Titanium complexes incorporating bicyclic guanidinate ligands. Structure of a novel titanium–aluminium complex

Synthetic routes to titanium complexes incorporating the bicyclic guanidinate, 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidinate, [hpp]−, are described; the first example of a chelating coordination mode for the [hpp]− anion and the trimetallic complex [Me2Al(hpp)2TiCl2·AlMe3] containing [hpp]− ligands that chelate to titanium and, in addition, bridge to an AlMe2 unit via nitrogen are reported.