Raman spectra of the pigments of several marine mollusc shells have been obtained using the 514.5 nm laser line of an Ar + laser. Shell species were chosen to obtain a variety of colour. The spectra obtained for the molluscan pigments indicated that they are polyacetylenic in nature, and, from the spectral features, it was deduced that the pigments were carotenoids, with unmethylated polyacetylenic backbones of various conjugation lengths. A logarithmic relationship was established between the number of conjugated double bonds (N) and the C C vibration (n 1 ) of previous reported data for finite polyacetylenic systems, and this relationship was used to evaluate the data obtained in this study. The aragonite and calcite phases of CaCO 3 were also identified to be present in different species of molluscs.

San rock art sites are found throughout southern Africa; unfortunately this unique heritage is rapidly being lost through natural weathering processes, which have been the focus of various studies conducted in the uKhahlamba Drakensberg Park since 1992. It has recently been shown that the ability of Raman spectroscopy to identify salts on rock faces on a micro, as well as nano scale, can make a contribution to these projects.In order to test the feasibility of undertaking on-site analyses, a small rock fragment with red and white pigments still attached, which had weathered off the rock face, was analysed with Raman spectroscopy under laboratory conditions, using a Dilor XY Raman instrument and a DeltaNu Inspector Raman portable instrument. A small sample of black pigment (<1 mm 2 ), collected from a badly deteriorated painting and a few relevant samples collected on site, were analysed as well. It was possible to identify most of the inorganic pigments and minerals detected with previous XRD and EDX measurements including whewellite and weddellite coatings, which could be a tool for carbon dating purposes. Two carotenoid pigments were detected for the first time in San rock art pigments. Animal fat was also observed for the first time on both red and white pigments, on the rock face adjacent to the paintings and in highest concentrations on the back of the rock fragment. The spectra quality makes successful on-site measurements a good prospect.

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Fischer-Tropsch (FT) synthesis is an important process to manufacture hydrocarbons and oxygenated hydrocarbons from mixtures of carbon monoxide and hydrogen (syngas). The catalysis process occurs on, for example, cobalt metal surfaces at elevated temperatures and pressures. A fundamental understanding of the reduction pathway of supported cobalt oxides, and the intermediate species present during the activation, can assist in developing improved industrial supported cobalt catalysts. Hard synchrotron X-rays have the unique ability to probe atomic processes both in terms of phases present as well as the crystallographic and local structure (using the pair distribution function approach) under realistic conditions. In this manuscript we present results from measurements during in situ hydrogen activation of a model Co/alumina catalyst using in situ synchrotron X-ray powder diffraction and pair-distribution function (PDF) analysis on beam line ID31 at the ESRF in Grenoble, France. The PDF analysis showed a substantially improved understanding of the reduction of cobalt oxides, as for the first time all cobalt could be accounted for by using total scattering analysis.

Fischer carbene complexes of tungsten with substituents containing up to two additional different transition metals, with all the metals in electronic contact with the carbene carbon atom, were synthesised and studied both in solution and in the solid state. For the complexes of the type [W(CO) 5 {C(OR¢)R}], the substituents chosen were heteroaromatic 2-benzo[b]thienyl (2-BT), or 2-BT p-bonded to a chromium tricarbonyl fragment ([Cr(CO) 3 (2-h 6 -BT)]) or ferrocenyl (Fc) as the R-substituent, while the OR¢-substituent was systematically varied between an ethoxy or a titanoxy group, to yield the complexes 1b (R¢ = Et, R = 2-BT), 2b (R¢ = Et, R = [Cr(CO) 3 (2-h 6 -BT)]), 3b (R¢ = TiCp 2 Cl, R = 21-BT), 4b (R¢ = TiCp 2 Cl, R = [Cr(CO) 3 (2-h 6 -BT)]), 5b (R¢ = Et, R = Fc) and 6b (R¢ = TiCp 2 Cl, R = Fc). The structural features and their relevance to bonding in the multimetal carbene compounds of both these tungsten and the analogous chromium complexes were investigated as they represent indicators of possible reactivity sites in multimetal carbene assemblies. The possibility of using DFT calculations to quantify the effect of metal-containing substituents on the carbene ligands was tested and correlated with experimental parameters by employing methods such as vibrational spectroscopy, molecular orbital analysis, and cyclic voltammetry.