Naslov
Hydrothermal reactions of [CoIII(C2O4)(NH3)4]+ and polyoxomolybdates: depolymerization of polyoxomolybdates and in situ reduction of cobalt
(Hydrothermal reactions of [CoIII(C2O4)(NH3)4]+ and polyoxomolybdates: depolymerization of polyoxomolybdates and in situ reduction of cobalt)

Autori
Damjanović, Vladimir ; Kuzman, Dino ; Vrdoljak, Višnja ; Muratović, Senada ; Žilić, Dijana ; Stilinović, Vladimir ; Cindrić, Marina

Izvornik
Crystal growth & design (1528-7483) 19 (2019), 11; 6763-6773

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
hydrothermal synthesis ; self-assembly ; polyoxomolybdates ; cobalt(II/III) complexes

Sažetak
The hexa-, hepta-, and octamolybdates as common precursors with dynamic configuration transformation in aqueous solution have been introduced into the hydrothermal reaction system containing the [CoIII(C2O4)(NH3)4]+ cation, leading to the isolation of four new compounds: [CoIII(C2O4)(NH3)4]3[(NH3)4CoIII(μ- C2O4)CoII(H2O)4][Mo7O24]·nH2O (n ≈ 9.25) (1), [CoIII(C2O4)(NH3)4]2[MoO4]·H2O (2), [CoIII(C2O4) (NH3)4]3(NH4)[CoII(OH)6Mo6O18]·6H2O (3), and [CoIII(C2O4)(NH3)4]2[CoII(C2O4)2(H2O)2]·4H2O as two polymorphic forms (4 and 4a). The choice of the starting polyoxomolybdate strongly influences the obtained products–while 2 was obtained in all reactions, 1 was isolated only in reactions with hexa- and octamolybdate, and 3 and 4 only with heptamolybdate as the molybdenum source. Three species present in the isolated products, the binuclear cation [(NH3)4CoIII(μ-C2O4)CoII(H2O)4]3+ in 1, the Anderson-type anion [CoII(OH)6Mo6O18]4– in 3, and the [CoII(C2O4)2(H2O)2]2– anion in 4 and 4a, were formed by the intramolecular reduction of the [CoIII(C2O4)(NH3)4]+ precursor. The presence of Co(II) in these compounds was confirmed by electron spin resonance studies. The compounds were characterized by elemental and thermogravimetric analysis as well as infrared spectroscopy and single crystal X-ray diffraction analysis.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Kemija

POVEZANOST RADA