Preparation and characterization of molybdenum and tungsten nitride nanoparticles obtained by thermolysis of molecular precursors

Synthesis of WN(NMe2)3 as a Precursor for the Deposition of WNx Nanospheres

“…Darkening of the solid to red-brown was observed under vacuum, and sublimation of 1 (90-105°C at 10 -1 Torr) was accompanied by substantial decomposition (Ͼ 40 %). [61] Although WN x nanoparticles have been synthesized previously, [61][62][63][64] their synthesis at low temperature via pyrolysis has not been reported. Crystals suitable for X-ray structure determination were obtained by vapor diffusion of pentane into a concentrated diethyl ether solution of 1 at low temperature.…”

“…1 H and 13 C NMR spectra of 1 in [D 6 ]benzene indicated the chemical equivalence of all six methyl groups due to symmetry (C 3v ) and free rotation of the dimethylamide ligands. In previous studies, WN x nanoparticles were synthesized at high temperature by thermolysis, [61,62] pulsed laser-ablation, [63] and a "urea glass" technique. Compound 1 adopts a pseudo-tetrahedral geometry, as can be seen in the ORTEP representation ( Figure 2).…”

Novel pseudo-morphotactic synthesis and characterization of tungsten nitride nanoplates

“…The similar examples can be found in references [34,35,37], where gaseous NH 3 or N 2 are used as the nitridizing agents. However the cases of ammonium dicyanamide [36], and ALD or CVD methods [22][23][24][25][26][27][28][29], other WN x phases are obtained.…”

“…Bai and coworkers [37] synthesized mesostructural b-W 2 N nanocrystals with a high surface area (89 m 2 /g) via a temperature-programmed reaction of H 2 WO 4 with ammonia at 700 1C. Although there are several methods developed for the successful synthesis of tungsten nitride nanocrystals, the facile, inexpensive and efficient routes for the shape-and size-controlled synthesis are not still available [3,19,34].…”

“…Tungsten nitrides and their related micro-/nanocrystals are usually synthesized by thermal treating tungsten containing precursors under an ammonia atmosphere [2,19,25], and the precursors are usually formed from soluble reagents, such as tungsten hexachloride [2,3,32], and bis(tert-butylimido)bis-(dimethylamido)-tungsten(IV) [33]. Cubic b-W 2 N nanoparticles with sizes of 2-3 nm were first synthesized by thermolysis of W(N t Bu) 2 (Ph 2 pz) 2 at 800 1C under a nitrogen condition [34]. Ma and coworkers [8] reported a synthesis of b-W 2 N nanoparticles (5-40 nm) with a direct-current arc discharge method using W and nitrogen as starting materials.…”