title: A new Nb₂₈ cluster based on tungstophosphate, [{Nb₄O₆(OH)₄}{Nb₆P₂W₁₂O₆₁}₄]³⁶⁻.
abstract: A structurally intriguing polyanion, [{Nb4O6(OH)4}{Nb6P2W12O61}4](36-) (2), was directly formed by controlling the reaction parameters and characterized by single-crystal X-ray diffraction, IR spectroscopy, and elemental analyses. Polyanion 2 is the first niobium-substituted Wells-Dawson-based tetramer and contains the largest Nb28 cluster encapsulated by four hexalacunary Wells-Dawson frameworks. The activities of compounds Na12[H24-2]·24H2O (2a), K12[H2P2W12O48]·24H2O, and K7[HNb6O19]·13H2O against three human tumor cell lines were investigated in vitro. The preliminary results revealed that 2a could efficiently inhibit the growth of the human breast cancer MCF-7 cells. Interestingly, the activity of 2a is significantly better than those of the simple reagents.
authors.affiliation: Key Laboratory of Polyoxometalate Chemistry of Henan Province, College of Chemistry and Chemical Engineering and ‡Pharmaceutical College, Henan University , Kaifeng 475004, P. R. China.
authors.forename: Dongdi
authors.initials: D
authors.lastname: Zhang
authors.forename: Zhijie
authors.initials: Z
authors.lastname: Liang
authors.forename: Songqiang
authors.initials: S
authors.lastname: Xie
authors.forename: Pengtao
authors.initials: P
authors.lastname: Ma
authors.forename: Chao
authors.initials: C
authors.lastname: Zhang
authors.forename: Jingping
authors.initials: J
authors.lastname: Wang
authors.forename: Jingyang
authors.initials: J
authors.lastname: Niu
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry* / Q000494:pharmacology; D001943:Breast Neoplasms / Q000188:drug therapy; D018360:Crystallography, X-Ray; D005260:Female; D006801:Humans; D061986:MCF-7 Cells; D008958:Models, Molecular; D009556:Niobium / Q000737:chemistry* / Q000494:pharmacology; D010710:Phosphates / Q000737:chemistry* / Q000494:pharmacology; D000071228:Polyelectrolytes; D011108:Polymers / Q000737:chemistry* / Q000494:pharmacology; D017973:Tungsten Compounds / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D000970:Antineoplastic Agents; D009556:Niobium; D010710:Phosphates; D000071228:Polyelectrolytes; D011108:Polymers; D017973:Tungsten Compounds