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Ruthenium(II) π‐coordination onto [28]hexaphyrins(1.1.1.1.1.1) has been accomplished. Reactions of bis‐AuIII and mono‐AuIII complexes of hexakis(pentafluorophenyl) [28]hexaphyrin with [RuCl2(p‐cymene)]2 in the presence of NaOAc gave the corresponding π‐ruthenium complexes, in which the [(p‐cymene)Ru]II fragment sat on the deprotonated side pyrrole. A similar reaction of the bis‐PdII [26]hexaphyrin complex afforded a triple‐decker complex, in which the two [(p‐cymene)Ru]II fragments sat on both sides of the center of the [26]hexaphyrin framework. [ABSTRACT FROM AUTHOR]

Considering the promising previous results of ct‐[RuCl(CO)(dppb)(bipy)]PF6 (where dppb = 1,4‐bis(diphenylphosphino)butane and bipy = 2,2′‐bipyridine) as an antitumor agent, novel biological assays evaluating its toxicogenic potential were performed. The genotoxicity of the compound was evaluated by the in vitro micronucleus test (V79, Chinese hamster lung fibroblasts; HepG2, hepatocellular carcinoma cells), in vivo bone marrow micronucleus test and comet assay in hepatocytes (Swiss mice). The animals were treated with 0.63, 1.25, 2.5 and 5.0 mg/kg body weight (bw) of the compound. Negative (water) and positive (cisplatin, 1.5 mg/kg bw; methyl methanesulfonate, 40 mg/kg bw) controls were included. The parameters considered in the comet assay were the percentage of tail DNA, tail moment and tail length. The results of the in vitro micronucleus tests showed the absence of genotoxicity in V79 cells, while the compound was genotoxic in HepG2 cells at a concentration of 1.25 μm. In the in vivo micronucleus test, the compound was not genotoxic at the different doses evaluated. In the comet assay, only the dose of 5.0 mg/kg bw resulted in a significant increase in the frequency of DNA damage in hepatocytes when compared to the negative control. The genotoxic effect observed in HepG2 cells and in the liver comet assay indicates that the compound was metabolized by hepatic cells. The genotoxicity of the ct‐[RuCl(CO)(dppb)(bipy)]PF6 was evaluated by the in vitro micronucleus test, in vivo bone marrow micronucleus test, and comet assay in hepatocytes. The results showed the absence of genotoxicity in V79 cells, while the compound was genotoxic in HepG2 cells and in hepatocytes from Swiss mice, indicating that the compound was metabolized by hepatic cells. [ABSTRACT FROM AUTHOR]

The dication complex trans(O,S)‐[Ru(bpy)(dmso‐O)2(dmso‐S)2](OTf)2 [1·(OTf)2; bpy = 2,2′‐bipyridyl; dmso = dimethyl sulfoxide; OTf– = CF3SO3–] was obtained from the reaction of cis(Cl),cis(S)‐[RuCl2(bpy)(dmso‐S)2] with Ag(OTf) in DMSO. The crystal structure of 1·(OTf)2 revealed two labile dmso‐O ligands and two less‐labile dmso‐S ligands positioned cis to each other. In DMSO, the equatorial dmso‐O in 12+ equilibrates with its linkage isomer dmso‐S to fac(S)‐[Ru(bpy)(dmso‐O)(dmso‐S)3]2+ [1iso2+] ([1iso2+]/[12+] = 3:97 at 298 K and 33:67 at 373 K). The linkage isomerization kinetic parameters, determined by 1H NMR, were ΔH = 22(1) kJ mol–1 and ΔS = 52(2) J mol–1 K–1. The two O‐bonded dmso ligands of 1·(OTf)2 were easily solvolyzed in MeCN to form trans(NMeCN,S)‐[Ru(bpy)(MeCN)2(dmso‐S)2](OTf)2 [2·(OTf)2]. Moreover, the reaction of 1·(OTf)2 with 1,10‐phenanthroline (phen) in acetone afforded cis‐[Ru(bpy)(phen)(dmso‐S)2](OTf)2 [3·(OTf)2] in very good yield (95 %) and excellent purity. 1·(OTf)2 was efficiently synthesized. In DMSO, the equatorial dmso‐O reversibly isomerizes into the S‐bonded form, 1iso·(OTf)2. In MeCN, both O‐bonded dmso ligands in 12+ are selectively replaced to form 2·(OTf)2. Finally, the reaction of 1·(OTf)2 with phen in acetone affords the cis‐bis‐heteroleptic complex 3·(OTf)2 in good yield. [ABSTRACT FROM AUTHOR]

Dicationic ruthenium(II)-p-cymene complexes containing curcumin ligands (curcH = curcumin, bdcurcH = bisdemethoxycurcumin) and ionic N-methyl-1,3,5-triaza-7-phosphaadamantane [PTA-Me]X (X = BF4 or I) have been synthesized and fully characterized for the first time. The solid-state structure of [Ru(p-cym)(curc)(PTA-Me)][SO3CF3][BF4] has also been determined by single-crystal X-ray diffraction. Modest antiproliferative activities of the complexes were observed against cisplatin-sensitive and cisplatin-resistant human ovarian carcinoma cells (A2780 and A2780cisR, respectively) and nontumorigenic human embryonic kidney (HEK293) cells. [ABSTRACT FROM AUTHOR]

A series of coupling products have been prepared by a ruthenium(II)-catalyzed direct ortho-C–H arylation of 2-(aryl/heteroaryl)-substituted quinazolines with (hetero)aryl bromides. Tri(hetero)aryl-substituted alkenes were also prepared by olefinic C–H activation of 2-(2-arylvinyl)quinazoline derivatives. High conversions and selectivities were achieved by choosing the appropriate ruthenium(II) carboxylate catalyst system, solvent, and reaction temperature. The possibility of a C(sp3)–H functionalization by applying an arylation/reduction reaction sequence was also demonstrated. [ABSTRACT FROM AUTHOR]

To study the fate of a molecular di-μ-oxo-bridged trinuclear ruthenium complex, [(NH3)5Ru-O-Ru(NH3)4-O-Ru(NH3)5]6+, also known as Ru-red, during the electro-driven water oxidation reaction, electrochemical in situ surface enhanced Raman spectroscopy (SERS) investigations have been conducted on an electrochemically roughened gold surface in acidic condition. It was previously described that on a basal plane pyrolitic graphite electrode in 0.1 M H2SO4 aqueous solution, Ru-red undergoes one electron oxidative conversion into a stable higher oxidation state ruthenium complex, Ru-brown, at <1.0 V ( vs normal hydrogen electrode (NHE)), and this leads to water oxidation and dioxygen release, but the fate of Ru-red during electrochemistry was not studied in much detail. In this investigation, Ru-red dispersed in acid electrolyte and immobilized on a roughened gold electrode without Ru-red in solution has been subjected to anodic controlled potential experiments, and in situ SERS was carried out at various potentials in succession. The electrochemical SERS data obtained for Ru-red are also compared with in situ SERS results of an electrodeposited ruthenium oxide thin film on the Au disk. Our study suggests that on a gold electrode in sulfuric acid solution containing Ru-red, one electron oxidative conversion of Ru-red to a higher oxidation state ruthenium compound, Ru-brown, occurs at ca. 0.74 V ( vs NHE), as supported by the electrochemical in situ SERS experiments. Moreover, at higher potentials and on Au disk, the Ru-red / Ru-brown are not stable and slowly decompose or electro-oxidize leading to deactivation of the tri-ruthenium catalytic system in acidic medium. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The RuIV-based transition metal catalysts [Ru(η3:η3-C10H16)Cl2(PPh3)] ( 1), [Ru(η3:η3-C10H16)Cl2(PCy3)] ( 2), and [Ru(η3:η3-C10H16)(CF3COO)2(PPh3)] (3) have been synthesized and investigated for their use as initiators in the thermally and photo-initiated ring-opening metathesis polymerization (photo-ROMP) of norborn-2-ene (NBE). Compounds 1 and 3 display significant photo-ROMP activity with NBE whereas compound 2, although active in the ROMP of NBE, shows virtually no latency at all. The results are discussed with respect to the structural features of the novel catalysts. [ABSTRACT FROM AUTHOR]