Supramolecular Tuning of Spin Crossover Properties in Isostructural Cocrystal Solvates

In order to improve strategies for the design of spin-crossover materials, it is necessary develop and understand structure–property relationships, this best achieved by obtaining isostructural materials. work we synthesized a series four cocrystal solvates using [Fe(3-bpp)2][A]2 complex 2,2-dipyridyl disulfide coformer in methanol ethanol (A = BF4– or PF6–). The properties materials were determined variable temperature single-crystal X-ray diffraction. They show same SCO behavior but with shifted temperatures, which has been related hydrogen bond basicity, pKBHX anions, solvents present. This relationship between basicity transition offers strategy supramolecular tuning specific