Alkylammonium formate

PILs containing alkylammonium cations have been investigated for their potential use in chromatography, such as eAN, ° ethylammonium acetate (EAA), ° pro-pylammonium nitrate (PAN), ° tributylammonium nitrate (TB AN), ° alkylammonium formates, and various alkylammonium thiocyanates. The early use of PILs in chromatography was primarily to characterize the solvent properties of the PILs, which was described in a comprehensive review by Poole in 2004. The solvent properties of PILs that make them potentially useful in chromatography are that they are polar, are cheap, are easy to make, can be miscible with water, can be air/moisture stable, and have high selectivity toward solutes that are polar and/or hydrogen donors or acceptors. 

Mann, J. P, A. McCluskey, and R. Atkin. 2009. Activity and Thermal Stability of Lysozyme in Alkylammonium Formate Ionic Liquids-Intluence of Cation Modification. Green Chemistry 11 (6) 785-792. 

Foreign cations can increasingly lower the yield in the order Fe, Co " < Ca " < Mn < Pb " [22]. This is possibly due to the formation of oxide layers at the anode [42], Alkali and alkaline earth metal ions, alkylammonium ions and also zinc or nickel cations do not effect the Kolbe reaction [40] and are therefore the counterions of choice in preparative applications. Methanol is the best suited solvent for Kolbe electrolysis [7, 43]. Its oxidation is extensively inhibited by the formation of the carboxylate layer. The following electrolytes with methanol as solvent have been used MeOH-sodium carboxylate [44], MeOH—MeONa [45, 46], MeOH—NaOH [47], MeOH—EtsN-pyridine [48]. The yield of the Kolbe dimer decreases in media that contain more than 4% water. 

Recently, the abilities of primary to tertiary alkylammonium ions with Me, Et, and -Bu groups to transport water to NB have been studied [48]. As the result of careful consideration of the ion-pair formation, it has been shown that the hydration numbers (w ) of the ammonium ions in NB, being little affected by the alkyl chain length, are simply dependent on the class of the ammonium ion % = 1.64, 1.04, 0.66, respectively, for the primary, secondary, and tertiary ammonium ions. 

In a similar manner, the diffusion of hexane into dichloromethane solutions containing mixtures of the alkylammonium salts of bromide and the olefinic acceptors o-CA and TCNE result in the formation of brown-red crystals [23]. X-ray analysis reveals the (1 1) complex of bromide with o-CA, in which the anion is located over the center of the C - C bond of the acceptor moiety (Fig. 15b) and Br - C contacts are shortened by as much as 0.6 A relative to the sum of van der Waals radii (Table 3). In bromide complexes with TCNE, the location of the anion relative to the acceptor is variable. In fact, a 2 1 complex [(Br )2,TCNE] is isolated in which both anions reside over the olefinic bond when the tetraethylammonium salt of bromide is used. In comparison, if the tetrapropyl- or tetrabutylammonium salts of the same anion are employed, the (1 1) complexes [Br ,TCNE] are formed in which the bromide donors are shifted toward the cyano substituents (Fig. 15a). In both cases however, the short intermolecular separations that are characteris-... 

Hexaco-ordinated Phosphorus Compounds. - The reaction of PCt with alkylammonium fluorides in the presence of secondary amines gives PF5-amine adducts (132)60. The additional presence of alcohols or phenols leads to the formation of alkoxy- or aroxypenta-f luorophosphates, ROPF -. The PF -amine adducts may also be converted into ROPF - by treatment with alcohols or into ArNHPF -by treatment with primary arylamines. 

The nitration of nitramine (153) with nitronium tetrafluoroborate, followed by neutralization of the resulting dinitraminic acid with ammonia, also generates ammonium dinitramide (152). Neutralization of this reaction with alkylamines, instead of ammonia, yields the corresponding alkylammonium salts of dinitramide. The nitration of ammonia with dinitrogen pentoxide (15 %) or nitronium salts like the tetrafluoroborate (25 %) yield ammonium dinitramide (152) through the initial formation of nitramine. 

The availability of formation constants for a large number of structurally diverse alkylammonium ions also encourages attempts to identify quantitatively those chemical features of a resident ligand species that are responsible for stability and selectivity within complexes of cucurbituril. In order to secure interpretable results, a subset of data was compiled, restricted to mono-substituted ammonium ions carrying exclusively alkyl or thioether residues [9]. Only included were moieties for which internal complexation with cucurbituril was established (NMR evidence) and for which substrate-specific overcrowding (such as with the arenes) was unlikely. A short list consisting of the first 24 guests in Table 1 was... 

In the reaction of amines with nitrous acid, one would expect the primary reaction to be the formation of an alkylammonium nitrite salt. Despite a few observations on the formation of such salts in the late nineteenth and early twentieth centuries, the formation of such salts was largely ignored until quite... 

Controlled evaporation of SUVs and MLVs on substrates has been shown to result in the formation of ultrathin films which retained the regular bilayer structure of vesicles [69, 425-427]. These immobilized bilayers, termed as cast multibilayers , cast multibilayers , or ordered cast (ultrathin) films , have provided an alternative to LB films [425-446]. Alkylammonium surfactants with azobenzene (33) and glutamate (34) functionalities have been used, for example, in the preparation of cast-film-forming SUVs. X-ray diffraction... 

Tetrabutylammonium(triphenylsilyl)difluorosilicate is a new fluoride source soluble in anhydrous, nonhygroscopic and neutral organic solvents. This reagent converts organic halides and sulfonates into fluorides, however, 4-6 equivalents are required. 1-Iodooctane is converted to 1-fluorooctane (33) in 74% yield, the rest (26%) being the alkene.221 Apparently with tetra-alkylammonium fluorides, the formation of alkenes is generally not completely suppressable. 

Carbon disulphide reacts additively with primary and secondary aliphatic amines to form alkylammonium salts of alkyldithiocarbamic acids. The products obtained with dimethylamine, diethylamine and piperidine, also certain derivatives of these products, are manufactured on a large scale for use as accelerators in the vulcanisation of rubber. With aromatic amines the disulphide reacts with elimination of hydrogen sulphide and formation of substituted thio-ureas, e.g. thiocarbanilide. 

The analysis of polymeric and gaseous products of the reaction of PMMA and di-methylamine at low dimethylamine levels shows that there was a clean reaction that produced 1 eq of anhydride (NOT Amide) per 1 eq of dimethylamine and per 1 eq of MMA. Note that this is in most close agreement with pathway 2a- 3a (Figure 2) in which most of the MMA carbonyls have been converted to COOH or alkylammonium COO salts followed by closure to anhydride. This shows that direct acyl addition (2c— 3c) to form amide, or reaction of carboxylate with adjacent ester (2b- 3b) to form anhydride (which liberates MeOH after proton transfer, and requires only 0.5 eq. dimethylamine per MMA group) are not the predominant pathways under these conditions. The Flory limit effect is consistent with random initial MAA formation, which after cyclization to anhydride (Figure 2) eventually leads to some groups trapped between rings which remain in the uncyclized acid form. 

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