Expanding the Size of Catecholesters – Modified Ligands for the Hierarchical Assembly of Dinuclear Titanium(IV) Helicates

Five 2,3-dihydroxybenzoic acid derivatives 1 – 5 were used as starting materials to obtain the corresponding methyl and ethyl esters. Those were applied as ligands in the hierarchical self-assembly of lithium-bridged dinuclear titanium(IV) complexes 1a–4a, 1b–3b, and 5b. The equilibria between the mononuclear triscatecholate complexes (monomer) and the dinuclear helicates (dimer) were observed by 1H NMR spectroscopy in [D6]DMSO and [D4]MeOH at room temperature.