted N-cyclic quaternary ammonium groups act as the steric hindrance to prevent nucleophilic attack by OH~-,increasing the alkali resistance of the electroactive molecule.The symmetrical battery with 0.50 M(DBPPy)Cl4shows negligible decay during the 13-day cycling test.As demonstration,the flow battery utilizing 1.0 M(DBPPy)Cl_(4) as the negolyte and 1-(1-oxyl-2,2',6,6'-tetramethylpiperidin-4-yl)-1'-(3-(trimethylammonio)propyl)-4,4'-bipyridinium trichloride as the posolyte exhibits a high capacity retention rate of 99.99%per cycle at 60 mA cm^(-2).
基金financial support from the National Natural Science Foundation of China(22105106)the Natural Science Foundation of Jiangsu Province of China(BK20210603)+1 种基金the Nanjing Science and Technology Innovation Project for overseas Students(NJKCZYZZ2022–05)the Start-up Funding from NUPTSF(NY221003)。
文摘Electrochromic technology has gained significant attention in various fields such as displays,smart windows,biomedical monitoring,military camouflage,human-machine interaction,and electronic skin due to its ability to provide reversible and fast color changes under applied voltage.With the rapid development and increasing demand for flexible electronics,flexible electrochromic devices(FECDs)that offer smarter and more controllable light modulation hold great promise for practical applications.The electrochromic material(ECM)undergoing color changes during the electrochemical reactions is one of the key components in electrochromic devices.Among the ECMs,viologens,a family of organic small molecules with 1,1'-disubstituted-4,4'-dipyridinium salts,have garnered extensive research interest,due to their well-reversible redox reactions,excellent electron acceptance ability,and the ability to produce multiple colors.Notably,viologen-based FECDs demonstrate color changes in the liquid or semisolid electrolyte layer,eliminating the need for two solid electrodes and thus simplifying the device structure.Consequently,viologens offer significant potential for the development of FECDs with high optical contrast,fast response speed,and excellent stability.This review aims to provide a comprehensive overview of the progress and perspectives of viologen-based FECDs.It begins by summarizing the typical structure and recent exciting developments in viologen-based FECDs,along with their advantages and disadvantages.Furthermore,the review discusses recent advancements in FECDs with additional functionalities such as sensing,photochromism,and energy storage.Finally,the remaining challenges and potential research directions for the future of viologen-based FECDs are addressed.
基金Project supported by the National Natural Science Foundation of China(21271043,21771038)Qishan Scholars Program of Fuzhou University(No.XQS-1403)
文摘A new iodiplumbate/organic hybrid constructed from asymmetric viologen and polyiodides,（PBPY-H2）2[PbI4（I3）2]（1, PBPY = N-（propionate）-4,4？-bipyridinium）, has been synthesized via solvothermal reaction and structurally determined by X-ray diffraction method. Compound 1 crystallizes in monoclinic system, space group P21/c with Mr = 1936.72, a = 11.622（2）, b = 14.839（3）, c = 13.372（2）A^°, β = 109.447（3）°, V = 2174.6（7）A^°^3, Z = 2, Dc = 2.958 g/cm^3, F（000） = 1712, μ（Mo Kα） = 11.011 mm^–1, the final R = 0.0389 and wR = 0.0854 for 3866 observed reflections with I 〉 2σ（I）. [Pb I4（I3）2]^4-mononuclear cluster of 1 features a seldom example of coordinated I-3 donors for the lead center. Intermolecular hydrogen bonds between [Pb I4＋4（I3）2]^4-clusters and（PBPY-H）2^4＋ dimmers contribute to the formation of a 2-D layer. Its absorption spectrum was investigated, and lower energy band gap of 1.42 eV was explained by DFT calculation. Interestingly, 1 exhibits photocatalytic activity for the degradation of rhodamine B.
基金the Natural Science Foundation of Zhejiang Province(No.LY20B020005)Shanghai Scientific and Technological Innovation Project(No.18JC1410600)for the financial support。
文摘Recently,increasing atte ntion has been paid on extending theπ-conjugation structures ofviologens(1,1’-disubstituted-4,4’-bipyridylium salts)by incorporating planar aromatic units into the bipyridinium backbones.Various viologen derivative s with extendedπ-conjugation structures have been synthesized,including the N-termini aromatic substituted viologens,the extendedπ-conjugated viologens(denoted as ECVs)as well as theπ-conjugated oligomeric viologens(denoted as COVs).These compounds typically exhibit interesting properties distinguished from those of an isolated viologen unit,which make them as new class of electron deficient supra-/molecular building blocks in supramolecular chemistry and materials science.In this review,we would like to highlight the recent advances of viologen derivatives with extendedπ-conjugation structures in versatile applications ranging from electrochromic and energy storage materials,the ECV/COV-based supramolecular self-assembly systems including the linear supramolecular polymers and 2D/3D supramolecular organic frameworks(SOFs),to the viologen-based covalent organic frameworks(COFs)/networks.We hope this review will serve as an in-time summary worthy of referring,more importantly,to provide inspiration in the rational design of novel molecules with unexplored properties and functions.
基金the financial support from the National Natural Science Foundation of China(No.21072061)Shanghai Leading Academic Discipline Project(No.B409)
文摘Compound 1 bearing urea and viologen groups has been designed and synthesized.It could be used as a colorimetric receptor for dicarboxylate anions due to the significant color changes of the solution upon the addition of dicarboxylates.More importantly,the color changes were related to the chain lengths of the dicarboxylates tested.UV-vis,＇H NMR and HRMS studies demonstrated that receptor 1 utilized hydrogen bonds and electrostatic interactions to form 1：1 stoichiometry complexes with these anions.In addition,the generation of cation radical 1＇ during the complexation process was also detected by EPR.
文摘Viologens (<i>N,N'</i>-dimethyl-4,4-bipyridinium) are advanced functional materials, found important applications in electrochromic devices, molecular machines, organic batteries, and carbohydrate oxidation catalysts in alkaline fuel. In this article, we investigated the design, synthesis and photophysical properties of <i>N,N'</i>-dimethyl-2,5-Bis(pyridinium)oxadiazole <b>4</b> and its precursor 2,5- Bis(pyridine)oxadiazole<b> 2</b>. The crystal structure and photophysical properties of viologen <b>4</b> and precursor <b>2</b> have been determined. The viologen molecule <b>4</b> crystallized in monoclinic form, space group <i>P</i>2<sub>1</sub>/<i>n</i> with four molecules in unit cell. Precursor molecule <b>2</b> also crystalized in monoclinic form, space group <i>C</i>2/<i>c</i> with four molecules in unit cell. From X-rd data, we found three cations in the molecular structure of viologen molecule <b>4</b>, which is unusual in viologens. In the three-dimensional molecular packing diagram of molecule <b>4</b>, the three cations and iodate anions are stabilized by C···C, C···I, N···I, N···H, H···I, N—H···I and C—H···I. The dihedral angle between planes having oxadiazole and two benzene rings are 5°and 8°, suggesting the molecule <b>4</b> is a slightly strained one. The molecular structure of precursor molecule <b>2</b> stabilized by C···C and N···H short contacts between the molecules. The molecule <b>4</b> displayed strong absorbance at 315 nm and emissions between 390 - 410 nm.
基金supported by the National Natural Science Foundation of China(No.20974008)
文摘In order to achieve monodisperse particles with high content of antibacterial groups covalently bonded on surface, a bicationie viologen, N-hexyl-N-（4-vinylbenzyl）-4,4＇-bipyridinium bromide chloride （HVV） was devised as a surfrner in dispersion polymerization of styrene （St） using a mixture of methanol （or ethylene glycol） and water as media. Effects of content of HVV, its addition profile and composition of reaction media on particles size and incorporation of HVV moieties were mainly investigated. The attachment of silver and gold nanoparticles on particle surface under UV irradiation ascertained the surface-bonded HVV segments. SEM, TEM observations and XPS, zata potential measurements indicated that increase of initial HVV contents and addition of HVV （when polymerization had been performed for 3 h） led to grown particles and enhanced immobilization of HVV moieties. Using a mixture of ethylene glycol and water as reaction media, small particles （520-142 nm） with highly attached HVV moieties were prepared. Furthermore, antibacterial efficacy of the resultant particles against S. aureus was assayed, and particles with more HVV moieties anchored on surface demonstrated greater efficiency of antibacterial activity.
基金supported by the National Natural Science Foundation of China(Nos.21603016,21704081,51603016 and21704005)Shaanxi College Students Innovation and Entrepreneurship Training Program(No.S201910710282)
文摘Two highly emissive pyrenoviologen derivatives were synthesized and used to fabricate fluorescent sensors for detection of picric acid(PA)with good sensitivity and selectivity.The sensitivity of the sensor was attributed to the specific electrostatic association effect of the cationic pyrenoviologens to the picrate anions,which also gave the sensor special selectivity among other compounds with similar structure.The electron transfer between them was attributed to the fluorescence response.Fluorescence lifetime measurements revealed that the quenching is static in nature.The novel and efficient pyrenoviologen derivatives-based sensors offered a strategy to fabricate real-life PA sensor.
基金This work is supported by the National Natural Science Foundation of China.
文摘A series of acrylic ester copolymers with viologen group as pendant were synthesizedthrough the reaction of MMA-EBA (Ethenyl bromoacetate) copolymer with 4-(4'-pyridyl)-N-alkyl (or arylalkyl) pyridiniums. These viologen copolymers can exchange their anionwith NH_4PF_6 in methanol to improve their solubility in organic solvents such as DMFand acetone. Compared with the corresponding low molecular viologens, these viologencopolymers have relatively lower color development rate under UV light and fade fasterin air due to less affinity to photo-reductant and deficiency of association between theircation radicals. Their photofatigue resistant ability is also slightly better than that of lowmolecular vinlogens.
基金Utah State University for providing faculty startup fundsthe Utah Science Technology and Research initiative (USTAR) UTAG award for supporting this study+1 种基金China CSC Study Abroad programUtah Energy Triangle Student Award for supporting his graduate program
文摘Methyl viologen （MV） as a bench-mark anolyte material has been frequently applied in aqueous organic redox flow batteries （AORFBs） towards large-scale renewable energy storage. However, only the first re- duction of MV was utilized in aqueous electrolytes because of the insoluble MV0generated from the second reduction of MV. Herein, we report that methyl viologen with bis（trifluoromethane）sulfonamide counter anion, MVTFSI, can achieve two reversible reductions in a nonaqueous supporting elec- trolyte. Paired with （Ferrocenylmethyl）trimethylammonium bis（trifluoromethanesulfonyl）imide, FcNFFSI, as catholyte, the MVTFS/FcNTFSI nonaqueous organic redox flow battery （NOARFB） can take advantage of either one electron or two electron storage of the methyl viologen moiety and provide theoretical energy density of 24.9Wh/L and a cell voltage of up to 1.5V. Using a highly conductive LiTFSI/CH_3CN supporting electrolyte and a porous Daramic separator, the NOARFB displayed excellent cycling performance, includ- ing up to a 68.3g energy efficiency at 40 mA/cm2, and more than 88g total capacity retention after 100 cycles.
文摘Abstract: : The substituted nitroarenes were reduced effectively to the corresponding aniline deriva tives by an insoluble resin with viologen structure as an electron-transfer catalyst(ETC) in dichloromethane-resin-water -three-phase system.
文摘A new copper iodide/organic hybrid incorporated with methyl viologen, [（MV）（Cu2I4）·H2O]n（1, MV = methyl viologen）, has been solvothermally synthesized and structurally determined by X-ray diffraction method. 1 crystallizes in tetragonal system, space group P42212 with Mr = 838.95, a = 12.4721（18）, c = 6.5892（13A, V = 1025.0（3） A3, Z = 2, Dc = 2.7125 g/cm3, F（000） = 756, μ（Mo Kα） = 8.097 mm–1, the final R = 0.0273 and wR = 0.0665 for 1062 observed reflections with I 〉 2σ（I）. In 1, the（Cu2I4）n2n- chain was constructed from edge-sharing of distorted Cu I4 tetrahedra. Its absorption spectrum and photoluminescence were investigated, and energy band gap of 1.76 e V indicates its semiconductor nature. Interestingly, 1 exhibits photocatalytic activity for the degradation of rhodamine B.
基金Supported by the National Natural Science Foundation of China
文摘Porphyrins and methyl viologen(MV;) are widely used as a photosensitizer and an electron acceptor respectively in photoinduced electron transfer systems. Literatures covered numerous examples of photochemical studies of porphyrins covalently linked to various electron acceptor units, such as viologen, which functioned as both a photosensitizer and an electron acceptor in the same molecule. However, the length of the linked chain between porphyrin and viologen is very important. To improve the rate of photoin-
基金supported by the Natural Science Foundation of China(Nos.22175138,21875180)the Key Research and Development Program of Shaanxi(No.2021GXLH-Z023)the Independent Innovation Capability Improvement Project of Xi’an Jiaotong University(No.PY3A066)。
文摘Developing efficient photosensitizers for C-P bond construction is highly important and remains a challenge due to the urgently needed for the synthesis of modified nucleosides,nucleotides,and other phosphine-containing ligands.Herein,two pyrene-tethered bismoviologen derivatives(Py-BiV^(2+))were designed and synthesized for visible-light-induced C-P bonds formation.The photochemical and electrochemical properties of Py-BiV^(2+)were studied systemically,certifying fine-tunable opto-electronic properties through the number of pyrene groups(4,n=1;6,n=2).The prepared Py-BiV^(2+)showed strong light absorption,while retaining good redox features and chromic response features that were inherent to viologens.4 exhibited accelerated photoinduced electron transfer in the presence of the electron donor(pyrene)and the generated 4(radical cation)showed higher stability.Accordingly,Py-BiV^(2+)directly served as photosensitizers for the first time in the visible-light-induced C(sp^(3))-P and C(sp^(2))-P bonds formation.As expected,these novel viologen derivatives exhibited good catalytic performance and good substrate expansibility under ambient conditions.
基金the financial supports from the National Natural Science Foundation of China (Nos. 31860516, 21662009, 21702037)Frontiers Science Center for Asymmetric Synthesis and Medicinal Molecules, Department of Education, Guizhou Province [Qianjiaohe KY No. (2020)004]Program of Introducing Talents of Discipline to Universities of China (111 Program, No. D20023)。
文摘By introducing a host molecule cucurbit[8]uril(CB[8]) into a charge transfer system containing an amphiphile 1-[11-(naphthalene-2-ylmethoxy)-11-oxoundecyl]pyridinium(NP) and an electron-deficient molecule methyl viologen(MV), a novel and anisotropic ternary building block was constructed by hostvip interactions, thereby leading to the morphology transformation of the final assemblies from thinfilms(NP/MV complexes) into diamond-like structures(NP/MV/CB[8] complexes). These intriguing assemblies were firstly discovered and were similar with the shape of well-known metal organic frameworks(MOFs), but just comprised three small organic molecules without metal ions. This finding can enrich the shape of current supramolecular assemblies and thus contributing to more potential applications in material science.
基金the Department of Science and Technology(DST),Ministry of Science and Technology,Government of India,for sponsoring this study under project no.DST/TMD/MES/2k18/02CSIR,Gov.of India,for the Senior Research Fellowship。
文摘Redox-flow batteries(RFBs)are a promising energy storage technology with remarkable scalability and safety for storing vast amounts of renewable energy and mitigating outputfluctuations of renewable power grids.We demonstrate a neutral pH aqueous RFB using a custom-designed 1’,1’’’,1’’’’’-(benzene-1,3,5-triyltris(methylene))tris(1-(3-(trimethyl ammonio)propyl)-[4’’,4’’’-bipyridine]-1,1’-diium)nonachloride(BTTMPB)as a 3 e-storage anolyte.The custom design with the high polarization in charge density has led to the excellent water solubility of 4.0 M in H_(2)O(321.6 A h L^(-1))and 2.4 M in 2.0 M NaCl(192.9 A h L^(-1)).The density functional theory(DFT)calculations and electrochemical experiments have shown 3 e-storage response of BTTMPB with a diffusion coefficient of 3.1×10^(-6)cm^(2) s^(-1)and rate con-stant of 1.6×10^(-2)cm s^(-1) for thefirst reduction process.The synthesized anolyte was paired with(Ferrocenylmethyl)trimethylammonium chloride(FcNCl)as catholyte enabling a 0.92 V aqueous RFB with 125.9 W h L^(-1)theoretical energy density.The aqueous RFB has an excellent cycling performance from 10-30 m A cm^(-2),energy efficiency up to 80%,capacity retention of 99.96%per cycle at 20 m A cm^(-2),and a high demonstrated energy density of 29.1 W h L^(-1).
