rationally inducing overlap between the stable high spin state (HSSS) and the metastable high spin state (HSMS) generated by a rapid frozen effect, a series of [FexMn1-x(bpp)2](BF4)2 [bpp = 2,6-bis(pyrazol-3-yl)pyridine] complexes was prepared. For all the materials, the thermal spincrossover (SCO) properties were measured and the stability of the metastable HSMS state was probed through the determination