In the presence of organic templates, six diruthenium diphosphonates, namely, [H3N(CH2)(3)NH3](2)[Ru-2(hedp)(2)] (1), [H3N(CH2)(4)NH3](2)[Ru-2(hedp)(2)](center dot)4H(2)O (2),[H3N(CH2)(5)NH3](2)[Ru-2(hedp)(2)]center dot 4H(2)O (3), [H3N(CH2) 3NH(3)][Ru-2(hedp)(hedpH)], H2O (4), [H3N(CH2) 4NH(3)][Ru-2(hedpH(0.5))(2)], 2H(2)O (5), and [H3N(CH2) 5NH(3)](2) {[Ru-2(hedp)(2)][Ru-2(hedpH)(2)]} (6) [hedp) 1-hydroxyethylidenediphosphonate, CH3C(OH)(PO3)(2)] have been synthesized under hydrothermal conditions. Compounds 1- 3 contain homovalent paddle wheel cores of Ru-2(II), (II)(hedp)(2)(4-) that are connected through edge-sharing of the {RuO5Ru} octahedra, resulting in infinite linear chains. Compounds 4-6 contain mixed-valent diruthenium(II, III) phosphonate paddlewheel cores of Ru-2(II), (III)(hedpH(n))(2)((3-2n)-) that are connected by phosphonate oxygen atoms, forming distorted square-grid layers in 4 and 6 or a kagome lattice in 5. Both the templates and the pH values are found to play important roles in directing the final products with particular topologies and oxidation states of the diruthenium unit. The magnetic studies show that weak antiferromagentic interactions are propagated between the homovalent diruthenium units in compounds 1-3. For compounds 4-6, weak ferromagnetic interactions are observed.