Crystal structures of three copper(II)-2,2′-bipyridine (bpy) compounds, [Cu(bpy)₂(H₂O)][SiF₆]·4H₂O, [Cu(bpy)₂(TaF₆)₂] and [Cu(bpy)₃][TaF₆]₂and a related coordination polymer, [Cu(bpy)(H₂O)₂SnF₆]_n

We report the hydrothermal syntheses and crystal structures of aquabis(2,2′-bipyridine-κ2 N,N′)copper(II) hexafluoridosilicate tetrahydrate, [Cu(bpy)2(H2O)][SiF6]·4H2O (bpy is 2,2′-bipyridine, C10H8N2), (I), bis(2,2′-bipyridine-3κ2 N,N′)-di-μ-fluorido-1:3κ2 F:F;2:3κ2 F:F-decafluorido-1κ5 F,2κ5 F-ditantalum(V)copper(II), [Cu(bpy)2(TaF6)2], (II), tris(2,2′-bipyridine-κ2 N,N′)copper(II) bis[hexafluoridotantalate(V)], [Cu(bpy)3][TaF6]2, (III), and catena-poly[[diaqua(2,2′-bipyridine-κ2 N,N′)copper(II)]-μ-fluorido-tetrafluoridotin-μ-fluorido], [Cu(bpy)(H2O)2SnF6] n , (IV). Compounds (I), (II) and (III) contain locally chiral copper coordination complexes with C 2, D 2, and D 3 symmetry, respectively. The extended structures of (I) and (IV) are consolidated by O - H⋯F and O - H⋯O hydrogen bonds. The structure of (III) was found to be a merohedral (racemic) twin.