Two- and Three -Dimensional Heterometallic Ln[Ru2-α-Ammonium Diphosphonate] Nets: Structures, Porosity, Magnetism, and Proton Conductivity

By virtue of its magnetic moment and variable valencies, the D-4h paddlewheel ruthenium dimer is a desirable molecular building block for the construction of functional networks. If in addition to the Ru open axial site the organic ligand is designed to allow transversal connections, a wider range of structural possibilities is expected. The organic ligand can also be modified to introduce other functionalities. In the present study we employed a diphosphonate containing a protonated amine, 1-ammoniummethylenediphosphonate [NH3CH(PO3)(2)(3-); (Hamdp)], as the ligand to construct paddlewheel Ru-2(Hamdp)(2) building block. Three networks of different structural dimensionalities were obtained. (H3O)(2)[Ru-2(II)(Hamdp)(2)] (1) forms one-dimensional chain of S = 1 RulI2 bridged at axial positions through Ru-O bonds. From 1 as a starting material, its reaction with lanthanide ions results in the bimetallic Dy(H2O)(3)[Ru-2(Hamdp)(2)][Ru-2(Hamdp)(2)(H2O)(2)]-[Ru-2(Hamdp)(amdp)](0.5)center dot 12H(2)O (2), which has a pillared-bilayer structure and Yb[Ru-2(Hamdp)(2)](2)[Ru-2(Hamdp)(2)(H2O)(2)]center dot 15H(2)O (3), which is a three-dimensional open framework, both contain mixed-valent Ru-2(II/III) units and show new connection topologies of the Ru-2 dimers. After activation 2 does not adsorb N-2 and CO2 but takes up 12 (HO)-O-2. In contrast, 3 take up all three gases. The optimum proton conductivities were moderate reaching 1.44 x 10(-6) for 2 and 0.93 x 10(-5) S cm(-1) for 3 at 95% relative humidity and 55 degrees C.