Over the last few years, pyridinophane-based tetradentate ligands have been used to explore a broad area of research, including valence tautomerism and spin crossover in cobalt systems, activation of CO2 and O2 molecules based on nickel complexes, stabilization and reactivity of high valent nickel and palladium complexes, catalytic cleavage of catechol, catalysis, photoluminescence , etc., while spin-state switching in iron(II) system have not been explored yet. Recently, we have reported a series of SCO cobalt(II) complexes coordinated by pyridinophane-based tetradentate ligands with linear and non-linear pseudohalides as coligands. Additionally, various bidentate nitrogen donor coligand e.g., 2,2'-bipyridine (bpy), 1,10phenanthroline (phen), and their derivatives which belong to the category of α-diimine-based ligands have been intensively applied to investigate SCO in iron(II) center. In contrast, βdiimine-based bidentate ligands like bik-R (bik = bis(1-alkyl-1H-imidazol-2-yl)ketone) (R = Et, Me, etc.) (Scheme 1) have not been explored yet, where more flexible β-diimine-based ligands forms a six-membered chelating ring with the metal center in comparison to less flexible αdiimine-based ligands which form five-membered chelating rings. We have recently reported reversible switching of photophysical properties of SCO, MMET under the application of temperature and light in cyanide-bridged molecular systems using bik-R as capping ligands, where we have shown that chelating and flexible nature along with the electronic effect of these bik-R ligands can significantly affect the switching behavior and associated photophysical properties of these materials.