Dy-SMM for Standalone Magneto Thermometry and Opto-Magnetic Temperature Sensing via Multiple Linear Regression

Herein, we address the longstanding challenge of enhancing thermal sensitivity in single-molecule magnets (SMMs) without altering their intrinsic magnetic properties or relying on synthetic modifications. The inherent trade-off between the high symmetry essential for magnetic performance and the low symmetry typically preferred for efficient luminescence has limited progress in conventional thermometric strategies. We demonstrate that magneto-thermometry, based on magnetic relaxation time (τ) and inverse magnetic susceptibility (1/<i>χ</i>), can serve as a powerful, standalone thermometric tool. An anilato-bridged dinuclear Dy-SMM achieved record high standalone relative magnetothermal sensitivities (<i>S</i>_max) of 11.91% K^-1 (S_r^τ) and 9.90% K^-1 (S_r^1/<i>χ</i>), with S_r > 1% K^-1 spanning 2-100 K, including the critical 2-45 K SMM operating range. To overcome the low luminescence thermometry sensitivity in the complex (S_r^λ < 0.25% K^-1), we apply multiple linear regression (MLR) to combine optical and magnetic parameters. This multiparametric sensing achieves <i>S</i>_max = 69.58% K^-1 (at 15 K) with S_r > 40% K^-1 in the SMM regime, establishing MLR-based opto-magnetic thermometry as a powerful strategy for precise, wide-range temperature sensing in SMMs.