Preparation and structure of the first complex of an early transition metal and a calixarene, calix[6]arene[TiCl 2 (µ-O)TiCl 3 ] 2

Hexamethoxycalix[6]arene reacts with TiCl4 to give a macrocycle to which two bimetallic units, (Cl3TiOTiCl2), have been attached; the X-ray crystal structure shows that the metal complex has broken an O–Me bond, linking one Ti atom to the calixarene through a full Ti–O bond and two TiOMe donor bonds, while the other Ti atom remains co-ordinatively unsaturated.