Syntheses, structures and catalytic activities of ruthenium (II) carbonyl iodide complexes with CNC-pincer bis (carbene) ligand

Two new pincer bis (carbene) ligands and corresponding ruthenium (II) carbonyl iodide complexes have been synthesized and characterized. The structures of complexes 3 and 4 have been determined by X-ray crystallography. Complexes 3 and 4 have been proved to be efficient catalysts in the transfer hydrogenation of acetophenone.     

Synthesis, structure and catalytic activities for the hydrogen transfer reactions of the ruthenium(II) carbonyl chloride complexes with pyridine-2,6-diimine

Two Ru(II) carbonyl chloride complexes with pyridine-2,6-diimine, (L)Ru(CO)Cl₂ (L = 2,6-diacetylpyridinebis(2,4,6-trimethylanil), 1; L = 2,6-diacetylpyridinebis(2,6-diisopropylanil), 2) have been synthesized and characterized. The structure of compound 1 has been determined by X-ray crystallography, which show the distorted octahedral geometry around Ru(II). Complexes 1 and 2 have been proved to be active in the transfer hydrogenation of acetophenone by propan-2-ol.     

三齿吡啶基钌配合物的对位取代基对氢转移催化活性的影响

Three stable 4-substituted pyridine-based ruthenium(II)complexes[RuCl2(PPh3)L](L=4-R-2,6-bis (diethylaminomethylene)pyridine,R=Br,H or allyloxy)were synthesized.The catalytic activities of the complexes toward transfer hydrogenation from alcohols to ketones were investigated.The electronic effects of the para-substituent in the pyridyl ring were probed and we found that the electron-donating group increased the catalytic activity.The result suggests that an electron-donating group is probably preferential for linking the catalytic ruthenium complex and the chemically inert supporting molecules such as a carbosilane dendrimer.     

Diffusion coefficients of Cu(II) complexes with ligands used in alkaline electroless copper plating solutions

The diffusion coefficient values of the Cu(II) complex compounds with EDTA, DTPA, NTA, Quadrol, glycerol, saccharose, (+)- and (±)-tartaric acid, OH^– ions obtained by polarographic measurements in alkaline solutions lie in the range (1.2–5.7) × 10^–6 cm² s^–1 (at 20 C and J = 3) depending on the size of complex species, and are less than those of free (hydrated) Cu(II) ions and methanediol anion (H₂C(OH)O^–) determined under the same conditions which are 7.0 × 10^–6 and 10 × 10^–6 cm² s^–1, respectively. The linear dependence of the polarographically determined diffusion coefficient values on the inverse radius of Cu(II) complex species is observed.     

Synthesis,characterization and antibacterial activity of Pd(II), Pt(II) and Ag(I) complexes of 4-ethyl and 4-(p-tolyl)-1-(pyridin-2-yl)thiosemicarbazides

Pd(II), Pt(II) and Ag(I) ions were found to form stable complexes with 4-(p-tolyl)- or 4-ethyl-1-(pyridin-2-yl)thiosemicarbazides (Hp-TPTS or HEPTS). The complex structure was elucidated by analysis (elemental and thermal), spectroscopy (electronic, IR and ¹H NMR spectra) and physical measurements (magnetic susceptibility and molar conductance). The ligands coordinate to the metal ions as monobasic bidentate through nitrogen and sulfur atoms. The electronic spectra of the Pt(II) complexes in DMF showed a metal to ligand charge transfer transition at 11,935–13,260 cm^?1. The structural, electronic and vibrational features of HEPTS and Hp?TPTS were discussed on the basis of semi-empirical quantum mechanic calculations [ZINDO/S and semi-empirical parameterization (PM3)]. The simulated IR and electronic spectra are found reasonable in accordance with the experimental data. Finally, the antibacterial activities of the ligands and their complexes were investigated and some were found promising.     

Electrical properties of Cu(II) and Ni(II): N-salicylidene polymethacrylic acid hydrazide complexes

Different types of chelated polymer complexes have been synthesized to obtain improved electrical properties. Compact discs from powders of the chelated polymers were prepared and heated in a specially designed holder. Electrical conductivity and dielectric constant of Cu(II) and Ni(II): N-salicylidene polymethacrylic acid hydrazide samples were measured at a fixed frequency (1600 Hz) throughout the temperature range 25-150°C. The AC conductivity as well as dielectric measurements showed maxima at 85°C. The water molecules which were trapped in the polymer matrix are believed to play the main role in conduction and dielectric behaviour of the polymeric material. From the AC conductance and dielectric constant measurements, the dielectric losses of these polymeric materials were calculated as a function of temperature.     

Reduction of nitroaromatics with poly(vinylpyridine) complexes of palladium(II) and platinum(II)

Palladium(II) and platinum(II) anchored to 2- and 4-vinylpyridine polymers of different molecular weights were used for the dihydrogen reduction of various nitroaromatics and benzaldehyde in ethanol at 50°C. Palladium(II) complexes were far more effective than their platinum(II) analogues and the activity decreased with increasing molecular weights of the polymers. The nitroaromatics were selectively and almost completely reduced to the corresponding anilines. During reduction, the orange palladium(II) complexes changed to voluminous green precipitates, which could be used repeatedly and preserved for a long time without any loss of activity. A rate equation of the type: rate = K[Cat] [H₂] has been derived and a reduction mechanism has been proposed on the basis of experimental results and kinetic data.     

Voltammetric investigation of polyelectrolyte-Cu(II) complexes

The complexation behaviours of poly(N-vinylcarbazole) (PNVCz), poly(acrylic acid) (PAA) poly(itaconic acid) (PIA) and their copolymers, synthesized by using different initial monomer compositions, with Cu(II) ions were investigated by the voltammetric technique. Their solutions were prepared in THF-water mixture according to the water-insoluble nature of PNVCz and its copolymers. The polymeric ligand-Cu(II) interactions, i.e. complex formations were studied as a function of copper ion concentration and copolymer composition. It was observed that although the cyclic voltammogram (CV) of Cu(II) alone in THF-water mixture was characterized by one redox wave, which has an irreversible nature, it became more reversible in the presence of polymer. Further, the CV results indicated the presence of two different electron transfer mechanisms, depending on the n _COOH/n _Cu(II) ratio and the carboxyl content of the copolymers.     

Synthesis of a new class of cyclometallated ruthenium(II) complexes and their application in dye-sensitized solar cells

We synthesized a new class of cyclometallated ruthenium(II) complexes, Ru(tctpy)(C^N)(NCS) (1, 2), where C^N is a bidentate cyclometallating ligand such as 2-phenylpyridinato or 2-(4-(2-phenylethynyl)phenyl)pyridinato. Although these complexes exist as stereoisomers, the microwave synthetic technique yielded only one isomer. These compounds act as light sensitizers and have excellent light-harvesting properties, especially in the near-IR region. Therefore, they can be used in dye-sensitized solar cells (DSCs). A DSC sensitized with 2 shows a 10% incident photon-to-current conversion efficiency at 900 nm.     

Nickel(II) complexes of whole set of the simple ethylenediaminetetracarboxylate ligands: DFT study of complexes invoking molecular orbital and configurational analysis

The whole set of the nickel(II) complexes with no derivatized edta-type hexadentate ligands has been investigated from their structural and electronic properties. Two more complexes have been prepared in order to complete the whole set: trans(O₅)-Mg[Ni(ed3ap)]·8H₂O and trans(O₅O₆)-Ba[Ni(eda3p)]·4H₂O complexes. trans(O₅) geometry has been verified crystallographicaly and trans(O₅O₆) geometry of the second complex has been predicted by the DFT theory and spectral analysis. Mutual dependance has been established between: the number of the five-membered carboxylate rings, octahedral/tetrahedral deviation of metal-ligand/nitrogen-neighbour-atom angles, charge-transfer energies (CTE) calculated by the Morokuma’s energetic decomposition analysis and energy of the absorption bands and HOMO–LUMO gap.     

NMF effect on photosensitized charge separation using partially quaternized poly(1-vinylimidazole)-bound ruthenium(II) complexes

The solvent effects on the photosensitized charge separation using partially quaternized poly(1-vinylimidazole)-bound ruthenium(II) complexes (RuQPIm), in which bis(2,2′-bipyridine)ruthenium(II) complexes are coordinated to the imidazolyl residues on the poly(1-vinylimidazole) partially quaternized by 1-bromohexadecane and the degree of quaternization is 19 (RuQPIm-19) and 44 (RuQPIm-44) molar percentage, have been investigated in methanol and methanol–NMF (NMF: N-methylformamide). These systems consist of RuQPIm-19 and RuQPIm-44 as photosensitizers, 1,1′-dimethyl-4,4′-bipyridinium dication (MV²⁺) and 1,1′-didodecyl-4,4′-bipyridinium dication (C₁₂V²⁺) as electron acceptors, and triethanolamine (TEOA) as a sacrificial donor. The addition of NMF mainly affect the forward and back reactions in the charge separation reactions. In RuQPIm-19 systems, the reaction proceeds through an interactive process, which is through the viologen having π–π interaction for MV²⁺ and van der Waals interaction for C₁₂V²⁺. In contrast, the reaction proceeds through a direct process by MV²⁺ having no interaction and through an interactive process by C₁₂V²⁺ undergoing van der Waals interaction with the polymer for RuQPIm-44 systems. For MV²⁺, the rates of MV^·+ formation increased, although the quenching efficiency decreased with increasing NMF content for RuQPIm-19 and RuQPIm-44. These results are attributed to stabilization of MV^·+ species by π–π interaction for RuQPIm-19 and steric repulsion between MV^·+ species and RuQPIm-44; namely, the restriction of the back reactions by these effects. In contrast, for C₁₂V²⁺, the rates of C₁₂V^·+ formation decreased and the quenching efficiency increased with the addition of NMF. These are attributed to that the addition of NMF increases the van der Waals interaction of the C₁₂V²⁺ with these polymers and the diffusion of the C₁₂V^·+ species into the bulk solution; namely, the back reaction is accelerated. Furthermore, it is suggested that the conformational changes in these polymers contribute to the charge separation reaction.     

Post-discharge plasma-chemical oxidation of Iron(II) complexes

The plasmachemical properties of an electric discharge in humid air are considered by examining the oxidation of Fe(II) to Fe(III) aquo-ions in a solution exposed to the discharge. The reaction product is characterised and quantified by means of the thiocyanate complex FeSCN²⁺. The reaction mechanism shows two distinct steps: a rapid step directly depending on the treatment time and a slow post-discharge step, which are both ascribed to species formed in the discharge (i.e., respectively to OH radical and to hydrogen peroxide or nitrate ions). These concerned species are able to react either at the liquid surface (OH) or to diffuse into the solution and react as solutes. Experimental arguments in favour of zero and first order reaction steps are given. A particular reactor design involving a multibladed electrode is tested at the juncture and its use considered for further industrial applications.     

Polymerization of styrene using pyrazolylimine nickel (II)/methylaluminoxane catalytic systems

The polymerization of styrene with two pyrazolylimine nickel (II) complexes of (2-(C₃HN₂Me₂-3, 5)(C(Ph) = N(4-R₂C₆H₂(R₁)₂-2, 6)NiBr₂ (Complex 1 , R₁ = ⁱPr, R₂ = H; Complex 2 , R₁ = H, R₂ = NO₂)) activated by methylaluminoxane was studied. The influences of polymerization parameters such as polymerization temperature, Al/Ni molar ratio, and reaction time on catalytic activity and molecular weight of the polystyrene (PS) were investigated in detail. The electron-withdrawing of nitro group in Complex 2 could not enhance the catalytic activity for styrene polymerization; however, the molecular weights of polymers were increased. Both of the two catalytic systems exhibited high activity [up to 8.45 × 10⁵ gPS/(mol Ni h)] for styrene polymerization and provide PS with moderate to low-molecular weights (M_w = 2.21 × 10⁴∼ 5.71 × 10³ g/mol) and narrower molecular weight distributions about 2.0. The obtained PS were characterized by means of IR, ¹H NMR, and ¹³C NMR techniques. The results indicated that the PS was atactic polymer. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Polymerization of styrene using novel bispyrazolylimine dinickel (II)/methylaluminoxane catalytic systems

The polymerization of styrene with a series of bispyrazolylimine dinickel (II) complexes of bis‐2‐(C₃HN₂(R₁)₂‐3,5)(C(R₂) = N(C₆H₃(CH₃)₂‐2,6)Ni₂Br₄ (complex 1 : R₁ = CH₃, R₂ = Ph; complex 2 : R₁ = CH₃, R₂ = 2,4,6‐trimethylphenyl; complex 3 : R₁ = R₂ = Ph; complex 4 : R₁ = Ph, R₂ = 2,4,6‐trimethylphenyl) in the presence of methylaluminoxane (MAO) was studied. The influences of polymerization parameters such as polymerization temperature, Al/Ni molar ratio, reaction time, and catalyst concentration on catalytic activity and molecular weight of the polystyrene were investigated in detail. The influence of the bulkiness of the substituents on polymerization activity was also studied. All of the four catalytic systems exhibited high activity (up to 10.50 × 10⁵ gPS/(mol Ni h)) for styrene polymerization and provide polystyrene with moderate to low molecular weights (M_w = 4.76 × 10⁴–0.71 × 10⁴ g/mol) and narrower molecular weight distributions about 2. The obtained polystyrene was characterized by means of FTIR, ¹H‐NMR, and ¹³C‐NMR techniques. The results indicated that the polystyrene was atactic polymer. The analysis of the end groups of polystyrene indicated that styrene polymerization with bispyrazolylimine dinickel complexes/MAO catalytic systems proceeded through a coordination mechanism. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

Synthesis and characterization of resins with ligands containing guanidinine derivatives. Cu(II) sorption and coordination properties

A new modification direction of acrylonitrile, vinyl acetate and divinylbenzene terpolymers (A, B) are presented. The aminolysis of nitrile groups of the terpolymers using ethylenediamine or hydroxylamine hydrochloride was a first stage of the modification. The resulting amine groups reacted with dicyandiamide (DCDA), cyanamide (CA) and sodium dicyanimide (SDC) in order to obtain the biguanidyl, guanidyl or nitrilguanidyl derivatives in the polymer side chain, respectively. The properties of all obtained resin such as water regain, nitrogen content, amine and carboxyl group concentration and sorption properties towards Cu(II) from nitric acid solutions were determined. The studies of IR spectra of all the resins were performed. Structures of ligand complexes with Cu(II) were studied using electron paramagnetic resonance spectroscopy.     

氰根桥联Fe（II）自旋交叉配位化合物材料的研究进展

自选交叉是有些配合物的一种奇特现象,这种材料能够用于信息储存技术。在温度、压力、磁场、光等的作用下发生高低自旋的转换,本文主要介绍Real组的研究成果。     

Synthesis,spectral and structural study of sulfur-containing copper(II) complexes

A series of four new copper(II) complexes [Cu(H₂L)(L¹)] 1, [Cu(H₂L)(PMDT)] 2, [Cu(H₂L)(Dien)] 3 and [Cu(H₂L)(L²)] 4 have been synthesized by template condensation (H₂L=thiodiglycolic acid, L¹=N-[(1)-1-(4-methylphenyl)ethylidene]benzohydrazide, PMDT=N,N,N′,N′,N ^′′-pentamethyldiethylene- triamine, Dien=diethylenetriamine L²=N-[(1)-pyridin-2-ylmethylidene]benzohydrazide). The bonding and stereochemistry of the complexes have been characterized by molar conductance, elemental analysis, magnetic susceptibility, infrared, UV–visible, electron paramagnetic resonance structural studies and electrochemical studies. g-Values were calculated for all complexes in polycrystalline form as well as in DMSO solution. The magnetic and spectral data indicate square pyramidal geometry for 1 and octahedral geometry for 2–4 complexes. Cyclic voltammograms for all the complexes are similar and involve two irreversible redox processes. Their biological properties have also been studied. The thio complexes show more antibacterial activity than the controlled one. The antibacterial activities of the compounds have also been tested against Escherichia coli with different concentrations.     

Sorption of Pb(II), Cd(II) and Zn(II) by iminodiacetate chelating resins in non-competitive and competitive conditions

Two chelating resins (CRs) bearing iminodiacetate (IDA) groups derived from acrylonitrile - divinylbenzene (AN-DVB) copolymers having 10 and 15 wt.% nominal cross-linking degrees and a high mobility of the functional groups caused by the presence of a longer spacer between the matrix and the IDA groups were synthesized and tested as sorbents for heavy metal ions like: Pb(II), Cd(II) and Zn(II) from aqueous solutions by batch and column techniques. Experimental data obtained from batch equilibrium tests have been analyzed by two isotherm models: Freundlich and Langmuir. The overall adsorption tendency of CRs toward Pb(II), Cd(II) and Zn(II), under non-competitive conditions, followed the order: Cd(II) > Pb(II) > Zn(II). Selectivity studies were performed in ternary mixture of Pb(II), Cd(II) and Zn(II) to check if the synthesized CRs can be useful for selective separation of heavy metal cations. The results revealed that the CRs with IDA groups exhibited high selectivity toward Pb(II), both in batch and column techniques. Regeneration of the resins was achieved using 0.1 M HCl solution.     

cis-Diaminedichloroplatinum(II) complexes reversibly bound to water-soluble polyaspartamide carriers for chemotherapeutic applications. I. Platinum coordination to preformed, carrier-attached ethylenediamine ligands

Copolyaspartamides3–5, bearing the ethylenediamine (en) ligand as a repetitive side-chain component in addition to various hydrosolubilizing groups, are synthesized from polysuccinimide1 by a two-step aminolytic ring opening reaction. The completely water-soluble polyamides, possessing inherent viscosities of 5–20 ml g^–1, are used as polymeric carriers for the anchoring of the biomedically important diaminedichloroplatinum(II) coordination complex. Conjugate formation is brought about by treatment of the carriers with the tetrachloroplatinate(II) dianion in aqueous solution at pH 6.0 ± 0.5. The resulting, water-soluble conjugates3-Pt-5-Pt, purified by dialysis (12,000–14,000 molecular mass cutoff) and isolated in the solid state by freeze-drying from aqueous solution, possess platinum contents in the typical range of 15–25%. The metal is bound as acis-dichloro-en-Pt(II) complex to the polymer main chain via a short spacer segment incorporating a biofissionable amide link suitable forin vivo release of the complex. The conjugates are of interest as water-soluble macromolecular platinum coordination compounds for potential use in the chemotherapy of cancerous diseases.Presented in part at the XXVII International Conference on Coordination Chemistry, Broadbeach, Australia, 2–7 July 1989, abstract T6.