Poly[[diaqua­bis­(2,2′-bipyridine)­bis­(μ3-5-hy­droxy­isophthalato)(μ2-5-hy­droxy­isophthalato)digadolinium(III)] trihydrate]

The asymmetric unit of the title coordination polymer, {[Gd2(C8H4O5)3(C10H8N2)2(H2O)2]·3H2O}n, contains two GdIII cations, one of which is surrounded by three 5-hy­droxy­isophthalate anions, one 2,2′-bipyridine ligand and two water mol­ecules in a distorted N2O7 tricapped trigonal–prismatic coordination geometry. The other Gd cation is coordinated by four 5-hy­droxy­isophthalate anions and one 2,2′-bipyridine ligand in a distorted N2O7 tricapped trigonal–prismatic coordination geometry. The 5-hy­droxy­isophthalate anions bridge the Gd cations, forming a layer structure. The layers are further connected by extensive O—H⋯O hydrogen bonding, assembling a three-dimensional supra­molecular network.