Three new ZnII sulfate complexes

The three zinc sulfate complexes presented herein display three completely different coordination modes, viz tri­aqua(1,10‐phenanthroline‐N,N′)(sulfato‐O)­zinc(II) hydrate, Zn(SO₄)(C₁₂H₈N₂)(H₂O)₃]·H₂O (octahedral, monomeric), bis(μ‐sulfato‐O:O′)­bis(2,9‐di­methyl‐1,10‐phenanthroline‐N,N′)­zinc(II)], Zn₂(SO₄)₂(C₁₄H₁₂N₂)₂] (tetrahedral, dimeric), and catena‐poly­di­aqua(2,2′‐bipyridyl‐N,N′)­zinc(II)]‐μ‐(sul­fato‐O:O′)], Zn(SO₄)(C₁₀H₈N₂)(H₂O)₂]_n (octahedral, polymeric, twofold crystallographic symmetry). In the first, the sulfate is monodentate, while in the other two it acts as a bidentate bridge between two different Zn centers. There is a variety of sulfate S—O bond lengths, depending on the different coordination conditions and hydrogen‐bonding interactions.