h at 10 K revealed that upon irradiation, the T value shows a continuous increase to reach a saturation value of 2.8 cm 3 mol -1 K, describing a complete photo-conversion from LS state to photo-induced HS state, which shows relaxation back to the LS ground state at 55 K (TLIESST = K) upon heating in dark (Fig. ). of the peaks I1 (486 nm) for the complex 5 and ligand L4. Adapted with permission from Ref. .