Oxygen-evolving Activity in Photosystem II Core Complex of Photosynthetic Membrane in the Presence of Native Lipid

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Efficient Mizoroki–Heck coupling reactions using phosphine-modified Pd(II)–picolinate complex

Efficient Mizoroki–Heck couplings were obtained using a very easily synthesizable palladium(II) complex of hemilabile N–O ligand (picolinate), with high turnover frequencies up to >10,000?h^?1, in just 15?min, with high selectivity of >99% to the desired products. Wide applicability of the simple-looking palladium complex catalyst was established with differently functionalized substrates. Catalyst screening studies revealed intricate details of dependence of catalyst performance on different reaction parameters and conditions and arriving at the optimized facile methodology.     

光系统II(PSII)抑制剂的比较分子场研究

以光系统II抑制剂DISCO(DIStance COmparisons)模型的活性构象分子作为模板,利用比较分子场分析方法对三类结构不同的化合物进行了三维构效关系的研究.研究结果有助于对DISCO重叠模型的评估和新型PSII抑制剂的设计与合成.     

Efficient simultaneous removal of U(VI) and Cu(II) from aqueous solution using core–shell nZVI@SA/CMC-Ca beads

Core–shell nanoscale zero-valent iron@alginate/carboxymethyl cellulose sodium composite loaded with calcium (nZVI@SA/CMC-Ca) beads were synthesized in this study using coaxial electronic injection method. The adsorbent structure was characterized via FT-IR, SEM, EDX and XPS. The adsorption behavior of U(VI) and Cu(II) on core–shell nZVI@SA/CMC-Ca beads was studied under various experimental parameters like pH, contact time and temperature. The isotherm and the kinetic data, pertaining to the adsorption of U(VI) and Cu(II) by core–shell nZVI@SA/CMC-Ca beads obeyed both the Langmuir and Freundlich isotherms model and the pseudo-second-order kinetics model, respectively. The thermodynamic parameters revealed the spontaneous and endothermic nature of the adsorption. The experiment of regeneration and reusability suggested core–shell nZVI@SA/CMC-Ca bead was a regenerated material.     

Zinc(II)–Organic Framework Films with Thermochromic and Solvatochromic Applications

Multiple-stimuli-responsive photoluminescence films based on a Zn^II–organic framework, {[Zn₂(Htpim)(3,4-pydc)₂] ⋅ 4 DMF ⋅ 4 H₂O}_n ( 1 , Htpim=2,4,5-tri(4-pyridyl)imidazole, 3,4-H₂pydc=3,4-pyridinedicarboxylic acid), were fabricated. This compound consisted of a 2D corrugated layer, {Zn(3,4-pydc)}_n, which was further pillared using a Y-shaped pillar N-donor ligand (Htpim) to form a 3D-pillared-layer framework with 1D open channels. The rectangular channels in the as-synthesized compound are fully occupied by guest DMF and H₂O molecules. The framework exhibits instant and reversible thermochromic properties corresponding to the removal of different H₂O and DMF guest molecules as temperature increases. The pale-yellow crystal undergoes significant redshifting to a greenish emission centered at 530 nm. Compound 1 also showed remarkable solvatochromic effects in the presence of various organic solvents without affecting its structural integrity. In addition, polycrystalline MOF films were grown on an α-Al₂O₃ support for switchable and fast-response thermochromic and solvatochromic sensors.     

Suzuki–Miyaura cross-coupling reactions in water using in situ generated palladium(II)–phosphazane complexes

The phosphazane derivatives(L1–3) were readily obtained by reaction of different ratios of PCl3 and PhNH2. The L1–3 derivatives were found to be efficient ligands in the palladium-catalyzed Suzuki C–C coupling reactions in water. It was determined that with the use of L1–3 /Pd(OAc)2 system as a catalyst, aryl halides undergo Suzuki cross-couplings with arylboronic acids to give the desired products in moderate to excellent yields.     

Synthesis of New Ruthenium(II) Bipyridyl Complexes and Studies on Their Photophysical and Photoelectrochemical Properties

IntroductionDye sensitizedsolarcells (DSSC)havebecomethefocusofmanyinvestigationssinceMichaelGr tzelandco workersmadethedyemoleculesadsorbedonaporousnet workoftheinterconnectednanometer sizedcrystallinesofawidebandgapsemiconductor.1 3Animpressivesolar to electricalenergyconversionefficiencyof 10 %hasbeenre portedanditmakespracticalapplicationfeasible .4 Thissystemconsistsofadye coatedsemiconductorelectrodeandacounterelectrodearrangedinasandwichconfigura tionandtheinter electrodespaceisfilled…     

Natriummetaphosphat (I) in Metaphosphors?ure (II)

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Catalytic Friedel–Crafts allylation using Zn(II) triflimidate

The activity of various metallic triflates and triflimidates in the Friedel–Crafts allylation of activated aromatic rings was examined. Zinc bis(trifluoromethylsulfonyl)amide was proved to be a good catalyst in the model reaction with anisole and prenyl acetate. The Friedel–Crafts allylation reaction of various aryl derivatives with allyl acetates was efficiently catalysed under mild conditions, using 3 mol% of Zn(NTf₂)₂ as the catalyst, without solvent, at 100 °C. The desired ortho and para mono-allylated products were selectively obtained in good yields. The para isomer was always favoured.     

Signal-to-noise enhancement using carbon fiber electrodes in the photoelectroanalytical detection of tris(2,2′-bipyridine)ruthenium(II)

Photoelectroanalytical chemistry (PEAC) is a sensitive and selective technique for the detection and quantitation of tris(2,2′-bipyridine)ruthenium(II). Currently, the detection limit of this method is restricted by background photocurrent due to photochemical processes which occur on the electrode surface. Since these processes increase as the illuminated electrode area increases, experiments were carried out using a cylindrical carbon fiber as the working electrode in a non-flowing system. Results were compared to both a glassy carbon and a platinum macroelectrode. Determination of the signal photocurrent density for the fiber electrode showed it to be of the same order of magnitude as the larger electrodes, while the background photocurrent density was more than two orders of magnitude lower than at the larger electrodes. The signal-to-noise ratio for the microelectrode was also much higher than for either macroelectrode. On the basis of these results, a theoretical detection limit of approximately 10⁻⁹M is possible using a carbon fiber electrode in an ordinary (static) electrochemical cell.     

Copper(II)–1,2-bis(thiocarbamoyl)hydrazine and copper(II)–(1-carbamoyl-2-thiocarbamoyl)hydrazine complexing in copper(II)hexacyanoferrate(II) gelatin-immobilized matrix systems

The complex formation that occurs in gelatin-immobilized copper(II)hexacyanoferrate(II) matrices upon contact with aqueous alkaline (pH 12.0) solutions of 1,2-bis(thiocarbamoyl)hydrazine, H₂NC(S)NHNHC(S)NH₂ and 1-carbamoyl-2-(thiocarbamoyl)hydrazine, H₂NC(O)NHNHC(S)NH₂ has been studied. The reaction of each of these ligands with copper(II) is preceded by the destruction of copper(II)hexacyanoferrate(II) in an alkaline medium to form a polymeric copper(II) hydroxide, which is involved in the subsequent copper(II)–ligand complex formation. In both Cu^II–N ligand systems, two complex compounds are formed; the water-insoluble Cu₂B₂(H₂O)₂ dimer and a water-soluble product of tentative composition [CuB(HB)]^– (H₂B=ligand).     

Copper(II)–8-mercaptoquinoline,copper(II)–5,8-dimercaptoquinoline and copper(II)–5-thiomethyl-8-mercaptoquinoline complexing in a copper(II)hexacyanoferrate(II) gelatin-immobilized matrix

Novel complexing processes in the Cu^II–8-mercaptoquinoline, Cu^II–5,8-dimercaptoquinoline and Cu^II–5-thiomethyl-8-mercaptoquinoline systems proceeding in the copper(II)hexacyanoferrate(II) gelatin-immobilized matrix in contact with aqueous solutions of the ligands indicated, have been studied. Under the conditions specified for complexing in the Cu^II–8-mercaptoquinoline system, only a monomeric water-insoluble coordination compound was formed. In the Cu^II–5,8-dimercaptoquinoline system, three coordination compounds were formed and, in the Cu^II–5-thiomethyl-8-mercaptoquinoline system, two such compounds were formed. Conversely, complexing in solution or solid phase results in the formation only coordination compounds in each of the system studied.     

Metal-ligand complexes involved in rheumatoid arthritis—III: Bovine serum albumin -copper(II), -zinc(II) and -lead(II) interactions investigated using potentiometric analysis and molecular filtration

The interactions between BSA and Cu²⁺, Zn²⁺ and Pb²⁺ have been studied in aqueous solution (37°, I = 150 mmol dm⁻³) using potentiometric analysis and molecular filtration. Formation constants for BSA/20-protonation and zinc complexing were determined. The relative binding order for the metal ions studied was Cu > Zn > Pb. The magnitude of the BSA/20-Zn β values were verified by molecular filtration as an independent method.     

Spectrophotometric Simultaneous Determination of Zinc(II), Manganese(II) and Iron(II) in Pharmaceutical Preparations Using OSC-PLS

The purpose of this paper is to develop a fast and sensitive spectrophotometric method for the simultaneous determination of zinc(II), manganese(II) and iron(II) in pharmaceutical preparations. The method presented in this work is based on the well-known reaction of these ions with 4-(pyridylazo)resorcinol (PAR)1. The application of quantitative chemometric methods, particularly PLS to multivariate chemical data is becoming more widespread owing to the availability of digitized spectroscop…     

Soft template synthesis in copper(II)–dithiooxamide–methanal,copper(II)–dithiooxamide–ethanal and copper(II)–dithiooxamide–propanone triple systems in a copper(II)hexacyanoferrate(II) gelatin-immobilized matrix

Novel complexing processes in the Cu^II–dithiooxamide–methanal, Cu^II–dithiooxamide–ethanal and Cu^II–dithiooxamide–propanone triple systems proceeding under specific conditions, to copper(II)hexacyanoferrate(II) gelatin-immobilized matrix systems in contact with aqueous-alkaline (pH 12) solutions containing dithiooxamide and methanal, ethanal or propanone, have been studied. It has been shown that template synthesis leading to the formation of macrocyclic coordination compounds (2,8-dithio-3,7-diaza-5-oxanonandithioamide-1,9)copper(II), (2,8-dithio-3,7-diaza-4,6-dimethyl-5-oxanonandithio-amide-1,9)copper(II) and (4,4,6-trimethyl-2,8-dithio-3,7-diazanonen-6-dithioamide-1,9)copper(II), respectively, takes place under such conditions. Dithiooxamide, methanal, ethanal and propanone act as ligand synthons in these processes.     

Liquid–liquid extraction of mercury(II) from aqueous solution using furosemide in benzyl alcohol

Journal of Radioanalytical and Nuclear Chemistry - A simple, efficient and economical liquid–liquid extraction method has been developed for quantitative extraction of mercury(II) from...     

Sensing amyloid-β aggregation using luminescent dipyridophenazine ruthenium(II) complexes

The aggregation of amyloid-β (Aβ) peptides has been associated with the onset of Alzheimer's disease. Here, we report the use of a luminescent dipyridophenazine ruthenium(II) complex to monitor Aβ fibrillization. This complex is not photoluminescent in aqueous solution nor in the presence of monomeric Aβ, but it presents a strong photoluminescence in the presence of Aβ fibril aggregates. One of the advantages of this metal complex is its large Stokes shift (180 nm). Furthermore, the long-lived photoluminescence lifetime of this ruthenium complex allows its use for the detection of fibrillar proteins in the presence of short-lived fluorescent backgrounds, using time-gating technology. We will present evidence of the advantages of dipyridophenazine ruthenium(II) complexes for monitoring protein fibrillization in highly fluorescent media.     

Rational Stepwise Construction of Different Heterometallic–Organic Frameworks (HMOFs) for Highly Efficient CO2 Conversion

The coordination preference of different metal ions and ligands have an immense influence on the constructions of functional MOF materials. In this work, two new monometallic complexes, namely [Ag(HL)(bipy)_0.5] ( 1 ) and {[Tb(L)_1.5(H₂O)] ⋅ 4 H₂O}_n ( 2 ) (bipy=4,4-bipyridine), have been synthesized successfully by employing a bifunctional 2-(imidazol-1-yl)terephthalic acid (H₂L) ligand. After that, two new different heterometallic–organic frameworks (HMOFs), namely {[TbAg(L)₂(H₂O)₃] ⋅ H₂O}_n ( 3 ) and [TbAg(L)₂(H₂O)]_n ( 4 ), were obtained from complexes 1 and 2 as the precursors based on a rational stepwise construction strategy and the theory of hard and soft acids and bases (HSAB principle), respectively. The HMOFs bearing dual metallic catalytic sites (Tb and Ag) can be used as heterogeneous catalysts without losing performance for the chemical fixation of CO₂ with epoxides including the sterically hindered epoxides, demonstrating some of the highest reported catalytic activity values. This work may provide a new synthetic route toward tailoring new HMOFs with excellent catalytic activity.     

Efficient Conversion of Tetrahydropyranyl (THP) Ethers to Their Corresponding Thiocyanates With in-situ–Generated Ph3P(SCN)2

Immediate and efficient one-pot conversion of tetrahydropyranyl (THP) ethers to their corresponding thiocyanates by in-situ–generated Ph₃P(SCN)₂ is described. Primary and secondary alkyls and also benzylic THP ethers are converted to their corresponding thiocyanates in excellent yields at room temperature by this method.