Phase formation in the Li2MoO4-A2MoO4-NiMoO4 (A = K, Rb, Cs) systems, the crystal structure of Cs2Ni2(MoO4)3, and color characteristics of alkali-metal nickel molybdates

• Published in: Russian journal of inorganic chemistry Vol. 56; no. 8; pp. 1216 - 1221
• Main Authors: Zolotova, E. S., Solodovnikova, Z. A., Ayupov, B. M., Solodovnikov, S. F.
• Format: Journal Article
• Language: English
• Published: Dordrecht SP MAIK Nauka/Interperiodica 01.08.2011
• Subjects: Boundaries; Chemistry; Chemistry and Materials Science; Color; Crystal structure; Holes; Inorganic Chemistry; Molybdates; Nickel; Spectra; Synthesis and Properties of Inorganic Compounds; Three dimensional; Molybdenum Trioxide; Double Molybdate; Subsolidus Region; Langbeinite; Molybdate
• DOI: 10.1134/S0036023611080298
• ISSN: 0036-0236

The subsolidus regions of the Li 2 MoO 4 -A 2 + MoO 4 -NiMoO 4 (A + = K, Rb, Cs) systems at 510°C have been triangulated by the intersecting-joins method. The A 2 MoO 4 -Li 2 Ni 2 (MoO 4 ) 3 , Li 2 MoO 4 -A 2 Ni 2 (MoO 4 ) 3 , A 2 Ni 2 (MoO 4 ) 3 -Li 2 Ni 2 (MoO 4 ) 3 (A = K, Rb, Cs), and ALiMoO 4 -A 2 Ni 2 (MoO 4 ) 3 (A = K, Rb) joins have been investigated. The subsolidus phase formation study has also been completed by spontaneous flux crystallization. No triple salts have been identified, but only compounds belonging to the boundary binary systems. The crystal structure of Cs 2 Ni 2 (MoO 4 ) 3 ( a = 10.7538 Å, Z = 4, space group P 2 1 3, R = 0.0082) belonging to the langbeinite type has been determined. It is built of a three-dimensional framework of vertexsharing MoO 4 tetrahedra and NiO 6 octahedra and cesium ions occupying large out-of-framework cavities. All alkali-metal nickel molybdates are yellow. These compounds are usable as pigments, as judged from their reflection spectra and calculated color characteristics, namely, colorfulness ( C ), lightness ( L ), and hue ( H ).