Nanocrystalline Gd2O2NCN (P3m1, crystallite size 30–40 nm) was synthesized upon ammonolysis of bis[[(N-carboxymethyl,N-carboxy-κO-methyl)amino-κN]-ethyl]-glycinato(3-)-κN,κO]gadolinium(III) (diethylenetriamine pentaacetic acid gadolinium(III) dihydrogen salt or gadopentetic acid, Gd-H2DTPA hereafter) at 900 °C. The conversion of Gd-H2DTPA into Gd2O2NCN takes place in several steps, probably via transient formation of iminodiacetate-, glycinate-, and carbamate-containing complexes of Gd. Thermal treatment in air of Gd-H2DTPA at 750 and 1300 °C delivers nanocrystalline bixbyite-type Gd2O3 (Ia3, crystallite size 30–70 nm); in an argon or nitrogen atmosphere the formation of monoclinic Gd2O3 (C2/m) was observed at 1300 °C. The synthesized Gd2O2NCN converts upon thermal treatment in air, nitrogen, or argon atmosphere into monoclinic Gd2O3 (C2/m). In ammonia atmosphere, Gd2O2NCN seems to be stable against decomposition, even upon prolonged exposure to 1000 °C. This study indicates that Gd-H2DTPA may be a robust, low-cost, and flexible precursor for nanoscaled Gd-based nanopowders. Moreover, precursor approaches based on metal complexes using H5DTPA as a ligand are suggested as promising access pathways towards nanocrystalline materials in the M/O/C/N system.
|Original language||English (US)|
|Number of pages||11|
|Journal||Zeitschrift fur Anorganische und Allgemeine Chemie|
|State||Published - Nov 17 2017|
All Science Journal Classification (ASJC) codes
- Inorganic Chemistry