Mixed Thiolate/Alkoxide Antimony Cages for Reversed-Bilayer Vesicle Self-Assembly and Dye Protection in Organic Media

Abstract

A new two-step synthesis produces moisture-stable antimony and arsenic dithiothreitol cages. Single crystal analysis reveals that the Sb compounds self-assemble into reversed bilayers in the solid state. Together with DLS, TEM, fluorescence microscopy, encapsulation studies, and spectroscopic measurements, these results are consistent with pnictogen-bond-directed vesicle formation in organic media. The Sb assemblies more efficiently encapsulate and protect rhodamine B than the arsenic analogue or a topological mimic that lacks pnictogen-bonding capability. This work provides a synthetically accessible tool for partitioning organic media to allow for orthogonal reactivity.