Binding properties of a series of isomeric m-phenylene ethynylene oligomers containing short amide sequences to a piperazinium dihydrochloride
salt were investigated by using circular dichroism (CD) measurements. Although these isomeric oligomers exhibited similar helical conformations,
high affinity was observed only for one oligomer. This behavior is presumably controlled by the orientation of amino groups of the amide
sequence and the folded conformation of the oligomer