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

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.