A 1D trimetallic coordination polymer containing mixed molybdenum-vanadium heteropolyoxometalate bridges, {[Ni(phen)2(H2O)]2[Ni(phen)2][VIV8MoVI6MoV2O40(PO4)]}{[Ni(phen)2(H2O)]2[VIV8MoVI6MoV2O40(PO4)2]}·5H2O·2EtOH (1) (phen = 1,10-phenanthroline, EtOH = ethanol), has been synthesised hydrothermally. An X-ray crystallographic study revealed that 1 is composed of 1D zigzag chains of {[Ni(phen)2(H2O)]2[Ni(phen)2][VIV8MoVI6MoV2O40(PO4)]}nn+ cations, {[Ni(phen)2(H2O)]2 [VIV8MoVI6MoV2O40(PO4)2]}− anions and solvent molecules. Both the cation and the anion in 1 are mixed molybdenum-vanadium heteropolyoxometalates with covalently linked nickel complex fragments. Magnetic investigations of 1 indicate spin glass behaviour and several magnetic transitions occur at low temperatures (below 20 K). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)