was assessed using the thermal sensitivity (Sr) and the temperature uncertainty (𝛿T), key figures of merit for evaluating the efficiency of optical temperature sensors. The temperature dependence of Sr values are depicted in Figures 7, S19 and S20. Sr value decreases with increasing temperature, with a maximum value of 1.09 % K -1 at 15 K and 2.98 % K -1 at 13 K for complexes 1 and 2 respectively. For complex 3, the Sr value remains nearly constant upon increasing temperature to around 200 K, then increases sharply to reach a maximum value of 0.81 % K -1 at 300 K. For complex 1, the Sr value reaches 0.725 % K -1 at 20 K and increases thereafter. applications around the region of magnetic relaxation. The temperature uncertainty (dT) in complexes 1 -3 varied from 0.5 to 0.0 units (Figure ) as identified in accordance with Equation . All the three complexes showed emission profiles sensitive to temperature with complex 2 displaying decent luminescent thermometric properties.