Polymer Communication Stereospecific interaction of one-handed helical polycations with chiral anions

Optically active polyamide helices were obtained by the reaction of axially dissymmetric (R )- or (S )-6,6 0 -dibromo-2,2 0 -diethoxy-1,1 0 binaphthyl, 3,6-diaminoacridine (proflavine), and carbon monoxide using a palladium catalyst. The acridine units in the chiral backbone were protonated with chiral 10-camphorsulfonic acid. Circular dichroism measurements revealed that (R )-(2)-camphorsulfonate anion ((R )-(2 )-CSA 2 ) is more easily incorporated into the protonated right-handed polyamide helix than (S )-(þ )-camphorsulfonate anion ((S )-(þ )-CSA 2 ) and that the left-handed cationic helix preferentially interacts with (R )-(2 )-CSA 2 to (S )-(þ)-CSA 2 . q 2002 Elsevier