Coating Keplerate based host-guest material PMo12O40 @{Mo72Fe30} surface with silver iron molybdate

• Published in: Inorganica Chimica Acta Vol. 516; p. 120123
• Main Authors: Tandekar, Kesar, Naulakha, Pragya, Supriya, Sabbani
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-02-2021; Elsevier Science Ltd
• Subjects: Host-guest Keplerate; Host-guest materials; Interface reactions; Liquid-solid interfaces; Metal oxides; Multi-component; Oxidation; Reduced polyoxometalate; Silver nitrate; Solid–liquid interface; α- AgFe(MoO4)2; Solid–liquid interface; α- AgFe(MoO4)2; Host-guest Keplerate; Reduced polyoxometalate; Multi-component
• ISSN: 0020-1693; 1873-3255
• DOI: 10.1016/j.ica.2020.120123

In a facile one pot solid–liquid interface synthesis, the green colored reduced host guest Keplerate [HxPMo12O40⊂H4MoVI72FeIII30 (CH3COO)15O254(H2O)98]·ca.60 H2O on treatment with AgNO3 plays the dual role of template as well as source for the deposition of a layer of mixed metal oxide α-AgFe(MoO4)2 on its surface. The system [(PMo12O40) ⊂ {Mo72Fe30}] ⊂ AgFe(MoO4)2] hence generated is a three component system of the type [(core)shell]shell where three different forms of molybdenum cluster assemble to form a complex inorganic hybrid material.
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•The formation of a complex metal oxide from a giant polyoxometalate compound.•The synthesis involves the reaction of a host-guest compound with silver nitrate.•Coating of α-AgFe(MoO4)2 on the surface of [(PMo12O40) ⊂ {Mo72Fe30}].•The compound has been characterized by routine analysis including microscopy.
The fresh green colored reduced crystals of [HxPMo12O40 ⊂ H4MoVI72FeIII30(CH3COO)15O252(H2O)102] · xH2O (1) dissolved in aqueous AgNO3 solution, when refluxed, results in formation of yellow precipitate which on calcination at 450 °C gives crystalline α-AgFe(MoO4)2. When the dried crystals of host guest [HxPMo12O40 ⊂ H4MoVI72FeIII30(CH3COO)15O254(H2O)98] · ca.60 H2O (2) are treated with aqueous AgNO3 solution in which it is not soluble, a layer of a mixed metal oxide α-AgFe(MoO4)2 is deposited on its surface with simultaneous oxidation of 2 generating a yellow colored compound [{(PMo12O40) ⊂ (Mo72Fe30)} 0.99 ⊂ {AgFe(MoO4)2} 0.01] (3). We have proposed a new synthetic pathway for the construction of a POM based three component hybrid material following a solid–liquid interface reaction, wherein the role of the template and the source of the metal oxide layer are played by the POM Keplerate 2.