TSIL compound, preparation method and method for selectively extracting inner transition elements from s-, d- and p-block metals using the TSIL compound

Abstract

The present invention discloses a TSIL compound of general formula (5) which contains a ciproloxacin-derived carbon backbone, which forms part of an extractant composition [together with CYPHOS NTf2 (6)] intended for the selective extraction of inner transition metals (lanthanides and actinides). The present invention also discloses the preparation of the extractant composition (5) + (6), which is a formulation capable of selectively extracting the periodic table elements of the f-block (actinides and lanthanides) at pH = 6. This selectivity with respect to the inner transition elements contrasts with the scarce selectivity and affinity with the s-, d- and p-block metals. The liquid-liquid extraction of this mixture (subject matter of this invention) can be separated and recycled several times once the extracted metal(s) has / have been released.

Description

[0001]

[0002] TSIL compound, preparation process and method for the selective extraction of inner transition elements from metals of the s, d and p series using the TSIL compound

[0003] TECHNICAL SECTOR

[0004] The present invention relates to the preparation of a compound called Task Specific Ionic Liquid (TSIL) with chemical formula (5), which together with an ionic liquid [CYPHOS NTf2] (6) generates a composition - extractant mixture (5) + (6) - for use in selective extraction processes that is very effective in selectively extracting elements known as internal transition metals (block f) compared to metals of the s, d and p series of the periodic table. Compared to the latter, the extraction selectivity by the aforementioned mixture (5) + (6) is very low or zero.

[0005] Advantageously, once the process of selective extraction of the internal transition metals using the extracting mixture (5)+(6) has been completed, the complete recovery of the complexed metal(s) is possible, enabling their recycling for later use as an extracting mixture in a new extraction process or cycle.

[0006] This invention has multiple applications in different areas, especially the extraction of the aforementioned elements, which are quite rare and widely distributed throughout the Earth's crust. It also has significant implications in the fields of nuclear chemistry and nuclear medicine.

[0007] Thus, the object of the present invention is the TSIL compound with chemical formula (5), the process for preparing said TSIL compound, as well as the process for selective extraction of internal transition metals (belonging to the two f blocks of the periodic table of elements) compared to the metals of the s, d and p series, using an extracting mixture (5) + (6) based on the TSIL compound. PRIOR STATE OF THE ART

[0008] The inner transition elements occupy a position between the elements lanthanum (Z=57) and hafnium (Z=72), and between actinium (Z=89) and rutherfordium (Z=104). The elements following lanthanum are called lanthanides or lanthanoids, while those following actinium are called actinides or actinoids. These elements, also called f-block elements, are characterized by their scarcity and dispersion in the Earth's crust. Separating one of these elements from the rest of the metals in the aforementioned f group and from the metals in the s, d, and p groups is a very difficult, tedious, and economically very expensive task.

[0009] In general, lanthanides are used as effective catalysts (hard Lewis acids) in industrial chemical processes. However, rare earth elements (REEs) are necessary and essential components in more than 200 products across a wide range of applications, especially high-tech consumer products such as mobile phones, computer hard drives, electric and hybrid vehicles, flat-screen monitors and televisions, and optics. Military and defense applications are highly relevant, as the presence of these elements in the manufacture of electronic displays, guidance systems, lasers, and radar and sonar systems is crucial.

[0010] On the other hand, all actinides are radioactive and release energy after their corresponding decay chains. Uranium and thorium (natural) and plutonium (synthetically produced) are the most abundant actinides on Earth. They are used in nuclear reactors, nuclear weapons, and nuclear medicine.

[0011] The methods used to separate and obtain free-form f-block elements from the rest of the s, d and p series metals are very numerous [Jia, J.-P.; Huang, J.-J.; Ma, Z.-L; Liu, X.- H.; Chen, X.-Y.; Li, J.-T.; He, L.-H.; Zhao, Z.-W. Trans. Nonferrous Met. Soc. China 2020, 30, 3147-3160] and most of them are based on liquid-liquid extraction procedures. Other alternatives exist such as the use of the hollow fiber renewal liquid membrane (HFRLM) process recycling mode [Allahyari, S.A.; Ahmadi, S.J.; Minuchehra, A.; Charkhi, A. RSC Adv. 2017, 7, 7413-7423.], a liquid membrane containing N,N,N0,N0- tetraoctyl-3-oxapentanediamide (TODGA) as the extractant [Panja, S.; Mohapatra, PK; Tripathi, SC; Manchanda VK Sep. Sci. Technol. 2010, 45, 1112-1120], including by high performance liquid chromatography [Telmore, V.M.; Kumar, P.; Jaison, P.G.; Mhatre, A.; Naik, H.J. Radioanal. Nucí. Chem. 2017, 313, 319-326; Friend, MT; Parker, T.G.; Mastren, T.; Mocko, V.; Brugh, M.; Birnbaum, ER; Fassbender, MEJ Chromatogr. A 2020, 1624, 461219],.

[0012] Within the liquid-liquid extractions, there are processes that use a phosphate buffer [Silva, RG; Moráis, CA; Oliveira, ED Miner. Eng. 2019, 134, 402-416], another that consists of a new dispersive liquid-liquid microextraction (DLLME) based on a hydrophobic deep eutectic solvent [Sadeghi, S.; Davami, AJ Mol. Liq. 2019, 291, 111242], liquid-liquid extraction using fatty acids [Didi, MA; Villemin, D.; Abderrahim, O.; Azzouz, AJ Radioanal. Nucí. Chem. 2014, 299, 1191-1198], through a separation process based on the use of 2-[4-(2,4,4-trimethylpentan-2-yl)phenoxy]acetic acid (POAA) [Su, J.; Xu, R.; Ni, S.; Li, F.; Sun, X.J. Clean. Prod. 2020, 254, 119931], the use of a high-efficiency chelator by functionalizing graphene oxide with phenanthroline diamide (GO-PDA) [Li, F.; Yang, Z.; Weng, H.; Chen, G.; Lin, M.; Zhao, C. Chem. Eng. J.2018, 332, 340-350], using a binary extractor composed of 1 ,5-bis[o-(d¡oxophosphoryl)-p- ethylphenoxy]-3-oxapentane and an amine such as trioctylamine [Safiulina, AM; Ivanets , DV ; Kudryavtsev, EM; Baulin , DV ; Baulin, VE; Water, AY Rus. J. Inorg. Chem. 2018, 63, 1679-1683], A / -r?-heptylaniline [Pawar, RR; Suryavanshi, VJ; Salunkhe, ST; Patil, SS; Mulik, GNJ Radioanal. Nucí. Chem. 2017, 311, 419-426.], a hexaacetate-calix(6)arene [Swamidoss, CMA; Ramaswamy , K. ; Tallam, VG Matt. Today: Proceedings 2020, 954- 957] or a bidentate ligand, 2,3-dihydroxynaphthalene [Tarafder, PK; Pradhan, SK; Mondal, RKJ Radioanal. Nucí. Chem. 2016, 309, 1021–1028],.

[0013] The use of ionic liquids (ILs) has been fundamental in many examples of selective chemical separation, which has also been implemented in this area. Thus, the use of IL together with extractive ligands is very well documented, for example, amines [Zuo, Y.;Chena, J.; Li, D. Sep. Pur. Tech. 2008, 63, 684-690], 1,3-diketones (SC-CO2 separation) [Fu, J.; Chen, Q.; Sun, T.; Shen, X. Sep. Pur. Tech. 2013, 119, 66-71], N,N-dialkylamides (SC-CO2 separation) [Rao, A.; Tomar, B.S. Sep. Pur. Tech. 2016, 161 , 159-164], diglycolamides [Luo, H.M.; Boll, R.A.; Bell, J.R.; Dai, S. Radiochim. Acía 2012, 100, 771-777], phosphine oxides (separation with oxalic acid) [Sengupta, A.; Singh, M.; Sundarajan, M.; Yuan, L; Fang, Y.; Yuan, X.; Feng, W. Chem. Commun. 2017, 75, 33- 36; Turanov, A.N.; Karandashev, V.K.; Artyushin, O.I. Sharova, EV; Khvostikov, VA Radiochem. 2021, 63, 162-168; Turanov, A.N.; Karandashev, V.K.; Baulin, D.V.; Baulin, V.E. Russ. J.Gen. Chem. 2020, 90, 1012-1019; Turanov AN; Karandashev, VK; Burmi, Zh, P.; Yarkevich, AN Russ. J. Gen. Chem. 2022, 92, 418-423], employing phosphane-derived ligands (decapping with acidic solutions) [Karamzadeh, Z.; Yaftian, MR; Shiri-Yector, Z.; Nilchi, A.; Dolatyari, L. Iran. J. Chem. Chem. Eng. 2016, 35, 89-95], methylimidazoles [excellent selectivities against uranium(VI) and Ln(lll)] [Li, W.; Yang, S.; Lv, H.; Liu, Z.; Wu, J.; Li, S.; Shen, Y. Radiochim. Acta 2016, 104, 681-690], with trioctylphosphine oxide [Shiri-Yekta, Z.; Yaftian, MR; Nilchi, AJ Iran. Chem. Soc. 2013, 10, 221-227], with an aqueous solution of / V, / V'-dimethyl- / V, / V'-dioctyl-4-oxaheptanodiamide (DMDOHA) [Ren, P.; Li, Y.; Wang, Z.; Geng, Y.; Yu, T.; Hua , R. Chem. Pap. 2020, 74, 2049-2057], with carbamoylmethylphosphine (CMPO) oxides [Turanov, AN; Karandashev, VK; Yarkevich, AN; Khvostikov, VA Radiochemistry 2019, 61, 694-699; Turanova, AN; Karandashevb, VK; Yarkevichc ANRadiochemistry 2013, 55, 382-387], with polymeric CMPO [Annam, S.; Rao, CVSB; Sivaraman, N.; Sivaramakrishna, A.; Vijayakrishna, K. React. Funct. Polym. 2018, 131 , 203- 210], N, N, N, / V-tetraoctyldiglycolamide (TODGA) and other derivatives [Zhang, Y.; Liu, Z.; Fan, F.; Zhu, L; Shen, Y. Sep. Sci. Technol. 2014, 49, 1895-1902; Feng, S.; Xinghai Shen, Radiochim. Acta 2020, 108, 757-767], amidas tetradentadas [Alyapyshev, MY; Women, VA; Tkachenko, LI Radiochemistry 2014, 56, 565-574] and N, A / -di(2-ethylhexyl)-diglycolamic acid [Ibrahim, SM; Zhang, Y.; Xue, Y.; Yang, S.; Ma, F.; Tian, ​​G. Solvent Ext. Ion Exc. 2020, 38, 417-429], Only the IL such as trioctylmethylammonium nitrate [A336][NOs] [Fu, X.; Zhang, F.; Wu, Q.; Li, Y.; Huang, Q.-G.; Yan, Z.-YJ Radioanal. Nuc. Chem. 2021 , 327:1251-1258],.

[0014] However, the use of so-called task-specific ionic liquids (TSILs) in combination with ionic liquids has not been used so frequently. A phosphoramidate-based TSIL has been used for selective uranium extraction [Xie, X.; Qin, Z.; He, Y.; Xiong, P.; Huang, Z.; Mao, Y.; Wei, H.; Zhuo, L. Sci. Rep. 2017, 7, 15735–15746], another TSIL consisting of 1-[3[[(diphenylphosphinyl)acetyl]amino]propyl]-3-tetradecyl-1 - / -3-imidazolium hexafluorophosphate functionalized ionic liquid was employed for general Ln(lll), Th(IV) and U(VI) extraction [Turanov, A.N.; Karandashev, V.K.; Artyushin O.I. Sharova EV Solvent Extr. Ion Exc. 2015, 33, 540-553.], and TSIL vapors similar to those described were developed for the extraction of actinides [Sengupta, A.; Mohapatra, P.K.; Iqbal, M.; Huskens, J.; Verboom, W. Sep. Pur. Tech. 2013, 118, 264-270; Ternova, D.; Ouadi, A.; Mazan, V.; Georg, S.; Boltoeva, M.; Kalchenko, V.; Miroshnichenko, S.; Billard, I.; Gaillard , CJ Solution Chem. 2018, 47, 1309-1325; Paramanik, M.; Raut, DR; Sengupta, A.; Ghosh, SK; Mohapatra, PK RSC Adv. 2016, 6, 19763-19767; Saha, A.; Tiwah, N.; Deb, SB; Saxena, MK ChemistrySelect 2019, 4, 7691-7697; Mary, L; Cruz, A.; Carretas, JM; Monteiro, B.; Hen, C.; Gomes, SS; Araújo, MF; Paiva, I.; Márgalo, J.; Leal, JP Sep. Pure. Tech.[2020, 237, 116354], In accordance with everything described in this background, and taking into account that none of the examples dedicate a section to the recovery of the TSIL-IL extracting system (where IL corresponds to the acronym in English for ionic liquid, ionic liquid), but only to the percentage of metal recovery (pickling or stripping) at the end of the extraction process, in this intellectual property document the need is detected to synthesize a compound that allows the selective extraction of internal transition elements (lanthanides and actinides) with very low affinity for the metallic elements of the dyp series, and their subsequent recovery with a high yield (at least 95%), for repeated use in subsequent extraction cycles.

[0015] DESCRIPTION OF THE INVENTION

[0016] In this specification the expression "extractant mixture" refers to the composition for use in selective extraction processes of elements from the f block series of the periodic table (i.e., the elements belonging to the lanthanide and actinide series) in samples containing these together with other metals from the s, d and p series, where said extractant mixture is formed by a compound ionic liquid TSIL with formula (5), dissolved in an ionic liquid (IL), used as a solvent, where the ionic liquid used is [CYPHOS NTf2] (6).

[0017] The present invention refers, in a first aspect, to a TSIL molecule or compound with a chemical formula (5), as well as to a formulation of an extractant mixture that is formed by said compound (TSIL) of chemical formula (5), together with the ionic liquid CYPHOS NTf2(6).

[0018] Another object of the present invention is the process for the selective extraction of actinide and lanthanide elements with a high affinity for other metals in the s, d and p series, using the extracting mixture of the TSIL compound with chemical formula (5). That is to say, the capacity offered by the aforementioned extracting mixture (5) + (6) to carry out liquid-liquid extractions of metals from block f versus metals in the s, d and p series and their subsequent recovery and recycling is also an object of the present invention. The metals in the s, d and p series are extracted with a low or zero percentage during the extraction process using the developed extracting mixture.

[0019] Advantageously, the extractant mixture prepared from the TSIL compound of chemical formula (5) and the IL (6) can be recycled once the extraction and separation of the extracted elements is completed.

[0020] The synthesized TSIL compound of formula (5) is reproduced below, and not only said compound but also a chemically acceptable salt thereof is the object of protection.

[0021] On the other hand, the extractant mixture or composition for use in selective extraction processes of metals of the two f series is also subject to protection, such that said extractant mixture is formed from the TSIL compound of formula (5) and the ionic liquid used as solvent [CYPHOS NTf2] (6), which is commercially available or easily prepared through a simple ion exchange. In the extractant mixture, the TSIL compound of formula (5) is added in variable proportions, its preferred concentration being 0.005 M.

[0022] Thus, the preparation process of the compound TSIL with chemical formula (5) is carried out from the antibiotic ciprofloxacin (1) using conventional functional group transformations. Specifically, the synthesis of the compound TSIL (5) takes place in three stages carried out under mild conditions (i.e., using temperature between room temperature and 0°C, atmospheric air pressure, etc.) and viable on an industrial scale.

[0023] First, the intermediate compound (2) is obtained after the / V-alkylation reaction of ciprofloxacin (1) with 1-bromoethane in the presence of excess / V, / V-diisopropyl(ethyl)amine (DIPEA), preferably in a mixture of water and acetonitrile at 40°C for 16 h.

[0024] In the second step, Weinreb amide (4) is synthesized from an amidation reaction using excess of A / ,O-dimethylhydroxylamine (3), preferably in the presence of thionyl chloride in dichloromethane (DCM) and triethylamine, at 0°C and for 30 minutes.

[0025] The third step, which leads to the final structure of TSIL (5), consists of an alkylation by adding excess 1-iodononane to the intermediate product (4) using acetonitrile as solvent, preferably, and refluxing the mixture for two days. The resulting compound, once purified, was treated with lithium bis(thioromethanesulfonyl)amide to generate the final product (5) by ion exchange.

[0026] It should be noted that the main interaction of the internal transition metals with TSIL (5), which acts as a selective chelator, takes place through the 1,3-dicarbonyl zone enhanced by the donor character provided by the Weinreb amide. It is presumed that this inductive effect hardens much more the Lewis base character of the mentioned dicarbonyl area, which allows it to have a higher affinity for the hardest Lewis acids of the periodic table of the elements (as is the case of the elements of the f block).

[0027] Furthermore, the present invention relates to a method for the selective extraction of internal transition metals using the TSIL compound of formula (5). Advantageously, this method allows for the subsequent separation and recovery of the extractant mixture for recycling, such that this method can be adapted and implemented on a larger scale. As detailed below, the method for the selective extraction of metals from the f block of the periodic table compared to other metals in the s, d and p series is carried out at a pH of 6.

[0028] Thus, specifically, the following steps form the procedure for selective extraction of metals from block f in a sample containing metals from this block f and other metals from the s, d and p series:

[0029] Preparation of an extracting composition from the TSIL compound of formula (5) and the ionic liquid [CYPHOS NTf2] (6), where the TSIL compound with formula (5) is added in variable proportions, preferably in a concentration of 0.005 M.

[0030] Introduction into a test tube of a sample to be separated, containing a metal or metal vapors from the f block and other metals belonging to the s, d and p series. Adjustment of the sample to a pH of 6 by the addition of a phosphate buffer.

[0031] Introduction into a test tube (with a volume greater than 5 ml) of the sample prepared in the previous stage and addition of the extracting composition prepared in the first stage, in a proportion of at least 2:1, with 1 being the extracting composition.

[0032] - Shake the test tube with the solution prepared in the previous step for at least 3 minutes.

[0033] Resting of the solution prepared in the previous stage, differentiating two liquid-liquid phases of different densities.

[0034] Separation of the two phases, where the organic phase corresponds to the extractant composition that includes the metal(s) of the f series initially contained in the sample to be separated.

[0035] - Addition to the organic phase recovered in the previous stage of an acidified solution at pH 0.5.

[0036] - Stirring of the solution obtained in the previous stage.

[0037] Resting of the solution prepared in the previous stage, differentiating two liquid-liquid phases of different densities.

[0038] Separation of the two phases, where the organic phase corresponds to the extracting composition and the aqueous phase contains the metal(s) of the f block series. Thus, advantageously, the described procedure allows to recover at least 95% of the organic phase corresponding to the extracting composition containing the TSIL compound of formula (5).

[0039] BRIEF DESCRIPTION OF THE DRAWINGS

[0040] To complement the description that follows and in order to help better understand the characteristics of the invention, according to a preferred example of practical implementation thereof, a set of images or figures are attached as an integral part of said description, in which the following has been represented for illustrative and non-limiting purposes:

[0041] Figure 1 shows a diagram of the selective extraction process of the metal(s) from the f block versus the metals of the s, d, and py series of the method of a preferred embodiment of the invention.

[0042] Figure 2 shows a diagram of the procedure followed for the recovery of the metal(s) from block f, from a solution used in the procedure detailed in the previous figure.

[0043] DETAILED DESCRIPTION OF THE INVENTION

[0044] As previously mentioned, the first step in the synthesis of the TSIL compound with formula (5) consists of the / V-alkylation of ciprofloxacin (1) (commercially available) with ethyl bromide, preferably in an acetonitrile / water mixture.

[0045] (Diagram 1).

[0046] Scheme 1 The second reaction step consisted of a Weinreb amidation of (2) using A,O-dimethylhydroxylamine (3) after in situ generation of the corresponding acid chloride with thionyl chloride in dichloromethane and triethylamine at 0°C for 30 minutes. This compound was preferably washed with water three times and the product (4) was recrystallized from diethyl ether (Scheme 2).

[0047] Diagram 2

[0048] The last step of the synthetic process involves molecule (4) which was subjected to a reaction with one equivalent of 1-iodononane, preferably in refluxing acetonitrile for two days. The solvent was evaporated in vacuo and then ion exchanged with lithium bis(trifluorosulfonyl)amide in dichloromethane was performed at room temperature for 8 hours (Scheme 3). TSIL (5) was isolated with a final yield of 86%.

[0049] Diagram 3

[0050] Examples

[0051] Example 1: Preparation of compound (2)

[0052] A solution of 1 equivalent of ciprofloxacin hydrochloride in MeC kJ / W (30 mL / mmol) with 6.66 equivalents of diisopropylethylamine was prepared in a flask in an ice bath under inert conditions. Then, 5 equivalents of bromoethane and 0.10 equivalents of potassium iodide were added dropwise. The mixture was stirred for 1 h. The flask was then placed in an oil bath at 40°C and stirred for 16 h. Finally, the solvent was evaporated in vacuo and the residue was dissolved in 40 mL of DCM and washed with phosphate buffer solution to pH = 6.5. The organic phase was dried with MgSO4 and the solvent was evaporated under reduced pressure to give compound (2) as a white solid. Yield 92%.

[0053] Example 2: Preparation of compound (4)

[0054] 1 equivalent of compound (2) was added to a round-bottom flask, together with 3 equivalents of triethylamine and a minimum amount of dry DCM. Then, under inert conditions and at 0°C, 3 equivalents of A,O-dimethylhydroxylamine (3), 3 equivalents of triethylamine, and 1.1 equivalents of thionyl chloride were added. The mixture was stirred for 30 minutes at this temperature. Volatile compounds were then removed under vacuum. The residue was dissolved in chloroform and washed 3 times with a saturated sodium bicarbonate solution to remove ammonium salts. It was then washed 3 times with a saturated potassium carbonate solution to remove unreacted compound (2). The organic solvent was dried over magnesium sulfate and the solvent was evaporated in vacuo. Finally, compound (4) was obtained as a yellowish solid after recnstallization with diethyl ether. Yield 88%.

[0055] Example 3: Preparation of compound (5)

[0056] A solution of 1 equivalent of compound (4) together with 2 equivalents of 1-iodononane was prepared in a pressure tube with the minimum possible amount of dry acetonitrile under inert conditions. The mixture was stirred under reflux for 2 days. The solvent was then removed under reduced pressure and the residue was dissolved in chloroform and 1.3 equivalents of lithium bistflamide (dissolved in water) was added. The mixture was left to stir overnight. The aqueous phase was then washed 3 times, the organic solvent fractions were combined and washed with water 3 more times. The organic phase was dried with MgSO4 and the solvent was removed by rotary evaporation. Compound (5) was obtained as a white solid after recrystallization with ethyl acetate. Yield 86%.

[0057] Example 4: Selective extraction processes of elements from the fa series pH = 6

[0058] Given the interest in extracting elements belonging to the f signals, to extract the analytes (metals of the f and d signals, for example) from an aqueous sample A, 5 ml of the aqueous sample A are taken into a test tube and the pH is adjusted with phosphate buffer solutions to pH 6. 1 mL of the extractant [0.005 M of compound (5) in (6)] is added (solution B). The test tube is vortexed for 3 minutes and the mixture is allowed to settle. The two phases are then separated, leaving the metal(s) of the inner transition signal in solution B and the rest of the metals (see table 1) in the aqueous sample A.

[0059] Figure 1 shows the detailed scheme of the selective extraction process of internal transition metals, such as Th, U, Lu, Yb, Gd, Nd, Sm, La, Y, Ce, Eu, Se, Pr, Tb, Dy, Ho, Er, Tm (see Table 1), compared to the rest of the metals in the periodic table.

[0060] The extraction efficiency of the f-sign metals from the rest of the metals (signs s, p and d) of the periodic table with solution B was calculated by determining the concentration of these elements in the aqueous phase (A). The content of the f-block metals in the organic phase (B) is estimated by the difference with the content in the aqueous phase (A). The concentration ratio (solution B / aqueous sample A) is a measure of the analyte distribution coefficient (K). Thus, the higher the analyte distribution coefficient (K), the higher the extraction efficiency.

[0061] To determine the concentration of each element, the aqueous solution (A) was analyzed using inductively coupled plasma mass spectrometry (ICP-MS). To do this, the most abundant and interference-free isotope of each element was selected, and the signal was recorded in the aqueous sample (A). From the signal obtained, and using the signal obtained with standards of known concentration, the concentration of each element in the sample can be calculated.

[0062] Table 1 shows some examples of the distribution coefficient with respect to the extractant mixture containing the TSIL compound of formula (5) referred to the initial concentration of 0.005 M (K) at pH 6, which have been calculated according to the process detailed previously. The K coefficient in Table 1 is the quotient between the concentration of the metal in the organic phase and the aqueous phase after extraction.

[0063] Thus, in Table 1 the value of distribution coefficients obtained for the metals of the signs f is observed, as well as for other metallic elements of the Periodic Table that can be found in their presence at pH = 6.

[0064] As can be seen from the data in the table above, the distribution coefficient K calculated for the metals in the f series was found to be significantly higher than for most other metals in the periodic table. The extractant mixture containing TSIL of formula (5) and solvent 6 was found to be extremely selective.

[0065] Example 5: Release of the extracted metal and recovery of the mixture (5+6) [with recycling of the extraction system (5)+(6)].

[0066] To recover the mixture (5)+(6) pure and without any metal, a solution C (5 ml) of a solution with nitric acid at pH = 0.5 is added to solution B containing the lanthanide and actinide metals in a test tube. The test tube is shaken in a vortex for 3 minutes and the aqueous solution is separated from the organic solution, recovering (5)+(6) and the aqueous phase containing the metals of the signs f.

[0067] Figure 2 shows the detailed scheme of the recovery process of the mixture (5)+(6).

[0068] The recovery of pure B solution with these internal transition metals was greater than 95% and could be used in several extraction cycles. This recovery allows for recycling and use in another extraction cycle.

Claims

CLAIMS 1. The compound TSIL with chemical formula (5) 2. A composition for use in selective extraction processes of internal transition elements, wherein said composition comprises a compound according to claim 1 a , characterized in that it comprises the TSIL compound of formula (5) and an ionic liquid CYPHOS NTf 2 (6).

3. A composition for use in selective extraction processes of internal transition elements, according to claim 2 a , characterized in that the TSIL compound with formula (5) is added in a concentration of 0.005 M.

4. Method for preparing the TSIL compound with formula (5), according to claim 1 a , characterized by comprising the following stages: / V-Alkylation reaction of ciprofloxacin to (1) with 1-bromoethane in the presence of DIPEA, to generate (2), Amidation reaction with A / ,Od¡methylhydroxylamine (3) using thionyl chloride, obtaining the intermediate (4). - Alkylation of (4) with 1-iodononane and subsequent ion exchange with lithium bis(thifurosulfonyl)amide, obtaining compound (5).

5. Method for preparing the TSIL compound with chemical formula (5), according to claim 4 a , characterized in that the reaction of ciprofloxacin (1) with 1-bromoethane by means of a / V-alkylation reaction is carried out in the presence of water:acetonitrile at 40 °C for 16 hours to obtain the product (2).

6. Method for preparing the TSIL compound with chemical formula (5), according to claim 4 a , characterized in that the reaction of (2) and (3) with thionyl chloride is carried out in the presence of triethylamine and dichloromethane as solvent and at 0 °C for 30 minutes, generating the intermediate (4).

7. Method for preparing the TSIL compound with chemical formula (5), according to claim 4 a , characterized in that the alkylation reaction of the intermediate (4) with 1-iodononane is carried out in the presence of acetonitrile and takes place under reflux for 48 hours, and then the subsequent ion exchange is carried out to give rise to the compound (5).

8. Method for selective extraction of internal transition elements in a sample, using the TSIL compound of formula (5) according to claim 1 a , characterized by comprising the following stages: Preparation of an extractant composition from the TSIL compound of formula (5) and the ionic liquid [CYPHOS NTf 2 ] (6). Introduction into a test tube of the sample to be separated, which contains metals from the f series and other metals belonging to the s, d and p series. - Adjustment of the sample to a pH of 6 by adding a phosphate buffer. The sample prepared in the previous step is introduced into a test tube and the extractant composition prepared in the first step is added in a ratio of at least 2:1, with 1 being the extractant composition. - Shake the test tube with the solution prepared in the previous step for at least 3 minutes. Resting of the solution prepared in the previous stage, differentiating two liquid-liquid phases of different densities. Separation of the two phases, where the organic phase corresponds to the extractant composition that includes the metals of the f series initially contained in the sample to be separated. - Addition to the organic phase recovered in the previous stage of an acidified solution at pH 0.

5. - Stirring of the solution obtained in the previous stage. Resting of the solution prepared in the previous stage, differentiating two liquid-liquid phases of different densities. Separation of the two phases, where the organic phase corresponds to the extractant composition and the aqueous phase corresponds to the metals of the f series. Where at least 95% of the organic phase corresponding to the extracting composition containing the TSIL compound of formula (5) is recovered.

9. Method for selective extraction of internal transition elements in a sample, according to claim 8 a , characterized in that in the preparation stage of the extracting composition from the TSIL compound of formula (5) and the ionic liquid [CYPHOS NTf 2 ] (6), the TSIL compound is used at a concentration of 0.005 M.

10. Method for selective extraction of internal transition elements in a sample, according to claim 8 a, characterized in that the sample to be separated contains metals from the s, p and d series, contained in the periodic table

Images