There are two common compositions: MX 2 L 2 and MX 2 L. The monoligand analogues usually contain linear MX 2 chains, and therefore tend to show primarily 1D magnetic behaviour, e.g. NiCl 2 (pyrazine) consists of ferromagnetic NiCl 2 chains antiferromagnetically coupled with T N = 10.2 K, CuCl 2 (pyrazine) is also a very good example of a 1D magnet with no order reported down to 1.8 K, but the strongest interaction in fact occurs through Cupyrazine-Cu bridges (J = -28 K), due to the JT distortion suppressing exchange in the CuCl 2 chain. Preliminary studies of the magnetism of pyrimidine analogues, MCl 2 (pym) M = Mn, Co, Cu, also detect no magnetic order down to 1.8 K although there are weak AFM interactions present. The strong interactions, particularly occurring through the CrCl 2 chain, and magnetic order found in CrCl 2 (pym) are therefore in striking contrast.