Structural Comparison of Iron Tetrapolyvanadate Fe2V4O13 and Iron Polyvanadomolybdate Fe2V3.16Mo0.84O13.42: A New Substitution Mechanism of Molybdenum(VI) for Vanadium(V)

• Published in: Inorganic chemistry Vol. 37; no. 26; pp. 6921 - 6927
• Main Authors: Wang, Xiandong, Heier, Kevin R, Stern, Charlotte L, Poeppelmeier, Kenneth R
• Format: Journal Article
• Language: English
• Published: American Chemical Society 28-12-1998
• DOI: 10.1021/ic980942t
• EISSN: 1520-510X
• ISSN: 0020-1669

Single crystals of the iron tetrapolyvanadate Fe2V4O13 and the iron polyvanadomolybdate Fe2V3.16Mo0.84O13.42 were grown from Fe2O3/V2O5 and Fe2O3/V2O5/MoO3 melts, respectively. Single-crystal X-ray diffraction revealed that the two structures are closely related. Both contained isolated Fe2O10 octahedral dimers with similar orientations. The unusual U-shaped V4O13 6- clusters in Fe2V4O13 were ordered while the U-shaped [V3.16Mo0.84O13.42]6- clusters in Fe2V3.16Mo0.84O13.42 were disordered. The substitution of molybdenum(VI) for vanadium(V) revealed a new substitution mechanism, in which a corresponding stoichiometric amount of oxygen was brought into the structure for charge balance with no reduction of the V5+ and Mo6+ ions. Crystal data:  for Fe2V4O13, monoclinic, space group P21/c (No. 14), with a = 8.300(2) Å, b =9.404(6) Å, c = 14.560(2) Å, β = 102.08(1)°, and Z = 4; for Fe2V3.16Mo0.84O13.42, monoclinic, space group P21/c (No. 14), with a = 7.678(1) Å, b = 9.456(2) Å, c = 8.336(2) Å, β = 109.50(2)°, and Z = 2.