Well-defined, bimetallic molecular clefts: A new approach to nitrogen fixation and transformation

A new macrocyclic scaffold has been developed that will assist in the construction of innovative bimetallic molecules where both the immediate environment and juxtaposition of the metals are defined by design. The hinged, or Pacman topology that these compounds adopt will help promote scientifically unique and potentially commercially exploitable chemistry of nitrogen by providing a well-defined and easily-studied reaction pocket. Initially, the preparation and characterisation of new, low valent, early transition metal (titanium, zirconium, vanadium, lanthanides) Pacman compounds for dinitrogen transformation will be considered. This is an original, prefabricated dinuclear approach to dinitrogen activation and will yield nonfragmentary compounds that are primed to react with organic substrates to form new N-E bonds (E = H, C, Si). The reactivity of these novel compounds will be controlled by judicious choice of metal and reasoned modification of the ligand periphery. Hydrogenation, silylation, cycloaddition and N-atom transfer reactions will be evaluated as stoichiometric and catalytic routes to the incorporation of dinitrogen-derived N into organic substrates.