CuAl(2)(acac)(4)(O(i)Pr)(4) was obtained by the reaction driven by the ligand rearrangement between anhydrous Cu(acac)(2) and Al(OPr(i))(3) in toluene under refluxing conditions. The single molecular nature and the stability of the precursor were evidenced by the presence of the molecular ion peak at m/z 749 in the EI mass spectrum. The FT-IR spectrum also confirmed the formation of the molecular precursor with strong bands appearing at 961, 1021, 1289, 1394, 1527 and 1594 cm(-1). Very low solubility as well as low stability of the precursor in common solvents hindered the growth of single crystals. The stability could be improved in acetic acid medium which was further used for the controlled hydrolysis of the precursor. A blue gel obtained on hydrolysis for 11 days showed the presence of acetate, isopropoxy and acac moieties in addition to the hydroxide group in the FT-IR spectrum. Fast hydrolysis assisted by ultrasonication with 1.5 ml of the hydrolyzing agent for 6 h resulted in a blue colored gel, the FT-IR spectrum of which also indicated the presence of acetate, isopropoxy, acac and hydroxide moieties. Both the gels showed a mass loss up to 78% according to thermal analysis in air up to 900 degrees C. While the PXRD pattern of the gel from the controlled hydrolysis yielded monophasic cubic CuAl(2)O(4) on heating at 900 degrees C in air for 12 h, phase pure product could be obtained within 12 h at 700 degrees C from the sonicated gel. Both the oxides were nanosized as observed in the TEM images. The particle size distribution obtained from the laser light scattering method showed monodispersity. The room-temperature Raman spectrum of CuAl(2)O(4) exhibited broad bands at 476, 505, 610, 712, 792 cm(-1) typical of nanosized crystallites and were assigned based on group theoretical analysis. The (27)Al NMR spectrum of CuAl(2)O(4) showed a sharp and intense resonance signal at around delta = 0.112 ppm characteristic of aluminium in octahedral coordination and one sharp signal at delta = 69 ppm corresponding to tetrahedrally coordinated aluminium. Heterogeneous catalytic reduction of p-nitrophenol using CuAl(2)O(4) was followed by UV/visible spectroscopy. CuAl(2)O(4) from the present procedure proved to be an effective catalyst for the reduction of p-nitrophenol.
Synthesis of mixed metal fluorides of the general formula, KMF 3 (M = Mg, Mn, Co, Ni, Cu and Zn), possessing perovskite structure was investigated in non-aqueous medium. The fluorides were characterized by powder X-ray diffraction, FT-IR spectroscopy, thermal analysis, SEM and TEM. Monophasic cubic phases were obtained for the central metal ions such as Mg, Mn, Co, Ni, and Zn and a tetragonally distorted phase was observed for Cu. The usage of non-aqueous medium is advantageous for the bulk synthesis of these fluorides, since it eliminated the generation and handling of the hazardous HF that has usually been encountered during aqueous preparations. The average crystallite size of the fluorides obtained by this approach was estimated to be in the range of 9-30 nm. SEM micrographs of KZnF 3 showed cubic morphology of perovskite phases. TEM studies on KCuF 3 confirmed the presence of tetragonal distortion. The fluoride content was determined by titrimetry and found to be nearly stoichiometric. Some of these fluorides were found to be thermally stable up to 225°C in air. These fluorides were employed as fluorinating agents in organic fluorination reactions, thereby suggesting their possible utilization for selective fluorination of aliphatic and aromatic hydrofluorocarbons (HFCs) that are industrially relevant.
The heterogeneous reaction between CuX (X = Cl–, I–) with alkali metal double alkoxides MAl(iOPr)4 (M = Na, K) for the synthesis of CuI containing single source precursor has been studied. The orange colored precursor obtained showed strong absorption in the UV region (235 nm) and photo luminescence emission band at 450 nm, which evidenced the formation of an adduct between the reactants. Controlled hydrolysis and decomposition of the gel yielded delafossite structured CuAlO2 along with some CuO.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.