Nuclear Spin Relaxation Modulation of Fluorinated Deep Eutectic Solvents for Radiofrequency Information Encoding and Display.

Abstract

Nuclear spin properties underpin nuclear magnetic resonance. The tunability of ¹⁹F spin systems renders fluorinated materials versatile platforms for diverse applications. Although frequency encoding of ¹⁹F nuclei enables high-density molecular encoding, the use of spin relaxation remains limited. Here, a ¹⁹F magnetic resonance display platform that exploits spin relaxation modulation through synergistic material-level design and instrument-level pulse sequence control is presented. Incorporation of paramagnetic metal ions into fluorinated deep eutectic solvents enables precise tuning of ¹⁹F relaxation times for information encoding. Tailored relaxation-selective pulse sequences allow selective visualization of the encoded information. Iron-containing fluorinated deep eutectic solvents further enable reversible data editing via photoredox responses. In addition, UV-printable paramagnetic fluorinated ionogels allow rapid and rewritable information display. This work expands nuclear magnetic information encoding by introducing controllable ¹⁹F spin relaxation as an additional information domain, thereby converting spin relaxation from a physical parameter into an information carrier and enabling a selective, responsive, and non-luminescent display platform well suited for high-confidential anticounterfeiting and information display.