The stabilisation of novel bonding modes in group 2 complexes

The proposed research seeks to prepare compounds featuring unprecedented bonding modes of the alkaline earth metals and substantially expand the very limited known range of such systems. The recent report of the first complex to feature a bond between two magnesium centres, in which the Mg atoms possess an oxidation state of +1, highlights a number of important questions such as whether the other alkaline earth elements can display analogous bonding modes. This proposal aims to synthesise such compounds featuring the other alkaline earth elements, e.g. the first examples of (beryllium-beryllium)2+ and (calcium-calcium)2+ units. Theorists have proposed these systems to be stable. This chemistry will also be extended towards the synthesis of novel complexes where the beryllium and calcium atoms are bonded to transition metals. The study of main group and transition metal compounds featuring low-coordinate centres and element-element bonds is of great importance, both from the investigation of the fundamental structure and bonding within these systems which challenge our accepted ideas of bonding and from the potential of these highly reactive centres to act as reaction catalysts.Information regarding the bonding within these metal-metal bonded species will come from structural, spectroscopic and theoretical calculations, together with an examination of the fundamental patterns of reactivity displayed by these compounds towards a range of small molecules; including, for example polar/non polar bonds, multiple bonds, diatomics and triatomics, allowing us to develop new reaction pathways such as insertion and cycloaddition-type chemistries. We will also investigate the use of these metal-metal bonded systems as precursors towards new metal-rich cluster compounds via controlled decomposition reactions. The high reactivity of these alkaline earth compounds, although posing practical challenges, makes them not only fascinating from both the fundamental study of their bonding, but also due to their potential application in small molecule activation and catalytic chemistry. Therefore, the results gained from this study will be of great benefit to the scientific community, both from this fundamental structure and bonding viewpoint and the eventual exploitation of their high reactivity in organic reactions and small molecule activation. Additionally, the use of Mg and Ca-based catalysts for these organic reactions would be cheaper and more environmentally benign than many of the lanthanide and transition metal systems currently being exploited for this purpose. The development of metal-rich cluster compounds, stabilised and solubilised by organic chemical groups, are potentially useful in the modelling of solid hydrogen storage materials using solution techniques, which may lead to increased understanding and therefore improvement and optimisation of these compounds.The stabilisation and study of such systems will challenge our accepted ideas of bonding for these elements. Investigation of the bonding within compounds such as these is essential as it contributes towards our understanding of the fundamental structure and bonding within the alkaline earth elements, it is therefore a highly desirable area of research for inorganic chemists and should be actively pursued. We therefore seek EPSRC funding for a 3 year PDRA at Nottingham, technician support, consumables, modest equipment costs associated with the setting up of an independent research laboratory and travel costs for conference attendance. This synthetically challenging research programme will benefit greatly from full participation by DLK, who, as a new lecturer, has a reduced teaching load.