The syntheses and characterization of a series of binuclear cobalt complexes of the octadentate Schiff-base calixpyrrole ligand L are described. The cobalt(II) complex [Co(2)(L)] was prepared by a transamination method and was found to adopt a wedged, Pac-man geometry in the solid state and in solution. Exposure of this compound to dioxygen resulted in the formation of a 90:10 mixture of the peroxo [Co(2)(O(2))(L)] and superoxo [Co(2)(O(2))(L)](+) complexes in which the peroxo ligand was found to bind in a Pauling mode in the binuclear cleft in pyridine and acetonitrile adducts in the solid state. The dioxygen compounds can also be prepared directly from Co(OAc)(2) and H(4)L under aerobic conditions in the presence of a base. The reduction of dioxygen catalyzed by this mixture of compounds was investigated using cyclic voltammetry and rotating ring disk electrochemistry and, in acidified ferrocene solutions, using UV-vis spectrophotometry, and although no formation of peroxide was seen, reaction rates were slow and had limited turnover. The deactivation of the catalyst material is thought to be due to a combination of the formation of stable hydroxy-bridged binuclear complexes, for example, [Co(2)(OH)(L)](+), an example of which was characterized structurally, and the catalytic resting point, the superoxo cation, is formed by a pathway independent of the major peroxo product. Collision-induced dissociation mass spectrometry experiments showed that, while [Co(2)(O(2))(L)]H(+) ions readily lose a single O atom, the resulting Co-O(H)-Co core remains resistant to further fragmentation. Furthermore, DFT calculations show that the O-O bond distance in the dioxygen complexes is not a good indicator of the degree of reduction of the O(2) unit and provide a reduction potential of ca. +0.40 V versus the normal hydrogen electrode for the [Co(2)(O(2))(L)](+/0) couple in dichloromethane solution.

The selective patterning of silver nanoparticles by a patent-pending process to act as a catalyst for metallization with electroless copper was explored on cotton, with a view towards application in the wearable technology sector. Whole area coverage or tracks serving as point-to-point connections were achieved by depositing the catalyst via spraying, or in a more controlled manner using a microdispenser, respectively.Optimization of the catalyst deposition is described, including substrate characterization via contact angle, FTIR and surface charge measurement. The effects of the copper plating bath temperature and dwell time in the plating bath are examined. With plating times as short as 10 minutes, samples of good conductivity (sheet resistance, R, = <10 Ω/sq) and consistency were produced. A higher or lower plating temperature (compared to supplier recommended conditions) increased or reduced the amount of copper deposited respectively. The technology was used to produce well-defined conductive tracks on cotton with widths between 1.5 and 4.0 mm.

The synthesis, properties and application of a Cu(2,2 0 -biquinoline-4,4 0 -dicarboxylic acid) 2 complex in dyesensitized solar cells (DSSC) are described. The complex is electrochemically stable and strongly absorbing with a molar extinction coefficient at l (max) ¼ 564 nm of 11 700 M À1 cm À1 (in MeOH).Experimental and computational data indicate that the HOMO, LUMO and electronic excited state energy levels are appropriate for functionality in a DSSC. From cyclic voltammetry the HOMO is estimated to be À5.27 eV, as supported by computational work, which locates the HOMO at À5.78 eV.From electrochemical, absorption and emission experiments, the MLCT energy levels are expected to be appropriate for electron injection into the TiO 2 conduction band. Our computations support this and locate the key MLCT transition at 563 nm. Despite this, the efficiency in DSSCs is extremely low (<0.1%) suggesting that the dye does not inject excited electrons into the TiO 2 conduction band.

The present study found that differences in admitting and testing practices may contribute to significant differences in rotavirus admission totals. Given these differences, caution should be used when using local case estimates for cost-effectiveness analyses and immunization program decisions. The present study illustrates that understanding the factors that influence the identification of a disease is important when interpreting and applying surveillance data.