Studies on molecular systems containing dynamic covalent bonds

Abstract

The aim of this study is to probe two molecular systems that contain dynamic covalent bonds. The first of these systems is a tri-component assembly composed of a boronic acid, guanidine, and diketone. The reversibility of this tri-ensemble was investigated via exchange experiments, which were followed by ¹H-NMR, ¹³C-NMR, and LC/MS. The data suggested that while the diketone and boronic acid moieties were exchangeable, the guanidine moiety was not. The scope of this study was then expanded to probe the formation of a supramolecular polymer that contained the same three functional groups as the tri-ensemble with the addition of a zinc-terpyridine linkage. The experiments on the supramolecular polymer were conducted using dynamic light scattering (DLS) and diffusion-ordered NMR spectroscopy (DOSY-NMR). The data from these studies indicated possible formation of dimers, but more research is needed to confirm these results.