Enantiopreferential DNA-binding of a novel dinuclear complex [(bpy)2Ru(bdptb)Ru(bpy)2]4+

A novel dinuclear ruthenium(II) complex [(bpy)₂Ru(bdptb)Ru(bpy)₂]⁴⁺ (bpy=2,2^′-bipyridyl; bdptb=2,2^′-bis(5,6-diphenyl-1,2,4-triazin-3-yl)-4,4^′-bipyridine) has been synthesized and characterized. The DNA-binding behaviors of this complex have been studied by viscosity, absorption and circular dichroism (CD) spectra. It has firstly been found that the dinuclear ruthenium(II) complex display the enantiopreferential DNA-binding after equilibrium dialysis.     

Oxidation of cyclohexane promoted by [Fe(III)(Salen)Cl] and [Mn(III)(Salen)Cl]

Salen complexes of iron(III) and manganese(III) were synthesized and employed as catalysts in the oxidation of cyclohexane, using hydrogen peroxide and tert–butylhydroperoxide. The reactions were carried out in acetonitrile at room temperature. The catalysts were characterized by infrared and Mössbauer spectroscopy, elemental analysis, conductivity and cyclic voltammetry. Conversions up to 10.2% (4.2% and 6.0% yields for cyclohexanol and cyclohexanone, respectively) were obtained for the system [Fe(III)(Salen)Cl]/tBuOOH.     

Pd[tBuNH(S)NHP(O)(OiPr)2-S]2Cl2 Complex as Air- and Moisture-Stable Catalyst for Palladium Catalyzed Suzuki Cross-Coupling Reaction

A highly efficient Suzuki cross-coupling reaction between phenyl bromide and phenylboronic acid catalyzed by the palladium complex Pd[tBuNH(S)NHP(O)(OiPr)₂-S]₂Cl₂ in acetonitrile, toluene, THF or DMF has been investigated. The bases we have employed for this reaction were Na₂CO₃, K₂CO₃ or Cs₂CO₃. It was established that using DMF and K₂CO₃ at 100 °C shows excellent yields of the product at the catalyst amount of 0.1 mmol. The cross-coupling reactions of iodo- and chloro-benzene with phenylboronic acid were also investigated. The influence of the halide nature was as expected.     

WGSR catalyzed by cis-[Rh(CO)2(amine)2]PF6 heterogenised on poly(4-vinylpyridine)

This paper describes catalytic activation studies of the water–gas shift reaction by cis-[Rh(CO)₂(amine)₂]PF₆ (amine = 4-picoline, 3-picoline, 2-picoline, pyridine, or 2,6-lutidine) heterogenised on poly(4-vinylpyridine) in aqueous 2-ethoxyethanol. The effect of varying the nature of the amine was investigated. The rhodium complexes bearing 4-picoline (4-pic) ligands proved to be most active among those surveyed, and displaying turnover frequencies for hydrogen production of 8.9 mol of H₂ per mole of Rh per day for 9.4x10^-5 mol cis-[Rh(CO)₂(4-pic)₂]PF₆/1.00 g poly(4-vinylpyridine), P(CO) = 0.9 atm at 100°C. This revised version was published online in July 2006 with corrections to the Cover Date.     

A novel DNA light switch [Ru(bpy)2pzip]2+ activated by cobalt(II) ion

A novel ruthenium(II) complex, [Ru(bpy)₂pzip]²⁺ has been synthesized and characterized. The DNA-binding properties of this complex have been studied by spectroscopic and viscosity measurements. The results indicated that the complex [Ru(bpy)₂pzip]²⁺ bound to double-stranded DNA in an intercalation mode. In the presence of Co²⁺, the emission of DNA–[Ru(bpy)₂pzip]²⁺ can be quenched. And when EDTA was added, the emission was recovered. The experiment results show that [Ru(bpy)₂pzip]²⁺ exhibited the “on–off–on” properties of molecular “light switch”.     

The carbonylation of ammonia to urea catalysed by [Ru3(CO)12]

Ammonia can be carbonylated catalytically to urea under mild conditions of temperature and pressure using [Ru₃(CO)₁₂] as catalyst precursor.     

[Ru(bpy)_2dppz]~(2+)的合成及其与DNA的相互作用研究

首先通过两步反应合成了"光开关"分子,[Ru(bpy)2dppz]2+(简称Ru-dppz; bpy=2,2'-联吡啶,dppz=二吡啶[3, 2-a; 2', 3'-c]吩嗪),并分别用紫外-可见吸收光谱法、核磁共振和质谱表征其结构。再利用荧光法考察了Ru-dppz与双链DNA(dsDNA)的相互作用。结果表明:随着Ru-dppz与dsDNA的结合,Ru-dppz荧光强度增加。根据荧光滴定实验结果,计算所得Ru-dppz与dsDNA的结合常数为1.5×107L/mol,结合比为0.14。     

邻菲咯啉衍生物钌配合物的制备及性能研究

钌-邻菲咯啉配合物已经广泛应用于电化学、光化学领域,以羟基苯基并[4,5]-邻菲咯啉（Hpip）为配体,合成二氯化三羟基苯基并[4,5]-邻菲咯啉钌（Ru（Hpip）3Cl2）。应用红外、紫外和荧光光谱对产物进行表征,用循环伏安法考察其电化学行为,研究pH、氧对其荧光强度的影响。结果表明Ru（Hpip）3Cl2在玻碳电极上有准可逆的电化学行为,在溶液中其对氧的响应倍数（I0／I）高达11．9。     

Two types of tetrasubstitution in [H4Ru4(CO)12]: spectroscopic characterization and crystal structure determination of [H4Ru4(CO)8(PMe2Ph)4] and [H2Ru4(CO)9(PMe2Ph)4]

Two tetrasubstituted tetranuclear ruthenium clusters containing dimethylphenylphosphine [H₄Ru₄(CO)₈(PMe₂Ph)₄] and [H₂Ru₄(CO)₉(PMe₂Ph)₄] were prepared and characterized spectroscopically as well as by X-ray crystallography. Both compounds show a structure based on the usual 60-electron tetrahedral framework with each ruthenium atom being bonded to one phosphine ligand. In the case of the nonacarbonyl derivative, one of the ruthenium atoms has one terminal carbonyl group and is also bonded to two semibridging carbonyl groups; two other metal–metal bonds are bridged by the hydride groups. In the case of the octacarbonyl compound all the ruthenium atoms are bonded to two terminal carbonyls and to two bridging hydrides. NMR spectroscopical information of [H₄Ru₄(CO)₈(PMe₂Ph)₄] suggests the presence of two isomers in solution which we propose to have D_2d and C_s symmetries. The observation of the NMR properties gives some observations about conditions that favour coupling between substituents in different ruthenium atoms.     

联吡啶钌体系电致化学发光测定盐酸苯海索的研究

首次建立了以金电极为工作电极电致化学发光测定盐酸苯海索的方法,采用循环伏安法和电致化学发光法研究了盐酸苯海索-Ru(bpy)32+体系的电化学行为和电化学发光行为。结果表明,在pH值8.0的磷酸盐缓冲溶液中,扫描速率为0.10 V.s-1时,电致化学发光(ECL)强度值与盐酸苯海索浓度在2.00×10-7~1.00×10-4mol.L-1范围内呈良好线性关系,其线性回归方程为:I(Counts)=300.00×105c-120.71,方法检出限为1.00×10-8mol.L-1(s/n=3)。不同时段测定5.9184×10-5mol.L-1的盐酸苯海索片溶液4次,所测样品含量值的RSD为1.55%。对样品进行加标回收率实验,回收率为97.50%~104.00%。该方法具有较好的稳定性和灵敏度,样品处理简单快速,用于盐酸苯海索片的测定,效果良好。     

DNA-enhanced assembly of [Ru(bpy)2ITATP] on an ITO electrode

A novel technique for controllable assembly of [Ru(bpy)₂ITATP]^3+/2+ (where bpy = 2,2′-bipyridine, ITATP = isatino[1,2-b]-1,4,8,9-tetraazatriphenylene) on an ITO electrode in the absence and presence of calf thymus DNA is proposed. The [Ru(bpy)₂ITATP]^3+/2+ and double stranded DNA is assembled onto the ITO electrode using repetitive voltammetric sweeping. The assembly is confirmed by ex situ cyclic voltammetry and the fluorescence microscopy. A pair of diffusion-controlled waves and prewaves for [Ru(bpy)₂ITATP]^3+/2+ is observed in the voltammetric sweeping process. The formal potential of the prewaves is found to be much negative than that of the diffusion-controlled waves. The controllable assembly of [Ru(bpy)₂ITATP]^3+/2+ on the ITO surface is accelerated by DNA and affected by ionic strength. With this DNA-prompted electrochemical technique, a multifunctional biomolecular film containing surface-confined redox center of controllable thickness is fabricated.     

DNA-promoted electrochemical assembly of [Ru(bpy)2IP] at an ITO electrode

A controllable assembly technique of [Ru(bpy)₂IP]^3+/2+ (where bpy = 2,2′-bipyridine and IP = imidazo[4,5,f][1,10]phenanthroline) promoted by calf thymus DNA at an ITO electrode is proposed. The stable assembled layer containing [Ru(bpy)₂IP]^3+/2+ and double stranded DNA is obtained on the ITO electrode using repetitive voltammetric sweeping, confirmed by ex situ voltammetry, X-ray photoelectron spectroscopy (XPS) and the inverted fluorescence microscopy. There exist two pairs of diffusion-controlled waves and two pairs of prewaves for [Ru(bpy)₂IP]²⁺ in the voltammetric sweeping process. The half-wave potentials of the prewaves are far more negative than those of the diffusion-controlled waves. These experimental results suggest that double stranded DNA is enable to accelerate and increase the controllable assembly of Ru(bpy)₂IP]^3+/2+ by using the ITO surface. The fluorescence microscopy imaging reveals that [Ru(bpy)₂IP]^3+/2+ has the ability to bind with double strand DNA. The fluorescence intensity of [Ru(bpy)₂IP]^3+/2+ with DNA is stronger than that without DNA.     

VB1和碳酸钠催化安息香缩合反应

以VB1为催化剂的安息香缩合反应通常在NaOH存在下进行,由于NaOH碱性较强,容易导致VB1结构破坏,重现性较低。探索了利用安全、温和的碱性试剂碳酸钠合成安息香的工艺条件,并通过单因素实验进行了优化。实验结果表明,10.5g(0.1mol)苯甲醛在15mL 95%乙醇加5mL水的混合溶液中,1.75g VB1和7.5mL10%Na2CO3催化下于75℃反应2.0h,收率可达到60.5%。     

Aggregation-induced emission of ruthenium(II) polypyridyl complex [Ru(bpy)2(pzta)]2+

A new ruthenium(II) complex [Ru(bpy)₂(pzta)]²⁺ (1) [bpy = 2,2′-bipyridine; pzta = 6-(pyrzin2-yl)-1,3,5-triazine-2,4-diamine] has been synthesized and characterized. This complex exhibits a typical aggregation-induced emission (AIE) behavior that it is faint in solution but intense in the aggregate state.     

Hydrogenation of cis‐1,4‐polyisoprene catalyzed by Ru(CHCH(Ph))Cl(CO)(PCy3)2

Hydrogenation is a useful method which has been used to improve oxidative and thermal degradation resistance of diene‐based polymers. The quantitative hydrogenation of cis‐1,4‐polyisoprene which leads to an alternating ethylene–propylene copolymer was studied in the present investigation. To examine the influence of key factors on the reaction, such as catalyst concentration, polymer concentration, hydrogen pressure, and temperature, a detailed study of the hydrogenation of cis‐1,4‐polyisoprene catalyzed by the Ru complex, Ru(CH?CH(Ph))Cl(CO)(PCy₃)₂ was carried out by monitoring the amount of hydrogen consumed. Infrared and ¹H‐NMR spectroscopic measurements confirmed the final degree of hydrogenation. The hydrogenation of cis‐1,4‐polyisoprene followed pseudo‐first‐order kinetics in double‐bond concentration up to high conversions of double bond, under all sets of conditions studied. The kinetic results suggested a first‐order behavior with respect to total catalyst concentration as well as with respect to hydrogen pressure. The apparent activation energy for the hydrogenation process, obtained from an Arrhenius plot, was 51.1 kJ mol^?1 over the temperature range of 130 to 180°C. Mechanistic aspects of the catalytic process are discussed. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3259–3273, 2004     

DFT研究钌配合物[Ru（bpy）2（o—R—pip）]^2＋与DNA键合

理论运用密度泛函（DFT）方法,计算钌（Ⅱ）配合物[Ru（bpy）2（o-R-pip）]^2＋（R=-OH,-H,-OCH3）的电子结构和与DNA键合倾向。证实了引入取代基（-OH）导致分子内氢键形成进而导致插入配体共轭面积的增大以及配合物最低空轨道LUMO和相邻的最低空轨道（LUMO＋x,X=0,1,2）的能量明显降低,可大大改善配合物与DNA的键合常数（Kb）。钌配合物与DNA的键合倾向,即Kb（3）〈Kb（2）〈Kb（1）,得以理论解释。     

DNA-promoted electrochemical assembly of [Ru(bpy)2dpp] on the ITO electrode by introducing copper(II) ion

The electrochemical assembly of [Ru(bpy)₂dpp]^3+/2+ (where bpy = 2,2′-bipyridine, dpp = 2,3-bis (2-pyridyl) pyrazine) promoted by calf thymus DNA on an ITO electrode based on the introduction of copper(II) ion has been investigated. There exists a diffusion-controlled wave and two prewaves for the complex in the differential pulse voltammetric sweeping process. The formal potential of the high prewave shift ca. 0.530 V negatively compared with that of the diffusion-controlled wave. Dpp ligand with two vacant chelating N sites in the complex can bite Cu²⁺ and the resultant heterometallic complex shows a weakened assembly in contrast to that of [Ru(bpy)₂dpp]^3+/2+ alone. Furthermore, double stranded DNA is able to accelerate the assembly of the ruthenium complex and heterometallic complex generated by chelating with Cu²⁺ by using the ITO surface, the prompted strength of the latter is far stronger than the former. Their assembled mechanism enhanced by DNA is proposed.