Lewis base complexes of alkali metal salts

Details Lewis base complexes of alkali metal salts Lewis base complexes of alkali metal salts

1989-08-18

1993-04-27

Ivy, C. Warren

Organic compounds -- part of the class 532-570 series

Organic compounds

Heterocyclic carbon compounds containing a hetero ring...

549505, 564512, 564 14, 568557, 568606, C07C21100

Patent

active

052063941

DESCRIPTION:

BRIEF SUMMARY
This invention relates to the preparation of alkali metal salt complexes of the formula (M.sub.x X.nL).sub.y, where M is an alkali metal, e.g. Li, Na or K, X is an anion, e.g. F.sup.-, Cl.sup.-, Br.sup.-, I.sup.-, SCN.sup.-, OCN.sup.-, ClO.sub.4.sup.-, CO.sub.3.sup.2-, L is a Lewis base, such as hexamethylphosphoramide (HMPA), tetramethylethylenediamine (TMEDA) or pentamethyldiethylenetriamine (PMDETA), x is the valency of the anion X, and is usually 1 or 2, n is usually 1, 2 or 4 and y is an integer up to infinity, depending upon the degree of lattice formation by the complex.
Alkali metal halide complexes of the above type are known: W. Setzer and P. v. R. Schleyer, Adv. Organomet. Chem. 1985, 24, 353; and are potentially useful commercial materials for a variety of purposes, particularly in the field of organic synthesis, where their solubility in organic media renders them useful as soluble, stoichiometrically controllable halogenating agents. This solubility is in marked contrast to the corresponding uncomplexed salts, e.g. the uncomplexed alkali metal halides, which are known to be high-melting-point materials often of extremely high lattice energy and therefore insoluble except in polar solvents. The Lewis base complexes of alkali metal salts are also of interest because of their low melting points in comparison with their uncomplexed precursors, and are potentially useful as low energy electrolytic sources of alkali metals: "Lithium: Current Applications in Science, Medicine and Technology", ed. R. O. Bach, Wiley, Chichester, 1985; they are potentially of great value as fast-ion conductors, e.g. in electrolyte and solvent systems for batteries, see Angew. Chem. Int. Ed. Engl. 25, 1986, No. 12, 1087-1089.
However, existing routes to such complexes are disadvantageous. For example, dissolution of uncomplexed alkali metal halides in neat donor or donor/hydrocarbon mixes requires total exclusion of water both from the halide and from the reaction system at large, both of which, in practice are extremely difficult to attain. In any case their frequently extremely high lattice energy often makes such dissolution impossible, D. Barr, W. Clegg, R. E. Mulvey and R. Snaith, J. Chem. Soc., Chem. Commun. 1984, 79; D. Barr, K. B. Hutton, J. H. Morris, R. E. Mulvey, D. Reed and R. Snaith, J. Chem. Soc., Chem. Commun. 1986, 127.
An alternative route involves the in situ formation of (M.Hal).sub.y at low temperatures in the presence of the donor, the presence of which restricts the growth of the lattice, i.e. the value of y. According to this procedure an alkali metal organic compound, such as a lithium alkyl or an iminolithium complex, is reacted with a halide source, such as aluminium chloride or n-butyl bromide, in the presence of the ligand, e.g.: ##STR1## However, these routes are still highly susceptible to hydration problems and require extreme precautions to avoid the presence of water, which precautions are largely impracticable for commercial-scale operation. Not only that, but such processes represent an extremely inefficient utilisation of lithium, since the starting materials t-BuLi (which is used initially to prepare the t-Bu.sub.2 C=NLi by reaction with t-BuCN) and n-BuLi are themselves obtained by the reaction of a butyl halide with lithium, which produces lithium halide as a by-product, e.g.
The present invention is based on the discovery of an alternative route for the preparation of Lewis base complexes of alkali metal salts, particularly lithium halide and thiocyanate complexes, that produces the complexes in high yield and high purity, and that does not apprently suffer from the hydration problems or product recovery problems associated with the known processes. In accordance with the present invention, alkali metal salt complexes of the formula (M.sub.x X.nL).sub.y, where M is an alkali metal, X is an anion, L is an organic electron-donating ligand (Lewis base), x is the valency of the anion X, n is a number such that n:l is the molar ratio of ligand to alkali metal salt in the complex, and y

REFERENCES:
patent: Re28456 (1975-07-01), Langer, Jr. et al.
patent: 3734963 (1973-05-01), Langer, Jr. et al.
patent: 3933879 (1976-01-01), Langer, Jr. et al.
patent: 4088666 (1978-05-01), Langer, Jr. et al.
patent: 4094876 (1978-06-01), Langer, Jr. et al.
patent: 4152401 (1979-05-01), Langer, Jr. et al.
patent: 4156603 (1979-05-01), Langer, Jr. et al.
patent: 4229354 (1980-10-01), Bogdanovic
patent: 4301081 (1981-11-01), Bogdanovic
patent: 4370488 (1983-01-01), Bogdanovic
patent: 5045244 (1991-09-01), Merlett
Magnus et al., "Alpha Lithiohexamethylphosphoric Triamide, etc.", Synthesis, No. 7, pp. 575-577, (Jul. 1980).
Barr et al., "The Isolation of a Highly Arene-Soluble Alkali Metal, etc.", J. Chem. Soc., Chem. Commun., pp. 127-129 (1986).
Barr, et al., "Crystal Structures of (Ph.sub.2 C.dbd.NLi.multidot.NC.sub.5 H.sub.5).sub.4, etc.", J. Chem. Soc., Chem. Commun., pp. 79-80 (1984).
Barr et al., "Synthesis, and Crystal and Solution Structures of the 1:1 TMEDA, etc.", J. Chem. Soc., Chem. Commun., pp. 145-147 (1988).
Snaith et al., "Reactions of Ammonium Salts with Butyllithium, etc.", J. Am. Chem. Soc., vol. 109, No. 25, pp. 7891-7893 (1987).

Affiliated with

Also associated with

Rating

Lewis base complexes of alkali metal salts does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Lewis base complexes of alkali metal salts, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Lewis base complexes of alkali metal salts will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2328642