Nd(III)‐Based Temperature‐Independent Manometer and Pressure‐Independent Thermometer with Slow Relaxation of Magnetization

Abstract Implementing multifunctional characteristics in a metallo‐supramolecular system with reversible stimuli‐induced response is a significant challenge. In this study, a simple, readily available macrocyclic Nd(III) complex [Nd L (CF 3 SO 3 ) 3 ] ( 1 ) exhibits tunable emission from the lanthanide center, which can be modulated by temperature and pressure. Within phase α at 1.5 GPa the onset of negative linear compressibility (NLC) along axis a takes place. At 3.0 GPa, single‐crystal X‐ray diffraction reveals the CF 3 SO 3 − ion ordering, inducing a non‐centrosymmetric phase β with modified material properties. Phase α shows strong pressure‐induced absorption and emission changes, suitable for precise, temperature‐independent luminescent manometry, with an emission line shift of Δ λ /Δ p = 2.85 nm GPa −1 in the NIR range. The designed optical sensor also enables remote temperature monitoring (15–460 K) through a pressure‐independent band intensity ratio of Nd(III) Stark components. Finally, field‐induced slow relaxation of magnetization is observed and analyzed using both standard fitting procedures and alternative approach that accounts for the influence of local vibration modes. This unique coexistence of these behaviors mark a significant step toward creating multifunctional supramolecular platforms, easily extendable to other systems with tunable properties.