Hydrothermal synthesis and structures of three new copper complexes: [{Cu(2,2 '-bipy}(2)(beta-Mo8O26)], [{Cu(py)(3)}(2){Cu(py)(2)}(2)-(alpha-Mo8O26)] and [Cu(py)(2)](4)[(SO4)Mo12O36]

Two interesting organic-inorganic hybrid solids [{Cu(2,2'-bipy)(2)}(2) (beta-Mo8O26)] (1), [{Cu(py)(3)}(2) {Cu(py)(2)}(2) (alpha-Mo8O26)] (2), and a new two-electron-reduced Keggin-core compound [Cu(py)(2)](4) [Mo12O36 (SO4)] (3), were synthesized by hydrothermal methods and structurally characterized by X-ray diffraction. The structure of 1 consists of discrete [{Cu(2,2'-bipy)(2)}(2) (beta-Mo8O26)] clusters, constructed from beta-[ Mo8O26](4-) subunits covalently bonded to two [Cu( 2,2'-bipy) (2)](2+) coordination cations via bridging oxo groups that connect two adjacent molybdenum sites. The structure of 2 consists of heterometallic dodecanuclear clusters, [{Cu(py)(3)}(2) {Cu(py)(2)}(2) (alpha-Mo8O26)], connected via pi-pi stacking contacts into an extended 1-D chain. Each [alpha-Mo8O26](4-) anion forms weak covalent interactions to two [Cu(py)(3)](+) and two [Cu(py)(2)](+) units through terminal oxo groups of the octamolybdate cluster. A new compound [Cu(py)(2)](4) [(Mo2Mo10O36)-Mo-V (SO4)] (3), with two-electron-reduced Keggin anions, was unexpectedly obtained from the similar hydrothermal treatment of 2. Compounds 1-3 are of interest due to their unusual Cu-coordination geometries; trigonal bipyramidal Cu(II), distorted tetrahedral, T-shaped trigonal, and linear Cu(I) are observed, and in 2, two distinct Cu(I)-coordination geometries are observed in the same structure!