Stepwise spin transition tuned by solvent ratios in an atypical 2-fold interpenetrated PtS-type framework.

A 2-fold interpenetrated PtS-type spin-crossover (SCO) framework (1) was synthesized, exhibiting solvent-dependent stepwise spin transitions tuned by methanol/dichloromethane ratios. The coordination geometry distortion of secondary building units (SBUs) plays a key role in determining the interpenetration pattern and offers insight into the formation of the interpenetrated framework.