Two-dimensional homochiral manganese(II)-azido frameworks incorporating an achiral ligand: partial spontaneous resolution and weak ferromagnetism

By incorporating an achiral diazine ligand, 2-pyridylmethylketazine, which can be locked in a chiral conformation upon coordination, into the manganese(II)-azido system, we induced a homochiral 2D network, in which neighboring Mn(II) ions are bridged via a diazine and two end-on azido ligands into chiral dimeric units, and neighboring units are interlinked via single end-to-end azido bridges. The interdimer chirality preservation is achieved via the homochiral 1D helical linkage formed by Mn(II) and end-to-end azido ions. The 2D layers are stacked in hetero- and homochiral fashion to yield simultaneously racemic and chiral crystals, indicating a partial spontaneous resolution. Both compounds behave as spin-canted weak ferromagnets, but the critical temperatures are different.