Method for producing ammoniacal nitrogen

Abstract

The present invention relates to a process for the production of ammoniacal nitrogen, which comprises carrying out dinitrogen reduction in the presence of a compound of formula (I) containing at least one element of group 13 of the periodic table and a reducing agent, and to the use of a compound of formula (I) for the dinitrogen reduction.

Description

[Technical Field] 【0001】 The present invention relates to a method for producing ammoniacal nitrogen by dinitrogen reduction in the presence of a compound (I) containing at least one element from Group 13 of the periodic table and a reducing agent, and to the use of the compound (I) for dinitrogen reduction. [Background technology] 【0002】 Nitrogen (N) plays an indispensable role in the composition of living organisms. It is a major component of proteins, particularly amino acids and enzymes, and nucleic acids, which make up DNA and RNA. It is also an essential nutrient for crop growth. However, although nitrogen is extremely abundant on the Earth's surface (more nitrogen than bound carbon, hydrogen, and phosphorus exists throughout the biosphere, hydrosphere, and atmosphere), it primarily exists in the form of dinitrogen (N2), a very stable gas. Humans can only benefit slightly from this abundance. Only microorganisms, such as rhizobia involved in symbiotic nitrogen fixation by leguminous plants, can utilize this form of nitrogen, converting it to ammoniacal nitrogen and then to organic nitrogen. This organic nitrogen can then be utilized by other organisms and converted into other forms of reactive nitrogen. 【0003】 Since the Industrial Revolution at the end of the 19th century, two major processes have dramatically altered the landscape of reactive nitrogen in order to meet the increasing demand for it in food production. Firstly, the increasing and massive use of fossil fuels (coal, oil, natural gas, etc.) for energy production, transportation, and industrial and domestic activities has greatly increased the amount of nitrogen oxides present in the environment. The second and most important process is the Haber-Bosch process. This method allows for the industrial-scale synthesis of ammonia from dinitrogen and dihydrogen (H2) in the presence of a solid catalyst, particularly one primarily composed of iron. Since the end of the 20th century, this method has produced approximately 200 million tons of ammonia (NH3) per year on a global scale, which is more than symbiotic nitrogen fixation, and it is still in use today. However, the Haber-Bosch process has the following drawbacks: In other words, this method is carried out under high pressure and high temperature, for example, a pressure of 100 to 300 bar and a temperature of 300 to 550 degrees Celsius. This makes the method energy-intensive, requires centralized and highly safe production, and incurs high operating and transportation costs. Furthermore, such a method generates a very large amount of carbon dioxide (about 1.5% of all CO2 production), causing environmental problems, and the yield obtained by this method remains low. 【0004】 Research is being conducted on methods for producing ammonia under milder conditions, such as electrochemical reduction. Electrochemical reduction involves applying an electric potential to a noble metal electrode catalyst, such as gold or ruthenium. However, yields remain low, and the raw materials are scarce and very expensive. Other methods have been developed using organometallic complexes or compounds of transition metals. In particular, U.S. Patent 6037459 discloses a method comprising the steps of contacting a compound corresponding to formula M(NR1R2)3 (where M is a transition metal (e.g., molybdenum), and R1R2 is selected from tertiary alkyl groups, phenyl groups, and substituted phenyl groups) with nitrogen to produce a metal complex containing a nitride ligand, and reducing the metal complex in the presence of a hydrogen source to produce ammonia. This method is carried out under ambient temperature and pressure conditions. However, U.S. Patent 6037459 states that the yield is low and does not disclose any demonstration of ammonia production. [Prior art documents] [Patent Documents] 【0005】 [Patent Document 1] U.S. Patent No. 6037459 [Overview of the project] [Problems that the invention aims to solve] 【0006】 Therefore, the object of the present invention is to overcome the shortcomings of the prior art, and in particular to provide a method for producing ammonia nitrogen that is simple, economical, industrializable, uses abundant raw materials, is recyclable, and can reduce carbon dioxide emissions. [Means for solving the problem] 【0007】 A first embodiment of the present invention is a method for producing ammoniacal nitrogen, comprising at least the following steps: i) Equation (I): R 1 R 2A step of contacting a composition containing a compound corresponding to MY(I), a reducing agent, and an organic solvent with dinitrogen (N2), In the above formula (I), - M is an element of Group 13 of the periodic table, preferably selected from boron, aluminum, and mixtures thereof, - R 1 and R 2 are the same or different and are selected from an alkyl group, an aryl group, an aryl-alkyl group, an -OR group, and an -SR group, and R is an alkyl group, an aryl group, or an aryl-alkyl group, - Y is a halogen -X, -OR 3 group, -SR 3 group, a triflate group, a mesylate group, and a triflimidate group, and R 3 is an alkyl group, an aryl group, or an aryl-alkyl group, a step, and ii) A hydrolysis step in an acidic medium, and is characterized by including. 【0008】 The method of the present invention is simple, easy to implement, economical, and enables the obtaining of ammonia nitrogen under relatively mild conditions. In particular, by using the compound of formula (I) defined above, the triple bond of dinitrogen can be activated in a reducing medium to generate an intermediate, and the intermediate can then provide ammonia nitrogen by hydrolysis. Finally, the above method can be industrialized, utilizes abundant raw materials, and these raw materials can be recycled, and the environmental impact can be reduced. 【Embodiments for Carrying out the Invention】 【0009】 Step i) The above compound of formula (I) R 1 R 2 MY 【0010】 According to the present invention, as the element M, boron is particularly preferred. 【0011】 Formula (I)R 1 R 2 The aforementioned compound of MY is not a radical compound. 【0012】 In the compound of formula (I), R 1 It forms one covalent bond with element M, R 2 It forms one covalent bond with element M. 【0013】 The aforementioned R 1 Base and R 2 base R 1 and R 2 R is either identical or different, and is selected from alkyl groups, aryl groups, aryl-alkyl groups, -OR groups, and -SR groups, where R is an alkyl group, aryl group, or aryl-alkyl group. 【0014】 R 1 Base and / or R 2 The alkyl group can be linear or branched, cyclic or acyclic. The alkyl group may contain 1 to 14 carbon atoms, preferably 2 to 10 carbon atoms. The alkyl group is preferably selected from an ethyl group, a propyl group, an isopropyl group, a cyclohexyl group, a bicyclo[2.2.1]-2-heptyl group, and an isopinocamphenyl group. Of these groups, one of the cyclohexyl group, the bicyclo[2.2.1]-2-heptyl group, or the isopinocamphenyl group is particularly preferred. 【0015】 R 1 Base and / or R 2 The alkyl group as a base may contain one or more heteroatoms, such as oxygen or sulfur atoms. It is understood that the carbon atoms of the alkyl group are directly bonded to element M in formula (I), and that the heteroatoms present in the alkyl group are not directly covalently bonded to other heteroatoms. 【0016】 R 1 Base and / or R 2The aryl group can be substituted or unsubstituted. The aryl group may contain 6 to 30 carbon atoms, preferably 6 to 18 carbon atoms. The aryl group is preferably selected from the phenyl group, the -C6F5 group, the 2,4,6-(Me)3-C6H2 group, and the 2,4,6-(iPr)3-C6H2 group. Of these groups, either the 2,4,6-(Me)3-C6H2 group or the 2,4,6-(iPr)3-C6H2 group is particularly preferred. 【0017】 R 1 Base and / or R 2 An aryl group, when substituted (i.e., in the substituent of the aryl group), may contain one or more heteroatoms, such as oxygen or nitrogen atoms. The carbon atom of the aryl group is understood to be directly bonded to element M in formula (I). 【0018】 R 1 Base and / or R 2 An aryl-alkyl group as a base is a group comprising at least one alkyl group and at least one aryl group directly bonded by a carbon-carbon covalent bond (of the aryl group) or via an oxygen or nitrogen atom, and the aryl group and alkyl group are R 1 Base and R 2 The group is defined above. The alkyl-aryl group can be directly bonded to element M of formula (I) via the carbon atoms of the aryl group or via the carbon atoms of the alkyl group. 【0019】 The R alkyl group of the -OR group or -SR group may be linear or branched, cyclic or acyclic. The R alkyl group may contain 1 to 10 carbon atoms, preferably 1 to 4 carbon atoms. 【0020】 The R aryl group of the -OR group or -SR group may be substituted or unsubstituted. The R aryl group may contain 6 to 30 carbon atoms, preferably 6 to 18 carbon atoms. The R aryl group is preferably selected from a phenyl group, a naphthyl group, anthracenyl group, or a pyrenyl group. 【0021】 The R aryl-alkyl group of the -OR group or -SR group is a group comprising at least one alkyl group and at least one aryl group directly bonded by a carbon-carbon covalent bond (of the aryl group) or via an oxygen atom or a sulfur atom, wherein the aryl group and alkyl group are as defined above with respect to the R group. 【0022】 R 1 Base and R 2 The group may also be covalently bonded, particularly via a carbon-carbon bond, to form a divalent group together, as described above R 1 Base and R 2 The group is as defined above. In this embodiment, the divalent group does not form a planar ring with element M. 【0023】 According to the example, the divalent group is an alkyl group (i.e., R 1 and R 2 (is an alkyl group), preferably a 9-bicyclo[3.3.1]nonane group. 【0024】 According to one embodiment of the present invention, R 1 and R 2 These are either identical or different, and are selected from alkyl groups, aryl groups, and aryl-alkyl groups. 【0025】 According to a preferred embodiment of the present invention, R 1 Base and R 2 At least one of the groups is an alkyl group, and is particularly preferably R 1 Base and R 2 Both groups are alkyl groups. 【0026】 According to a particularly preferred embodiment of the present invention, R 1 and R 2 They are identical. 【0027】 R of compound (I) 1 Base and R 2The groups are non-stabilizing groups. In other words, their function is to reduce the R generated during the aforementioned method. 1 R 2 M 〇 The goal is not to stabilize the radical, but rather to increase its reactivity towards nitrogen (N2) as a result. 【0028】 The aforementioned Y base Y is halogen-X, -OR 3 Base, -SR 3 Selected from the group, triflate (-OSO2CF3) group, mesylate (-OSO2CH3) group, and trifluimidate (NTf2 or N(SO2CF3)2) group, R 3 This is an alkyl group, an aryl group, or an aryl-alkyl group. 【0029】 X is preferably a chlorine atom or a bromine atom, and particularly preferably a chlorine atom. 【0030】 R 3 Alkyl groups can be linear or branched, cyclic or acyclic. 3 The alkyl group may contain 1 to 10 carbon atoms, preferably 1 to 4 carbon atoms. 【0031】 R 3 The aryl group may be substituted or unsubstituted. 3 The aryl group may contain 6 to 30 carbon atoms, preferably 6 to 18 carbon atoms. 3 The aryl group is preferably selected from a phenyl group, a 2,4,6-(Me)3-C6H2 group, a 2,4,6-(iPr)3-C6H2 group, and a naphthyl group. 【0032】 R 3 An aryl-alkyl group is a group comprising at least one alkyl group and at least one aryl group directly bonded by a carbon-carbon covalent bond (of the aryl group) or via an oxygen atom or a sulfur atom, where the aryl group and alkyl group are R 3 The base is as defined above. 【0033】 Y is preferably halogen X. 【0034】 The Y group of compound (I) is a nucleofugal group. In other words, its function is R 1 R 2 M 〇 The goal is to facilitate the formation of radicals. 【0035】 According to a particularly preferred embodiment of the present invention, the compound of formula (I) is selected from dialkylchloroboranes, dialkylbromoboranes, dialkylchloroaluminum compounds, and dialkylbromoaluminum compounds, for example, a halide of diisopinocamphorborane, dicyclohexylborane, or bis(bicyclo[2.2.1]-2-heptyl)borane, or a haloborane based on 9-borabicyclo[3.3.1]nonane. 【0036】 The compounds of formula (I) have the advantage of being readily available commercially or readily available through synthesis. 【0037】 The compound of formula (I) is a Lewis acid, that is, it has the properties of a chemical substance in which one of the constituent elements of the chemical substance has an empty electron orbital. 【0038】 The reducing agent can be selected from potassium, sodium, mercury-based and sodium-based amalgams, lithium, and mixtures thereof. Potassium is preferred. 【0039】 The use of amalgam makes it easier to measure the amount of reducing agent used in step i). 【0040】 The organic solvent may be a conventional organic solvent, an ionic liquid, or a mixture thereof. 【0041】 Ionic liquids are well known to those skilled in the art and are considered to be molten salts at room temperature (e.g., 18-25°C). Ionic liquids have an organic cation moiety and function as solvents in the present invention, just like conventional organic solvents. 【0042】 In this invention, conventional organic solvents mean salt-free organic solvents or organic solvents that are not in the form of salts. 【0043】 The organic solvent in step i) is preferably selected from aprotic organic solvents. 【0044】 According to one embodiment of the present invention, the organic solvent in step i) is selected from a nonpolar aprotic organic solvent (such as a conventional organic solvent), an ionic liquid, and a mixture thereof. 【0045】 According to the first alternative embodiment of this design, the organic solvent in step i) is selected from nonpolar aprotic organic solvents. 【0046】 According to a second alternative embodiment of this design, the organic solvent in step i) is selected from ionic liquids. 【0047】 The nonpolar aprotic organic solvent in step i) is preferably selected from THF (tetrahydrofuran) and methyl-THF. 【0048】 The ionic liquid in step i) is preferably selected from ammonium salts, imidazolium salts, phosphonium salts, pyrrolidinium salts and piperidinium salts, and particularly preferably alkylammonium salts, alkylimidazolium salts, alkylphosphonium salts, alkylpyrrolidinium salts and alkylpiperidinium salts. 【0049】 The ionic liquid in step i) preferably includes a bis(trifluoromethanesulfonyl)imidate type anion. 【0050】 Examples of ionic liquids include triethylbutylammonium bis(trifluoromethanesulfonyl)imidate, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imidate, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imidate, trimethylbutylammonium bis(trifluoromethanesulfonyl)imidate, 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imidate, N-propyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imidate, or 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imidate. 【0051】 The ionic liquid is preferably immiscible with water. This facilitates subsequent purification processes. 【0052】 During step i), the composition comprising the compound of formula (I), the reducing agent, and the organic solvent is brought into contact with dinitrogen (N2). 【0053】 Step i) is carried out in a dry or anhydrous medium. In other words, step i) is preferably carried out in a glove box or in a device suitable for avoiding contact with air and / or moisture. 【0054】 In fact, contact with air and / or moisture is H2 and / or R 1 R 2 MOMR 1 R 2 This leads to the formation of by-products such as [specific examples of by-products]. 【0055】 Step i) can be continued for approximately 1 to 20 hours, preferably approximately 2 to 12 hours. 【0056】 Step i) can be carried out at a temperature preferably in the range of about -80°C to 60°C, and particularly preferably in the range of about 0°C to 30°C. 【0057】 Step i) is preferably carried out under stirring, for example, using a mechanical or magnetic stirrer. Stirring promotes contact between the composition and dinitrogen, thereby allowing the reaction to proceed. 【0058】 To allow the reaction between dinitrogen and compound (I), the reaction is preferably carried out under a dinitrogen atmosphere, particularly under a dry dinitrogen atmosphere. 【0059】 Step i) can be carried out at a pressure in the range of approximately 0.1 bar to 200 bar, preferably 1 bar to 100 bar. A pressure of at least 20 bar, preferably at least 40 bar, is advantageous in improving the yield of ammoniacal nitrogen. A pressure of 1 bar is advantageous from an industrial standpoint. 【0060】 The reducing agent used in step i) may correspond to 0.1% to 20% by weight, preferably 0.1% to 10% by weight, of the total weight of the composition. 【0061】 The compound of formula (I) used in step i) may correspond to 0.1% to 10% by weight, preferably 2% to 6% by weight, of the total weight of the composition. 【0062】 During step i), compound (I) reacts with dinitrogen to form one or more chemical species based on nitrogen and element M, in particular the following formula (II): N(MR) 1 R 2 ) 3-x H x The chemical species, x being an integer in the range of 0 to 3, forms a chemical species. 【0063】 The formation of one or more chemical species based on nitrogen and element M as defined above is particularly described by the execution of a radical chain reaction using at least one or more radicals based on element M that are sufficiently unstable to react with nitrogen in dinitrogen. 【0064】 Surprisingly, equation (I), namely Y, M, R 1 , R2 Compound (I) according to the definition has the ability to activate the triple bond of dinitrogen in a reducing medium to minimize or even avoid the dimerization of the radical. 【0065】 Step II) During step ii), the nitrogen and element M-based chemical species are hydrolyzed in an acidic medium to form ammoniacal nitrogen. 【0066】 In this invention, ammoniacal nitrogen is the two most reduced forms of nitrogen: ammonium (NH4) + ) and ammonia (NH3). Therefore, ammoniacal nitrogen is ammonium (NH4 + ), ammonia (NH3) and mixtures thereof are selected. Generally, depending on the conditions of step ii), especially the amount of acid, ammonium (excess acid), or ammonia (N(MR) 1 R 2 ) 3-x H x A stoichiometric quantity will be obtained for this purpose. 【0067】 Step ii), hydrolysis in an acidic medium, can be carried out by contacting the crude reaction product obtained in the preceding step i) with an acidic solution or gaseous acid (in gaseous form). 【0068】 The acidic solution may comprise an aqueous solvent (e.g., water) and at least one acid (such as hydrochloric acid, hydrobromic acid, sulfuric acid, or nitric acid), or an aprotic organic solvent and at least one acid (such as hydrochloric acid, hydrobromic acid, sulfuric acid, or nitric acid). 【0069】 The aprotic organic solvent can be selected from ethers such as diethyl ether or dioxane, and alkanes such as hexane or heptane. 【0070】 The gaseous acid may be hydrochloric acid gas. 【0071】 Step ii) is advantageous in yielding ammonium, especially when the acid is used in excess with respect to the compound of formula (I). 【0072】 The aqueous solvent is preferably water. 【0073】 The acidic solution may have a pH in the range of 0 to 6. 【0074】 Step ii) can be continued for about 1 to 30 minutes, preferably about 2 to 10 minutes. Step ii) is a very fast, almost instantaneous step. 【0075】 Step ii) is preferably carried out at a temperature in the range of about -20°C to 40°C, and particularly preferably in the range of about 0°C to 20°C. 【0076】 Step ii) is preferably carried out with stirring. 【0077】 Step ii) is preferably carried out at atmospheric pressure. 【0078】 Step ii) is ammonia NH3 and / or ammonium NH4 + This makes it possible to bring about such results. 【0079】 Other steps of the aforementioned method This method may further include step i') after step i) and before step ii), which involves removing the organic solvent. 【0080】 This embodiment is particularly useful when the organic solvent is a conventional organic solvent. 【0081】 Step i') can be carried out by evaporating a conventional organic solvent. 【0082】 The method described above may include a purification step i) after step i) or, if present, step i'). This step i) allows for the removal of at least some of the by-products (e.g., salts) that may be formed in step i). In other words, step i) allows for the separation of the nitrogen and element M-based chemical species formed in step i) from the salt. 【0083】 Step i) can be carried out by extraction using the reaction mixture formed in step i) or, if present, step i'), particularly with a nonpolar organic solvent. The chemical species or the nitrogen- and element M-based chemical species formed in step i) are readily soluble in the nonpolar organic solvent and can be separated from the salt by filtration. 【0084】 The nonpolar organic solvent can be selected from alkanes such as hexane, pentane, or heptane. 【0085】 A preferred nonpolar organic solvent is pentane. 【0086】 When the organic solvent in step i) is a conventional organic solvent, the purification step i) can be carried out after step i) or step i') by filtering the reaction mixture formed in step i) or step i'), as described above. 【0087】 When the organic solvent in step i) is an ionic liquid, the purification step i) can be carried out after step i) by filtering the reaction mixture formed in step i), in particular by filtration, as described above. 【0088】 The method may further include step i0) of preparing the compound of formula (I) prior to step i). 【0089】 The compound of formula (I) can be prepared by double hydroboration or by the hydroalumination protocol described in the following papers: HCBrown, N. Ravindran, J.Am.Chem.Soc. 1976, 98, 1798-1806 and HCBrown, N. Ravindran, J.Am.Chem.Soc. 1976, 98, 1785-1798, or by the reaction of 2 equivalents of an alkene with 1 equivalent of a monohaloborane (for example, one corresponding to formula YBH2, where Y is as defined in this invention) at room temperature in THF or diethyl ether. 【0090】 Generally, one equivalent of compound MH2Y is equivalent to two equivalents of the alkene R'CH=CH2. It reacts with to form the compound (R'CH2CH2)2MY. 【0091】 The method of the present invention preferably does not use any gaseous chemical species other than dinitrogen (N2) as an initiator. 【0092】 The method may further include step iii) of recycling compound (I). In this embodiment, step ii) is preferably carried out by contacting the crude reaction product obtained in the preceding step i), i'), or i) with an acidic solution containing an aprotic organic solvent and at least one acid, or with a gaseous acid, under an inert atmosphere. The acidic solution and the gaseous acid are as defined above. 【0093】 Therefore, step iii) can be performed after step ii) as follows: - If the organic solvent is a conventional organic solvent, remove the solvent from, for example, step i), i"), or ii) if present, preferably by evaporation, and use a nonpolar solvent to remove NH4 + Precipitate and separate / recover compound (I); or - If the organic solvent is an ionic liquid, remove the solvent from, for example, step i), or from ii) if present, and use a distillation system to recover NH3 and separate / recover compound (I). 【0094】 The nonpolar solvent can be as described above. 【0095】 A second embodiment of the present invention is the use of a compound of formula (I) as defined in the present invention for dinitrogen reduction. [Examples] 【0096】 Example 1: Method for producing ammoniacal nitrogen from dinitrogen using dicyclohexylchloroborane as the compound of formula (I) A 120 mg solution of dicyclohexylchloroborane (1 M in hexane), sold by Sigma-Aldrich under reference number 411124, was added to 4 mL of anhydrous tetrahydrofuran, followed by the addition of 15 mg of potassium. The resulting composition was placed under a pure, dry nitrogen atmosphere and stirred for 12 hours. At the end of the reaction, the mixture was brown. An excess solution of HCl (2 M) in Et2O was added under an inert atmosphere, and H x -N(BCy2) 3-x NH4 + It was quantitatively converted to Cy2BCl. After removing the solvent and volatile compounds by evaporation, a solid residue remained. This solid was extracted with hexane to obtain NH4. + Separate Cy2BCl from NH4. + It is obtained as a white solid. The yield relative to the initially introduced Cy2BCl is 38%. 【0097】 Example 2: Method for producing ammoniacal nitrogen from dinitrogen using (+)-B-chlorodiisopinocampheylborane as the compound of formula (I) 48 mg of (+)-B-chlorodiisopinocampheylborane (Ipc2BCl), sold by Sigma-Aldrich under reference number 317012, was added to 4 mL of anhydrous tetrahydrofuran, followed by the addition of 15 mg of potassium. The resulting composition was placed under a pure, dry nitrogen atmosphere and stirred for 12 hours. At the end of the reaction, the mixture was brown. An excess solution of HCl (2M) in Et2O was added under an inert atmosphere, and H x-N(BIpc2) 3-x was quantitatively converted to NH4 + and Cy2BCl. Removal of the solvent and volatile compounds by evaporation leaves a solid residue. This solid is extracted with hexane to separate Ipc2BCl from NH4 + . NH4 + is obtained as a white solid. The yield based on the initially introduced Ipc2BCl is 15%. 【0098】 Example 3: Control method (not part of the present invention) 120 mg of a solution of dicyclohexylchloroborane (1 M in hexane), sold by Sigma-Aldrich under the reference number 411124, was added to 4 mL of anhydrous tetrahydrofuran, and then 15 mg of potassium was added. The resulting composition was placed under a pure dry argon atmosphere and stirred for 12 hours. An excess of HCl (2 M) in Et2O solution was added under an inert atmosphere. The formation of NH4 + was not observed. 【0099】 Example 4: Control method (not part of the present invention) A suspension of 15 mg of potassium in 4 mL of anhydrous tetrahydrofuran was stirred for 12 hours under a pure dry dinitrogen atmosphere. An excess of HCl (2 M) in Et2O solution was added under an inert atmosphere. The formation of NH4 + was not observed. 【0100】 Example 5: Method for producing ammoniacal nitrogen from dinitrogen using bis(bicyclo[2.2.1]-2-heptyl)chloroborane as the compound of formula (I). 38 mg of a solution of bis( bicyclo[2.2.1]-2-heptyl)chloroborane, sold by Sigma-Aldrich under the reference number 771880, was added to 4 mL of anhydrous tetrahydrofuran, and then 15 mg of potassium was added. The resulting composition was placed under a pure dry dinitrogen atmosphere and stirred for 12 hours. At the end of the reaction, the mixture was brown. An excess of HCl (2 M) in Et2O solution was added under an inert atmosphere, and H x -N(BBCH2) 3-x was converted to NH4 +It was quantitatively converted to BCH2BCl. When the solvent and volatile compounds were removed by evaporation, a solid residue remained. This solid was extracted with hexane to separate BCH2BCl from NH4 + NH4 + is obtained as a white solid. The yield based on the initially introduced bis(bicyclo[2.2.1]-2-heptyl)chloroborane is 43%. 【0101】 Example 6: Method for producing ammoniacal nitrogen from dinitrogen using dicyclohexylchloroborane as the compound of formula (I) In an autoclave, 120 mg of a solution of dicyclohexylchloroborane (1 M in hexane) sold under reference number 41124 from Sigma-Aldrich was added to 4 mL of anhydrous tetrahydrofuran, and then 15 mg of potassium was added. The autoclave was then sealed. The resulting composition was pressurized with pure dry nitrogen under stirring for 12 hours (20 bar: Example 6-1, 40 bar: Example 6-2, 80 bar: Example 6-3). At the end of the reaction, the mixture was brown. An excess of HCl (2 M) in Et2O solution was added under an inert atmosphere to quantitatively convert H x -N(BCy2) 3-x to NH4 + and Cy2BCl. When the solvent and volatile compounds were removed by evaporation, a solid residue remained. This solid was extracted with hexane to separate Cy2BCl from NH4 + NH4 + is obtained as a white solid. The yields based on the initially introduced Cy2BCl are as follows. - 60% for a pressure of 20 bar (Example 6-1) - 76% for a pressure of 40 bar (Example 6-2) - 94% for a pressure of 80 bar (Example 6-3)

Claims

[Claim 1] A method for producing ammoniacal nitrogen, wherein the ammoniacal nitrogen is ammonium (NH ４ ＋ ), ammonia (NH ３ ), and a mixture thereof selected, and at least the following steps: i) Equation (I): R １ R ２ A composition containing a compound equivalent to MY(I), a reducing agent, and an organic solvent is prepared using dinitrogen (N ２ The step of bringing it into contact with, In the above formula (I), - M is an element in group 13 of the periodic table. - R １ and R ２ They are either the same or different, and are selected from alkyl groups, aryl groups, aryl-alkyl groups, -OR groups, and -SR groups, where R is an alkyl group, aryl group, or aryl-alkyl group. - Y is a halogen - X, -OR ３ group, -SR ３ group, a triflate group, a mesylate group, and a trifluimidate group, and R ３ is an alkyl group, an aryl group, or an aryl - alkyl group, step, and ii) Hydrolysis step in an acidic medium, A method characterized by including [Claim 2] The method according to claim 1, characterized in that the element M is selected from boron, aluminum, and mixtures thereof. [Claim 3] The two aforementioned bases R １ and R ２ The method according to claim 1, characterized in that is an alkyl group. [Claim 4] The method according to claim 1, characterized in that Y is halogen X. [Claim 5] The method according to claim 1, characterized in that the reducing agent is selected from potassium, sodium, mercury-based and sodium-based amalgams, lithium, and mixtures thereof. [Claim 6] The method according to claim 1, characterized in that step i) is performed at a temperature in the range of -80°C to 60°C. [Claim 7] The method according to claim 1, characterized in that the reducing agent used in step i) corresponds to 0.1% to 20% by weight of the total weight of the composition. [Claim 8] The method according to claim 1, characterized in that the compound of formula (I) used in step i) corresponds to 0.1% to 10% by weight of the total weight of the composition. [Claim 9] The method according to claim 1, characterized in that step ii) hydrolysis in an acidic medium is carried out by contacting the crude reaction product obtained in the preceding step i) with an acidic solution or gaseous acid. [Claim 10] The method according to claim 9, characterized in that the acidic solution has a pH in the range of 0 to 6. [Claim 11] The method according to claim 1, characterized in that the organic solvent in step i) is selected from nonpolar aprotic organic solvents. [Claim 12] The method according to claim 1, further comprising step i') of evaporating the organic solvent after step i) and before step ii). [Claim 13] The method according to claim 1, characterized in that the organic solvent in step i) is selected from ionic liquids. [Claim 14] The method according to claim 1, characterized in that, after step i) or step i') if present, the reaction mixture formed in step i) or step i') if present is purified by extraction using a nonpolar organic solvent. [Claim 15] Use of the compound of formula (I) as defined in claim 1 for dinitrogen reduction.