The commensurate modulated structure of the metastable state in spin crossover complex [Fe(abpt)(2)(NCS)(2)]

Two new polymorphs (C and D) of [t-Fe(abpt)(2)(NCS)(2)] are characterized, a commensurate modulated structure with the c axis tripled in the thermally quenched metastable high spin state at 25 K is found in polymorph C.