A one-dimensional copper( ii ) coordination polymer containing [Fe(pytpy) ₂ ] ²⁺ (pytpy = 4′-(4-pyridyl)-2,2′:6′,2″-terpyridine) as an expanded 4,4′-bipyridineligand: a hydrogen-bonded network penetrated by rod-like polymers

The one-dimensional coordination polymer [{(H2O)(NO3)2CuFe(1)2}2(NO3)4·2.15MeCN·5.85H2O]n assembles when the pendant pyridine donors in [Fe(1)2]2+ (1 = 4′-(4-pyridyl)-2,2′:6′,2″-terpyridine) are treated with Cu(NO3)2·3H2O, exemplifying [Fe(1)2]2+ as an expanded 4,4′-bipyridine ligand. In the solid state, the polymer chains are threaded through hydrogen-bonded macrocycles comprising coordinated and non-coordinated water molecules and nitrate ions, the macrocycles being motifs within interconnected sheets in the structure.