Magnetism in a helicate complexes arising with the tetradentate ligand.

The synthesis of [M(dimphen)(NCS)2] (1; M = FeII), (2; M = CoII), (3; M = MnII) and [Fe(dimphen)(NCSe)2] (4), where dimphen = [1,2-bis(9-methyl-1,10-phenanthrolin-2-yl)ethane], are reported. The crystal packing structures of 1-3, show intermolecular π-π stacking and NCSSCN interactions. The complex 1 shows ferromagnetic interaction, and the complex 2 displays single-molecular magnet behaviour.