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.
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/
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.
