The complex [Co(bpydiol-H)₃]·H₂O, where bpydiol is 2,2′-bipyridine-3,3′-diol, features a simple octahedral tris-chelate complex that forms a honeycomb-like six-connected 3-D network of 4⁹6⁶ topology through weak C–H⋯O hydrogen bonding. The network shows significant channels and the material is remarkably robust. The water guest molecules can be solvent exchanged for 1,2-dibromobenzene molecules. Cu(II) complexes of bpydiol are also reported: [Cu(bpydiol-H)X], where X = Cl⁻, Br⁻, or NO₃⁻, which all have coordination chain structures. The coordination chains in [Cu(bpydiol-H)(NO₃)] assemble through weak CH..ONO₂ hydrogen bonds to form a corrugated 2-D network.