19824-59-0Relevant articles and documents
Method for synthesizing penta(dimethylamino)tantalum
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Paragraph 0019; 0020; 0021; 0022; 0023; 0024, (2017/08/30)
The invention discloses a method for synthesizing penta(dimethylamino)tantalum. The method comprises the following steps: adding a mixture of tantalum pentachloride and alkane CnH(2n+2) (n is not smaller than 6) into an inert atmosphere shielded reactor, adding dimethylamine into the reactor under the condition of stirring, carrying out a reaction, keeping the temperature of a reaction system to 0 DEG C to -30 DEG C, and carrying out a reaction for 8 to 12 hours while keeping the temperature to 0 DEG C to -30 DEG C after dropwise adding is completed; dropwise adding an n-butyl lithium.alkane CnH(2n+2) (n is not smaller than 6) solution, carrying out a reaction for 4 to 20 hours while keeping the temperature to 0 DEG C to -30 DEG C, and maintaining a reflux reaction for 4 to 12 hours; and carrying out depressurizing until the pressure intensity is 1,000Pa to 7,000Pa to completely distill off an alkane CnH(2n+2) (n is not smaller than 6) solvent, transferring a product to a sublimator, and carrying out depressurizing until the pressure intensity is 50Pa to 300Pa, so as to collect the product, i.e., penta(dimethylamino)tantalum. According to the method disclosed by the invention, selected reagents are the conventional reagents and are moderately-priced and readily available, and the operation process is simple and is free of potential safety hazards; by using the serpentine sandwiched sublimator, the product purity is improved, and the reaction yield is increased; and the solvent required by the reaction can be reused, and no waste is generated, so that the method is pollution-free to environments.
New octahedral Ta(V) hydrazido-substituted compounds for atomic layer deposition: Syntheses, X-ray diffraction structures of TaCl(NMe2)3[N(TMS)NMe2] and Ta(NMe2)4[N(TMS)NMe2], and fluxional behavior of the amido and hydrazido ligands in solution
Huang, Shih-Huang,Pilvi, Tero,Wang, Xiaoping,Leskel?, Markku,Richmond, Michael G.
, p. 1754 - 1759 (2010/07/04)
The synthesis and structural characterization of new tantalum(V) compounds containing a single hydrazido(I) ligand are reported. Hydrazinolysis of TaCl(NMe2)4 using trimethylsilyl(dimethyl)hydrazine affords the compound TaCl(NMe2)3[N(TMS)NMe2] in essentially quantitative yield. Metathetical replacement of the chloride ligand in TaCl(NMe2)3[N(TMS)NMe2] by LiNMe2 gives the all-nitrogen coordinated compound Ta(NMe2)4[N(TMS)NMe2]. VT 1H NMR studies support the existence of low-energy pathways involving rotation about the Ta-N bonds of the ancillary amido and hydrazido ligands in both hydrazido-substituted compounds. X-ray crystallographic analyses confirm the octahedral disposition about the tantalum metal in TaCl(NMe2)3[N(TMS)NMe2] and Ta(NMe2)4[N(TMS)NMe2] and the presence of an η2-hydrazido(I) ligand. Preliminary data using Ta(NMe2)4[N(TMS)NMe2] as an ALD precursor for the preparation of tantalum nitride and tantalum oxide thin films are presented.
Crystal structure of TaCl(NMe2)4 and its reactions with lithium amides and water. Indirect observation of an equilibrium among TaCl(NMe2)4 Ta(NMe2)5 and ta 2(μcl)2(nme
Chen, Shu-Jian,Cai, Hu,Xue, Zi-Ling
, p. 167 - 171 (2009/05/30)
Reactions of TaCl(NMe2)4 (2) with LiNR2 (R = SiMe3, Et), yielding Ta(NMe2)4(NR 2) (R = SiMe3, 4; Et, 7), Ta(NMe2)5 (1), (Me2N)3/
Unexpected formation of (dimethylaminomethylene)methylamide complexes from the reactions between metal chlorides and lithium dimethylamide
Zhang, Xin-Hao,Chen, Shu-Jian,Cai, Hu,Im, Hee-Jung,Chen, Tianniu,Yu, Xianghua,Chen, Xuetai,Lin, Zhenyang,Wu, Yun-Dong,Xue, Zi-Ling
, p. 1338 - 1341 (2009/02/01)
Reactions of MCl5 (M = Nb, Ta) with LiNMe2 have been found to yield M(NMe2)4(η2-MeNCH 2NMe2) (M = Nb, 2a; Ta, 2b) containing a chelating ligand (dimethylaminomethylene)methylamide, as confirmed by NMR spectroscopy, DFT calculations, and their reactivity studies.
Formation of tantalum tuck-in complexes by activation of methyl C-H bonds in pentamethylcyclopentadiene groups by carbazole ligation
Riley, Patrick N.,Parker, Jennifer R.,Fanwick, Phillip E.,Rothwell, Ian P.
, p. 3579 - 3583 (2008/10/08)
The reaction of [Cp*TaCl4] with the potassium salt of carbazole (cbK, >3 equiv) in hydrocarbon solvents leads to the species [(C5Me4CH2)Ta(cb)2Cl] (1), in which one of the ring methyl C-H bonds of the Cp* ligand has been cleaved along with free cbH. Spectroscopic and structural studies of 1 show a lack of a plane of symmetry through the molecule with nonequivalent cb ligands. A minor component of the reaction mixture is believed to be the substitutional isomer 2, in which both carbazole ligands are equivalent. Alkylation of 1 with LiCH2SiMe3 or PhCH2MgCl generates the corresponding monoalkyl derivatives [(C5Me4-CH2)Ta(cb)2(R)] (7 or 8, respectively). Structural studies of 1, 7, and 8 support an η1:η5-CH2C5Me4 (σ:η5-CH2C5Me4) description for the metalated ligands, with significant slippage toward an η1:η3-CH2C5Me4 resonance form. To compare the extent of π-bonding between cb and dialkylamido ligands, the complex [(cb)2Ta(NMe2)3] (9) was synthesized and structurally characterized. The molecular structure of 9 consists of a tbp arrangement of nitrogen atoms with trans, axial cb ligands. The Ta-cb distances are 0.2 A? longer than the Ta-NMe2 distances. An improved (safer) procedure for the synthesis of [Ta(NMe2)5] is presented.
