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Diytterbium decavanadate 24-hydrate, Yb2V10O28.24H2O

1985; Wiley; Volume: 41; Issue: 6 Linguagem: Inglês

10.1107/s0108270185005637

1600-5759

B. E. Rivero, G. Punte, G. Rigotti, A. Navaza,

Metal-Organic Frameworks: Synthesis and Applications

Mr= 1735.85, triclinic, P1, a = 9.287 (5), b=9.821(5), c=23.33(2)A, a=99.13(15), fl= 81.51(15), y=90.57(4) ° , V=2077(3)A 3, Z=2, D m = 2.7, D x = 2.77 Mg m -3, ,;l,(Mo K~t) = 0.7107/~, /t=6.3mm -~, F(000)=1668, T=298+2K, R= 4.4% for 4559 independent observed reflections. The unit cell contains two independent (V10028) 6- anions located on symmetry centers and four (Yb(H20)8) 3+ polyhedra. The V-O distances within the polyanions range between 1.578 (4) and 2.346 (5)/~,. The coor- dination geometry at Yb 3+ ions is a distorted square antiprism with Yb-water-O distances ranging between 2.255 (6) and 2.428 (7)/k. The 16 interstitial water molecules are inserted between layers parallel to (001) containing decavanadate groups and rare-earth poly- hedra which are not in direct contact. A net of hydrogen bonds stabilizes the structure. Introduction. Crystallographic studies on hydrated rare-earth decavanadates were undertaken as part of a more general research program on crystal chemistry and physicochemical properties of decavanadate salts (Rigotti, Punte, Rivero, Escobar & Baran, 1981). The structures of the 25-hydrate rare-earth salts (Rivero, Rigotti, Punte & Navaza, 1982, 1984) and that of the 24-hydrate compound presented here were solved in order to correlate structural changes with ionic-radius size and with the different number of water molecules of crystallization.