Synthesis and characterization of a spin crossover iron(II)-iron(III) mixed valence supramolecular pseudo-dimer exhibiting chiral recognition, hydrogen bonding, and pi-pi interactions.

Reaction of iron(II) and the 3 : 1 Schiff base condensate of 5-methylpyrazole-3-carboxaldehyde and tris(2-aminoethyl)amine in air gives a pseudo-dimer complex with a triple helix structure made of Delta-Delta and Lambda-Lambda pairings of spin crossover iron(II) and low spin iron(III) cations that are held together by three pi-pi and hydrogen bonding interactions.