Such changes in dielectric constant is rather unusual and generally Δε (HS-LS) varies from -0.07 to +0. was set as a reference then the apical pyrazolyl ring exhibited positional disorders in the two rotational positions. 63.7˚ is the dihedral angle between the positionally disordered pyrazolyl ring at 110 K in the LS state, while it is 75.5˚ at 180 K in the HS state (Fig. ). Thus, it can be seen in the dielectric measurement profile that it shows a weak hysteretic transition similar to the temperature where a spin transition occurs (Fig. ) . as bridging ligand (Fig. ). The compound exhibits a four-step spin-transition having transitions at 189 K, 178 K, 136 K and 112 K. When the dielectric measurement was performed as a function of temperature, a similar trend was observed with dielectric properties as well, transitions were observed at 201, 165, 132, and 115 K (Fig. ). This shows the synergy between the SCO and dielectric behavior. Then a light-induced dielectric study was performed, and at 10 K there was a sudden drop in the dielectric constant (ε') from 16.37 to 16.02 when irradiated with 505 nm light.