Weakly aligned Ti3C2Tx MXene liquid crystals: measuring residual dipolar coupling in multiple co-solvent systems

Abstract

Residual Dipolar Coupling (RDC), acquired relying on weakly alignment media, is highly valuable for the structural elucidation of organic molecules. Arising from the striking features of no background signals and low critical concentrations, two-dimensional (2D) liquid crystals (LCs) show the clear advantages of acting as alignment media to measure RDCs. So far, creating multisolvent compatible 2D LC media through a simple and versatile method is still formidably challenging. Herein, we report the rapid creation of aligned media based on the Ti₃C₂T_x MXene, which self-aligned in multiple co-solvents including CH₃OH-H₂O, DMSO-H₂O, DMF-H₂O, and acetone-H₂O. We demonstrated the applicability of these aligned media for the RDC measurement of small organic molecules with different polarities and solubilities. Notably, Ti₃C₂T_x MXene LCs without chemical modification enabled RDC measurements on aromatic molecules. The straightforward preparation of Ti₃C₂T_x media and its compatibility with multiple solvents will push RDC measurement as a routine methodology for structural elucidation. It may also facilitate the investigation of solvation effects on conformational dynamics.