Crystallization and Structural Characterization of Two Europium Molybdates, Eu4Mo7O27 and Eu6Mo10O39

• Published in: Journal of solid state chemistry Vol. 161; no. 1; pp. 85 - 92
• Main Authors: Naruke, H., Yamase, T.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01.10.2001; Elsevier
• Subjects: Condensed matter: structure, mechanical and thermal properties; crystal structures; europium molybdates; Exact sciences and technology; Inorganic compounds; Physics; polyoxomolybdates; rare-earth molybdates; Salts; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; thermal decomposition; rare-earth molybdates; europium molybdates; thermal decomposition; polyoxomolybdates; crystal structures; Inorganic compounds; Europium Oxides; Europium Polymolybdates; Crystal growth from vapors; XRD; Rare earth compounds; Experimental study; Molybdates; Characterization; Lamellar structure; Temperature range 65-273 K; Low temperature; Crystal growth from melts; Crystal structure
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1006/jssc.2001.9284

Crystals of two new europium molybdates, Eu4Mo7O27 and Eu6Mo10O39, were grown in a melt of Eu2O3·6.1–6.5MoO3 obtained by thermal decomposition of [Eu2(H2O)12Mo8O27]·6H2O or firing of the Eu2O3+8MoO3 mixture at 800°C for 2h in air. Repeated uses of reaction containers are effective in the crystallization. Eu4Mo7O27 crystallized in monoclinic, C2/c (No. 15), a=23.031(1), b=14.720(1), c=14.4097(7) Å, β=105.174(2)°, V=4714.8(4) Å3, Z=8, R1=0.035, and wR2=0.064. Eu4Mo7O27 is a layer compound consisting of {MoO4}- and {Mo3O11}-containing layers parallel to the bc plane and interstitial Eu atoms. Eu6Mo10O39 crystallized in monoclinic, C2/c (No. 15), a=12.3008(5), b=19.6596(9), and c=13.7691(4) Å, β=100.8934(9)°, V=3269.8(2) Å3, Z=4, R1=0.036, and wR2=0.101. The structure of Eu6Mo10O39 is constructed of three-dimensionally arranged {MoO4} and {Mo2O7} groups and Eu atoms, being closely related to the structure of Ce6Mo10O39. In both compounds, Eu atoms achieve seven- or eight-fold coordination by O atoms (<2.7 Å), and two EuOn polyhedra share their edges or faces with a short Eu···Eu separations ranging from 3.6297(8) to 3.7168(6) Å.