Template‐Directed Self‐Recognition of Alkyl‐Bridged Bis(catechol) Ligands in the Formation of Helicate‐Type Complexes

A controlling influence on the self‐assembly in the complexation reaction of a mixture of methylene‐ and ethylene‐bridged bis(catechol) ligands ( 1 ‐H₄ and 2 ‐H₄, respectively) with titanium(IV ) ions is exerted by alkali metal cations (see scheme). Thus, not a complicated mixture of complexes, but as a result of a self‐recognition of the ligands only well‐defined products are formed.