Acyclic tertiary diamines and 1,4,7,10-tetraazacyclododecane with fluorine-containing β-diketones: Leading to low melting ionic adducts

Separating Rare-Earth Elements with Ionic Liquids

“…However, the synthesis of this IL is quite involved, entailing a multistep process including anion metathesis of an IL halide salt and ammonium hfca [95]. Alternatively, Gupta et al [96,97] and Li et al [98] reported a method for synthesizing PILs utilizing β-diketones and tertiary amines, entailing a simple single pot neutralization reaction. Yet, none of the ILs synthesized by this method have been applied to extraction processes.…”

Perfluoro alkyl 1,3-diketonates of cyclic and acyclic secondary amines

“…The monotrialkylammonium diketonates exhibit higher thermal stabilities and, in general, much lower T m values than diammonium bis[diketonate] salts [2,14]. However, a few of the latter exhibit melting points at <25 8C similar to the monoammonium derivatives.…”

“…Analogously, other cyclic amines (B, D, E, F) were reacted with 4 to form salts (13,16,18,20) in varying yields. Additional 1,3-diketones (1, 2, 3, 5) were also reacted under similar conditions with morpholine (A) to form ionic liquids (6,7,8,10); N-acetylmorpholine (B) with 1,3-diketones (1, 3, 5) gave ionic liquids (11,12,14); 3-methyl-N-acetyl piperidine (C) with 5 produced 15; 2,2,6,6, tetramethyl-4-aminopiperidine (D) with 3 gave 17; 4,4-dimethylimidazoline (E) with 4 formed 18; and 1,3-bispiperidine propane (F) with 1 produced 19 (Scheme 1, Table 1). …”

“…Compound 7 has the highest melting point of the morpholinium diketonates at 102 8C very likely because of improved packing ease. The N-acetyl-morpholine 1,3-diketonates (11)(12)(13)(14) are all viscous liquids at 25 8C. As is typical of these low melting salts, none exhibits any detectable vapor pressure at ambient temperature.…”

“…Cyclic trialkylammonium cations have been utilized in a one-pot, two step syntheses of new functionalized ionic liquids using Michael-type addition reactions [3]. While a very large number of quaternary tetraalkyl ammonium salts have been synthesized [4][5][6][7][8][9][10][11][12][13], there were few quaternary trialkyl ammonium (R 3 NH + ) compounds until the recently reported reactions of N,N,N 0 ,N 0 -tetramethylalkane diamines with fluorine-containing 1,3-diketones to form bis-quaternary ammonium salts which often are rather low melting [14].…”