The hydrothermal reactions of a Cu(II) starting material, a molybdate source, 2,2'-bipyridine or terpyridine, and the appropriate alkyldiphosphonate ligand yield two series of bimetallic organophosphonate hybrid materials of the general types [Cu-n(bpy)(m)MoxOy(H2O)(p){O3P(CH2)(n)PO3}(z)] and [Cu-n(terpy)(m)MoxOy(H2O)(O3P(CH2)(n7)PO3}(z)]. The bipyridyl series includes the one-dimensional materials [Cu(bpy)(MoO2)(H2O)(O3PCH2PO3)] (1) and [{Cu(bPy)(2)}{Cu(bpy)(H2O)}(Mo5O15)(O3PCH2CH2CH2CH2PO3)](H2O)-H-. (5(.)H(2)O) and the two-dimensional hybrids [{Cu(bpy)(MO2O5)(H2O)(O3PCH2PO3)](H2O)-H-. (2(.)H(2)O), [{Cu(bpy)}(2)(MO4O12)(H2O)(2)(O3PCH2CH2PO3)](.)2H(2)O (3(.)2H(2)O), and [Cu(bPY)(Mo2O5)(O3PCH2CH2CH2PO3)](4). The terpyridyl series is represented by the one-dimensional [{Cu(terpy)(H2O)}(2)(Mo5O15)(O3PCH2CH2PO3)](.)3H(2)O (7(.)3H(2)O) and the two-dimensional composite materials [Cu(terpy)(Mo2O5)(O3PCH2PO3)] (6) and [{Cu(terpy)}(2)(MO5O15)(O3PCH2CH2CH2PO3)] (8). The structures exhibit a variety of molybdate building blocks including isolated {MoO6} octahedra in 1, binuclear subunits in 2, 4, and 6, tetranuclear embedded clusters in 3, and the prototypical {Mo5O15(O3PR)(2)}(4-) cluster type in 5, 7, and 8. These latter materials exemplify the building block approach to the preparation of extended structures.