EFFECT OF MORPHOLOGICAL STRUCTURE OF AMINOMETHYL POLYSTYRENE RESIN ON THE CATALYTIC PROPERTIES OF POLYMER-SUPPORTED RUTHENIUM COMPLEXES

 Polymer-supported ruthenium complexes Ⓟ-Phen-Ru-①, Ⓟ-Phen-Ru-②, Ⓟ-Phen-Ru-③, Ⓟ-Phen-Ru-④, Ⓟ-Phen-Ru-⑤, Ⓟ-Phen-Ru-⑥ and Ⓟ-Phen-Ru-⑦ were prepared using aminomethyl polystyrenes of different morphological structures as supports. A variety of alcohols were oxidized efficiently into the corresponding ketones, carboxylic acids or aldehydes with iodosylbenzene (PhIO) catalyzed by aminomethyl polystyrene-supported ruthenium complexes under mild reaction conditions in acetonitrile. The influences of morphological structure of the polymer supporters on the catalytic properties of these metal complexes were investigated in detail.     

Preparation,crystal structures and properties of half-sandwich ruthenium complexes containing salicylbenzoxazole ligands

Three half-sandwich ruthenium complexes [Ru(p-cymene)LCl] containing salicylbenzoxazole ligands [LH = 2-(5-methyl-benzoxazol-2-yl)-4-methyl-phenol (2a), LH = 2-(5-methyl-benzoxazol-2-yl)-4-chloro-phenol (2b), and LH = 2-(5-methyl-benzoxazol-2-yl)-4-bromo-phenol (2c)] were synthesized and characterized. All half-sandwich ruthenium complexes were fully characterized by ¹H and ¹³C NMR spectra, MS, elemental analyses, and UV–vis as well as cyclic voltammetry (CV). The molecular structures of 2a, 2b, and 2c were confirmed by single-crystal X-ray diffraction. Single-crystal X-ray structures show that the synthesized ruthenium complexes are three-legged piano-stools with a six-membered metallocycle formed by coordination of the bidentate salicylbenzoxazole ligands to the metal centers. Data from CV and UV–vis absorption of the ruthenium complexes indicated that by changing the substituent on the para position of (donating or withdraw group) the salicylbenzoxazole ligands, minor changes in redox and electronic properties of the ruthenium complexes were observed.     

环戊二烯基钌配合物催化的高选择性苯乙炔二聚反应

Transition metal vinylidene complexes (M=C=CHR) have attracted a great deal of attention in recent years as a new type of organometallic intermediates that may have unusual reactivity[1]. Their reactivity has been explored and their application to organic synthesis is developed[2]. Recent reports on the ruthenium-vinylidene complexes[3]suggest that the reaction of ruthenium-vinylidene complexes with a base generates the coordinatively unsaturated ruthenium acetylide species, which are involved in a number of catalytic and stoichiometric reactions of alkynes. For example,the coordinatively unsaturated ruthenium acetylide species C5Me5Ru(PPh3)-C≡CPh,formed from the reaction of the vinylidene complex C5Me5Ru(PPh3) (Cl)=C=CHPh with a base was reactive toward a variety of small molecules and active in catalytic dimerization of terminal alkynes[4]. The dimerization of terminal alkyne is an effective method of forming enynes, but its synthetic application in organic synthesis has been limited dueto low selectivity for dimeric products[5]. In this communication, we report that three ruthenium complexes were used as catalysts for the highly selective dimerization of phenylacetylene.     

钌(II)多吡啶配合物光断裂DNA的实验研究

研究了一系列钌(II)多吡啶配合物对pBR 322 DNA 的光断裂作用, 并与光谱法和粘度法的研究结果进行了对比. 实验结果表明, 钌(II)多吡啶配合物光断裂DNA的能力不仅与配合物与DNA相互作用的结合模式和结合强度有关, 还与配合物自身的电子结构有关; 钌(II)多吡啶配合物对DNA的光断裂存在立体选择性; 其断裂机理是激发态的配合物与溶液中的氧分子发生能量转移生成单线态氧活性氧化物种, 将鸟嘌呤碱基氧化而导致DNA断裂. 本研究对于遗传工程中的化学核酸酶以及以DNA为靶标的药物设计有重要的意义.     

An electrochemical study of antineoplastic gallium, iron and ruthenium complexes with redox noninnocent alpha-N-heterocyclic chalcogensemicarbazones

The electrochemical properties of a series of alpha-N-heterocyclic chalcogensemicarbazones (HL), namely, thiosemicarbazones, selenosemicarbazones, and semicarbazones, and their gallium(III), iron(III), and ruthenium(III) complexes with the general formula [ML(2)][Y] (M = Ga, Fe or Ru; Y = PF(6)(-), NO(3)(-), or FeCl(4)(-)) were studied by cyclic voltammetry. The novel compounds were characterized by elemental analysis, a number of spectroscopic methods (NMR, UV-vis, IR), mass spectrometry and by X-ray crystallography. All complexes show several, mostly reversible, redox waves attributable to the reduction of the noninnocent chalcogensemicarbazone ligands at lower potentials (<-0.4 V vs NHE) than the metal-centered iron or ruthenium redox waves (>0 V vs NHE) in organic electrolyte solutions. The cyclic voltammograms of the gallium complexes display at least two consecutive reversible one-electron reduction waves. These reductions are shifted by approximately 0.6 V to lower potentials in the corresponding iron and ruthenium complexes. The electrochemical, chemical, and spectroscopic data indicate that the ligand-centered reduction takes place at the CH(3)CN double bond. Quantum chemical calculations on the geometric and electronic structures of 2-acetylpyridine (4)N,(4)N-dimethylthiosemicarbazone (HL(B)), the corresponding metal complexes [Ga(L(B))(2)](+) and [Fe(II)(L(B))(2)], and the one-electron reduction product for each of these species support the assignment of the reduction site and elucidate the observed order of the ligand-centered redox potentials, E(1/2)([Fe(II)(L)(2)]) < E(1/2)(HL) < E(1/2)([Ga(L)(2)](+)). The influence of water on the redox potentials of the complexes is reported and the physiological relevance of the electrochemical data for cytotoxicity as well as for ribonucleotide reductase inhibitory capacity are discussed.     

Transfer hydrogenation of ketones catalysed by half‐sandwich (η6‐p‐cymene) ruthenium(II) complexes incorporating benzoylhydrazone ligands

Neutral half‐sandwich η⁶‐p ‐cymene ruthenium(II) complexes of general formula [Ru(η⁶‐p ‐cymene)Cl(L)] (HL = monobasic O, N bidendate benzoylhydrazone ligand) have been synthesized from the reaction of [Ru(η⁶‐p ‐cymene)(μ‐Cl)Cl]₂ with acetophenone benzoylhydrazone ligands. All the complexes have been characterized using analytical and spectroscopic (Fourier transform infrared, UV–visible, ¹H NMR, ¹³C NMR) techniques. The molecular structures of three of the complexes have been determined using single‐crystal X‐ray diffraction, indicating a pseudo‐octahedral geometry around the ruthenium(II) ion. All the ruthenium(II) arene complexes were explored as catalysts for transfer hydrogenation of a wide range of aromatic, cyclic and aliphatic ketones with 2‐propanol using 0.1 mol% catalyst loading, and conversions of up to 100% were obtained. Further, the influence of other variables on the transfer hydrogenation reaction, such as base, temperature, catalyst loading and substrate scope, was also investigated.     

Preparation, spectrochemical, and computational analysis of L-carnosine (2-[(3-aminopropanoyl)amino]-3-(1H-imidazol-5-yl)propanoic acid) and its ruthenium (II) coordination complexes in aqueous solution

This study reports the synthesis and characterization of novel ruthenium (II) complexes with the polydentate dipeptide, L-carnosine (2-[(3-aminopropanoyl)amino]-3-(1H-imidazol-5-yl)propanoic acid). Mixed-ligand complexes with the general composition [ML(p)(Cl)(q)(H?O)(r)]·xH?O (M = Ru(II); L = L-carnosine; p = 3 - q; r = 0-1; and x = 1-3) were prepared by refluxing aqueous solutions of the ligand with equimolar amounts of ruthenium chloride (black-alpha form) at 60 °C for 36 h. Physical properties of the complexes were characterized by elemental analysis, DSC/TGA, and cyclic voltammetry. The molecular structures of the complexes were elucidated using UV-Vis, ATR-IR, and heteronuclear NMR spectroscopy, then confirmed by density function theory (DFT) calculations at the B3LYP/LANL2DZ level. Two-dimensional NMR experiments (1H COSY, 13C gHMBC, and 1?N gHMBC) were also conducted for the assignment of chemical shifts and calculation of relative coordination-induced shifts (RCIS) by the complex formed. According to our results, the most probable coordination geometries of ruthenium in these compounds involve nitrogen (N1) from the imidazole ring and an oxygen atom from the carboxylic acid group of the ligand as donor atoms. Additional thermogravimetric and electrochemical data suggest that while the tetrahedral-monomer or octahedral-dimer are both possible structures of the formed complexes, the metal in either structure occurs in the 2? oxidation state. Resulting RCIS values indicate that the amide-carbonyl, and the amino-terminus of the dipeptide are not involved in chelation and these observations correlate well with theoretical shift predictions by DFT.     

Multimetallic ruthenium(II) complexes as electrochemiluminescent labels

Two homometallic complexes containing two and three ruthenium polypyridyl units linked by amino acid lysine (Lys) and the related dipeptide (LysLys) were synthesized and their electrochemical, spectroscopic, and electrochemiluminescence (ECL) properties were investigated. The electrochemical and photophysical data indicate that the two metal complexes largely retain the electronic properties of the reference compound for the separate ruthenium moieties in the two bridged complexes, [4-carboxypropyl-4'-methyl-2,2'-bipyridine]bis(2,2'-bipyridine)ruthenium(II) complex. The ECL studies, performed in aqueous media in the presence of tri-n-propylamine as co-reactant, show that the ECL intensity increases by 30% for the dinuclear and trinuclear complexes compared to the reference. Heterogeneous ECL immunoassay studies, performed on larger dendritic complexes containing up to eight ruthenium units, demonstrate that limitations due to the slow diffusion can easily be overcome by means of nanoparticle technology. In this case, the ECL signal is proportional to the number of ruthenium units. Multimetallic systems with several ruthenium centers may, however, undergo nonspecific bonding to streptavidin-coated particles or to antibodies, thereby increasing the background ECL intensity and lowering the sensitivity of the immunoassay.     

Synthesis, characterization, redox property and biological activity of Ru(II) carbonyl complexes containing O,N-donor ligands and heterocyclic bases

Stable ruthenium(II) carbonyl complexes having the general composition [RuCl(CO)(PPh3)(B)(L)] (where B=PPh3, pyridine, piperidine or morpholine; L=anion of bidentate Schiff bases (Vanmet, Vanampy, Vanchx)) were synthesized from the reaction of [RuHCl(CO)(PPh3)2(B)] with bidentate Schiff base ligands derived from condensation of o-vanillin with primary amines such as methylamine, 2-aminopyridine and cyclohexylamine. The new complexes were characterized by elemental analysis, IR, UV-Vis and 1H NMR spectral data. The redox property of the complexes were studied by cyclic voltammetric technique and the stability of the complexes towards oxidation were related to the electron releasing or electron withdrawing ability of the substituent in the phenyl ring of o-vanillin. An octahedral geometry has been assigned for all the complexes. In all the above reactions, the Schiff bases replace one molecule of PPh3 and hydride ion from the starting complexes, which indicate that the Ru-N bonds present in the complexes containing heterocyclic nitrogen bases are stronger than the Ru-P. The Schiff bases and their ruthenium(II) complexes have been tested in vitro to evaluate their activity against bacteria, viz., Staphylococcus aureus (209p) and E. coli (ESS 2231).     

空间因素对敏化剂性质的影响

本文介绍了一种新的敏化剂cis-(NCS)₂-bis(2,2′-bipyridyl-3,3′-dicar-boxylate)ruthenium(Ⅱ)的合成,测定了它的吸收光谱及氧化还原电位,并将这种染料吸附到具有大比表面的TiO₂纳晶电极上测量它的光电转换效率。另外,参照文献分别合成出cis-(NCS)₂-bis(2,2′-bipyrdyl-4,4′-or 5,5′-dicarboxylate)Ru(Ⅱ)染料,测定它们的光电及光物理性质并以此为依据讨论了空间因素对敏化剂性质的影响。     

Ruthenium metallopharmaceuticals

The well-developed synthetic chemistry of ruthenium, particularly with ammine, amine and imine ligands, provides for many approaches to innovative new metallopharmaceuticals. Advantages of utilizing ruthenium am(m)ine complexes in drug development include, (1) reliable preparations of stable complexes with predictable structures; (2) the ability to tune ligand affinities, electron transfer and substitution rates, and reduction potentials; and (3) an increasing knowledge of the biological effects of ruthenium complexes. Many Ru(II) and Ru(III) am(m)ine complexes selectively bind to imine sites in biomolecules. Collectively, these lend ruthenium complexes to redox-activation and photodynamic approaches to therapy as well as the development of radiopharmaceuticals containing one of several radionuclides of ruthenium. Ruthenium red and the related Ru360 strongly inhibit calcium ion uptake in the mitochondria. A number of ruthenium compounds with anticancer activity appear to penetrate tumors through a transferrin-mediated process and bind to cellular DNA following intracellular activation by reduction. Ruthenium complexes exhibit both nitric oxide release and scavenging functions that can affect vasodilation and synapse firing. Simple ruthenium complexes are unusually effective in suppressing the immune response by inhibiting T cell proliferation.     

Interaction of aryldiazonium salts with some schiff-base complexes of cobalt and ruthenium

The interaction of aryldiazonium ions with some Schiff-base complexes of cobalt and ruthenium have been studied. With cobalt, one-electron oxidation of [Co(II)Salen] occurred; with [Co(I)Salen] the corresponding Co(III)-aryl complexes were isolated. In the case of ruthenium oxidation also occurs, [Ru(Salen)(CO)py] gave the corresponding monocation. The results, especially for ruthenium, are in contrast to the stabilisation of both nitrosyl and aryldiazonium adducts in analogous porphyrin complexes.     

Synthesis, characterization and electrochemical studies of mixed ligand complexes of ruthenium(ii) with DNA

Two mixed ligand complexes of ruthenium(ii) [Ru(bzimpy)(bpy)(OH(2))](2+) (1) and [Ru(bzimpy)(phen)(OH(2))](2+) (2) have been synthesized and characterized by FAB mass, (1)H NMR, cyclic voltammetry and spectroelectrochemical measurements. Controlled potential electrolysis of these complexes results in the conversion of ruthenium(ii) to ruthenium(iii) at 0.6 V and ruthenium(iii) to ruthenium(iv) at 0.8 V vs. SCE. The binding constant of these complexes with DNA has been determined electrochemically and found to be (3.58 +/- 0.25) x 10(4) and (2.87+/- 0.2) x 10(4) M(-1). Viscosity measurements suggest that these complexes bind with DNA through intercalation. Such intercalative binding to DNA has been found to induce chirality to the two complexes. Electrochemically generated ruthenium(iv) species of these complexes have been found to bring about oxidative cleavage in DNA.     

Half-sandwich ruthenium complexes with Schiff base ligands bearing a hydroxyl group: Preparation,characterization and catalytic activities

Three half-sandwich ruthenium(II) complexes with hydroxyl group functionalized Schiff-base ligands [Ru(p-cymene)LCl] ( 2a-2c ) have been synthesized and characterized. All ruthenium complexes were fully characterized by ¹H and ¹³C NMR spectra, mass spectrometry and infrared spectrometry. The molecular structure of ruthenium complex 2c was confirmed by single-crystal X-ray diffraction methods. Furthermore, these half-sandwich ruthenium complexes were found to exhibit high catalytic activity for nitro compounds reduction using NaBH₄ reducing agent in the presence of cetyltrimethylammonium bromide (CTAB) in water at room temperature.     

手性钌配合物的合成、抗肿瘤活性及其与血清蛋白的相互作用

合成了手性钌配合物Δ, Λ-[Ru(bpy)₂(pyip)]²⁺, 通过元素分析、核磁共振、质谱和CD光谱对配合物进行了表征. 采用MTT法评价了3种异构体对多种肿瘤细胞株的体外抗肿瘤活性以及对正常细胞的毒性. 结果表明, Δ-[Ru(bpy)₂(pyip)]²⁺的抗肿瘤活性明显优于其异构体, 对A375, SW480, MCF-7和A549的半数抑制浓度低于顺铂. 通过荧光光谱法研究了在生理pH条件下, 手性钌配合物与牛血清白蛋白(BSA)之间的结合作用以及荧光猝灭机制. 依据Scatchard方程测定了结合常数和结合位点数, 根据热力学方程讨论了两者间的主要作用力类型. 结果表明, 钌配合物对牛血清白蛋白的荧光猝灭机制为静态猝灭. Δ-1, 1和Λ-1与牛血清白蛋白的结合常数分别为1.16×10⁵, 5.12×10⁴和3.64×10⁴, 结合位点数均为1, 主要作用力类型是静电作用. 钌配合物在体内能够被血清蛋白存储转运且结合时对蛋白构象无影响.     

A Dye-sensitized Nanocrystalline Solid State Photovoltaic Cell

Dye-sensitized photovoltaic cells based on nanocrystalline TiO, film are of considerabletechnological interest because of their high conversion efficiency and potential low cost.However the liquid junction photovoltaic cells have a series of technological problems inpractical applications. Recently, the replacement of liquid electrolyte by solid stateconductors such as ionic conducting polymers' and organic hole tfansport materialsZ hasbeen tested. In this papef, we report the fabrication of …     

Combined ruthenium(II) and lipase catalysis for efficient dynamic kinetic resolution of secondary alcohols. Insight into the racemization mechanism

Pentaphenylcyclopentadienyl ruthenium complexes (3) are excellent catalysts for the racemization of secondary alcohols at ambient temperature. The combination of this process with enzymatic resolution of the alcohols results in a highly efficient synthesis of enantiomerically pure acetates at room temperature with short reaction times for most substrates. This new reaction was applied to a wide range of functionalized alcohols including heteroaromatic alcohols, and for many of the latter, enantiopure acetates were efficiently prepared for the first time via dynamic kinetic resolution (DKR). Different substituted cyclopentadienyl ruthenium complexes were prepared and studied as catalysts for racemization of alcohols. Pentaaryl-substituted cyclopentadienyl complexes were found to be highly efficient catalysts for the racemization. Substitution of one of the aryl groups by an alkyl group considerably slows down the racemization process. A study of the racemization of (S)-1-phenylethanol catalyzed by ruthenium hydride eta(5)-Ph(5)CpRu(CO)(2)H (8) indicates that the racemization takes place within the coordination sphere of the ruthenium catalyst. This conclusion was supported by the lack of ketone exchange in the racemization of (S)-1-phenylethanol performed in the presence of p-tolyl methyl ketone (1 equiv), which gave <1% of 1-(p-tolyl)ethanol. The structures of ruthenium chloride and iodide complexes 3a and 3c and of ruthenium hydride complex 8 were confirmed by X-ray analysis.     

Catalytic and biological activities of Ru(III) mixed ligand complexes containing N,O donor of 2-hydroxy-1-naphthylideneimines

A series of stable low spin Ru(III) complexes of the type [RuX2(EPh3)2(L)] (where E = P or As; X = Cl or Br; L = mono basic bidentate Schiff bases) have been synthesized and were characterized by analytical, spectral and electrochemical data. A distorted octahedral geometry has been proposed for all the complexes. These complexes catalyze oxidation of primary alcohols and secondary alcohol with high yields in the presence of N-methylmorpholine-N-oxide (NMO). The ruthenium(III) Schiff base complexes show growth inhibitory activity against the bacteria Staphylococcus aureus (209p) and E. coli ESS (2231).     

Ruthenium complexes of the general formula [RuCl2(PHOX)2] and their catalytic activity in the Mukaiyama aldol reaction

New ruthenium phosphinooxazoline (PHOX) complexes were synthesized and applied in the Mukaiyama aldol reaction. Four ruthenium complexes of the general formula [RuCl₂(PHOX)₂] were synthesized from [RuCl₂(dmso)₄] and the corresponding PHOX ligands through thermal ligand exchange. Two of the complexes were characterized structurally. Achiral PHOX ligands gave the ruthenium complexes as single isomers, whereas chiral PHOX ligands gave a mixture of isomers and also some incomplete substitution. After activation by chloride abstraction, one of the new ruthenium complexes was applied as catalyst in the Mukaiyama aldol reaction to give silyl-protected β-hydroxyl alcohols in 74–92% isolated yields (room temperature, 18–24 h reaction time, 1 mol % catalyst loading).     

非手性PNNP型钌配合物催化仲醇的外消旋化研究

制备了两种非手性PNNP型钌配合物Ru(BF4)2P2N2(3a,P2N2=N,N'-双-[邻-(二苯基膦)苯哑甲基]乙二胺)和Ru(BF4)2P2H4(3b,P2N2H4=N,N'-双-[邻-(二苯基膦)苯甲基]乙二胺),并以(R)-苯乙醇的消旋化为探针反应,分别考察了添加剂、溶剂、催化剂用量及温度等对两种钌配合物催化反应的影响,得到了较理想的反应条件,即4%3a,2 mL甲苯,lequiv.Ag2O,70℃下,在氮气保护下反应12 h.反应结果发现钌配合物3a可以较好地催化仲醇的消旋化,其中(R)-和(S)-苯乙醇消旋化反应后,ee都为58%;另外(S)-对甲基苯乙醇和(S)-对氟苯乙醇消旋化反应后,ee值分别为85%和71%.并初步试探了以苯乙醇为探针底物,钌配合物结合脂肪酶Candida antarctica催化的动态动力学拆分.