Complex surface architectures: the discovery of the third orthogonal dynamic covalent bond

Abstract

The SOSIP-TSE methodology was until recently based on only two orthogonal dynamic covalent bonds : Disulfides and hydrazones. The introduction of boronate esters to these architectures was possible, but they lacked orthogonality. We here show the first known example of three completely orthogonal dynamic covalent bonds, namely disulfides, hydrazones and boronate esters. After chosing the appropriate substrates, with adapted reactivity and stability, the conditions for the orthogonal exchange reactions were determined by experiments in solution. The compatibility of this system with surface architectures was then determined by 1H-NMR and mass spectrometry. The system was further enhanced by using more stable boronate esters, that showed impressive stability in acidic and aqueous conditions, while keeping their dynamic character when needed. These new more stable boronate esters were also shown to have impressive characteristics in surface architectures, showing their potential.