Self-assembly and peripheral guest-binding of two triangular Zn(II) helicates

Abstract

A novel complex [Zn II 3 L 2 ] 6+ was designed and then synthesized by using subcomponent self-assembly of zinc trifluoromethanesulfonate (Zn(OTf) 2 ), 2,4,6-tri(3-aminophenoxy) triazine, and 2-formylpyridine in CH 3 CN solution. The target compound's structure as a sandwich-like helicate was verified by 1 H NMR and ESI-MS measurements, and the hostguest interactions between the complex and a number of guest molecules were investigated. It was discovered that the effect of the host-guest interaction significantly changed when the aldehyde component was replaced by 3-methylpyridine-2-carboxaldehyde, which suggested that the guest-binding sites may occur around the peripheral apertures of the complex. Also the binding behavior of the tetraphenylborate guests was further investigated, which quantified the host-guest stoichiometry in the ratio of 1:2.