A new polymorph of dichlorido(1,10-phenanthroline)platinum(II)

► A third polymorph (III) of [PtCl2(1,10-phenanthroline)] has been found. ► The X-ray crystal structure of III has been solved. ► In the supramolecular columnar stacks of III the Pt⋯Pt distances are >4 Å. ► III is less dense than the other two known polymorphs and probably the least stable.