Highly Sensitive\nSolid Ratiometric Luminescent Thermometer\nBased on N,C-Chelating Four-Coordinate Organoboron Compounds

Realizing\nratiometric thermometers using single-component organic\nsolid-state luminophores is attractive but challenging. Here, we synthesized\na series of N,C-chelated tetra-coordinated organoboron compounds and\ncharacterized their structures. Among them, sample <b>BN2Br</b> can be used as a luminescent thermometer and exhibits a high temperature\nsensitivity (3.67% K<sup>–1</sup>), a wide response range of\n120–280 K, and good reversibility, which is mainly due to the\ntemperature-dependent intermolecular stacking effect in the solid\nstate. The proposed ratiometric thermometry protocol may provide new\ninsights for developing photonic thermometers.