A convenient preparation of La2CuO4 from molecular precursors

Abstract

Exhaustive hydrolysis of a mixture of [La4(CO3)(O2CNBu2)10] and [Cu(O2CNBu2)(py∗)2] (py∗ = 4-dimethylamino pyridine) in molar ratio 1/2 corresponding to a La/Cu molar ratio 2/1 was carried out in toluene at room temperature. The carbamato derivatives of lanthanum and copper can be easily prepared by extraction of the metal ions from aqueous solution into heptane by the NHBu2/CO2 system, according to a method previously reported. The copper precursor was selected among a number of derivatives in respect of its easy tractability. The tetragonal modification T’ of La2CuO4 was obtained by treatment at 600 °C of the intermediate mixed carbonate. The thermal treatment of T’-La2CuO4 at 850 °C, followed by cooling down to room temperature, afforded the orthorhombic modification of the mixed oxide

Recent Advances in the Chemistry of Metal Carbamates

“…In contrast to the reactivity of carbon dioxide, the CO 2 moiety within a carbamato ligand is not susceptible to nucleophilic attack and this feature enables specific modifications to the coordinative sphere of metal carbamato complexes. For instance, carbonylation [42], hydrogenation [231] and ligand exchange reactions using methyl lithium or pyridines [278,297] have been performed without affecting the integrity of the carbamato ligand(s).…”

“…1.65 Tb 0.35 O 3.82 , Ce 1.80 La 0.20 O 3.90 , La 2 CuO 4 , Y 3 Al 5 O 12 and Y 2.98 Nd 0.02 Al 5 O 12 , are finally produced (Scheme 42b)[146,154,297].…”

Heterometallic Rare-Earth Complexes: A Review on Magnetism, Catalysis and Transformation to Nanomaterials

“…One of them involves the thermal decomposition of an amorphous precursor [La2Cu(DTPA) 1.6]•6H2O [118] (H5DTPA = diethylenetriaminepentaacetic acid) initially at 450 °C to eliminate volatile organic constituents, and then by heat treatment at 650 °C yielded La2CuO4 with an average crystallite size of around 29 nm. An alternate approach to synthesize La2CuO4 included hydrolyzing a mixture of [La4(CO3)(O2CNBu2)10] and [Cu(O2CNBu2)(py)2] (py = 4-dimethylaminopyridine) in a toluene solution, resulting in the isolation of the compound [La2Cu(CO3)4]•5H2O [119]. The subsequent procedure involved heating the isolated precursor at 600°C, yielding a tetragonal polymorph with an average crystallite size of 15 nm.…”