Thirty new nitrogen-containing ligands have been synthesised and the coordination chemistry of the majority of these has been investigated. The coordination chemistry of previously reported ligands related to these has also been investigated. The ligands contain a central benzene ring to which nitrogen-containing heterocycles have been appended via one or two linking atoms. In this manner, between two and six such groups have been attached to a benzene ring to give ligands which display a great variety of modes of coordination to transition metals. These complexes have been characterised by combinations of N.M.R. spectroscopy, mass spectrometry, elemental analysis and X-ray crystallography - the X-ray crystal structures of thirty one complexes have been determined. Among these thirty one structures are chelated and macrocyclic complexes containing monochiral ligands, a supramolecular ten-component cage containing a guest molecule, a new N₃(arene) mode of coordination, as well as a number of complexes in which arene-arene and metal-arene interactions are observed. Cyclometallated complexes of some of these ligands have also been prepared, the dynamic N.M.R. processes of which have been investigated by variable temperature ¹H N.M.R. methods.