Discrete Oligocarbamates Exhibit Sequence-Dependent Fluorescence Emission and Quenching

Abstract

The encoded precision of biological polymers enables a few simple monomers (e.g., four nucleotides in nucleic acids) to create complex macromolecular structures that accomplish a myriad of functions. Similar spatial precision in synthetic polymers and oligomers can be harnessed to create macromolecules and materials with rich and tunable properties. Recent exciting advances in iterative solid- and solution-phase synthetic strategies have led to the scalable production of discrete macromolecules, which in turn has enabled the study of sequence-dependent material properties. Our recent example of a scalable synthetic strategy using inexpensive vanillin-based monomers to create sequence-defined oligocarbamates (SeDOCs) enabled the preparation of isomeric oligomers with different thermal and mechanical properties. We show that unimolecular SeDOCs also exhibit sequence-dependent dynamic fluorescence quenching that persists from solution to the solid phase. We detail the evidence for this phenomenon and show that changes in fluorescence emissive properties are dependent on macromolecular conformation, which in turn is driven by sequence.