Hydrothermal synthesis and structures of three new copper complexes: [{Cu(2,2′-bipy}2(β-Mo8O26)], [{Cu(py)3}2{Cu(py)2}2(α-Mo8O26)] and [Cu(py)2]4[(SO4)Mo12O36]Electronic supplementary information (ESl) available: ESR spectra of 1 and 3, IR spectra of 1–3. See http://www.rsc.org/suppdata/dt/b1/b111480h/