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Arene Complexes (arene + complex)
Selected AbstractsMedicinal Organometallic Chemistry: Designing Metal Arene Complexes as Anticancer AgentsCHEMISTRY - AN ASIAN JOURNAL, Issue 11 2008Abstract The field of medicinal inorganic chemistry is rapidly advancing. In particular organometallic complexes have much potential as therapeutic and diagnostic agents. The carbon-bound and other ligands allow the thermodynamic and kinetic reactivity of the metal ion to be controlled and also provide a scaffold for functionalization. The establishment of structure,activity relationships and elucidation of the speciation of complexes under conditions relevant to drug testing and formulation are crucial for the further development of promising medicinal applications of organometallic complexes. Specific examples involving the design of ruthenium and osmium arene complexes as anticancer agents are discussed. [source] Study on an Aldol Reaction Catalyzed by Ti(IV)/Calix[n]arene ComplexesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 6 2005Annunziata Soriente Abstract Ti(IV)/calixarene complexes, formed in situ or previously prepared with standard procedures, can be conveniently used as efficient catalysts in the aldol reaction of Chan's silyloxydiene with a range of aldehydes bearing either activating or deactivating groups, including aromatic, heteroaromatic and ,,,-unsaturated ones. The structure of both calixarene ligand and aldehyde, as well as the reaction conditions, strongly influence the efficiency of the reaction. NMR experiments in conjunction with the experimental results suggest that the structure of the catalytic species in the Ti(IV)/calixarene system prepared in situ is strongly dependent on the concentration and temperature adopted. [source] Cu[Al(ORF)4] Starting Materials and their Application in the Preparation of [Cu(Sn)]+ (n=12, 8) ComplexesCHEMISTRY - A EUROPEAN JOURNAL, Issue 27 2009Gustavo Santiso-Quiñones Dr. Abstract Naked copper,? A newly developed simple two-step route to weakly coordinated CuI starting materials that were used to prepare novel copper,cyclosulfur adducts, including the first M+,S12 complex (see figure, RF= C(CF3)3, C(CH3)(CF3)2, or CH(CF3)2). Reactions with the [Al{OC(CF3)3}4], counterion mimic gas-phase chemistry inside a mass spectrometer (to form [Cu(S12)]+). An effective route to stable, almost-"naked" CuI salts of weakly coordinating anions (WCAs) of the type [Al(ORF)4], has been developed. Born,Fajans,Haber cycles and theoretical calculations suggest that this methodology is useful for the generation of CuI salts regardless of the larger WCA used. The first homoleptic CuI,arene complex [Cu(1,2-F2C6H4)2]+[Al{OC(CF3)3}4], (1), the first CuI,methylenechloride complex [Cu(CH2Cl2)Al{OC(CH3)(CF3)2}4] (2), and the donor-free dimer [CuAl{OCH(CF3)2}4]2 (3) were synthesized in quantitative yields by sonicating Li[Al(ORF)4] (RF=C(CF3)3, C(CH3)(CF3)2, or CH(CF3)2), AgF, and a three-fold excess of CuI in 1,2-F2C6H4 (1) or CH2Cl2 (2, 3). Substances 1,3 are good starting materials for further CuI chemistry, and the reaction of 1,3 with the weak Lewis base cyclooctasulfur gave the first CuI,sulfur complexes of type [Cu(S12)(S8)]+[Al{OC(CF3)3}4], (4), [Cu(CH2Cl2)(S12)]+[Al{OC(CF3)3}4], (5), [A1Cu(1,5-,1,,1 -S8)CuA1] (6; A1=[Al{OC(CH3)(CF3)2}4],), and a CuI,S8 1D coordination polymer with [Cu2(S8)2A22] (7; A2=[Al{OCH(CF3)2}4],), as a monomeric repeat unit. Complexes 4 and 5 are the first example of any metal coordinated to cyclo-S12 and 4 is the first example of a complex having an element in two allotropic modifications as a ligand. [source] Osmium(II) and Ruthenium(II) Arene Maltolato Complexes: Rapid Hydrolysis and Nucleobase BindingCHEMISTRY - A EUROPEAN JOURNAL, Issue 9 2007Abstract Density functional calculations show that aquation of [Os(,6 -arene)(XY)Cl]n+ complexes is more facile for complexes in which XY=an anionic O,O-chelated ligand compared to a neutral N,N-chelated ligand, and the mechanism more dissociative in character. The O,O-chelated XY=maltolato (mal) [M(,6 - p -cym)(mal)Cl] complexes, in which p -cym=p -cymene, M=OsII (1) and RuII (2), were synthesised and the X-ray crystal structures of 1 and 2,2,H2O determined. Their hydrolysis rates were rapid (too fast to follow by NMR spectroscopy). The aqua adduct of the OsII complex 1 was 1.6,pKa units more acidic than that of the RuII complex 2. Dynamic NMR studies suggested that O,O-chelate ring opening occurs on a millisecond timescale in coordinating proton-donor solvents, and loss of chelated mal in aqueous solution led to the formation of the hydroxo-bridged dimers [(,6 - p -cym)M(,-OH)3M(,6 - p -cym)]+. The proportion of this dimer in solutions of the OsII complex 1 increased with dilution and it predominated at micromolar concentrations, even in the presence of 0.1,M NaCl (conditions close to those used for cytotoxicity testing). Although 9-ethylguanine (9-EtG) binds rapidly to OsII in 1 and more strongly (log,K=4.4) than to RuII in 2 (log,K=3.9), the OsII adduct [Os(,6 - p -cym)(mal)(9EtG)]+ was unstable with respect to formation of the hydroxo-bridged dimer at micromolar concentrations. Such insights into the aqueous solution chemistry of metal,arene complexes under biologically relevant conditions will aid the rational design of organometallic anticancer agents. [source] Medicinal Organometallic Chemistry: Designing Metal Arene Complexes as Anticancer AgentsCHEMISTRY - AN ASIAN JOURNAL, Issue 11 2008Abstract The field of medicinal inorganic chemistry is rapidly advancing. In particular organometallic complexes have much potential as therapeutic and diagnostic agents. The carbon-bound and other ligands allow the thermodynamic and kinetic reactivity of the metal ion to be controlled and also provide a scaffold for functionalization. The establishment of structure,activity relationships and elucidation of the speciation of complexes under conditions relevant to drug testing and formulation are crucial for the further development of promising medicinal applications of organometallic complexes. Specific examples involving the design of ruthenium and osmium arene complexes as anticancer agents are discussed. [source] Organometallic Ruthenium Inhibitors of Glutathione- S -Transferase P1-1 as Anticancer DrugsCHEMMEDCHEM, Issue 12 2007Han Ang Dr. Abstract Ruthenium,arene complexes conjugated to ethacrynic acid were prepared as part of a strategy to develop novel glutathione- S -transferase (GST) inhibitors with alternate modes of activity through the organometallic fragment, ultimately to provide targeted ruthenium-based anticancer drugs. Enzyme kinetics and electrospray mass spectrometry experiments using GST P1-1 and its cysteine-modified mutant forms revealed that the complexes are effective enzyme inhibitors, but they also rapidly inactivate the enzyme by covalent binding at Cys,47 and, to a lesser extent, Cys,101. They are highly effective against the GST Pi-positive A2780 and A2780cisR ovarian carcinoma cell lines, are among the most effective ruthenium complexes reported so far, and target ubiquitous GST Pi overexpressed in many cancers. [source] | ||||||||||