Nanoporous magnets of chiral and racemic [{Mn(HL)}₂Mn{Mo(CN) ₇}₂] with switchable ordering temperatures (T_c = 85 K ↔ 106 K) driven by H₂O sorption (L = N,N- dimethylalaninol)

Molecule-based solids represent a rare opportunity to combine, adjust, and interrelate structural and physical functionalities to develop multifunctional materials. Here we report on a series of porous supramolecular magnets whose magnetic properties are related to their sorption state. A family of magnets of the formula [{Mn(HL)(H₂O)}₂Mn{Mo(CN)₇} ₂]·2H₂O have been obtained by assembling the heptacyanometalate building unit {Mo(CN)₇}^4- with Mn(II) in the presence of protonated N,N-dimethylalaninol (L) as ligand, the latter being either as a racemic mixture or as a chiral R- or S-enantiomer. The resulting magnets possess an open framework structure and exhibit a T _C with a switching behavior (T_C = 85 K ↔ 106 K) as a function of the hydration state. Moreover, chiral magnets are formed with the optically active ligands. The H₂O and gas (N₂, CO ₂, CO) sorption features, the magnetic behavior of both the hydrated and dehydrated magnets, and the crystal structures of the hydrated chiral (S) and racemic magnets are described.