Mary McNamara

Copper(II) Complexes of Salicylic Acid Combining Superoxide Dismutase Mimetic Properties with DNA Binding and Cleaving Capabilities Display Promising Chemotherapeutic Potential with Fast Acting in Vitro Cytotoxicity against Cisplatin Sensitive and Resistant Cancer Cell Lines

The complexes [Cu(salH)(2)(H(2)O)] (1), [Cu(dipsH)(2)(H(2)O)] (2), {Cu(3-MeOsal)(H(2)O)(0.75)}(n) (3), [Cu(dipsH)(2)(BZDH)(2)] (4), [Cu(dipsH)(2)(2-MeOHBZDH)(2)]·EtOH (5), [Cu(sal)(phen)] (6), [Cu(dips)(phen)]·H(2)O (7), and [Cu(3-MeOsal)(phen)]·H(2)O (8) (salH(2) = salicylic acid; dipsH(2) = 3,5-diisopropylsalicylic acid; 3-MeOsalH(2) = 3-methoxysalicylic acid; BZDH = benzimidazole; 2-MeOHBZDH = 2 methanolbenzimidazole and phen =1,10-phenanthroline) were prepared and characterized. Structures of 4, 5, and 8 were determined by X-ray crystallography. Compounds 1-8 are potent superoxide dismutase mimetics, and they are inactive as inhibitors of COX-2 activity. Compounds 1, 4, and 5 exhibit moderate inhibition of COX-1. Complexes 6-8 display rapid micromolar cytotoxicity against cisplatin sensitive (breast (MCF-7), prostate (DU145), and colon (HT29)) and cisplatin resistant (ovarian (SK-OV-3)) cell lines compared to 1-5, and they exhibit potent in vitro DNA binding and cleavage capabilities.

FT-IR and raman spectra of a series of metallo-β-cyclodextrin complexes

A series of metallo-β-CD complexes were prepared and formulated as [M2(OH)2β-CD·2 H2O]n−. Changes in the FT-IR and Raman Spectra ofβ-CD on coordination may be taken as evidence for complexation and support for a hydroxy bridged binuclear structure. Further support was obtained from uv/visible and magnetic moment measurements.

FT-IR and raman spectral evidence for metal complex formation withβ-cyclodextrin as a first sphere ligand

Changes occurring in the FT-IR and Raman spectra ofβ-CD when complexed to Mn(III), in a compound formulated as Mn2(OH)2CD, may be taken as indicating the formation of a complex in whichβ-CD is acting simultaneously as a first and second sphere ligand.

Preparation and Characterization of a Composite of Gold Nanoparticles and Single-Walled Carbon Nanotubes and Its Potential for Heterogeneous Catalysis

Abstract A single-walled carbon nanotube-supported gold nanoparticle composite was prepared and characterized by X-ray diffraction, scanning transmission electron microscopy/scanning electron microscopy/transmission electron microscopy, energy-dispersive X-ray analysis, atomic absorption spectroscopy, nitrogen adsorption, Raman spectroscopy, and ultraviolet-visible spectroscopy. The Au particles were found to be crystalline, with a well-defined and narrow particle-size distribution, centered around 7 nm. The activity and selectivity of the composite for solventless aerobic oxidation of a secondary alcohol were examined, and a conversion efficiency of 95% was obtained.

Polynuclear hydroxy-bridged Structure in metallo-β-cyclodextrin complexes: A study of magnetic susceptibility versus temperature

Data of the variation of magnetic susceptibility with temperature were obtained by the Gouy balance method for a series of metallo-/β-CD complexes. The results support the proposal for the presence of polynuclear hydroxy-bridged structures with interacting paramagnetic centres giving rise to an antiferromagnetic character for these complexes. In the case of the Cu(II) complex estimates of the Cu-Cu distance and the Cu-O-Cu bond angle were obtained from the data.

Enantioselective Complexation of Amino Acids by 6A-Deoxy-6A-hydroxyethylamino-β-Cyclodextr in and its Metallo-Derivatives in Aqueous Solution

Enantioselectivity towards several amino acids by metallo-6A-deoxy-6A-hydroxyethyl-amino-β-cyclodextrins (metallo-βCDeas) was investigated by potentiometric titration of the various amino acid/metallo-βCDea systems with NaOH solution. It was shown that the cyclodextrin derivative is capable of distinguishing between enantiomers of amino acid species in the presence of certain metal ions (Co2+, Ni2+, Cu2+and Zn2+). Ni2+-βCDea complexes show the most enantioselectivity, whereas for Cu2+- and Co2+-βCDea complexes less selectivity is observed. As expected, Zn2+-βCDea complexes exhibit no enantioselectivity. Stability and selectivity, however, do not go hand in hand, since the most stable complexes are formed with Cu2+. Several factors play a role in determining stability and selectivity in binary and ternary complexes and further study is required to gain a more comprehensive understanding of these.

Hexakis(prop-2-enamide)copper(II) bis(perchlorate) and hexakis(prop-2- enamide)manganese(II) bis(perchlorate)

The structures of [Cu(AA)(6)](ClO(4))(2), (I), and [Mn(AA)(6)](ClO(4))(2), (II) (AA is acrylamide, also known as prop-2-enamide; C(3)H(5)NO), display both intra- and intermolecular N-H...O hydrogen bonding. A three-dimensional network is propagated via the perchlorate counter-ions. There are two crystallographically independent molecules in the copper complex, with the most significant difference between them being the conformation of one symmetry-related pair of AA ligands which are in the unusual syn conformation. The copper complex exhibits syn/anti disorder of the =CH(2) group in one pair of symmetry-related AA ligands. The Cu(II) and Mn(II) centres are both situated on centres of inversion. The copper complex cation has octahedral coordination geometry with typical Jahn-Teller distortions.

Structural property relationships in conjugated polymers

The synthesis of a series of PPV derivative polymers by the Wittig-Horner reaction is described. The structure of each polymer is varied and the effects of these variations on the optical properties is explored. The effects of alkyloxy side chains is observed between the PPV derivatives Poly(-p-phenylvinylene-co-2,5-bis-octyloxy phenylvinylene.) PPV-OPV and Poly (para-2,5-bis-(n-octyloxy)-phenylvinylene) POPV. The phenyl units of the soluble PPV derivative POPV are replaced by alternate naphthyl units in the polymer Poly(2,5-bis(n-octyloxy)-1,4-phenylene vinylene-1,5-bis(n-octyloxy)-2,6-naphthylene vinylene) POPN-ONV and then fully by naphthyl units in Poly(2,6-bis-(n-octyloxy)-1,5-NaphthyleneVinylene) PONV. The addition of alkyloxy sidechains served to red shift the fluorescence emission as expected. The systematic conversion of phenyl to naphthyl units blue shifted the emission considerably while reducing the Stokes shift. There is evidence to suggest some localization of the pi electrons over the aromatic units of the polymer backbone. PONV is shown to have greater stability towards photo-oxidation then either POPV or PPV-OPV.

Relationships for electron-vibrational coupling in conjugated π organic systems

A series of π conjugated systems were studied by absorption, photoluminescence and vibrational spectroscopy. As is common for these systems, a linear relationship between the positioning of the absorption and photoluminescence maxima plotted against inverse conjugation length is observed. The relationships are in good agreement with the simple particle in a box method, one of the earliest descriptions of the properties of one-dimensional organic molecules. In addition to the electronic transition energies, it was observed that the Stokes shift also exhibited a well-defined relationship with increasing conjugation length, implying a correlation between the electron-vibrational coupling and chain length. This correlation is further examined using Raman spectroscopy, whereby the integrated Raman scattering is seen to behave superlinearly with chain length. There is a clear indication that the vibrational activity and thus nonradiative decay processes are controllable through molecular structure. The correlations between the Stokes energies and the vibrational structure are also observed in a selection of PPV based polymers and a clear trend of increasing luminescence efficiency with decreasing vibrational activity and Stokes shift is observable. The implications of such structure property relationships in terms of materials design are discussed.

An insight into the superior performance of a gold nanocatalyst on single wall carbon nanotubes to that on titanium dioxide and amorphous carbon for the green aerobic oxidation of aromatic alcohols

Abstract Gold nanocomposites based on three supports, single wall carbon nanotubes, carbon black and TiO 2 , were prepared using an in-situ reduction technique and characterized. They were tested for their suitability as heterogeneous catalysts in the green aerobic oxidation of 1-phenylethanol, 2-phenylethanol and benzylalcohol of industrial importance. For all reactions, the use of single wall carbon nanotubes as supports resulted in superior reaction efficiency and specificity for aldehyde to that of TiO 2 and carbon black. The gold nanocatalysts can be reused over several reaction cycles with a minimal degeneration in catalytic activity. The activity of the gold nanoparticle catalyst was related to the shape and size of the gold particles and the properties of the support. The selectivity was ascribed to the functional groups on the substrate, the properties of the supports and the particle size distributions of the gold nanoparticles.