The reaction of anhydrous iron(II) chloride and the tetradentate ligand L was carried out in dry methanol under an argon atmosphere. It was followed by the sequential addition of bidentate ligand bik* and sodium tetraphenyl borate, which formed an immediate precipitate. After filtration, the precipitate was dissolved in acetonitrile, and diethyl ether was diffused into the solution to obtain the analytically pure crystalline product of 1 in good yield (Scheme 2 and Figure ). The purity of complex 1 in bulk was confirmed by elemental analysis studies and powder X-ray diffraction measurements (Figure ). The thermal stability of 1 was determined by thermogravimetry analysis (TGA) from 303 K to 473 K with a scan rate of 10 K min -1 under nitrogen atmosphere (Figure ). The TGA curve shows that complex 1 is stable up to 425 K, indicating the absence of interstitial solvent molecules, which is consistent with the single-crystal X-ray structure studies (vide infra). The remarkable thermal stability of 1 might come from the strong coordinating effect of both ligands. It is important to mention that the absence of interstitial solvent molecules offers us an opportunity to explore the impact of ligand-modification on the magneto-structural relationship of the SCO behavior of 1 without any interference coming from the interstitial solvent molecules, which is rarely observed in SCO studies. Also, such rock crystallinity and stability allow to explore the impact of slightly harsh perturbation such as applied external pressure on the observed SCO profile.