Supramolecular Modulation of Spin Crossover in an Fe(II) Dinuclear Triple Helicate.

A spin-crossover (SCO) active dinuclear Fe(II) triple helicate of the form [Fe2L3]4+ was combined with additional supramolecular components in order to manipulate the interhelical separation and steric congestion and to study the magneto-structural effects on the ensuing composite materials. A more separated array of SCO units produced more extensive spin-transitions, while a tightly arranged lattice environment stabilized the low-spin state. This study highlights the important interplay between crystal packing, intermolecualr interactions, and the magentic behavior of SCO materials.