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A METHOD FOR SYNTHESIS OF HALIDE SALTS

20250214937 · 2025-07-03

    Inventors

    Cpc classification

    International classification

    Abstract

    A method for synthesis of halide salts of the general formula: Z.sup.n+X.sup..sub.n. The method including reacting a first reactant being formate salt with a second reactant being a diatom halogen: X.sub.2.

    Claims

    1. A method for synthesis of halide salts of the general formula (I):
    Z.sup.n+X.sup..sub.n Formula I wherein: X.sup. represents a halogen anion, and Z.sup.n+ represents a cation having a valency n, the method comprising reacting a first reactant being formate salt of the general formula (II):
    Z.sup.n+(COOH.sup.).sub.n Formula II with a second reactant being a diatom halogen: X.sub.2.

    2. The method of claim 1 wherein said diatom halogen X.sub.2 is selected from the group consisting of Br.sub.2 and I.sub.2.

    3. The method of claim 1 wherein said cation (Z.sup.n+) is an inorganic cation of a metal selected from the group consisting of Cs.sup.+, Ag.sup.+, Pb.sup.2+, Sn.sup.2+, Bi.sup.3+, and Sn.sup.4+.

    4. The method of claim 1 wherein said cation (Z.sup.n+) is Pb.sup.2+.

    5. The method of claim 1 wherein said cation (Z.sup.n+) is an organic cation of the general formula (III), (IV), or (V): ##STR00015## wherein: R, R.sup.1, R.sup.2, R.sup.3, R.sup.4 each independently represents hydrogen or an organic substituent moiety, wherein at least one of R.sup.1, R.sup.2, R.sup.3 is not hydrogen; a denotes the number of R moieties, A represents a five-membered or six-membered aliphatic or aromatic hydrocarbon ring, optionally having at least one heteroatom substituting the carbon atom selected from the group consisting of oxygen, nitrogen, and sulfur, Y represents a substituent of the ring A other than hydrogen. bdenotes the number of Y moieties, wherein b is zero or an integer in the range of 1 to 4 if A represents the five-membered ring, or b is zero or an integer in the range of 1 to 5 if A represents the six-membered ring.

    6. The method of claim 5 wherein the organic substituent independently for each of R, R.sup.1, R.sup.2, R.sup.3, and R.sup.4, is selected from the group consisting of C.sub.1-C.sub.16 alkyl, C.sub.6 aryl, C.sub.10 aryl, C.sub.7-26 aralkyl and heterocycle substituent.

    7. The method of claim 5 wherein the organic substituent independently for each of R, R.sup.1, R.sup.2, R.sup.3, and R.sup.4, is selected from the group consisting of: C.sub.1-C.sub.16 alkyl constituting acyclic, straight or branched hydrocarbon chain comprising from 1 to 16 carbon atoms in the chain, optionally comprising at least one heteroatom substituting the carbon atom or hydrogen atom in the C.sub.1-C.sub.16 alkyl moiety, wherein the heteroatom is selected from the group consisting of phosphorus, silicon, oxygen, nitrogen, sulfur, iodine, chlorine, bromine, and fluorine; C.sub.6 aryl or C.sub.10 aryl constituting an aromatic monocyclic system comprising six carbon atoms forming the ring system, or an aromatic bicyclic system comprising ten carbon atoms forming the bicyclic system, optionally comprising at least one heteroatom substituting the carbon atom or hydrogen atom in the C.sub.6 aryl or C.sub.10 aryl moiety, wherein the heteroatom is selected from the group consisting of phosphorus, silicon, oxygen, nitrogen, sulfur, iodine, chlorine, bromine, and fluorine; C.sub.7-26 aralkyl constituting the C.sub.6 aryl or C.sub.10 aryl substituent linked to the nitrogen atom of the organic cation through the C.sub.1-C.sub.16 alkyl, optionally comprising at least one heteroatom substituting the carbon atom or hydrogen atom, wherein the heteroatom is selected from the group consisting of: phosphorus, silicon, oxygen, nitrogen, sulfur, iodine, chlorine, bromine and fluorine; and heterocycle substituent constituting monovalent substituent derived by removing hydrogen from a five-, six-, or seven-membered saturated or unsaturated alicyclic moiety or aromatic heterocycle moiety, comprising carbon atoms and from one to four ring heteroatoms selected from the group consisting of nitrogen, oxygen, and sulfur.

    8. The method of claim 5 wherein the organic substituent independently for each of R, R.sup.1, R.sup.2, R.sup.3 and R.sup.4, is selected from the group consisting of: C.sub.1-C.sub.16 alkyl substituent selected from the group consisting of methyl, ethyl, propyl, isopropyl n-butyl, tert-butyl, isobutyl, sec-butyl, n-pentyl, isopenthyl, neopenthyl, methylethyl, diispropylethyl, 2-methylhexyl, 3-methylheptyl, 2,3-dimethylpentyl, 4-ethyl-2-methyloctyl, 4-isopropylnonyl, hexyl, 2-methylpentyl, 3-methylpentyl, 2,2-dimethylbutyl, and 2,3-dimethylbutyl, 1-methylhexyl, 2-methylhexyl, 1,1-dimethylpentyl, 1,2-dimethylpentyl, 1,3-dimethylpentyl, 2,2-dimethylpentyl, 3-ethylpentyl, 2,2,3-trimethylbutyl, 2-methylheptyl, 3-methylheptyl, 2,3-dimethylhexyl, 3,4-dimethylhexyl, 2,3,4-trimethylpentyl, 3,3-dimethylhexyl, 2,2-trimethylpentyl, 2,4-dimethylhexyl, 2,2,4-trimethylpentyl, 2,3,3-Trimethylpentyl, 3,3,4-trimethyl-pentyl, 3,4,4-trimethylpentyl, 2,4,4-trimethylpentyl, 2-methylheptyl, 3-methylheptyl, 2,3-dimethylhexyl, 3,4-dimethylhexyl, 2,3,4-trimethylpentyl, 3,3-dimethylhexyl, 2,2-trimethylpentyl, 2,4-dimethylhexyl, optionally comprising at least one heteroatom substituting the carbon atom or hydrogen atom in the C.sub.1-C.sub.16 alkyl moiety, wherein the heteroatom is selected from the group consisting of phosphorus, silicon, oxygen, nitrogen, sulfur, iodine, chlorine, bromine, and fluorine; C.sub.6 aryl or C.sub.10 aryl substituent selected from the group consisting of phenyl and naphthyl, optionally comprising at least one heteroatom substituting the carbon atom or hydrogen atom in the C.sub.6 or C.sub.10 aryl moiety, wherein the heteroatom is selected from the group consisting of: phosphorus, silicon, oxygen, nitrogen, sulfur, iodine, chlorine, bromine, and fluorine; C.sub.7-26 aralkyl substituent selected from the group consisting of benzyl, butylphenyl, ethylphenyl, propylphenyl, pentylphenyl, hexylphenyl, ethylnaphtyl, and methylnaphtyl, optionally comprising at least one heteroatom substituting the carbon atom or hydrogen atom, wherein the heteroatom is selected from the group consisting of phosphorus, silicon, oxygen, nitrogen, sulfur, iodine, chlorine, bromine and fluorine; and heterocycle substituent selected from the group consisting of furan, tetrahydrofuran, thiophene, diazepine, isoxazole, piperidine, dioxane, pyridine, and pyrimidine.

    9. The method of claim 5 wherein said cation (Z.sup.n+) is the organic cation of the formula (VI), (VII), or (VIII): ##STR00016##

    10. The method of claim 1 comprising heating the reactants to the temperature of 25 to 130 C. until obtaining the halide salt.

    11. The method of claim 1 wherein reacting the reactants is carried out in the absence of a solvent.

    12. The method of claim 1 wherein reacting the reactants is carried out in the presence of a solvent.

    13. The method of claim 3, wherein reacting the reactants is carried out in the presence of a solvent and wherein the solvent is selected from the group consisting of water and acetone.

    14. The method of claim 5, wherein reacting the reactants is carried out in the presence of a solvent and wherein the solvent is selected from the group consisting of water, alcohols, and acetonitriles.

    15. The method of claim 1, further comprising recrystallizing the obtained halide salt.

    Description

    BRIEF DESCRIPTION OF DRAWINGS

    [0045] Aspects and features of the present invention will become apparent by describing, in detail, exemplary embodiments of the present invention with reference to the attached drawings, in which:

    [0046] FIG. 1 presents a reaction of a method for synthesis of halide salts according to the present disclosure;

    [0047] FIG. 2 presents an embodiment of a reaction of a method for synthesis of halide salts according to the present disclosure;

    [0048] FIG. 3 presents in situ formation of formate salt and the following reaction of a method for synthesis of halide salts according to the present disclosure;

    [0049] FIG. 4 presents 1H-NMR spectrum of methylammonium iodide synthesized according to one of the embodiments;

    [0050] FIG. 5 presents 13C-NMR spectrum of methylammonium iodide synthesized according to one of the embodiments;

    [0051] FIG. 6 presents IR spectrum of methylammonium iodide synthesized according to one of the embodiments;

    [0052] FIG. 7 presents IR spectrum of methylammonium bromide synthesized according to one of the embodiments;

    [0053] FIG. 8 presents 1H-NMR spectrum of formidinium iodide synthesized according to one of the embodiments;

    [0054] FIG. 9 presents 13C-NMR spectrum of formamidinium iodide synthesized according to one of the embodiments;

    [0055] FIG. 10 presents IR spectrum of formamidinium iodide synthesized according to one of the embodiments;

    [0056] FIG. 11 presents 1H-NMR spectrum of tetramethylammonium iodide synthesized according to one of the embodiments;

    [0057] FIG. 12 presents 13C-NMR spectrum of tetramethylammonium iodide synthesized according to one of the embodiments;

    [0058] FIG. 13 presents IR spectrum tetramethylammonium iodide synthesized according to one of the embodiments;

    [0059] FIG. 14 presents 1H-NMR spectrum tetramethylammonium iodide synthesized according to one of the embodiments;

    [0060] FIG. 15 presents 13C-NMR spectrum triethylammonium iodide synthesized according to one of the embodiments;

    [0061] FIG. 16 presents 13C-NMR spectrum of tetramethylammonium iodide synthesized according to one of the embodiments;

    [0062] FIG. 17 presents IR spectrum of tetramethylammonium iodide synthesized according to one of the embodiments;

    [0063] FIG. 18 presents 1H-NMR spectrum of imidazolium iodide synthesized according to one of the embodiments;

    [0064] FIG. 19 presents 13C-NMR spectrum of imidazolium iodide synthesized according to one of the embodiments;

    [0065] FIG. 20 presents IR spectrum of imidazolium iodide synthesized according to one of the embodiments;

    [0066] FIG. 21 presents 1H-NMR spectrum of pyridinium iodide synthesized according to one of the embodiments;

    [0067] FIG. 22 presents 13C-NMR spectrum of pyridinium iodide synthesized according to one of the embodiments;

    [0068] FIG. 23 presents IR spectrum of aniline hydroiodide synthesized according to one of the embodiments;

    [0069] FIG. 24 presents 13H-NMR spectrum of phenylammonium iodide synthesized according to one of the embodiments;

    [0070] FIG. 25 presents 1H-NMR spectrum of 3-aminopropionic acid hydroiodide synthesized according to one of the embodiments;

    [0071] FIG. 26 presents 13C-NMR spectrum of 3-aminopropionic acid hydroiodide synthesized according to one of the embodiments;

    [0072] FIG. 27 presents IR spectrum of 3-aminopropionic acid hydroiodide synthesized according to one of the embodiments;

    [0073] FIG. 28 presents 1H-NMR spectrum of N-methylglycine hydroiodide synthesized according to one of the embodiments;

    [0074] FIG. 29 presents 13C-NMR spectrum of N-methylglycine hydroiodide synthesized according to one of the embodiments;

    [0075] FIG. 30 presents IR spectrum of N-methylglycine hydroiodide synthesized according to one of the embodiments;

    [0076] FIG. 31 presents 1H-NMR spectrum of glycine hydroiodide synthesized according to one of the embodiments;

    [0077] FIG. 32 presents 13C-NMR spectrum of glycine hydroiodide synthesized according to one of the embodiments;

    [0078] FIG. 33 presents IR spectrum of glycine hydroiodide synthesized according to one of the embodiments;

    [0079] FIG. 34 presents 1H-NMR spectrum of benzylammonium iodide synthesized according to one of the embodiments;

    [0080] FIG. 35 presents 13C-NMR spectrum of benzylammonium iodide synthesized according to one of the embodiments;

    [0081] FIG. 36 presents IR spectrum of benzylammonium iodide synthesized according to one of the embodiments;

    [0082] FIG. 37 presents X-ray diffraction pattern of PbI2 synthesized according to one of the embodiments;

    [0083] FIG. 38 presents X-ray diffraction pattern of PbBr2 synthesized according to one of the embodiments;

    DETAILED DESCRIPTION OF EMBODIMENTS

    [0084] Reference will now be made to embodiments, examples of which are illustrated in the accompanying drawings. Aspects and features of the embodiments will be described with reference to the accompanying drawings. The present invention, however, may be embodied in various different forms and should not be construed as being limited only to the illustrated embodiments. Rather, these embodiments are provided as examples so that this disclosure will be thorough and complete, and will fully convey the aspects and features of the present invention to those skilled in the art. It shall be understood that not all of the features shown in the embodiments are essential and the scope of the protection is defined not by means of literally shown embodiments, but by the features provided in the claims.

    [0085] The method for synthesis of halide salts according to the present disclosure involves reacting a formate salt of the general formula Z.sup.n+(HCOO).sub.n with a diatom halogen: X.sub.2, preferably Br.sub.2 or 12 as schematically shown in FIG. 1. The formate salt: Z.sup.n+(COOH.sup.).sub.n reduces the molecular (diatom) halide X.sub.2 to ions: X.sup. to form the halide salt of the general formula Zn.sup.n+(X.sup.).sub.n, whereas the formate ions: HCOO-transform to gaseous and/or liquid byproducts comprising C, O and/or H. It is suspected that the reaction by products comprises CO and/or CO.sub.2, and H.sub.2O and/or H.sub.2, and more likely H.sub.2O. However, due to the volatile nature of the byproducts the chemical formulas of the byproducts are under investigation.

    [0086] The reaction may occur with providing the stoichiometric ratio of the substrates. However, if one of the substrates, either the formate salt (Z.sup.n+(COOH.sup.).sub.n) or the halide (X.sub.2) is provided in excess, the reaction proceeds until total consumption of the other-deficient substrate. Thereby, no particular limitation for a ratio of these two substrates is required to carry out the synthesis of the halide salts, e.g. the halogen X.sub.2 can be added in the amount ranging from 0.5 to 1,2 molar equivalents of the formate salt Z.sup.n+(HCOO).sub.n.

    [0087] To maintain a reasonable reaction time, preferably the reactants: Z.sup.n+(COOH.sup.).sub.n and X.sub.2 are heated to the temperature of at least 25 C., and preferably to the temperature of at least 60 C. or more, and more preferably the reactants are heated to a temperature between 25 and 130 C., and preferably between 6 and 130 C. For example, the mixture of Z.sup.n+(COOH.sup.).sub.n and X.sub.2 can be heated to a temperature such as 25 C., 30 C., 40 C., 50 C., 60 C., 70 C., 75 C., 80 C., 85 C., 90 C., or 95 C., and most preferably 70 C., to obtain the halide salt. During heating the mixture of reactants: Z.sup.n+(COOH.sup.).sub.n and X.sub.2 can be agitated, e.g. stirred or shackedto provide an increased level of molecules interactions. However, in the case of smaller amounts of the reactants, e.g., in the order of milligrams/milliliters, agitation is not necessarily required. Agitation of the reactants is preferably carried out throughout all the reaction duration. Agitating can be preferably performed from a few seconds to a few hours, and preferably from 1 minute to 4 hours, e.g., from 30 minutes to 1 hour.

    [0088] Furthermore, the optimum synthesis conditions and times of the reaction may vary depending on the reactants used. Unless otherwise specified, solvents or solvent-free conditions, temperatures, pressures, and other reaction conditions may be readily selected by one of ordinary skill in the art to obtain optimum results for a particular reaction. Optionally, the reaction product may be purified by re-crystallization. For instance, the halide salt-being the reaction product can be obtained in pure form, in liquid or solid state-depending on its melting point, by simple removal of a reaction media such as solvent-if present, under reduced pressure and temperature below boiling or sublimation or decomposition point of the obtained halide salt. If the substrates are used in the stoichiometric ratio, both the substrates can be consumed in total, thereby, not contaminating the product, which enables one to achieved improved purity of the obtained halide salt.

    [0089] In the course of the reaction, no acids such as hydrohalic acids (HX) are synthesizedthe pH value of the reaction media, throughout the reaction of formate salt with the halide (X.sub.2), remains neutral, ca. pH=7. It is believed that the reaction of the formate salt with the halide: X.sub.2 occurs by a free radical mechanism, and the halide: X.sub.2 does not interact with protons H.sup.+ e.g. supplied with the solvent; it is further suspected that the reduction of halide: X.sub.2 by formate salt constitutes a reaction that is privileged notwithstanding the solvent used, because the reaction leads to the halide salts in the solvent-free conditions as well. Is it further suspected that the solvent molecules, if present in the reaction medium, do not interact with the reactants forming intermediate products or transitional states (such as low-energy transitional states).

    Substrates and Products

    [0090] The method for synthesis according to the present disclosure allows obtaining halide salts according to the general formula (I):


    Z.sup.n+X.sup..sub.n Formula I [0091] wherein: [0092] Z.sup.n+ represents a cation being either inorganic cation-preferably the cation of metal, or organic cation, preferably being ammonium derivative having the positive charge substantially localized on the nitrogen atom; n stands for valency of the cation Z.sup.n+, n preferably equals 1, 2, 3 or 4; it will be readily apparent from the description of the present disclosure that for the organic cations typically n=1, whereby for the inorganic cations n may vary e.g. n=1, 2, 3 or 4. [0093] X.sup.is a halogen ion, preferably Br or I.

    Organic Cation Z.SUP.n+

    [0094] Preferably, the organic cation Z.sup.n+ of the halide salt is a derivative of amine, being either aliphatic amine, aromatic amine, aliphatic-aromatic amine, or aryloamine, including, where applicable, primary amine, secondary amine, tertiary amine; or derivative of imine such as e.g., formamidinium cation. The halide salt is obtained from the corresponding formate salt, comprising said organic cation Z.sup.n+, as shown schematically in FIG. 1.

    [0095] Preferably, the organic cation (Z.sup.n+) is represented by the general formula (III), (IV), or (V):

    ##STR00003## [0096] wherein [0097] R, R.sup.1, R.sup.2, R.sup.3, R.sup.4 each independently represents hydrogen or an organic substituent, with the proviso that at least one of R.sup.1, R.sup.2, R.sup.3 is not hydrogen; [0098] adenotes the number of R moieties at nitrogen atom, a may equal 1 or 2-so as to provide N.sup.+; [0099] A represents a five-membered or six-membered aliphatic or aromatic hydrocarbon ring, optionally having at least one heteroatom substituting the carbon atom, the heteroatom is preferably selected from oxygen, nitrogen, and sulphur. [0100] Y represents a substituent, other than hydrogen, being the substituent at the ring A, wherein Y is preferably a chemically inert group, i.e. the group that is not able to chemically interfere with the formation of the formate salt or with the final reaction product, i.e. the halide salt. Preferably, the substituent Y is selected from the group consisting of alkyl, aryl, carboxy, alkoxy, halogen, thiol, hydroxy, trihaloalkyl, and (per)haloalkyl. [0101] bdenotes the number of Y moieties, wherein b is zero or an integer in the range of 1 to 4 if A represents a five-membered ring, or b is zero or an integer in the range of 1 to 5 if A represents six-membered ring.

    [0102] As mentioned above R, R.sup.1, R.sup.2, R.sup.3, R.sup.4 each independently represents hydrogen or an organic substituent, wherein at least one of R.sup.1, R.sup.2, R.sup.3 is not hydrogen; the organic substituent, independently for each of R, R.sup.1, R.sup.2, R.sup.3, and R.sup.4, is preferably selected from: [0103] C.sub.1-C.sub.16 hydrocarbon substituent constituting straight or branched C.sub.1-C.sub.16 alkyl substituent. The term C.sub.1-C.sub.16 alkyl as used herein, either alone or in combination with other the organic substituent, denotes acyclic, straight or branched chain alkyl substituent comprising from 1 to 16 carbon atoms in the chain; for example, the C.sub.1-C.sub.16 alkyl substituent may be selected from the group consisting of methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl, isobutyl, sec-butyl, n-pentyl, isopenthyl, neopenthyl, methylethyl, diispropylethyl, 2-methylhexyl, 3-methylheptyl, 2,3-dimethylpentyl, 4-ethyl-2-methyloctyl, 4-isopropylnonyl, hexyl, 2-methylpentyl, 3-methylpentyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, 1-methylhexyl, 2-methylhexyl, dimethylpentyl (including 4 isomers, such as 2,2-dimethylpentyl), 3-ethylpentyl, 2,2,3-trimethylbutyl, 2-methylheptyl, 3-methylheptyl, 2,3-dimethylhexyl, 3,4-dimethylhexyl, 2,3,4-trimethylpentyl, 3,3-dimethylhexyl, 2,2-trimethylpentyl, 2,4-dimethylhexyl, 2,2,4-trimethylpentyl, 2,3,3-trimethylpentyl, 3,3,4-trimethyl-pentyl, 3,4,4-trimethylpentyl, 2,4,4-trimethylpentyl, 2-methylheptyl (including 5 isomers, such as 2-methylhept-1-yl. 2-methylhept-2-yl etc.), 3-methylheptyl, 2,3-dimethylhexyl, 3,4-dimethylhexyl, 2,3,4-trimethylpentyl, 3,3-dimethylhexyl, 2,2-trimethylpentyl, 2,4-dimethylhexyl, 2,2,4-trimethylpentyl, 2,3,3-trimethylpentyl, 3,3,4-trimethyl-pentyl, 3,4,4-trimethylpentyl, and 2,4,4-trimethylpentyl (including 5 isomers, such as 2,4,4-trimethylpent-1-yl, 2,4,4-trimethylpent-2-yl). Optionally, the C.sub.1-C.sub.16 alkyl can comprise at least one heteroatom, and preferably from 1 to 6 heteroatoms, where applicable, substituting the carbon atom or hydrogen atom in the C.sub.1-C.sub.16 alkyl moiety, wherein the heteroatom is selected from the group consisting of phosphorus, silicon, oxygen, nitrogen, sulphur, iodine, chlorine, bromine, and fluorine; no-limiting examples of the C.sub.1-C.sub.16 alkyl comprising at least one heteroatom are: 2,2,2-trifluorethylamin, 2,2,2-trichlororethylamin, tris(perfluoropropyl)amine. Optionally the C.sub.1-C.sub.16 alkyl can be further substituted with one or more than one functional group, such as amino, carboxy, and/or methoxy; [0104] C.sub.6 aryl or C.sub.10 aryl substituent. The term C.sub.6 aryl or C.sub.10 aryl as used herein, either alone or in combination with other the organic substituent, denotes either an aromatic monocyclic system comprising six carbon atoms forming a ring system or an aromatic bicyclic system containing ten carbon atoms forming bicyclic system; for example, Ce aryl or C.sub.10 aryl substituents may be selected from the group consisting of phenyl and naphthyl. Optionally, the C.sub.6 aryl or C.sub.10 aryl can comprise at least one heteroatom, and preferably from 1 to 6 heteroatoms, where applicable, substituting the carbon atom or hydrogen atom in the C.sub.6 aryl or C.sub.10 aryl moiety, wherein the heteroatom is selected from the group consisting of phosphorus, silicon, oxygen, nitrogen, sulphur, iodine, chlorine, bromine, and fluorine; non-limiting examples of C.sub.6 aryl or C.sub.10 aryl comprising at least one heteroatom are: 4-chlorophenylamine, 2-aminothiophenol, and 4-fluorophenylamine; [0105] C.sub.7-26 aralkyl substituent. The term C.sub.7-26 aralkyl as used herein, either alone or in combination with other the organic substituent, denotes the aryl moietyas defined above, that is linked (substituted) to the nitrogen atom of the cation through the alkyl moiety, wherein the term alkyl is as defined above; for example, C.sub.7-27 aralkyl substituents may be selected from the group consisting of benzyl and butylphenyl. Optionally, the C.sub.7-26 aralkyl can comprise at least one heteroatom, and preferably from 1 to 6 heteroatoms, where applicable, substituting the carbon atom or hydrogen atom in the C.sub.7-26 aralkyl moiety, wherein the heteroatom is selected from the group consisting of phosphorus, silicon, oxygen, nitrogen, sulphur, iodine, chlorine, bromine and fluorine; non-limiting example of C.sub.7-26 aralkyl comprising at least one heteroatom is 4-fluoro-phenylethyl-amine; [0106] heterocycle substituent. The term heterocycle as used herein, either alone or in combination with other the organic substituent, means a monovalent substituent derived by removing a hydrogen from a five-, six-, or seven-membered saturated or unsaturated heterocycle, including aromatic heterocycle; the heterocycle moiety comprises carbon atoms and from one to four ring heteroatoms selected from nitrogen, oxygen, and sulfur; for example, the heterocycle substituent may be selected from the group consisting of furan, tetrahydrofuran, thiophene, diazepine, isoxazole, piperidine, dioxane, pyridine, and pyrimidine.

    [0107] Non-limiting examples of the organic cation Z.sup.n+ used in the composition of the formic salt Z.sup.n+(HCOO.sup.) to obtain the halide salt Z.sup.n+(X.sup.), according to the present invention (FIG. 1), include: ammonium cations, including alkylammonium cations, dialkylammonium cations, and trialkylammonium cations, amidinium cations, formamidinium cations; for instance Z.sup.n+ can denote: methylammonium CH.sub.3(H.sub.3) N.sup.+, ethylammonium CH.sub.3CH.sub.2(H.sub.3)N.sup.+, propylammonium C.sub.3H.sub.7(H.sub.3)N.sup.+, butylammonium C.sub.4H.sub.9(H.sub.3)N.sup.+, pentylammonium H.sub.3C.sub.5H.sub.11N.sup.+, hexylammonium H.sub.3C.sub.6H.sub.13N.sup.+, heptylammonium C.sub.7H.sub.15(H.sub.3)N.sup.+or octylammonium C.sub.8H.sub.17(H.sub.3)N.sup.+ cation, formamidinium (H.sub.2NHCNH.sub.2).sup.+, guanidinium (H.sub.2N).sub.2CNH.sub.2).sup.+ cation, or acetamidinium cation (H.sub.2NH.sub.3CCNH.sub.2).sup.+.

    [0108] Further, the non-limiting examples of the organic cation Z.sup.n+ include the cations represented by the following formula (VI), (VII), or (VIII):

    ##STR00004##

    [0109] Thus, the developed method involving the reaction shown in FIG. 1 enables one to obtain halide salts, including bromide salts and iodide salts, depending on the halide used: Br.sub.2, I.sub.2, such as methylammonium halide, dimethylammonium halide, propylammonium halide, methylethylammonium halide, butylammonium halide, pentylammonium halide, hexylammonium halide, heptylammonium halide, octylammonium halide formamidinium halide, guanidinium halide, acetamidinium halide, benzylammonium halide, benzyl-methyl ammonium halide, phenethylammonium halide, N,N-dimethylpropane-1,3-diammonium halide, N,N-diethylethane-1,2-diammonium halide, iso-butylammonium halide, iso-propylammonium halide, morpholinium halide, phenylammonium halide, dimethylammonium halide, trimethyl ammonium hailde, tertramethylammonium halide, di-isopropylammonium halide, hexane-1,6-diammonium halide, triewthyl ammonium halide, t-butylammonium halide, 4-tertbutyl-phenylammonium halide, butane-1,4-diammonium halide, propane-1,3-diammonium halide, ethane-1,2-diammonium halide, diethylamine halide, N,N-Diethylethane-1,2-diammonium halide, cyclohexylethylammonium halide, 2-(phenylene)di(etyylammonium) halide, 4-t-butylbenzylammonium halide, 2-thiophenmethylammonium halide, 2-(4-Fluorophenyl)ethylammonium halide, 4-Fluorobenzylammonium halide, 5-aminovaleric acid halide, cyclohexanemethylammonium halide, 2-(4-methoxyphenyl)ethylammonium halide, neopentylammonium halide, 1,4-diazabicyclo[2.2.2]octane halide, N, N-dimethylethylenediamine dihalide, dibutylammonium halide, N,N-diethyl-1,3-propanediamine dihalide, piperazinium dihalide, pyrrolidinium halide, 1,4-phenylenediammonium dihalide, 5-azoniaspiro[4.4]nonane halide, cyclohexyl ammonium halide, 4-(trifluoromethyl)benzylammonium halide, 2,4,4-trimethylpentan-2-ammonium halide, N, N-dimethyl-1,3-propanediammmonium dihalide, dodecylammonium halide, dimethylammonium halide, dethylammonium halide, 1-hexyl-1,4-diazabicyclo[2.2.2]octan-1-ium halide, morpholinium halide, n-octlyammonium halide, 4-hydroxyphenethylammonium halide, 4-chlorophenylammonium halide, 4-methoxyphenethylammonium halide, 2-furanmethylammonium halide, biphenylammonium halide, triphenylammonium halide, 2-thiophenethylammonium halide, diethanolammonium halide, ethanolammonium halide, diphenylammonium halide2,2-dipmethylpropane-1,3 diammonium halide, methoxyethylammonium halide, 2-pyrrolidin-1-ium-1-ylethylammonium halide, quinuclidine-1-ium halide, piperidinium halide, tert-octylammonium halide, etc.

    Inorganic Cation Z.SUP.n+

    [0110] Preferably, the inorganic cation Z.sup.n+of the halide salt constitutes a cation of metal Me.sup.n+, such as Me.sup.+, Me.sup.2+, Me.sup.3+ and Me.sup.4+. Non-limiting examples of the inorganic cation Z.sup.n+ used as the component of the formic salt Z.sup.n+(HCOO.sup.)to obtain the halide salt Z.sup.n+(X.sup.) according to the present invention (FIG. 1), include the inorganic cations selected from the group consisting of: Cs.sup.+, Ag.sup.+, Pb.sup.2+, Sn.sup.2+, Bi.sup.3+, and Sn.sup.4+. More preferably the inorganic cation is Pb.sup.2+.

    [0111] Thus, the developed method involving the reaction shown in FIG. 1 enables one to obtain halide salts, including bromide salts and iodide salts, depending on the halide used: Br.sub.2, I.sub.2, such as cesium halide (CsX), silver halide (AgX), lead (II) halide (PbX.sub.2), tin (II) halide (SnX.sub.2), bismuth (III) halide (BiX.sub.3) and tin (IV) halide (SnX.sub.4), including: CsI, CsBr, AgI, AgBr, PbBr.sub.2, PbI.sub.2, SnBr.sub.2, SnI.sub.2, BiBr.sub.3, BiI.sub.3SnBr.sub.4, SnI.sub.4.

    Solvents

    [0112] The reaction, depending on the nature of the substrates, can be carried out in solvent-free conditions, for example for the respective formates (Z.sup.n+(HCOO.sup.).sub.n) being liquids in ambient conditions. FIG. 2 presents the embodiment of synthesis the halide salt, carried out in solvent-free conditions. The methylammonium formate-liquid at room temperature, reacts with iodine (I.sub.2) (solid), in the atmosphere of air or under inert gas (e.g. argon), under heating to a temperature of 25-130 C. and agitating, in solvent-free conditions. The obtained product can constitute pure methylammonium iodide crystalsin the case of using the stoichiometric ratio of the substratesdue to the total consumption of both the substrates, in solvent-free conditions; however, if the molar ratio of the substrates used is non-stoichiometric, e.g. 1:1 then the reaction can be carried out until total consumption of the deficient substrate. This embodiment thereby indicates that the solvent molecules are not necessarily needed to conduct the reaction. Similar to the above-described reaction of halide with methylammonium formatethe ethylammonium formate, propylammonium formate, butylammonium formate, or pentylammonium formate can be subjected to the reaction.

    [0113] Alternatively, the reaction can be carried out in a solvent environmentfor example for the respective formates (Z.sup.n+(HCOO.sup.).sub.n) being solids in ambient conditions, the solvent allows interacting one reactant (Z.sup.n+(HCOO.sup.).sub.n) with the other reactant (X.sub.2)as the molecules of the substrates can move in the solvent. Also, it is a common practice to conduct a chemical reaction in a solvent medium, i.a. to improve agitating the mixture of reactants and provide better heat transfer within the reaction chamber. Thereby, the solvent aims at providing respective solubility of the reactants to improve the amounts of molecules interactions to better the product yield. The non-limiting examples of the solvents that can be used according to the present disclosure include polar solvents, non-polar solvents, being either protic or a-protic, organic or inorganic compounds. Further, a mixture of two or more solvent components can be used as the solvent. Non-limiting exemplary embodiments of the solvent, respectively inorganic and organic are water, methanol, ethanol, isopropanol, ethers, e.g. tetrahydrofuran or acetonitrile, or any mixture thereof, such as ethanol-water mixture, ethanol-ether mixture, isopropanol-water mixture, or acetonitrile-water mixture. E.g. alcoholic solvents can be used in pure form or in the form of their mixture with water, e.g. in form of water-alcohol azeotropes, such as a mixture of 95.63 wt % ethanol and 4.37 wt % water. Also, substantially pure ethanol can be used as the organic polar solvent. The amount of solvent used is not particularly limited. For example, the amount of the solvent may range between 5 to 30 parts by volume (v/W), and preferably amount of the solvent may range between 6 to 8 parts by volume (v/W).

    [0114] The purpose of solvent is to provide desired dissolution of at least one of the reactants, whereby the other reactant (undissolved) remains suspended in the reaction mixture, or to provide the desired dissolution of both the reactants. The use of the solvent thereby allows for desired agitation of the reactants to facilitate their chemical interaction.

    [0115] The respective formate: (Z.sup.n+(HCOO.sup.).sub.n) for synthesis the corresponding halide salt, can be supplied to a reaction chamber in a form of commercially available products, such as, e.g. commercially available ammonium formate, formamidinium formate methylammonium formate. Alternatively, the respective formate: (Z.sup.n+(HCOO.sup.).sub.n) can be prepared in situ (in the reaction chamber), e.g., by using known methods. The exemplary scheme for the synthesis of halide salt comprising the organic cation according to the present disclosure, involving in situ preparation of the salt of formic acid is schematically shown in FIG. 3. The formula R.sub.yNH.sub.3-y represents amine compound, which can be e.g., methylamine, which reacts with formic acid (Reaction 1) leading to the respective salt formate: R.sub.yNH.sub.3-y.sup.+HCOO.sup., such as e.g. methylammonium formate. Following the synthesis of the formate salt, respective halide X.sub.2 is added to the reaction chamber (Reaction 2) resulting in halide salt. Reaction 1 can be carried out in wateras the solvent. Alternatively, other solvents can be used such as polar/non-polar organic solvent; or Reaction 1 can be carried out in solvent-free conditions.

    [0116] Reaction 2 can be carried out in solvent-free conditions as well. If both reactions 1 and 2 are conducted as solvent-free, the obtained halide salt is already crystalline; this can be done preferably if one of the substrates is liquid in ambient conditions, or in the temperature of reaction. Furthermore, if the solvent is present, either in Reaction 1 or in Reaction 2, or both reactions, the obtained halide salt, can be obtained by crystallizing the post-reaction mixture.

    [0117] The orders in Reaction 1 have no particular limitation. For example, the primary/secondary/tertiary/quaternary amine can be reacted with formic acid in the organic or inorganic polar or non-polar solvent. The amount of the amine in Reaction 1 ranges from 0.1 molar equivalents to 2.0 molar equivalents with respect to the formic acid. Furthermore, the ammonium formate salts can be isolated in a liquid or solid state. The addition of formic acid to the amine is preferably performed at a temperature ranging between 40 C. to 80 C., in order to avoid condensation reaction with loss of water and amide formation. The said polar organic or inorganic solvent in Reaction 1 is preferably water, methanol, ethanol, isopropanol, tetrahydrofuran or acetonitrile, and more preferably water. The amount of the said organic solvent is not particularly limited, e.g., it can range between 5 to 30 parts by volume (v/W), such as 6 to 8 parts by volume.

    [0118] Further, halogen (X.sub.2) in Reaction 2 can be added preferably in the amount ranging between 0.5 to 1.2 molar equivalents of the formate salt, for example of 0.5 to 1 molar equivalents. The temperature in the reaction chamber during Reaction 2 is preferably maintained in the range of 60 C. to 130 C., for example, the temperature of Reaction 2 can be maintained at 60 C., 70 C., 75 C., 80 C., 85 C., 90 C., or 95 C., and more preferably 70 C. During Reaction 2 the reactants are agitated. The duration of Reaction 2, depending on the given formate salt, may range, e.g., from 1 minute to 4 hours, for example, 30 minutes to 1 hour. The obtained halide salt can be obtained in pure form in liquid or solid state by simple removal of the reaction media, such as solvent, under reduced pressure and temperature below boiling or sublimation or decomposition point of the obtained halide salt.

    Embodiment 1Synthesis of Methylammonium Iodide (Starting from Methylamine)

    [0119]
    CH.sub.3NH.sub.3.sup.+I.sup.

    [0120] As a start, 25.0 ml of formic acid was added slowly under cooling (10 C.) to 56.1 ml of methylamine (40 wt % in H.sub.2O). The resulting solution was heated to 40 C. and 82.3 g of iodine (I.sub.2) was added gradually. Afterward, the product was heated to 110 C. for the time necessary to remove the water. The formed solid was taken up with a 50 ml of hot ethanol and subsequently precipitated in an excess of cold diethyl ether. Afterward, crystals were collected by filtration; the obtained crystals were washed with diethyl ether, and dried in vacuum oven at 60 C., to yield 85.79 g of methylammonium iodide (83% yield).

    [0121] .sup.1H NMR (300 MHZ, DMSO-d6), d: 2.37 (s, 3H) 7.49 (s, 3H). .sup.13C NMR (75 MHZ, DMSO-d6), d: 25.00 (ppm).

    [0122] FIGS. 4, 5 present respective spectra of the obtained product.

    Embodiment 2Synthesis of Methylammonium Iodide (Starting from the Isolated Ionic Liquid Methylammonium Formate)

    [0123]
    CH.sub.3NH.sub.3.sup.+I.sup.

    [0124] 6 g of methylammonium formate was heated at 100 C. Under vigorous stirring, 9.9 g of iodine (I.sub.2) was added gradually. The following precipitate was dissolved in small amounts of hot ethanol and subsequently precipitated in an excess of cold diethyl ether. Afterwards, the crystals were collected by filtration; the crystals were washed with diethyl ether and dried in vacuum oven at 60 C. to yield 11 g of methylammonium iodide (89% yield).

    [0125] FIG. 6, presents the respective spectrum of the obtained product

    Embodiment 3Synthesis of Methylammonium Bromide (Starting from Methylamine)

    [0126]
    CH.sub.3NH.sub.3.sup.+Br.sup.

    [0127] 6.86 ml of formic acid was added slowly under cooling (10 C.) to 15.46 ml of methylamine (40 wt % in H.sub.2O). The resulting solution was further cooled and 1.47 ml (4.6 g) of bromine (Br.sub.2) was added gradually. Afterwards the product was heated to 110 C. to remove the water. The formed solid was redissolved with a few 50 ml of hot ethanol and subsequently precipitated in an excess of cold diethyl ether. Afterward, crystals were collected by filtration; the crystals were washed with diethyl ether, and dried in vacuum oven at 60 C., to yield 15.82 g of methylammonium bromide (79% yield). 1H NMR (300 MHZ, DMSO-d6), (s, 3H). 13C NMR (75 MHZ, DMSO-d6) (ppm).

    [0128] FIG. 7 presents IR spectrum of the obtained product (methylammonium bromide).

    Embodiment 4Synthesis of Methylammonium Bromide (Starting from the Isolated Ionic Liquid Methylammonium Formate)

    [0129]
    CH.sub.3NH.sub.3.sup.+Br.sup.

    [0130] 6 mL of methylammonium formate was cooled at 10 C. Under vigorous stirring, 2 mL of bromine (Br.sub.2) were slowly added. The following precipitate was dissolved in small amounts of hot ethanol and subsequently precipitated in an excess of cold diethyl ether. Afterwards, the crystals were collected by filtration; the crystals were washed with diethyl ether and dried in vacuum oven at 60 C. to yield 7.2 g of methylammonium bromide (83% yield).

    Embodiment 5Synthesis of Formamidinium Iodide (Starting from Formamidine Acetate)

    ##STR00005##

    [0131] 5.0 ml of formic acid was added to 6.57 g of formamidine acetate at room temperature. After the solid was completely dissolved, 8.0 g of iodine (I.sub.2) was added gradually. Afterwards the product was heated to 120 C. to remove the water. The formed solid was redissolved with 50 ml of hot ethanol and subsequently precipitated in an excess of cold diethyl ether. Afterward, crystals were collected by filtration; the crystals were washed with diethyl ether, and dried in vacuum oven at 60 C., to yield 7.28 g of formamidinium iodide (91% yield).

    [0132] .sup.1H NMR (300 MHZ, DMSO-d6), d: - - - (d, 4H) - - - (quint, 1H). 13C NMR (75 MHz, DMSO-d6), d (ppm).

    [0133] FIGS. 8, 9, 10 present respective spectra of the obtained product (formamidinium iodide).

    Embodiment 6Synthesis of Formamidinium Iodide (Starting from Isolated Ionic Liquid Formamidine Formate)

    ##STR00006##

    [0134] 10 g of formamidine formate was heated at 100 C. Under vigorous stirring, 13.5 g of iodine (I.sub.2) was added gradually. The following precipitate was dissolved in small amounts of hot ethanol and subsequently precipitated in an excess of cold diethyl ether. Afterwards, the crystals were collected by filtration; the crystals were washed with diethyl ether and dried in vacuum oven at 60 C. to yield 14.7 g of formamidinium iodide (80% yield).

    Embodiment 7Synthesis of Tetramethylammonium Iodide (Starting from of Tetramethylammonium Hydroxide)

    [0135]
    (CH.sub.3).sub.4N.sup.+I.sup.

    [0136] 4.80 g of tetramethylammonium hydroxide pentahydrate was weighed and dissolved in 8.0 ml of water. At 10 C., 1.0 ml of formic acid was added into the solution first. Reaction was left at 25 C. for 10 hours. Afterward, 3.36 g of iodine was added. The mixture was agitated for 12 hours at 70 C. The reaction solution was cooled to 25 C. Afterward, crystals as products were collected by filtration, washed with diethyl ether, and air-dried at 50 C., to afforded 5.01 g of title compound (94% yield).

    [0137] .sup.1H NMR (600 MHZ, DMSO-d6), d: 3.20 (s, 12H). .sup.13C NMR (150 MHz, D2O), d: 55.85. d (ppm).

    [0138] FIGS. 11, 12, 13, present respective spectra of the obtained product (tetramethylammonium iodide).

    Embodiment 8Synthesis of Pyridinium Iodide (Starting from Pyridine)

    ##STR00007##

    [0139] 2.10 g of pyridine was weighed and mixed with 10 ml of water. At 10 C., 1.0 ml of formic acid was added into the solution first. Reaction was left at 25 C. for 10 hours. Afterward, 3.36 g of iodine was added. The mixture was agitated for 12 hours at 70 C. The reaction solution was cooled to 25 C. Afterward, 10 ml of ethanol was added, and agitating was performed for 10 minutes, then cold diethyl ether was added. Crystals as products were collected by filtration; the crystals were washed with diethyl ether, and air-dried at 50 C., to afforded 4.60 g of pyridinium iodide (86% yield).

    [0140] FIGS. 20, 21, 22 present respective spectra of the obtained product (pyridinium iodide).

    Embodiment 9Synthesis of Imidazolium Iodide (Starting from Imidazole)

    ##STR00008##

    [0141] 2.70 g of imidazole was weighed and mixed with 12 ml of water. At 10 C., 2.0 ml of formic acid was added into the solution first. Reaction was left at 25 C. for 10 hours. Afterward, 6.72 g of iodine (I.sub.2) was added. The mixture was agitated for 12 hours at 70 C. The reaction solution was cooled to 25 C. Afterward, 15 ml of ethanol was added, and agitating was performed for 10 minutes, then cold diethyl ether was added. Crystals as products were collected by filtration; the crystals were washed with diethyl ether, and air-dried at 50 C., to afforded 9.88 g of imidazolium iodide (95% yield).

    [0142] FIGS. 17, 18, 19 present respective spectra of the obtained product (imidazolium iodide).

    Embodiment 10Synthesis of Triethylammonium Iodide (Starting from Triethylamine)

    ##STR00009##

    [0143] 2.14 g of triethylamine was weighed and dissolved in 7 ml of water. At 10 C., 800 ml of formic acid was added into the solution first. Reaction was left at 25 C. for 10 hours. Afterward, 2.69 g of iodine (I.sub.2) was added. The mixture was agitated for 12 hours at 70 C. The reaction solution was cooled to 25 C. Afterward, 9 ml of ethanol was added and agitating was performed for 10 minutes. Crystals as products were collected by filtration; the crystals were washed with diethyl ether, and air-dried at 50 C., to afforded 4.23 g of triethylammonium iodide (87% yield).

    [0144] FIGS. 14, 15, 16 present respective spectra of the obtained product (triethylammonium iodide).

    Embodiment 11Synthesis of Aniline Hydroiodide (Starting from Aniline)

    ##STR00010##

    [0145] 2.47 g of aniline was weighed and dissolved in 8 ml of water. At 10 C., 1 ml of formic acid was added into the solution first. Reaction was left at 25 C. for 10 hours. Afterward, 3.36 g of iodine (I.sub.2) was added. The mixture was agitated for 12 hours at 70 C. The reaction solution was cooled to 25 C. Afterward, 10 ml of ethanol was added and agitating was performed for 10 minutes, then cold diethyl ether was added. Crystals as products were collected by filtration; the crystals were washed with diethyl ether, and air-dried at 50 C., to afforded 3.73 g of aniline hydroiodide (64% yield).

    [0146] FIG. 23 presents respective spectrum of the obtained product (aniline hydroiodide).

    Embodiment 12Synthesis of Benzylamine Hydroiodide (Starting from Benzylamine)

    ##STR00011##

    [0147] 2.13 g of benzylamine was weighted and dissolved in 8.0 ml of water. At 10 C., 750 ml of formic acid was added into the solution first. Reaction was left at 25 C. for 10 hours. Afterward, 2.52 g of iodine (I.sub.2) was added. The mixture was agitated for 12 hours at 70 C. The reaction solution was cooled to 25 C. Afterward, 10 ml of ethanol was added and agitating was performed for 10 minutes, then cold diethyl ether was added. Crystals as products were collected by filtration, washed with diethyl ether, and air-dried at 50 C., to afforded 5.54 g of benzylamine hydroiodide (89% yield).

    [0148] FIGS. 33, 34, 35 present respective spectra of the obtained product (triethylammonium iodide).

    Embodiment 13Synthesis of Glycine Hydroiodide (Starting from Glycine)

    ##STR00012##

    [0149] 1.50 g of glycine was weighed and dissolved in 16 ml of water. At 50 C., 2.0 ml of formic acid was added into the solution first. Then reaction was left at 50 C. for 10 hours. Afterward, 6.72 g of iodine (I.sub.2) was added. The mixture was agitated for 12 hours at 70 C. The reaction solution was cooled to 25 C. Afterward, 30 ml of ethanol was added and agitating was performed for 10 minutes, then cold diethyl ether was added. Crystals as products were collected by filtration; the crystals were washed with diethyl ether, and air-dried at 50 C., to afforded 4.63 g of glycine hydroiodide (43% yield).

    [0150] FIGS. 30, 31, 32 present respective spectra of the obtained product (3-aminopropionic acid hydroiodide).

    Embodiment 14Synthesis of 3-Aminopropionic Acid Hydroiodide (Starting from -Alanine)

    ##STR00013##

    [0151] 1.78 g of -alanine was weighed and dissolved in 13 ml of water. At 25 C., 2.0 ml of formic acid was added into the solution first. Reaction was left at 25 C. for 10 hours. Afterward, 6.72 g of iodine was added. The mixture was agitated for 12 hours at 70 C. The reaction solution was cooled to 25 C. Afterward, 25 ml of ethanol was added, and agitating was performed for 10 minutes, then cold diethyl ether was added. Crystals as products were collected by filtration, washed with diethyl ether, and air-dried at 50 C., to afford 9.68 g of 3-aminopropionic acid hydroiodide (84% yield).

    [0152] FIGS. 24, 25, 26 present respective spectra of the obtained product (3-aminopropionic acid hydroiodide).

    Embodiment 15Synthesis of N-Methylglycine Hydroiodide (Starting from Sarcosine)

    ##STR00014##

    [0153] 1.78 g of sarcosine was weighed and dissolved in 13 ml of water. At 25 C., 2.0 ml of formic acid was added into the solution first. Reaction was left at 25 C. for 10 hours. Afterward, 6.72 g of iodine (I.sub.2) was added. The mixture was agitated for 12 hours at 70 C. The reaction solution was cooled to 25 C. Afterward, 30 ml of ethanol was added, and agitating was performed for 10 minutes, then cold diethyl ether was added. Crystals as products were collected by filtration, washed with diethyl ether, and air-dried at 50 C., to afford 9.60 g of N-methylglycine hydroiodide (83% yield).

    [0154] FIGS. 27, 28, 29 present respective spectra of the obtained product (N-methylglycine hydroiodide).

    Embodiment 16Synthesis of Lead (II) Iodide (Starting from Lead (II) Acetate)

    [0155] 5 g lead (II) acetate were dissolved in 10 ml of water. Subsequently, 10 mL of formic acid were added, resulting in a colorless precipitate. The intermediate product was filtrated and washed with cold water. Subsequently, the wet intermediate product was dissolved in 170 mL of hot water. 20 mL of acetone and 4 g of iodine (I.sub.2) were added gradually to the solution under vigorous stirring. The mixture was further agitated for 30 minutes and crystallization of the lead (II) iodide (6 g, 85% yield) was performed in the refrigerator over night.

    [0156] FIG. 36 presents the respective X-ray diffraction pattern of the obtained product (lead (II) iodide).

    Embodiment 17Synthesis of Lead (II) Bromide (Starting from Lead (II) Acetate)

    [0157] 5 g lead (II) acetate were dissolved in 10 ml of water. Subsequently, 10 mL of formic acid were added, resulting in a colorless precipitate. The intermediate product was filtrated and washed with cold water. Subsequently, the wet intermediate product was dissolved in 170 mL of hot water. 20 mL of acetone and 0.8 mL of bromine were slowly added to the solution under vigorous stirring. The mixture was further agitated for 30 minutes and crystallization of the colorless lead (II) bromide (3.5 g, 62% yield) was performed in the refrigerator over night.

    [0158] FIG. 36 presents the respective X-ray diffraction pattern of the obtained product (lead (II) bromide).