Ditopic complex formation of the crown-containing 2-styrylbenzothiazole

The complex formation of 2-styrylbenzothiazole containing a 15-crown-5 ether fragment with alkaline earth metal cations, proton, Ag+ and Hg2+ was studied by optical and X-ray diffraction methods. The compound is able to bind the metal cations through the participation of two centers: the crown ether moiety and the heterocyclic part. The alkaline earth metal cations form complexes with the macrocyclic part of the molecule. The formation of a strong sandwich complex was found in the case of Ba2+. The proton coordinates with the N atom of the heterocyclic fragment of the molecule. The Ag+ and Hg2+ cations bind with both centers of the molecule: the crown ether fragment and the heterocyclic residue.