Crystal structures of three copper(II)-2,2'-bi-pyridine (bpy) compounds, [Cu(bpy)(2)(H(2)O)][SiF(6)]·4H(2)O, [Cu(bpy)(2)(TaF(6))(2)] and [Cu(bpy)(3)][TaF(6)](2) and a related coordination polymer, [Cu(bpy)(H(2)O)(2)SnF(6)] (n).

We report the hydro-thermal syntheses and crystal structures of aqua-bis-(2,2'-bi-pyridine-κ(2) N,N')copper(II) hexa-fluorido-silicate tetra-hydrate, [Cu(bpy)(2)(H(2)O)][SiF(6)]·4H(2)O (bpy is 2,2'-bi-pyridine, C(10)H(8)N(2)), (I), bis-(2,2'-bi-pyridine-3κ(2) N,N')-di-μ-fluorido-1:3κ(2) F:F;2:3κ(2) F:F-deca-fluorido-1κ(5) F,2κ(5) F-ditantalum(V)copper(II), [Cu(bpy)(2)(TaF(6))(2)], (II), tris-(2,2'-bi-pyridine-κ(2) N,N')copper(II) bis[hexa-fluorido-tantalate(V)], [Cu(bpy)(3)][TaF(6)](2), (III), and catena-poly[[di-aqua-(2,2'-bi-pyridine-κ(2) N,N')copper(II)]-μ-fluorido-tetra-fluorido-tin-μ-fluorido], [Cu(bpy)(H(2)O)(2)SnF(6)] (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.