| Abstract: | New asymmeric cylindrical macrotricyclic ligands have been prepared containing two diaza-12-crown-4 units connected by diethyleneoxy or triethyleneoxy and meta- or para-xylylene bridges, 2-4 . These materials were prepared in three steps by first treating 6-tosyl-6-aza-3,9-dioxa-1,11-undecanediyl ditosylate with 3-oxa-1,5-pentanediamine or 3,6-dioxa-1,8-octanediamine to form ditosyl-substituted bis(diaza-12-crown-4)s connected by a diethyleneoxy or triethylencoxy bridge. These latter compounds were detosylated and treated with either para- or meta-α,α'-dibromoxylene to give new asymmetric cylindrical macrotricycles 2-4 . The solid state structure of one of these ligands, 3 , has been determined by X-ray diffraction methods. |
