Methyl groups control coordination number, stoichiometry, network and magnetism in a Cu(II)-azide-pyrazine (6,3) 2D net

The methyl groups of [Cu-2(2,5-dimethylpyrazine)(N-3)(4)](n), 1, force penta-coordination on the Cu(II) ions, which, together with the di-mu-(1,1)azido zigzag chains, result in a (6,3) 2D net with dominant ferromagnetic interactions.