Publications by authors named "Manuel A S Aquino"

The title compound, [Ru(CHN)](PF)·3CHO, was obtained from the reaction of Ru(bimpy)Cl [bimpy is 2,6-bis-(1-benzimidazol-2-yl)pyridine] and bimpy in refluxing ethanol followed by recrystallization from diethyl ether/aceto-nitrile. At 125 K the complex has ortho-rhom-bic (2) symmetry. It is remarkable that the structure is almost centrosymmetric.

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The title compound, [Ru(μ-OCCH)(CHClN)]PF·CHCl, was obtained a rapid substitution reaction of 3-chloro-pyridine for water in [Ru(μ-OCCH)(HO)]PF in 2-propanol and subsequent crystallization from a di-chloro-ethane solution. The cationic diruthenium(II,III) tetra-acetate core lies on a crystallographic inversion center with Ru-Ru and Ru-N bond lengths of 2.2738 (3) and 2.

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With an inversion center at the mid-point of the two Re(III) atoms, the title compound, [Re2Cl2{O2C(CH2)2CH3}4], exhibits a paddle-wheel or lantern-type structure with four n-butyrate groups bridging two Re(III) atoms in a syn-syn fashion. The axial chloride ligands together with the Re-Re quadruple bond [2.2330 (3) Å] complete an essentially octa-hedral geometry around each Re(III) atom.

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Achiral [Ru2(μ-O2CR)4(MeOH)2](PF6) (R = CH3 or C6H5) reacts with the chiral diphosphines R,R- and S,S-Chiraphos (two chiral centers on ligand between the coordinating P atoms) and R-Prophos (one chiral center on ligand between the coordinating P atoms) leading to a disassembly of the paddlewheel core and the highly diastereoselective production of Λ-[Ru(η(2)-O2CC6H5)(η(2)-R,R-Chiraphos)2](PF6) (Λ-R,R-III), Δ-[Ru(η(2)-O2CC6H5)(η(2)-S,S-Chiraphos)2](PF6) (Δ-S,S-III) (the R = CH3 complexes of Chiraphos were reported in a earlier communication in this journal), and Λ-[Ru(η(2)-O2CCH3)(η(2)-R-Prophos)2](PF6) (Λ-R,R-VI), respectively, in high yield and purity. Reactions of the same starting material with R,R- and S,S-o-tolyl-Dipamp (chiral centers are the coordinating P-atoms) lead to an inversion in the chirality-at-metal producing Λ-[Ru(η(2)-O2CC6H5)(η(2)-S,S-o-tolyl-Dipamp)2](PF6) (Λ-S,S-IV), Δ-[Ru(η(2)-O2CC6H5)(η(2)-R,R-o-tolyl-Dipamp)2](PF6) (Δ-R,R-IV), Λ-[Ru(η(2)-O2CCH3)(η(2)-S,S-o-tolyl-Dipamp)2](PF6) (Λ-S,S-V), and Δ-[Ru(η(2)-O2CCH3)(η(2)-R,R-o-tolyl-Dipamp)2](PF6) (Δ-R,R-V). X-ray crystallography of all but Λ-S,S-V and Δ-R,R-V and solid-state circular dichroism (CD) show that only the indicated diastereomers are present in the solid-state.

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In the title compound, [Sn(C13H11N4S)(CH3)3], the Sn(IV) atom is coordinated by an S atom from the 1,5-diphenyl-thio-carbazonato (L) ligand [Sn-S 2.4710 (6) Å] and by three methyl groups [Sn-C 2.123 (3)-2.

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The title compound, [Ru(2)(CH(3)CO(2))(4)(C(6)H(4)N(2))(2)]PF(6)·C(2)H(4)Cl(2), was obtained via a rapid substitution reaction in 2-propanol whereby 3-cyano-pyridine replaces the axial water mol-ecules in the diaquatetra-μ-acetato-diruthenium(II,III) hexa-fluorido-phosphate starting material. The product rapidly precipated and crystals were grown from 1,2-dichloro-ethane. The 1,2-dichloro-ethane mol-ecule of solvation exhibits disorder with two different orientations [occupancy ratio 0.

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[Ru(2)(μ-O(2)CCH(3))(4)(MeOH)(2)](PF(6)) reacts with chiral diphosphines (R,R)- and (S,S)-chiraphos, leading to disassembly and production of the enantiomers Λ-[Ru(η(2)-O(2)CCH(3))(η(2)-(R,R)-chiraphos)(2)](PF(6)) and Δ-[Ru(η(2)-O(2)CCH(3))(η(2)-(S,S)-chiraphos)(2)](PF(6)) in high yield and purity. X-ray crystallography and solid-state circular dichroism (CD) show that only the indicated isomers are present in the solid state. Solution CD measurements also indicate their predominance in solution.

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The title compound, C(23)H(23)NO(5)·CH(2)Cl(2), was obtained via the alkyl-ation of the 12-hydr-oxy-2,3,8,9-tetra-methoxy-benzo[c]phenanthridine salt. The benzo[c]phenanthridine ring system is essentially planar, with a mean out-of-plane deviation of 0.026 Å.

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The Fe(II) of the binuclear Fe(II)Fe(III) active site of pig purple acid phosphatase (uteroferrin) has been replaced in turn by five M(II) ions (Mn(II), Co(II), Ni(II), Cu(II), and Zn(II)). An uptake of 1 equiv of M(II) is observed in all cases except that of Cu(II), when a second more loosely bound Cu(II) is removed by treatment with edta. The products have been characterized by different analytical procedures and by UV-vis spectrophotometry.

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Background: Mixed-valent diruthenium tetracarboxylate complexes were shown to have slight antineoplastic activity against P388 leukemia cell lines. However these complexes suffered from poor water-solubility, which may have detrimentally affected their activity.

Materials And Methods: Mixed-valent diruthenium tetracarboxylates of the type [Ru2(O2CR)4(L)2] (PF6) with L = imidazole, 1-methylimidazole and H2O when R = CH3, L = ethanol when R = Fc (ferrocenyl) or Fc-CH=CH- and of the type M3[Ru2(O2CR)4(H2O)2]4H2O, M = Na+ when R = m-C6H4SO3- and M = K+ when R = p-C6H4SO3-, were tested for cytotoxicity against HeLa and multidrug resistant CoLo 320DM human cancer cell lines.

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