Selective inclusion of cesium ion in a cryptand-type Ti(IV) complex derived from a tripodal tris-2,3-dihydroxynaphthalene ligand

A novel tripodand-type ligand (L1) having three 2,3-dihydroxynaphthalene end groups and a C-3 symmetric 1,3,5-tryimethylbenzene based backbone was prepared by the reaction of 1,3,5-tris(bromomethyl)-2,4,6-trimethylbenzene with 3-(2-(hydroxymethyl)allyloxy)naphthalene-2-ol followed by triple Claisen rearrangement. A 1:1 titanium complex which acts as a metallo-cryptand is obtained by the reaction of ligand (L1) with Ti(IV)(=O)(acac)(2) in the presence of base. The formation of the metallo-cryptand strongly depends on templating effects by counter cations and it shows a high selectively for the encapsulation of cesium cations in its cavity.