Pentakis(dimethylamido) Tantalum(V)

Abstract

[19824-59-0] Ta(NMe2)5 (MW = 401.33 g mol−1) InChI = 1S/5C2H6N.Ta/c5*1-3-2;/h5*1-2H3;/q5*-1;+5 InChIKey = VSLPMIMVDUOYFW-UHFFFAOYSA-N (tantalum(V) starting material used in chemical vapor deposition, hydroamination of alkynes, hydroaminoalkylation of olefins, and as a precursor for the preparation of various tantalum(V) coordination compounds) Alternate names: tantalum(V)pentakis(dimethylamide). Physical Data: mp 100 °C; sublimes at 90 °C (0.5 mmHg). Solubility: soluble in ethers, hydrocarbons, and aromatic solvents. Solutions in chlorinated solvents slowly decompose at room temperature. Form Supplied in: commercially available as an orange solid. Analysis of Reagent Purity: 1H NMR and 13C NMR spectra in C6D6 at room temperature display singlets at 3.27 and 46.0 ppm, respectively. Preparative Methods: TaCl5 is added to LiNMe2 in pentane at room temperature and the product subsequently sublimed (yield = 73%).1 Although this method gives Ta(NMe2)5 in high yield, it has been mentioned2 that it can lead to an unreacted mixture of TaCl5 and LiNMe2, which can detonate or undergo a highly exothermic reaction upon isolation. Alternatively, TaCl5 is added to LiNMe2 in a diethyl ether/hexane mixture at 0 °C and the resulting mixture is extracted with benzene and condensed to dryness. Sublimation of the residue yields Ta(NMe2)5 in a range of 33–44%.3 Handling, Storage, and Precautions: it is a corrosive, reactive, and flammable material, which is also oxygen and moisture sensitive. It should be kept away from sources of ignition and stored in a tightly closed container in a dry and well-ventilated place. Always handle and store it under inert gas and avoid the formation of dust and aerosols. Inhalation or contact with skin must be avoided. In case of fire, use carbon dioxide or dry powder.