Two new tungsten complexes, [W(NtBu) 2 (NMe 2 ){(iPrN) 2 CNMe 2 }] (2) and [W(NtBu) 2 (H){(iPrN) 2 CNMe 2 }] (3), as precursors for metal-organic chemical vapor deposition (MOCVD) of tungsten nitride thin films were synthesized from the starting compound [W(NtBu) 2 (Cl){(iPrN) 2 CNMe 2 }] (1) by substitution of the chloro ligand by a dimethylamido and a hydrido group, respectively. Compounds 1-3 were characterized by 1 H NMR, 13 C NMR, EI-MS, IR, and elemental analysis including single-crystal X-ray diffraction studies on 1 and 3. The thermal properties of the compounds were studied by thermogravimetric and differential thermal analysis. Precursors 2 and 3 were compared for the growth of tungsten nitride thin films by MOCVD. The obtained films were characterized by X-ray diffraction and scanning electron microscopy and by depth-profiling the composition with secondary neutron mass spectroscopy. Films grown without ammonia had surprisingly low nitrogen levels, indicating that 2 and 3 are not suited as single-source precursors for pure WN x phases. When ammonia was used as a co reactant gas, the carbon content in the films decreased significantly and crystalline β-W 2 N was obtained. Interestingly, films grown in the presence of ammonia by amido compound 2 yielded lower carbon contents than films obtained from hydrido compound 3. Supporting Information Available: X-ray crystallographic data in CIF format for the structures of compounds 1 and 3 and schemetic of the MOCVD reactor and table with film composition (PDF). This material is available free of charge via the Internet at http://pubs.acs.org. CM061999D

Films. -As revealed by single crystal XRD compound (IV) crystallizes in the space group C2/c with Z = 1 and compound (IV) in the space group P21/n with Z = 4. Compounds (V) and (VI) yield amorphous films of carbon-rich β-WNxCy and β-W2N in the absence of NH3. Thus (V) and (VI) behave as poor single-source precursors. However, when NH 3 is used as a coreactant gas in the MOCVD process, both compounds yield crystalline tungsten nitride films. (V) yields a film with much less carbon contamination (2 at.%) than compound (VI) (11 at.%). -(RISCHE, D.; PARALA, H.; GEMEL, E.; WINTER, M.; FISCHER*, R. A.; Chem.

High-vacuum thermolyses (400-1000 degrees C) of the intramolecularly coordinated gallanes [Me(2)N(CH(2))(3)](2)GaX [X = Cl (1), Br (2)] and (Me(2)NCH(2)CD(2)CH(2))(2)GaBr (2D(4)) have been investigated with matrix-isolation FTIR techniques. Around 850 degrees C, the fragmentation of these compounds was completed, and their typical IR absorptions could no longer be detected in argon matrices. Products have been identified with IR spectroscopy with the help of ab initio and DFT calculations and known literature data. In the case of precursors 1 and 2, respectively, we identified GaH(3), XGaH(2), X(2)GaH, GaH, GaX, HX, HCN, CH(4), H(2)C=CH(2), H(2)C=CHCH(3), H(2)C=NMe, [H(2)CCHCH(2)]., and H(2)C=CHCH(2)NMe(2). In the case of the precursor 2D(4), we found GaH(3), GaH(2)D, BrGaH(2), BrGaDH, GaH, GaD, GaBr, HBr, HCN, CH(4), H(2)C=CD(2), H(2)C=CDCH(3), H(2)C=NMe, [H(2)CCDCH(2)]., and H(2)C=CDCH(2)NMe(2). Among the monomeric hydrides, BrGaH(2) and BrGaDH were isolated for the first time. These compounds have been characterized by their six normal modes, and the experimental frequencies have been compared to the results of MP2(fc)/6-311+G(2d,p) and B3LYP/6-311+G(2d,p) calculations. These results have been interpreted by assuming that the intramolecularly coordinated precursors 1, 2, and 2D(4) eliminate their ligands through Ga-C homolysis and beta-hydrogen elimination.