First transition metal coordination compound supported on metal–oxygen cluster with bicapped quasi-Keggin structure: [Cu(en)2(H2O)]4[Cu(en)2]3.5[PMoVI8VIV6O42Cu(en)(1,10′-phen)]3·14H2O

A novel compound, [Cu(en)2(H2O)]4[Cu(en)2]3.5[PMoVI8VIV6O42Cu(en)(1,10′-phen)]3·14H2O 1 (en = ethylenediamine, phen = phenanthroline), was synthesized hydrothermally (170 °C, 10 days, autogeneous pressure) and characterized by IR, ESR, elemental analyses and X-ray crystallography. The results of structure determination show that compound 1 contains three different structure cluster anions [PMoVI8VIV6O42]7− supporting complex cation [Cu(en)(1,10′-phen)]2+, in which one cluster anion possesses typical bicapped Keggin structure, while other two polyanions only have bicapped quasi-Keggin structures, and [Cu(en)(1,10′-phen)]2+ is linked through oxygen atoms to different V positions of two bicapped quasi-Keggin units.