Heterometallic Network Complexes of the Ambidentate, Extended-Reach Linear Ligand 1-(4‘-pyridyl)pyridin-4-one

An investigation into the ability of the ambidentate, “extended-reach” ligand 1-(4‘-pyridyl)pyridin-4-one (pypyd) to form polymeric network complexes has resulted in the X-ray characterization of the compounds [Cu(pypyd)2(H2O)2](ClO4)2·pypyd 1, [Co2Dy2(pypyd)8(H2O)2(NCS)4(NO3)4][Co(NCS)4] 2, and [NiYb(pypyd)4(NCS)2(NO3)2](NO3) 3. The homometallic copper complex, 1, forms a (4,4) sheet polymer with additional intrasheet cross-linking via hydrogen bonding of noncoordinated pypyd molecules to the aqua ligands on the Cu centers. The heterometallic Co/Dy complex, 2, also produces a contiguous (4,4) sheet but without the hydrogen bonded pypyd cross-link. The heterometallic Ni/Yb compound, 3, forms a more complex array comprised of mutually interpenetrating networks each of three-dimensional (6,4) topology. The crystal structure of an acetic acid adduct of pypyd, 4, is also reported.