By employing a multidentate ligand, 2,2'-bipyridine-5,5'-dicarboxylic acid (H(2)bpdc), with both O-donors and N-donors, five uranyl-Cu(II)/Zn(II) heterometallic coordination polymers, (UO2)Cu(mu(4)-bpdc)(mu(3)-bpdc) (1-Cu), (UO2)Zn(mu(4)-bpdc)(mu(3)-bpdc) (1'-Zn), (UO2)CuCl(mu(3)-bpdc)(mu(2)-Hbpdc)(H2O) (2-Cu), (UO2)2Cu(2)Cl(2)(mu(3)-bpdc)(2)(mu(2)-Hbpdc)(2)(H2O)3 center dot 2H(2)O (2-Cu'), and (UO2)(2)Zn(mu(3)-SO4)(mu(4)-bpdc)(mu(3)-bpdc)(H2O)(3) (3-Zn), were prepared under hydrothermal conditions. Thermal stability and luminescent properties of 1-Cu, 1'-Zn, 2-Cu, and 3-Zn were also investigated. Isostructural compounds 1-Cu and 1'-Zn both have a three-dimensional (3D) framework built by polycatenating of two sets of paralleling two-dimensional (2D) grids with octahedral transition metal cations (Cu or Zn) as the cross-linking nodes. As far as we know, compounds 1-Cu and 1'-Zn are the first two cases that possess polycatenated networks in heterometallic uranyl-organic coordination polymers. Compound 2-Cu contains 3-fold interpenetrated 2D networks which are built by the connection of [(UO2)(2)(bpdc)(2)(Hbpdc)(2)](2-) secondary building units and Cu(II). A one-dimensional tilted ladder-like structure in 2-Cu' is constructed by uranyl-bpdc chains connected by Cu(II) and Hbpdc(-). Compound 3-Zn displays a layered-like 2D network contain an unusual [(UO2)(2)Zn(mu(3)-SO4)] unit. Interestingly, different anions could lead to the change of coordination sites of transition metal cations, resulting in structural diversity of heterometallic uranyl-organic frameworks.
