Electro‑copolymerized film of ruthenium catalyst and redox mediator for electrocatalytic water oxidation

Electro-copolymerized film containing ruthenium complexes as electron-transfer(or redox)mediators and water-oxidation catalysts by an oxidative copolymerization method is presented.The addition of the redox mediator significantly improved the electrocatalytic water-oxidation activity and reduced the overpotential to 220 mV.The prepared electrode showed a water-oxidation catalytic rate constant kobs of 31.7 s^(-1)and an initial turnover frequency of 1.01 s^(-1)in 1000 s by potential electrolysis at 1.7 V applied bias vs NHE(normal hydrogen electrode).The kinetic isotope effect study suggests that the catalytic water oxidation reaction on the electrode surface occurs via a bimolecular coupling mechanism.

Electronic Structures, DNA-binding, SAR, and Spectral Properties of Ruthenium Methylimidazole Complexes [Ru（MeIm）4L]^2＋（L=iip,tip,2ntz）

Theoretical studies on the electronic and geometric structures, the trend in DNA-binding affinities as well as the the structure-activity relationship （SAR） of a series of water-soluble Ru（II） methylimidazole complexes, i.e. [Ru（Mehn）4iip]^2＋ （1） （MeIm=l-methylimidazole, iip=2-（1H-imidazo-4-group）-lH-imidazo[n,5-f][1,10]phenanthroline）, [Ru（MeIm）4tip]^2＋ （2） （tip=2-（thiophene-2-group）-lH-imidazo[4,5-f] [i,10]phenanthroline）, and [Ru（Melm）42ntz]^2＋ （3） （2ntz=2-（2-nitro-l,3-thiazole-5-group）-lH-imidazo[4,5-f][1,10]phenanthroline）, were car- ried out using the density functional theory （DFT）. The electronic structures of these Ru（II） complexes were analyzed on the basis of their geometric structures optimized in aqueous solution, and the trend in the DNA-binding constants （Kb） was reasonably explained. The results show that the replacement of imidazole ligand by thiophene ligand can effectively improve the DNA-binding affinity of the complex. Meanwhile, it was found that introduc- ing the stronger electronegative N atom and NO2 group on terminal loop of intercalative ligand can obviously reduce the complex＇s LUMO and HOMO-LUMO gap energies. Based on these findings, the designed complex [Ru（MeIm）42ntz]^2＋ （3） can be expected to have the greatest Kb value in complexes 1-3. In addition, the structure-activity relationships and antitumor mechanism were also carefully discussed, and the antimetastatic activity of the designed complex 3 was predicted. Finally, the electronic absorption spectra of this series of complexes in aqueous solution were calculated, simulated and assigned using DFT/TDDFT methods as well as conductor-like polarizable continuum model （CPCM）, and were in good agreement with the experimental results.

Samarium(II) Diiodide Induced Polarity Inversion of π-Allyl Palladium Complexes: The Formation of Allylic Selenides

Allylic acetates were reduced with Pd(0)-SmI2 in the presence of ArSeBr to form corresponding allylic selenides in good yields.

Transformations of biomass-based levulinate ester into γ-valerolactone and pyrrolidones using carbon nanotubes-grafted N-heterocyclic carbene ruthenium complexes

As a renewable biomass-based compound with wide applications in food additives,fine chemical synthesis and fuels,γ-valerolactone(GVL)has attached much attention.While,pyrrolidones are widely used in pharmaceutical,agrochemical,material industrial and other chemical production.In this research,we demonstrated transformations of biomass-based ethyl levulinate(EL)into GVL and pyrrolidones by using heterogeneous catalysts(CNT-Ru-1)with N-heterocyclic carbene ruthenium(NHC-Ru)complex grafted on multi-walled carbon nanotube(CNT).The Ru catalyst showed high efficiency on EL hydrogenation to GVL with both EL conversion and GVL yield exceeding 99%.Moreover,the Ru catalyst readily promoted reductive amination of EL in the presence of various amines for pyrrolidone synthesis.Finally,the Ru catalyst was also applicable to hydrogenation of various carbonyl compounds for the synthesis of the corresponding alcohols with excellent catalytic performance.The research provides insight for heterogenizing the homogeneous noble metal-based catalysts with high catalytic active for biomass-based transformations.

Oxidation of Alcohols Catalyzed by Ruthenium Complexes with Iodosylbenzene as Oxidant

Five ruthenium complexes such as Phen-Ru-Phen, Phen-Ru-Bipy, Phen-Ru-Quin, Quin-Ru-Quin and Bipy-Ru-Quin (where Phen=1, 10-phenanthroline, Quin=8-hydroxyquinoline, Bipy=2, 2′-bipyridine) were synthesized and used as catalysts for the oxidation of benzylic and primary aliphatic alcohols with iodosylbenzene as oxidant. The oxidations were carried out at room temperature, affording the corresponding aldehydes and ketones with high selectivity.

New insight into the adsorption of ruthenium,rhodium,and palladium from nitric acid solution by a silica-polymer adsorbent

A porous silica-polymer-based adsorbent,isoBuBTP/Si O2-P,was prepared by a vacuum impregnation method and used for the recovery of ruthenium,rhodium,and palladium from nitric acid solution.The experimental results revealed that iso Bu-BTP/SiO2-P exhibited unique adsorption properties such as high saturation adsorption capacity(Ru:0.35 mmol g^-1,Rh:0.32 mmol g^-1,Pd:1.05 mmol g^-1)and excellent selectivity over other metal ions,such as lanthanides(SF(PGM/M)>40)in 1 M HNO3 solution.The adsorption process conformed to the pseudosecond-order model and Langmuir model.From the UV,FTIR,and XPS analyses,it can be concluded that the strong affinity between functional groups(C–N=C)and metal ions as well as NO3-played a role in coordination during the adsorption process.Furthermore,the desorption behavior was studied,and it was found that the adsorbed Pd,Rh,and Ru could be eluted with a 0.01 M nitric acid–0.1M thiocarbamide solution,5M hydrochloric acid,and sodium hypochlorite(CP)solution,respectively.Finally,based on those findings,a simple process for the separation and recovery of Pd,Rh,and Ru from high-level liquid waste using iso Bu-BTP/SiO2-P was designed and proposed.

Synthesis of a New Type of Amphilic and Water - soluble Tertiary Phosphine Ligands Substituted by an Ethoxylated Phosphonic Acid Chain and Their Palladium Complexes

The highly water-soluble phosphine ligands Na2O3PCH2CH2NH(CH2CH2O)nCH2CH2N- (CH2PPh2)2 (n=1,2,3) were prepared by a new and simple route under mild conditions in good yield; the palladium (II) complexes of the ligands 3a~c with 2:1 or 4:1 -PPh2 to Pd2+ molar ratio were also prepared and characterized .

New Ruthenium Complexes of Fullerene C60&C70

The new complexes [Ru(NO)(PPh3)]2(h2-Cm)(m=60 1 or 70 2) have been prepared by heating a solution of C60(or C70) with [Ru(NO)2(PPh3)2] in toluene. They have been characterized by elemental analysis, IR, UV/VIS, XPS, 13C and 31P NMR spectroscopy. The photovaltaic effect for the new compounds has been studied.

Synthesis and Characterization of Ferroceneterminated Ruthenium Phenylacetylide Complexes with Alligator Clips

Ferrocene-terminated trans-Ru(dppm)2 (dppm=Ph2PCH2PPh2)-containing molecular wires with alligator clips were prepared. They are suitable for self-assembly on gold electrode to investigate the influence of metal incorporation on the electron transportation property of the molecular wires.

Half-sandwich Ruthenium Complexes with Naphthalene-based Schiff Base Ligands:Syntheses,Characterization and Catalytic Activities for the Reduction of Nitroarenes

Three half-sandwich ruthenium（II） p-cymene complexes containing naphthalenebased Schiff base ligands [Ru（p-cymene）LCl]（2 a～2 c） have been synthesized and characterized. Both Schiff-base ligands and ruthenium complexes were fully characterized by ^1H and ^13C NMR spectra, mass spectrometry and infrared spectrometry. The molecular structure of ruthenium complex 2 b was confirmed by single-crystal X-ray diffraction methods. For the complex： C（24H23ClN2ORu, Mr = 524.02, monoclinic, space group P21/c, a = 12.3888（4）, b = 17.3296（6）, c = 20.7744（7）A°, β = 92.8000（10）°, V = 4454.8（3） A°^3, Z = 8, Dc = 1.563 g/cm^3, μ = 0.936 mm^-1, F（000） = 2128, S = 1.154, the final R = 0.0309 and w R = 0.0703. Moreover, these ruthenium complexes are active catalysts for the hydrogenation of nitroarenes to aromatic anilines in the presence of sodium tetrahydroborate（NaBH4） reducing agent.

SYNTHESIS AND CHARACTERIZATION OF ZEROVALENT PALLADIUM COMPLEXES

A series of nine Pd(0)complexes(L)Pd(L')[L=bis(diphenylphosphino) methane(dppm),1,2-bis(diphenylphosphino)ethane(dppe),and 1,1'-bis(diphenyl- phosphino)ferrocene(dppf),respectively;L=dibenzylideneacetone(dba),2,3,5, 6-tetrachloro-1.4-benzoquinone(q)and 2,3-dichloro-1,4-naphthoquinone(nq)] were synthesized and characterized by means of elemental analyses,IR,UV, 1~H-NMR and^(31)P-NMR spectra.The redox wave peak potentials of the ferrocenyl group of complexes with dppf were measured by using CV method.Results showed that all the diphosphorus ligands behaved as chelating bidentate ligand and dba,q,nq were coordinated to the Pd(0)atom through their C=C moieties,not their carbonyl ones.Analytical data also showed that there were interactions between the two different ligands in each complex.

Chiral palladium complexes based on derivatives of benzylamine and 2α-hydroxypinan-3-one

Synthesized and characterized new chiral palladium complexes, some of which contain asymmetric donor nitrogen atom. Nitrogen-containing derivatives (+) - and (-)-2α-hydroxypinan-3-one- (1R,2R,5R)-3-(benzylimino)-2,6,6-trimethylbicy- clo[3.1.1]heptane-2-ol (HL1), (1S,2S,3S,5S)-3- (benzylamino)-2,6, 6-trimethylbicyclo[3.1.1]- heptane-2-ol (HL2), (1R,2R,5R)-3-((S)-α-methyl- benzylimino)-2,6,6-trimethylbicyclo[3.1.1]- heptane-2-ol (HL3), (1R,2R,3R,5R)-3-((S)-α-methyl- benzylamino)-2,6,6-trimethylbicyclo[3.1.1]- heptane-2-ol (HL4) -were studied as optically active ligands.

Palladium Complexes with N,O-Bidentate Ligands Based on N-Oxide Units from Cyclic Secondary Amines:Synthesis and Catalytic Application in Mizoroki-Heck Reaction

Palladium-catalyzed Mizoroki-Heck reaction is a powerful and efficient method for construction of Csp2–Csp2 bonds.Herein,four palladium complexes(I—IV)with N,O-bidentate ligands(L1—L4)based on N-oxide units from cyclic secondary amines were easily synthesized and successfully applied in Mizoroki-Heck reaction of aryl bromides with electron-deficient olefins.X-ray diffraction analyses indicated the palladium(II)atom of II took the distorted square planar geometry and was four-coordinated by nitrogen and oxygen atoms from two ligands(L2).Two free chloride ions were presented as counter anions in complex II.But the palladium(II)center of IV was coordinated by nitrogen and oxygen atoms from one ligand(L4)as well as two chlorine atoms,which exhibited the nearly square-planar geometry.The study on catalytic properties of palladium complexes revealed that complex II exhibited high activity superior to the other complexes.The coupling reactions of a series of aryl bromides and olefin derivatives proceeded in the presence of 2—5 mol%palladium complex II,giving the desired products in good to excellent yields.The advantages of this method such as good compatibility of functional groups,high yields,and short reaction times made it more attractive for constructing Csp2–Csp2 bonds in the synthesis of functional molecules and materials.

Synthesis and Catalytic Activity of a Two-core Ruthenium Carbene Complex: a Unique Catalyst for Ring Closing Metathesis Reaction

The reaction of a ruthenium carbide complex RuCl2（C：）（PCy3）2 with [H（Et2O）x]＋[BF4]- at a molar ratio of 1：2 produced a two-core ruthenium carbene complex, {[RuCl（=CHPCy3）（PCy3）]2（μ-Cl）3}＋·[BF4]-, in the form of a yellow-green crystalline solid in a yield of 94%. This two-core ruthenium complex is a selective catalyst for ring closing metathesis of unsubstituted terminal dienes. More importantly, no isomerized byproduct was observed for N-substrates when the two-core ruthenium complex was used as the catalyst at an elevated temperature（137 °C）, indicating that the complex is a chemo-selective catalyst for ring closing metathesis reactions.

Quantitative Structure Anti-Cancer Activity Relationship (QSAR) of a Series of Ruthenium Complex Azopyridine by the Density Functional Theory (DFT) Method

A series of ruthenium azopyridine complexes have recently been investigated due to their potential cytotoxic activities against renal cancer (A498), lung cancer (H226), ovarian cancer (IGROV), breast cancer (MCF-7) and colon cancer (WIDR). Thus, in order to predict the cytotoxic potentials of these compounds, quantitative structure-activity relationship studies were carried out using the methods of quantum chemistry. Five Quantitative Structure Activity Relationship (QSAR) models were obtained from the determined quantum descriptors and the different activities. The models present the following statistical indicators: regression correlation coefficient R2 = 0.986 - 0.905, standard deviation S = 0.516 - 0.153, Fischer test F = 106.718 - 14.220, correlation coefficient of cross-validation = 0.985- 0.895 and = 0.010 - 0.001. The statistical characteristics of the established QSAR models satisfy the acceptance and external validation criteria, thereby accrediting their good performance. The models developed show that the variation of the free enthalpy of reaction , the dipole moment μ and the charge of the ligand in the complex Ql, are the explanatory and predictive quantum descriptors correlated with the values of the anti-cancer activity of the studied complexes. Moreover, the charge of the ligand is the priority descriptor for the prediction of the cytotoxicity of the compounds studied. Furthermore, QSAR models developed are statistically significant and predictive, and could be used for the design and synthesis of new anti-cancer molecules.

A Novel Octanuclear Molecular Loop Formed by Linkage of Oxo-centered Triruthenium Cluster Units

A novel dimeric complex [Ru3 (μ3-O)(μ-CH3COO)(CO)]2(μ-dppf)(μ-odppf)(dppf = 1, 1'-bis(diphenylphosphio)ferrocene, odppf = 1, 1'-bis(oxodiphenylphosphoranyl)ferrocene) (1) of oxo-centered triruthenium-aectate cluster units was synthesized and characterized by X-ray crystallography. Compound 1 exhibits a cyclic structure formed by linkages of two triruthenium cluster units Ru3 (μ3-O)(μ-CH3COO)6(CO) through dppf and odppf ligands, respectively. The diameter of the molecular loop is ca. 1.0 nm.

Electrogenerated chemiluminescence sensor for the determination of metoclopramide using ordered mesoporous carbon for immobilizing tris(2,2'-bipyridyl)ruthenium

A novel electrogenerated chemiluminescence(ECL)sensor for the determination of metoclopramide was developed by employing ruthenium complex as an ECL signal producer and an ordered mesoporous carbon(OMC)material as modified material.The ECL sensor was fabricated by adsorption ruthenium complex into a mixture of OMC and Nafion,which showed good electrochemical and ECL behaviors.It was found that the ECL intensity of the sensor fabricated was greatly enhanced in the presence of metoclopramide.Based on this finding,a highly sensitive and reproducible ECL method was developed for the determination of metoclopramide.The result showed that the ECL intensity was linear with the concentration of metoclopramide in the range from 1.0×10-10 to 5.0×10-7M and the detection limit was 3×10-11M.The ECL sensor exhibited a long-term stability and a fine reproducibility with relative standard deviation of 1.0 % for 1.0×10-10M metoclopramide in 18 continuous determinations.The developed method has been applied to the determination of metoclopramide in tablet samples with satisfactory results.

Highly efficient oxidation of alcohols using Oxone~ as oxidant catalyzed by ruthenium complex under mild reaction conditions

Aromatic and alkyl alcohols were oxidized to the corresponding aldehydes or ketones at room temperature with high conversion and selectivity using Oxone （2KHSOs-KHSO4.K2SO4） as oxidant catalyzed by ruthenium complex Quin-Ru-Quin （where Quin = 8-hydroxyquinoline）. The reaction time is very short and the preparation of complex is simple.

Synthesis and Photochemical Properties of a New Substituted Phenol Covalently Linked to Ruthenium (Ⅱ) Tris-bipyridine Containing Four Ester Groups as Sensitizer

As photosensitizer for solar cell, a new ruthenium (Ⅱ) complex with four ester groups hadbeen synthesized, in which a phenol substituted by {[(2-hydroxy-5-tert-butylbenzyl)(pyridyl-2-methyl)amino]methyl} is covalently linked to ruthenium (Ⅱ) tris-bipyridine. The structures ofthe new compounds were confirmed by NMR and ESI-MS spectra. The electrochemical andphotochemical properties were also studied.

Synthesis and Structural Characterization of a Ruthenium Complex:trans-RuCl_2(COD)Py_2

A new ruthenium complex trans-RuCl2（COD）Py2 has been synthesized and characterized by elemental analysis, IR, IH NMR and single-crystal X-ray diffraction. Crystal data： trans- RuCl2（COD）Py2, Mr = 438.35, monoclinic, space group P21/c, a = 8.9116（9）, b = 14.6175（15）, c = 13.7582（14）A, β = 101.994（1）°, V= 1753.1（3）A^3, Z= 4, Dc= 1.661 g/cm^3, F（000）= 888,μ = 1.199 mm^-1, R = 0.0376 and wR = 0.0789 for 2492 observed reflections with I 〉 2σ（I）.