Synthesis, characterization, volatility, and thermal stability of fluorinated copper(II) aminoalkoxide complexes as potential vapour deposition precursors

Abstract

The sodium aminoalkoxides Na[OCR(CF3)CH2NMeR′] {R = H, R′ = Me (1a); R = R′ = Me (1b); R = CF3, R′ = Me (1c); R = Me, R′ = Et (1d); R = CF3, R′ = Et (1e)} were synthesized by reaction of the corresponding fluorinated epoxide {OCH2CR(CF3); R = H (A), Me (B), CF3 (C)} with a secondary amine (HNMe2 or HNMeEt), followed by deprotonation with sodium hydride. Compounds 1a–e were isolated as white powders and characterized by combustion elemental analysis and NMR spectroscopy. Epoxides A and C are commercially available, while epoxide B was prepared by in situ deprotonation and alkylation of A. Reactions of 1a–e with copper(II) chloride in THF afforded [Cu{OCR(CF3)CH2NMeR′}2] {R = H, R′ = Me (2a); R = R′ = Me (2b); R = CF3, R′ = Me (2c); R = Me, R′ = Et (2d); R = CF3, R′ = Et (2e)}; compounds 2b and 2c have previously been reported but not structurally characterized, while 2a, 2d, and 2e are new to this report. All copper(II) compounds were characterized by combustion elemental analysis and single crystal X-ray crystallography. The physical properties of 2a–e were also evaluated using thermogravimetric analysis, melting point, and sublimation (at 5 mTorr) data, with comparison to previously reported non-fluorinated [Cu{OCHMeCH2NMe2}2] (III; [Cu(dmap)2]).