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1.
Three different mesoporous silica nano‐sized materials ( SC1 , SC2 , and SC3 ), loaded with [Ru(bipy)3]2+ dye (bipy=bipyridine) and functionalized on the external surface with three macrocyclic copper(II) complexes ( C1 , C2 , and C3 ), were synthesized and characterized. When SC1 , SC2 , and SC3 were suspended in water, the entrapped [Ru(bipy)3]2+ dye was free to diffuse from the inner pores to the solution. However, addition of anions induced certain degrees of pore blockage, with subsequent dye release inhibition. Small monovalent and divalent anions were unable to induce complete pore blockage, whereas bulky and highly charged anions induced marked reductions in [Ru(bipy)3]2+ delivery. The best [Ru(bipy)3]2+ delivery inhibitors were ATP and hexametaphosphate anions. Inhibition was ascribed to the interaction of the anions with the grafted CuII complexes on the surface of the SC1 , SC2 , and SC3 supports. The hexametaphosphate anion was selected to prepare two capped materials ( SC1‐mPh and SC3‐mPh ). Studies of the [Ru(bipy)3]2+ dye release from solids SC1‐mPh and SC3‐mPh alone and in the presence of a collection of selected anions (HS?, F?, Br?, Cl?, I?, CN?, HPO42?, AcO?, citrate, NO32?, HCO3?, SO42?, and S2O82?), amino acids (alanine and histidine), thiol‐containing biomolecules (cysteine, methylcysteine, homocysteine, and glutathione (GSH)), and oxidants (H2O2) were performed. None of the chemicals tested, except hydrogen sulphide, was able to induce remarkable cargo delivery in both solids. The observed dye release was ascribed to a demetalation reaction of the C1 and C3 complexes induced by the hydrogen sulphide anion.  相似文献   

2.
We report the preparation of a MCM‐41 mesoporous material that contains the dye [Ru(bipy)3]Cl2 (bipy=bipyridine) inside the mesopores and functionalised with suitable binding groups at the entrance of the pores. Solids S1 – S3 were obtained by the reaction of the mesoporous material with N‐methyl‐N′‐propyltrimethoxysilylimidazolium chloride, N‐phenyl‐N′‐[3‐(trimethoxysilyl)propyl]thiourea, or N‐phenyl‐N′‐[3‐(trimethoxysilyl)propyl]urea, respectively. A study of the dye delivery of these systems in buffered water (pH 7.0, 2‐[4‐(2‐hydroxyethyl)piperazin‐1‐yl]ethanesulfonic acid (HEPES), 10?3 mol dm?3) in the presence of a family of carboxylate ions was carried out. In the interaction of the anions with the surface of the solids, the response depends on the characteristics of the binding groups (i.e., imidazolium, urea and thiourea) at the pore outlets and their specific interaction with the corresponding anion. The interaction of long‐chain carboxylate ions with the binding sites at the surface of the solids resulted in a remarkable inhibition of the delivery of the dye. This inhibition was observed clearly for the dodecanoate anion, whereas the octanoate, decanoate, cholate, deoxycholate, glycodeoxycholate and taurocholate anions induced a certain pore blockage that varied according to the solid studied. The interaction of smaller anions, such as acetate, butanoate, hexanoate and octanoate, with the solids had no effect on the dye release process. The possible use of the gating system for the chromo‐fluorogenic detection of anionic surfactants through selective dye delivery inhibition was also explored. Molecular dynamic simulations that use force‐field methods have been made to theoretically study the capping carboxylate mechanism. The calculations are in agreement with the experimental results, thus allowing a representation of the dye delivery inhibition in the presence of long‐chain carboxylate ions.  相似文献   

3.
Three new hybrid gated mesoporous materials ( SN3‐1 , SNH2‐2 , and SN3‐3 ) loaded with the dye [Ru(bipy)3]2+ (bipy=bipyridine) and capped with different tetrathiafulvalene (TTF) derivatives (having different sizes and shapes and incorporating different numbers of sulfur atoms) have been prepared. The materials SN3‐1 and SN3‐3 are functionalized on their external surfaces with the TTF derivatives 1 and 3 , respectively, which were attached by employing the “click” chemistry reaction, whereas SNH2‐2 incorporates the TTF derivative 2 , which was anchored to the solid through an amidation reaction. The final gated materials have been characterized by standard techniques. Suspensions of these solids in acetonitrile showed “zero release”, most likely because of the formation of dense TTF networks around the pore outlets. The release of the entrapped [Ru(bipy)3]2+ dye from SN3‐1 , SNH2‐2 , and SN3‐3 was studied in the presence of selected explosives (Tetryl, TNT, TNB, DNT, RDX, PETN, PA, and TATP). SNH2‐2 showed a fairly selective response to Tetryl, whereas for SN3‐1 and SN3‐3 dye release was found to occur with Tetryl, TNT, and TNB. The uncapping process in the three materials can be ascribed to the formation of charge‐transfer complexes between the electron‐donating TTF units and the electron‐accepting nitroaromatic explosives. Finally, solids SNH2‐2 and SN3‐1 have been tested for Tetryl detection in soil with good results, pointing toward a possible use of these or similar hybrid capped materials as probes for the selective chromo‐fluorogenic detection of nitroaromatic explosives.  相似文献   

4.
The synthesis and characterization of two new capped silica mesoporous nanoparticles for controlled delivery purposes are described. Capped hybrid systems consist of MCM‐41 nanoparticles functionalized on the outer surface with polymer ε‐poly‐L ‐lysine by two different anchoring strategies. In both cases, nanoparticles were loaded with model dye molecule [Ru(bipy)3]2+. An anchoring strategy involved the random formation of urea bonds by the treatment of propyl isocyanate‐functionalized MCM‐41 nanoparticles with the lysine amino groups located on the ε‐poly‐L ‐lysine backbone (solid Ru‐rLys‐S1 ). The second strategy involved a specific attachment through the carboxyl terminus of the polypeptide with azidopropyl‐functionalized MCM‐41 nanoparticles (solid Ru‐tLys‐S1 ). Once synthesized, both nanoparticles showed a nearly zero cargo release in water due to the coverage of the nanoparticle surface by polymer ε‐poly‐L ‐lysine. In contrast, a remarkable payload delivery was observed in the presence of proteases due to the hydrolysis of the polymer’s amide bonds. Once chemically characterized, studies of the viability and the lysosomal enzyme‐controlled release of the dye in intracellular media were carried out. Finally, the possibility of using these materials as drug‐delivery systems was tested by preparing the corresponding ε‐poly‐L ‐lysine capped mesoporous silica nanoparticles loaded with cytotoxic drug camptothecin (CPT), CPT‐rLys‐S1 and CPT‐tLys‐S1 . Cellular uptake and cell‐death induction were studied. The efficiency of both nanoparticles as new potential platforms for cancer treatment was demonstrated.  相似文献   

5.
Excitation of Ru(bipy)32+ ion by visible radiation of wavelength λ = 436 nm in aqueous medium in presence of inorganic peroxides, peroxomonosulfate (PMS), peroxodisulfate (PDS), and peroxodiphosphate (PDP) was found to generate Ru(bipy)33+. The kinetics of this photochemical oxidation of Ru(bipy)32+ by each peroxide was followed spectrophotometrically and found to obey a total second-order, first-order each in [Ru(bipy)32+] and [peroxide]. In the absence of light, thermal reaction of PMS and PDS with Ru(bipy)32+ occurred but only when at 1.0 M [H+] and > 10?2M [peroxide]. The reaction of PMS with the complex is found to be cyclic, ie., Ru(bipy)33+ formed oxidizes PMS itself and such a reaction was not observed in the case of PDS and PDP. The effects of pH, [peroxide], and [Ru(bipy)32+] on the visible light induced oxidation of Ru(bipy)32+ by these peroxides are investigated. The results are discussed with suitable reaction mechanisms.  相似文献   

6.
RuII compounds have been universally investigated due to their unique physical and chemical properties. In this paper, a new RuII compound based on 2,2′‐bipy and Hpmtz [2,2′‐bipy = 2,2′‐bipyridine, Hpmtz = 5‐(2‐pyrimidyl)‐1H‐tetrazole], namely [Ru(2,2′‐bipy)2(pmtz)][PF6] · 0.5H2O was prepared and characterized by elemental analysis, IR and single‐crystal X‐ray diffraction. [Ru(2,2′‐bipy)2(pmtz)][PF6] · 0.5H2O shows a mononuclear structure and forms a three‐dimensional network by non‐classic hydrogen bonds. The ability of generation of ROS (reactive oxygen species) makes it has a low phototoxicity IC50 (half‐maximal inhibitory concentration) after Xenon lamp irradiation on Hela cells in vitro. The results demonstrate that [Ru(2,2′‐bipy)2(pmtz)][PF6] · 0.5H2O with high light toxicity and low dark toxicity may be a potential candidate for photodynamic therapy.  相似文献   

7.
Light‐driven water splitting was achieved using a dye‐sensitized mesoporous oxide film and the oxidation of bromide (Br?) to bromine (Br2) or tribromide (Br3?). The chemical oxidant (Br2 or Br3?) is formed during illumination at the photoanode and used as a sacrificial oxidant to drive a water oxidation catalyst (WOC), here demonstrated using [Ru(bda)(pic)2], ( 1 ; pic=picoline, bda=2,2′‐bipyridine‐6,6′‐dicarboxylate). The photochemical oxidation of bromide produces a chemical oxidant with a potential of 1.09 V vs. NHE for the Br2/Br? couple or 1.05 V vs. NHE for the Br3?/Br? couple, which is sufficient to drive water oxidation at 1 (RuV/IV≈1.0 V vs. NHE at pH 5.6). At pH 5.6, using a 0.2 m acetate buffer containing 40 mm LiBr and the [Ru(4,4′‐PO3H2‐bpy)(bpy)2]2+ ( RuP 2+, bpy=2,2′‐bipyridine) chromophore dye on a SnO2/TiO2 core–shell electrode resulted in a photocurrent density of around 1.2 mA cm?2 under approximately 1 Sun illumination and a Faradaic efficiency upon addition of 1 of 77 % for oxygen evolution.  相似文献   

8.
A method for the chemical modulation of the photoluminescence of a DNA-bound diruthenium(II) complex, [(bipy)2Ru(bpib)Ru(bipy)2]4+ (bipy = 2,2′-bipyridine, bpib = 1,4-bis([1, 10]phenanthroline [5,6-d]imidazol-2-yl) benzene) by the introduction of Cu2+ ion and EDTA has been developed. The diruthenium(II) complex showed strong photoluminescence both in buffer solutions and on an indium-tin oxide (ITO) surface, which was not modulated by Cu2+ or EDTA. The DNA-bound [(bipy)2Ru(bpib)Ru(bipy)2]4+ with a binding constant of 3.8 × 104 M−1 showed an enhancement in the luminescence based on the electrostatic interaction between the complex and DNA. The presence of Cu2+ was found to quench the luminescence of DNA-bound [(bipy)2Ru(bpib)Ru(bipy)2]4+, but the quenched luminescence was recovered by addition of an equimolar concentration of EDTA. Hence, the photoluminescence of DNA-bound [(bipy)2Ru(bpib)Ru(bipy)2]4+ depends strongly on the introduction of Cu2+ and EDTA.  相似文献   

9.
通过水热合成技术,一个新颖的基于Zn配合物修饰的Keggin型钴钨酸的有机-无机杂化化合物:[Zn(2,2’-bipy)3]3{[Zn(2,2’-bipy)2(H2O)]2 [HCoW12O40] 2 }.H2O已经被合成,化合物通过红外光谱、热重分析和单晶X-射线衍射进行了表征。单晶X-射线衍射的结果显示标题化合物是由一个单支撑的{[Zn(2,2’-bipy)2(H2O)]2 [HCoW12O40] 2}6-多阴离子,三个[Zn(2,2’-bipy)3]2+阳离子和一个水分子构成。有趣的是[Zn(1)(2,2’-bipy)3]2+阳离子通过氢键连接在一起形成螺旋链。另外标题化合物在空气中是稳定的,并且在室温下显示了强的荧光。  相似文献   

10.
The perchlorate salt of the dicationic bipy–ruthenium complex cis‐[Ru(6,6′‐Cl2bipy)2(H2O)2]2+ effectively catalyzes addition of β‐diketones to secondary alcohols and styrenes to yield the α‐alkylated β‐diketones. In a catalytic addition reaction of acetylacetone to 1‐phenylethanol, the κ2‐acetylacetonate complex [Ru(6,6′‐Cl2bipy)2(κ2‐acac)]ClO4 was isolated after the catalysis; this complex is readily synthesized by reacting cis‐[Ru(6,6′‐Cl2bipy)2(H2O)2](ClO4)2 with acetylacetone. [Ru(6,6′‐Cl2bipy)2(κ2‐acac)]ClO4 is unreactive toward 1‐phenylethanol in the presence of HClO4; it also fails to catalyze the addition of acetylacetone to 1‐phenylethanol. On the basis of these observations, it is proposed and confirmed by independent experiments that the catalytic addition of β‐diketones to the secondary alcohols is in fact catalyzed by the Brønsted acid HClO4, which is generated by the reaction of cis‐[Ru(6,6′‐Cl2bipy)2(H2O)2](ClO4)2 with the β‐diketone.  相似文献   

11.
A new strategy of three‐electrode system fabrication in polymer‐based microfluidic systems is described here. Standard lithography, hot embossing and UV‐assisted thermal bonding were employed for fabrication and assembly of the microfluidic chip. For the electrode design the gold working (WE) and counter electrodes (CE) are placed inside a main channel through which the sample solution passes. A silver reference electrode (RE) is embedded in a small side channel containing KCl solution that is continuously pushed into the main channel. In the present work, the overall electrochemical set up and its microfabrication is described. Conditions including silver ion concentration, cyclic voltammetry (CV) settings, and the flow rate of KCl solution in the RE channel were optimized. The electrochemical performance of the three‐electrode system was evaluated by CV and also by amperometric oxidation of ferro hexacyanide ([Fe(CN)6]4?) and ruthenium bipyridyl ([Ru(bipy)3]2+) at 400 mV and 1200 mV, respectively. CV analysis using ferri/ferro hexacyanide showed a stable, quasi‐reversible redox reaction at the electrodes with 96 mV peak separation and an anodic/cathodic peak ratio of 1. Amperometric analysis of the electrochemical species resulted in linear correlation between analyte concentration and current response in the range of 0.5–15 µM for [Fe(CN)6]4?, and 0–1000 µM for [Ru(bipy)3]2+. Upon the given experimental conditions, the limit of detection was found to be 3.15 µM and 24.83 µM for [Fe(CN)6]4? and [Ru(bipy)3]2+, respectively. As a fully integrated three‐electrode system that is fabricated on polymer substrates, it has great applications in microfluidic‐based systems requiring stable electrochemical detection.  相似文献   

12.
1H NMR titration and X-ray diffraction analysis revealed that [Ru(bipy)3]2+ forms an outer-sphere inclusion complex with p-sulfonatothiacalix[4]arene in a ratio of 1: 1 in both aqueous solutions and the solid state. According to cyclic voltammograms and fluorimetric data, the outer-sphere association of [Ru(bipy)3]2+ with p-sulfonatothiacalix[4]arene changes the reversible character of the electrochemical oxidation of [Ru(bipy)3]2+ and lowers its emission intensity. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1863–1870, September, 2008.  相似文献   

13.
Four inorganic‐organic hybrid compounds with the formulae (1,10‐phen)(VO2)(IO3) ( 1 ), (2,2′‐bipy)(VO2)(IO3) ( 2 ), [Cu3(2,2′‐bipy)3Cl3(IO3)2]·I1.5 ( 3 ), and [Cu(2,2′‐bipy)(H2O)(IO3)2]· (H2O)2 ( 4 ) are hydrothermally synthesized at 120 °C for 6 d and characterized by single‐crystal X‐ray diffraction. The use of two different bidentate organodiamine ligands 1,10‐phen and 2,2′‐bipy in the V/I/O system gives rise to compounds 1 and 2 , which crystallize in a monoclinic system with the space group C2/c, a = 17.8131(6) Å, b = 15.0470(7) Å, c = 12.9902(4) Å, β = 133.095(2)°, V = 2542.49(17) Å3 for 1 and space group P21/c, a = 13.3095(5) Å, b = 15.0993(8) Å, c = 13.0454(4) Å, β = 116.971(2)°, V = 2335.88(17) Å3 for 2 . The use of the bidentate organodiamine ligand 2,2′‐bipy in the Cu/I/O system gives rise to the variety in the structure of products 3 and 4 , which crystallize in a triclinic system with the same space group . a = 8.5143(2) Å, b = 10.4908(3) Å, c = 22.8420(6) Å, α = 93.769(10)°, β = 91.723(10)°, γ = 112.111(10)°, V = 1882.83(9) Å3 for 3 and a = 6.731(6) Å, b = 10.110(4) Å, c = 12.899(6) Å, α = 106.00(5)°, β = 95.45(4)°, γ = 107.69(6)°, V = 788.4(9) Å3 for 4 . The solid‐state structures of the compounds 1 and 2 have chains with repeat units of alternative corner sharing of [VO4N2] octahedra and [IO3] pyramids. Compound 3 is a chain containing [IO3] pyramids and [VO4N] square pyramids and compound 4 consists of Cu(2,2′‐bipy)2+ linked by one water molecule and two [IO3] pyramids. The thermal stabilities of the compounds are investigated.  相似文献   

14.
《化学:亚洲杂志》2017,12(20):2670-2674
The development of easy and affordable methods for the detection of cyanide is of great significance due to the high toxicity of this anion and the potential risks associated with its pollution. Herein, optical detection of cyanide in water has been achieved by using a hybrid organic–inorganic nanomaterial. Mesoporous silica nanoparticles were loaded with [Ru(bipy)3]2+, functionalized with macrocyclic nickel(II) complex subunits, and capped with a sterically hindering anion (hexametaphosphate). Cyanide selectively induces demetallation of nickel(II) complexes and the removal of capping anions from the silica surface, allowing the release of the dye and the consequent increase in fluorescence intensity. The response of the capped nanoparticles in aqueous solution is highly selective and sensitive towards cyanide with a limit of detection of 2 μm .  相似文献   

15.
Summary Thermal substitution of chloride in Ru(bipy)2Cl2 · 2H2O with diazadienes (dad) RN=CR-CR=NR yields the mixed [(bipy)2Ru(dad)]2+ complexes, which are analogous to the [Ru(bipy)3]22+ cation. Full n.m.r. assignments are given for several complexes; conformational rigidity is displayed by dad-attached phenyl groups in one of them. The u.v. spectra, which show dad-dependent first c.t.-absorption bands, are compared to that of [Ru(bipy)3]2+.Ruthenium Complexes with Diazadienes. Part I.,Transition Met. Chem., 6, 185 (1981).  相似文献   

16.
An improvement in the photodegradation performance for dyes due to interaction between carbon and titania in a self‐assembled mesoporous C? TiO2 composite catalyst, even for the difficult degradation of azo dyes, is reported herein. The dye removal process involves adsorption of the dye from water by the mesoporous carbon–titania, followed by photodegradation on the separated dye‐loaded solid. Such adsorption–catalysis cycles can be carried out more than 80 times without discernible loss of photocatalytic activity or the anatase content of the composite. In each run, about 120 mg dye per g catalyst can be degraded. The mesoporous carbon–titania catalyst also exhibits a high capacity for converting methyl orange in aqueous solution under visible light. Characterization by XRD, TEM, and N2 sorption techniques has revealed that the self‐assembled composite catalyst has an ordered mesostructure, uniform mesopores (4.3 nm), a large pore volume (0.30 cm3 g?1), and a high surface area (348 m2 g?1). The pore walls are composed of amorphous carbon and anatase nanoparticles of size 4.2 nm, which are well dispersed and confined. X‐ray photoelectron spectroscopy (XPS), surface photovoltage spectroscopy (SPS), and UV/Vis absorption results indicate doping of carbon into the anatase lattice and a change in the bandgap of the semiconductor. The synergistic improvement in the composite catalyst can be attributed to the following features: (1) carbon doping of the anatase lattice modifies its bandgap and enhances its activity under visible light; (2) confinement within carbon pore walls prevents aggregation of tiny anatase nanoparticles, improving their activity and stability; (3) the mesopores provide a confined space for photocatalysis; and (4) the strong adsorption ability of porous carbon for organic substances ensures that large quantities can be processed and inhibits further diffusion of the adsorbed organic substances, thereby enhancing the mineralization on anatase.  相似文献   

17.
Summary The kinetic behaviour of cis-[Ru(bipy)2(H2O)2]2+ towards the anating ligand pyridine-2-aldoxime as a function of temperature, ligand concentration, substrate complex concentration and pH is reported and the rate expression Rate = k 1 k 2[Ru(bipy)2(H2O)2]2+ [LL]/(k -1 + k 2[LL]) is established where k 1 is the water dissociation rate constant for the slow step, k -1 is the rate constant for the aquation, k 2 is the ligand-capturing rate constant of the five-coordinate intermediate [Ru(bipy)2(H2O)]2+ and LL is pyridine-2-aldoxime. The reaction is pH-dependent in the pH range 3.65–5.50. The enthalpy and entropy of activation were obtained using Eyring plots. The results are in conformity with a dissociative mechanism.  相似文献   

18.
The title complex, [CdCl(NCS)(C10H8N2)]n, represents an unusual CdII coordination polymer constructed by two types of anionic bridges and 2,2′‐bipyridyl (bipy) terminal ligands. These two types of bridges are arranged around inversion centers. The distorted octahedral coordination of the CdII center is provided by two chloride ions, one N‐ and one S‐donor atom from two thiocyanate ions, and a pair of N atoms from the chelating bipy ligand. Interestingly, adjacent CdII ions are interconnected alternately by paired chloride [Cd...Cd = 3.916 (1) Å] and thiocyanate bridges [Cd...Cd = 5.936 (1) Å] to generate an infinite one‐dimensional coordination chain. Furthermore, weak interchain C—H...S interactions between the bipy components and thiocyanate ions lead to the formation of a layered supramolecular structure.  相似文献   

19.
A promising alternative strategy for designing mesoporous metal–organic frameworks (MOFs) has been proposed, by modifying the symmetry rather than expanding the length of organic linkers. By means of this approach, a unique MOF material based on the target [Zn8(ad)4] (ad=adeninate) clusters and C3‐symmetric organic linkers can be obtained, with trigonal microporous (ca., 0.8 nm) and hexagonal mesoporous (ca., 3.0 nm) 1D channels. Moreover, the resulting 446‐MOF shows distinct reactivity to transition and lanthanide metal ions. Significantly, the transmetalation of CoII or NiII on the ZnII centers in 446‐MOF can enhance the sorption capacities of CO2 and CH4 (16–21 %), whereas the impregnation of EuIII and TbIII in the channels of 446‐MOF will result in adjustable light‐emitting behaviors.  相似文献   

20.
The crystal structure of the title complex, (η6‐hexamethylbenzene)bis(trifluoromethanesulfonato‐O)(2,4,6‐trimethylanil­ine‐N)ruthenium(II), [Ru(CF3O3S)2(C12H18)(C9H13N)], is described. The complex has the classic three‐legged piano‐stool structure with a planar arene 1.667 Å from the metal, two monodentate O‐bound tri­fluoro­methane­sulfonate ligands [Ru—O 2.169 (2) and 2.174 (2) Å] and one N‐bound mesidine ligand [Ru—N 2.198 (2) Å]. The Ru—N distance is relatively long and the average Ru—O distance is relatively short when compared with previously characterized RuII complexes.  相似文献   

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