A new rigid benzene-bridged macrotricyclic ligand

A macrotricyclic ligand composed of two benzene rings connected by four 2,2 '-oxydiphenoxide bridges a) has been prepared by treating 1,2,4,5-tetrakis[ 2-(2-hydroxyphenoxy)phenoxymethyl]benzene with 1,2,4,5-tetrakis(bromomethyl )benzene in acetonitrile in the presence of potassium carbonate. Ligand 2 i s of interest because of its similarity to macrocycle 1 which interacts str ongly with cesium ions. The proposed more direct route of treating an exces s of 2,2'-oxydiphenol with 1,2,4,5-tetrakis(bromomethyl)benzene to prepare 2 did not give the desired macrocycle but gave bis(tribenzo-11-crown-3) (8) . An X-ray crystal structure study of 2 showed that the benzene rings which are linked by the four 2,2'-oxydiphenoxide bridges are connected in a nons ymmetric pattern. The structure of 8 was also determined using X-ray diffra ction methods, and is reported.