Lanthanide Discrimination with Hydroxyl-Decorated Flexible Metal

Oct 16, 2018 - Synopsis. We report two new metal−organic frameworks, derived from the natural amino acids serine and threonine, featuring hexagonal ...
1 downloads 0 Views 3MB Size
Download PDF
Article pubs.acs.org/IC

Cite This: Inorg. Chem. XXXX, XXX, XXX−XXX

Lanthanide Discrimination with Hydroxyl-Decorated Flexible Metal−Organic Frameworks Marta Mon,† Rosaria Bruno,‡ Rosangela Elliani,‡ Antonio Tagarelli,‡ Xiaoni Qu,†,§ Sanping Chen,§ Jesús Ferrando-Soria,*,† Donatella Armentano,*,‡ and Emilio Pardo*,† †

Instituto de Ciencia Molecular, Universidad de Valencia, Paterna 46980, Valencia, Spain Dipartimento di Chimica e Tecnologie Chimiche, Università della Calabria, Rende 87036, Cosenza, Italy § College of Chemistry and Materials Science, Northwest University, Xi’an 710069, China Downloaded via UNIV OF LOUISIANA AT LAFAYETTE on October 17, 2018 at 00:30:23 (UTC). See https://pubs.acs.org/sharingguidelines for options on how to legitimately share published articles.

‡

S Supporting Information *

ABSTRACT: We report two new highly crystalline metal−organic frameworks (MOFs), derived from the natural amino acids serine (1) and threonine (2), featuring hexagonal channels densely decorated with hydroxyl groups belonging to the amino acid residues. Both 1 and 2 are capable of discriminating, via solid-phase extraction, a mixture of selected chloride salts of lanthanides on the basis of their size, chemical affinity, and/or the flexibility of the network. In addition, this discrimination follows a completely different trend for 1 and 2 because of the different locations of the hydroxyl groups in each compound, which is evocative of steric complementarity between the substrate and receptor. Last but not least, the crystal structures of selected adsorbates could be resolved, offering unprecedented snapshots on the capture process and enabling structural correlations with the separation mechanism.

■

INTRODUCTION Lanthanides are elements of essential importance1 with a key role in many important fields,2 but their very similar size and chemical properties greatly complicate their separation. Today, the separation of lanthanides is mainly carried out by solventextraction methods,3 although other techniques such as chromatographic separation,4 fractional crystallization,5 or ion exchange5 have also been evaluated. However, these methods require many steps, which eventually drives up production costs. In this context, the search for simpler and less-costly methods still continues.6 Metal−organic frameworks (MOFs)7−11 are an emerging type of porous crystalline materials that have find applications in many different important fields.9,12,13 In particular, their use in the selective capture and/or separation of gases14,15 and even small molecules,16 driven by their porous nature and rich host−guest chemistry,17−24 is very relevant from both ecological and industrial perspectives. Initially, in MOFs and other porous materials, molecular sieving,25 where shape/size selectivity determined which molecules can access the porosity, was considered to be the only key factor accounting for such separations. However, other unique characteristics of MOFs, such as flexibility19,26,27 and adaptability,28−30 together with the tunable functionality of the channels, have proven to be important in this respect because it has been underpinned with the precious help of X-ray crystallography.31−35 In fact, MOFs have shown promising results, for example, in the selective capture of metals,36−38 separation of organic molecules,39 and even encapsulation and structure resolution of molecules of unknown structure.40 © XXXX American Chemical Society

Despite this great potential, the applicability of MOFs in lanthanide separation has only been barely explored, and the very few reported works on this subject are focused on their size-selective crystallization properties.41−44 In this work, we investigate the possibility of achieving postsynthetic lanthanide discrimination,45 via solid-phase extraction (SPE), using MOFs with both appropriate functional groups capable of retaining lanthanides and flexibility to enable recognition based on the ionic radii and chemical affinity.

■

RESULTS AND DISCUSSION Synthesis and X-ray Crystal Structure. Here, we report two novel chiral three-dimensional (3D) MOFs, prepared using ligands derived from the natural amino acids L-serine and L-threonine, both featuring functional channels decorated with hydroxyl (−OH) groups, with the formulas {SrIICuII6[(S,S)serimox]3(OH)2(H2O)}·38H2O (1) and {SrIICuII6[(S,S)threonine]3(OH)2(H2O)}·36H2O (2) (where serimox = bis[(S)-serine]oxalyldiamide34 and threomox = bis[(S)threonine]oxalyldiamide; Scheme 1 and Figures 1, 2, and S1−S3). The presence of hydroxyl groups pointing toward the accessible void space of the MOF (Figure 1), together with the high flexibility of these types of amino acid based MOFs,36,37 provides an adaptable functional environment capable of interacting with lanthanides. Compounds 1 and 2 were synthesized as green hexagonal prisms with a slow diffusion technique (see the Supporting Received: August 27, 2018

A

DOI: 10.1021/acs.inorgchem.8b02409 Inorg. Chem. XXXX, XXX, XXX−XXX

Article

Inorganic Chemistry Scheme 1. Chemical Structures of the Chiral (*) Bis(serine)oxalamide and Bis(threonine)oxalamide Ligands (left) and Chemical Structures of the Corresponding Dicopper(II) Motifs Building the MOFs 1 and 2 (right)

Figure 2. View of a portion of X-ray crystal structure of 1 in the ab plane (a) showing the dianionic bis(hydroxo) dicopper(II) building blocks further connected by Sr2+ ions (b) with bond lengths details of copper environments in (c). Cu, Sr, and O atoms from serine moieties are represented as green, blue and red spheres, respectively, whereas the ligands (except oxygen of serine fragment) are depicted as sticks (carbon: gray, oxygen: red and nitrogen: light blue). Free water molecules residing in the pores are omitted for clarity.

mox]3(OH)2(H2O)}·9H2O·4CH3CN (LaCl3@1), (CeCl 3 ) 0.8 {Sr II Cu II 6 [(S,S)-serimox] 3 (OH) 2 (H 2 O)}·7H 2 O· 5CH 3 CN (CeCl 3 @1), (DyCl 3 ){Sr I I Cu I I 6 [(S,S)-serimox] 3 (OH) 2 (H 2 O)}·15H 2 O·3CH 3 CN (DyCl 3 @1), (ErCl3)1.5{SrIICuII6[(S,S)-serimox]3(OH)2 (H2O)}·12H2O· 5CH 3 CN (ErCl 3 @1), (LaCl 3 ) 0.8 {Sr II Cu II 6 [(S,S)-threomox]3(OH)2(H2O)}·3H2O·6CH3CN (LaCl3@2), (CeCl3)1.5{SrIICuII6[(S,S)-threomox]3(OH)2(H2O)}·15H2O· 3CH 3 CN (CeCl 3 @2), (DyCl 3 ) 0.5 {Sr II Cu II 6 [(S,S)-threomox] 3 (OH) 2 (H 2 O)}·3H 2 O·7CH 3 CN (DyCl 3 @2), and (ErCl3)0.5{SrIICuII6[(S,S)-threomox]3(OH)2(H2O)}·12H2O· 4CH3CN (ErCl3@2) were also obtained (see the Supporting Information). The crystal structures of 1, 2, LaCl3@1, CeCl3@1, DyCl3@ 1, ErCl3@1, LaCl3@2, CeCl3@2, DyCl3@2, and ErCl3@1 could be determined by conventional and synchrotron single crystal X-ray diffraction (Tables S1 and S2 and Figures 1−4 and S1−S6; see the Supporting Information for structural details). Their chemical identity was further confirmed by inductively coupled plasma, scanning electron microscopy− energy-dispersive X-ray, and elemental (C, H, and N) analyses (see the Experimental Section and Tables S3 and S4). They all are isomorphs and crystallize in the chiral P63 space group, consisting of honeycomb-like 3D strontium(II)−copper(II) networks (Figures 1, 2, and S1−S3). These uninodal sixconnected acs nets, in both 1 and 2, are built up from transoxamidato-bridged dicopper(II) units, {CuII2[(S,S)-L]}, where L = serimox (1) and threomox (2) (Figure 1a,b), which act as linkers between the SrII ions through the carboxylate groups (Figures S1−S3). Neighboring Cu2+ and Cu2+/Sr2+ ions are further interconnected by aqua/hydroxo groups (in a 1:2 statistical distribution) linked in a μ3 fashion (Figures S1 and S3). The crystal structures of 1 and 2 show hexagonal channels of ca. 0.8 nm as the virtual diameter featuring highly flexible hydroxyl arms (Videos S1 and S2), belonging to the amino acid residues of serine and threonine for 1 and 2, respectively. These arms remain confined and stabilized by lattice water

Figure 1. Perspective views of the 3D open frameworks of 1 (a) and 2 (b) along the c axis (the crystallization water molecules are omitted for clarity). Cu and Sr atoms are represented by cyan and blue polyhedra, respectively, whereas the ligands are depicted as sticks. The O atoms from the L-serine and L-threonine residues are represented as red spheres.

Information). Thereafter, the capabilities of 1 and 2 to capture and separate equimolar mixtures of chloride salts of lanthanides of decreasing sizeLaCl3, CeCl3, TbCl3, DyCl3 and ErCl3were evaluated. Both materials are capable of discriminating these lanthanide salts. More interestingly, not only do 1 and 2 separate some of them, but, in addition, they do it differently, most likely as a consequence of the different nature and arrangement of the amino acid residues within the channels of the serine (−CH2OH) and threonine [−CH(OH)CH3] residues. In order to determine the maximum lanthanide uptake capacities, we first soaked ca. 5 mg of 1 and 2 in saturated CH3CN solutions containing a selection of the salts LaCl3, CeCl3, DyCl3, and ErCl3 (TbCl3 was not selected because of its similar size to DyCl3). After several days, the corresponding adsorbates of the formulas (LaCl3)0.8{SrIICuII6[(S,S)-seriB

DOI: 10.1021/acs.inorgchem.8b02409 Inorg. Chem. XXXX, XXX, XXX−XXX

Article

Inorganic Chemistry

Figure 3. Perspective views of the crystal structures showing a single hexagonal channel of LaCl3@1 (a), CeCl3@1 (b), DyCl3@1 (c), ErCl3@1 (d), LaCl3@2 (e), CeCl3@2 (f), DyCl3@2 (g), and ErCl3@2 (h) along the crystallographic c axis and details of the coordination environment of the different lanthanide(III) chlorides captured. La3+, Ce3+, Dy3+, Er3+, and Cl− ions are represented as brown, yellow, pink, orange, and green spheres, respectively.

bonding in ErCl3@1, involving all of the amino acid arms within the pores [Er···OOH = 2.386(2) and 2.853(2) Å], and further direct binding with the oxamate moiety of the net [Er··· Ooxamate = 2.711(2) and 2.815(2) Å], observed uniquely in ErCl3@1 (Figures 3d and S6a,b), must be behind the efficient capture of ErCl3 in 1. For LaCl3, CeCl3, and DyCl3, the concerted interactions gradually decrease in overall strength, losing either symmetric net interactions or OH moiety direct binding (Figures 4 and S4−S6), which supports and explains the lower capture in the SPE experiment. While in the serine-derived MOF, the more stable conformation is reached by grasping the smallest ErIII cation, in threonine, slightly more hindered because of the presence of an extra −CH3 group, larger lanthanides such as CeIII are better separated (see below). The concurrence of the latter apparently antagonist concepts is clearly explained when looking at the CeCl3@2 crystal structure (Figures 3f and S4c,d). Ce atoms are simultaneously bounded to OH− from threonine [Ce···OOH = 2.924(2) Å] and O atoms from carboxylate of the oxamate ligand [Ce···Ooxamate = 2.652(2) Å] and then also packed by a water molecule [Ce···Owater = 2.918(2) Å], which, in turn, is an active portion of the coppermetal-ion environment of the net (Figure S4c). This outlines a more efficient binding than those observed in LaCl3, DyCl3, and ErCl3, where the stabilizing links with the oxamate moiety of the net are weakened (Figures 3e,g,h, 4, and S5 and S6). This is most-likely due to the presence of the methyl group of threonine, which, being close to the wall of the net (Figure S2), creates a quite hindered “hole”, forcing lanthanides toward the center of the pores. The intrinsic flexibility and structural adaptability of the functional channels in 1 and 2 (Figures 2, 4, and S1−S6) must be at the origin of the exhibited “tunable” structures/conformations of the hydroxyl-decorated chains. Thermogravimetric Analysis (TGA) and Powder X-ray Diffraction (PXRD). The experimental PXRD patterns of polycrystalline samples of 1, 2, and the eight adsorbates are consistent with the theoretical ones (Figures S7−S10), confirming the purity of the bulk. The solvent contents were confirmed for all 10 compounds by TGA (Figure S11) and CHN analyses (see the Supporting Information). The permanent porosity of both 1 and 2 was established by

Figure 4. Perspective views of details in the crystal structures of LaCl3@1 (a and b) and LaCl3@2 (c and d) showing the diverse La3+ interactions depending on nature of MOFs’ pores. Views in the ac plane and along the c crystallographic axis have been compared. Cu, Sr, and O atoms from the serine (a and b) and threonine (c and d) moieties are represented by green, blue, and red spheres, respectively, whereas the ligands (except O atoms of the serine or threonine fragment) are depicted as sticks (C, gray; O, red; N, light blue). La and Cl atoms are represented by brown and light-green spheres, respectively. Free water molecules residing in the pores are omitted for clarity.

molecules in the pores of the MOFs (Figures 1, 2, and S2). The structures of LaCl3@1, CeCl3@1, DyCl3@1, ErCl3@1, LaCl3@2, CeCl3@2, DyCl3@2, and ErCl3@1, determined by single-crystal X-ray diffraction, confirm the preservation of the networks of 1 and 2 after lanthanide capture. Crystallography confirms that the lanthanides are hosted in the pores, being grasped or weakly interacting, by supramolecular interactions, via the serine or threonine derivative arms (Figures 3, 4, and S4−S6). Even though the expected dynamic disorder did not allow modeling of some chloride-confined anions in the CeCl3@1, CeCl3@2, and ErCl3@1 crystal structures (Supporting Information), a closer look at all of them showed different arrangements depending on the nature of the guest/ target lanthanide. This suggests that the different strengths and nature of interactions must be at the origin of the different capture properties (vide infra). This leads to either direct binding between the hydroxyl groups of the amino acid residues and lanthanoids or weaker chlorine-mediated hydrogen-bonding interactions. For instance, the straight HO−Er C

DOI: 10.1021/acs.inorgchem.8b02409 Inorg. Chem. XXXX, XXX, XXX−XXX

Article

Inorganic Chemistry

the serine residue, which is only observed in ErCl3@1 (Figures 3d and S6a,b) strongly supported by symmetric oxamate interactions. Conversely, in 2, medium-sized TbIII and DyIII cations are almost not captured by the MOF (≤3%) and the CeCl3 salt showed, in turn, the highest uptake in a very fast manner (ca. 26% in 20 min). This behavior can be, again, rationalized when looking at the CeCl3@2 crystal structure (Figures 3f and S4c,d). CeIII cations are triply linked by the OH− group from the threonine residue, a carboxylate O atom from the oxamate network, and a water molecule, which is also bonded, acting as a bridge, to adjacent copper-metal ions of the network (Figure S4c). This direct binding is not observed for LaCl3 and DyCl3, while it is unassisted in ErCl3, which are thus retained by means of weaker intermolecular interactions, and, consequently, a poor uptake of them is shown (Figures 3, 4c,d, and S5c,d and S6c,d). Finally, lanthanide salts captured in both 1 and 2 could be easily extracted from the MOFs by using H2O or CH3OH solutions, and the resulting materials (1′ and 2′) were completely reusable, as confirmed by the PXRD patterns (Figure S15).

measuring the N2 and CO2 adsorption isotherms (Figures S12 and S13). Lanthanide Separation Experiments. Encouraged by the lanthanide capture properties shown by 1 and 2 as well as the different coordination environments observed in each casemost likely due to their different sizes and/or chemical nature and the high flexibility of the amino acid residues (Videos S1 and S2)we explored the separation capacities of both MOFs via SPE. For that, 50 mg each of polycrystalline samples of 1 and 2 was soaked in dimethylformamide solutions of an equimolar mixture of ErCl3, DyCl3, TbCl3, CeCl3, and LaCl3 (3.5 mL, 0.05 mmol; see the Supporting Information). The separation process was monitored, in three independent experiments, through inductively coupled plasma mass spectrometry analysis of the decreased amount of each lanthanide within the solution at specific time intervals (see Figures 5 and S14 and Tables S5−S8 and the Experimental Section in the Supporting Information).

■

CONCLUSIONS In summary, we report two novel flexible and highly crystalline MOFs, prepared from the natural amino acids L-serine and Lthreonine, featuring hexagonal functional channels decorated with the −CH2OH and −CH(OH)CH3 amino acid residues. They are capable of discriminating and separating, to a certain extent, lanthanide salts in dimethylformamide solutions. The unprecedented snapshots obtained by single-crystal X-ray crystallography allowed rationalization of the lanthanide discrimination on the basis of the flexibility and disposition of the amino acid residues, the radius of the lanthanide, and its affinity/interactions with O atoms from the pores. The present results open new perspectives for the application of these types of porous crystalline materials on such a challenging and industrially important separation.

■

ASSOCIATED CONTENT

S Supporting Information *

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.inorgchem.8b02409. Additional preparations and physical characterizations, Figures S1−S15, and Tables S1−S8 (PDF) Video S1 (AVI) Video S2 (AVI)

Figure 5. Kinetic profile of the selective capture of different lanthanide chlorides represented as a decrease of the concentration of each salt (%) versus time for compounds 1 (a) and 2 (b). Data for the preparation of this picture are collected in Figure S14. See the Experimental Section and also Tables S5 and S7 in the Supporting Information for further details.

Accession Codes

CCDC 1826449−1826458 contain the supplementary crystallographic data for this paper. These data can be obtained free of charge via www.ccdc.cam.ac.uk/data_request/cif, or by emailing [email protected], or by contacting The Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: +44 1223 336033.

In 1, we observed that the uptake of each lanthanide is inversely proportional to the respective ionic radii (Figure 5a). The removal of larger lanthanides, LaIII and CeIII, is virtually none (≤4%), the concentrations of medium-sized TbIII and DyIII within the solution decrease in ca. 10% and 12%, respectively, and, finally, the smaller ErIII cations are removed in the highest percentage (ca. 25%) after 3 h of suspension. These results agree with the nature and directionality of the interactions observed at the crystal structures. For instance, the higher uptake shown by 1 for ErCl3 is a direct consequence of the direct binding of the ErIII cation with both O atoms from

■

AUTHOR INFORMATION

Corresponding Authors

*E-mail: [email protected]. *E-mail: [email protected]. *E-mail: [email protected]. ORCID

Sanping Chen: 0000-0002-6851-7386 D

DOI: 10.1021/acs.inorgchem.8b02409 Inorg. Chem. XXXX, XXX, XXX−XXX

Article

Inorganic Chemistry

Journaux, Y.; Pardo, E. Selective Gas and Vapor Sorption and Magnetic Sensing by an Isoreticular Mixed-Metal-Organic Framework. J. Am. Chem. Soc. 2012, 134, 15301−15304. (17) Li, Q.; Zhang, W.; Miljanic, O. S.; Sue, C.-H.; Zhao, Y.-L.; Liu, L.; Knobler, C. B.; Stoddart, J. F.; Yaghi, O. M. Docking in MetalOrganic Frameworks. Science 2009, 325, 855−859. (18) Inokuma, Y.; Arai, T.; Fujita, M. Networked Molecular Cages as Crystalline Sponges for Fullerenes and Other Guests. Nat. Chem. 2010, 2, 780−783. (19) Matsuda, R. Materials Chemistry: Selectivity from Flexibility. Nature 2014, 509, 434−435. (20) Duplan, V.; Hoshino, M.; Li, W.; Honda, T.; Fujita, M. In Situ Observation of Thiol Michael Addition to a Reversible Covalent Drug in a Crystalline Sponge. Angew. Chem., Int. Ed. 2016, 55, 4919−4923. (21) Abhervé, A.; Grancha, T.; Ferrando-Soria, J.; Clemente-León, M.; Coronado, E.; Waerenborgh, J. C.; Lloret, F.; Pardo, E. SpinCrossover Complex Encapsulation within a Magnetic Metal−organic Framework. Chem. Commun. 2016, 52, 7360−7363. (22) Mon, M.; Pascual-Á lvarez, A.; Grancha, T.; Cano, J.; FerrandoSoria, J.; Lloret, F.; Gascon, J.; Pasán, J.; Armentano, D.; Pardo, E. Solid-State Molecular Nanomagnet Inclusion into a Magnetic MetalOrganic Framework: Interplay of the Magnetic Properties. Chem. Eur. J. 2016, 22, 539−545. (23) Li, P.; Modica, J. A.; Howarth, A. J.; Vargas, L. E.; Moghadam, P. Z.; Snurr, R. Q.; Mrksich, M.; Hupp, J. T.; Farha, O. K. Toward Design Rules for Enzyme Immobilization in Hierarchical Mesoporous Metal-Organic Frameworks. Chem. 2016, 1, 154−169. (24) Fortea-Pérez, F. R.; Mon, M.; Ferrando-Soria, J.; Boronat, M.; Leyva-Pérez, A.; Corma, A.; Herrera, J. M.; Osadchii, D.; Gascon, J.; Armentano, D.; Pardo, E. The MOF-Driven Synthesis of Supported Palladium Clusters with Catalytic Activity for Carbene-Mediated Chemistry. Nat. Mater. 2017, 16, 760−766. (25) Li, W.; Zhang, Y.; Zhang, C.; Meng, Q.; Xu, Z.; Su, P.; Li, Q.; Shen, C.; Fan, Z.; Qin, L.; Zhang, G. Transformation of MetalOrganic Frameworks for Molecular Sieving Membranes. Nat. Commun. 2016, 7, 11315. (26) Bradshaw, D.; Claridge, J. B.; Cussen, E. J.; Prior, T. J.; Rosseinsky, M. J. Design, Chirality, and Flexibility in Nanoporous Molecule-Based Materials. Acc. Chem. Res. 2005, 38, 273−282. (27) Gonzalez, M. I.; Kapelewski, M. T.; Bloch, E. D.; Milner, P. J.; Reed, D. A.; Hudson, M. R.; Mason, J. A.; Barin, G.; Brown, C. M.; Long, J. R. Separation of Xylene Isomers through Multiple Metal Site Interactions in Metal−Organic Frameworks. J. Am. Chem. Soc. 2018, 140, 3412−3422. (28) Rabone, J.; Yue, Y.-F.; Chong, S. Y.; Stylianou, K. C.; Bacsa, J.; Bradshaw, D.; Darling, G. R.; Berry, N. G.; Khimyak, Y. Z.; Ganin, A. Y.; Wiper, P.; Claridge, J. B.; Rosseinsky, M. J. An Adaptable PeptideBased Porous Material. Science 2010, 329, 1053−1057. (29) Katsoulidis, A. P.; Park, K. S.; Antypov, D.; Martí-Gastaldo, C.; Miller, G. J.; Warren, J. E.; Robertson, C. M.; Blanc, F.; Darling, G. R.; Berry, N. G.; Purton, J. A.; Adams, D. J.; Rosseinsky, M. J. GuestAdaptable and Water-Stable Peptide-Based Porous Materials by Imidazolate Side Chain Control. Angew. Chem., Int. Ed. 2014, 53, 193−198. (30) Warren, J. E.; Perkins, C. G.; Jelfs, K. E.; Boldrin, P.; Chater, P. A.; Miller, G. J.; Manning, T. D.; Briggs, M. E.; Stylianou, K. C.; Claridge, J. B.; Rosseinsky, M. J. Shape Selectivity by Guest-Driven Restructuring of a Porous Material. Angew. Chem., Int. Ed. 2014, 53, 4592−4596. (31) Inokuma, Y.; Yoshioka, S.; Ariyoshi, J.; Arai, T.; Hitora, Y.; Takada, K.; Matsunaga, S.; Rissanen, K.; Fujita, M. X-Ray Analysis on the Nanogram to Microgram Scale Using Porous Complexes. Nature 2013, 495, 461−466. (32) Tejeda-Serrano, M.; Mon, M.; Ross, B.; Gonell, F.; FerrandoSoria, J.; Corma, A.; Leyva-Pérez, A.; Armentano, D.; Pardo, E. Isolated Fe(III)−O Sites Catalyze the Hydrogenation of Acetylene in Ethylene Flows under Front-End Industrial Conditions. J. Am. Chem. Soc. 2018, 140, 8827−8832.

Donatella Armentano: 0000-0002-8502-8074 Emilio Pardo: 0000-0002-1394-2553 Notes

The authors declare no competing financial interest.

■

ACKNOWLEDGMENTS This work was supported by the MINECO (Spain; Project CTQ2016-75671-P and Excellence Unit “Maria de Maeztu” MDM-2015-0538) and the Ministero dell’Istruzione, dell’Università e della Ricerca (Italy). M.M., R.B., and X.Q. thank the MINECO, the MIUR (Project PON R&I FSE-FESR 20142020), and the China Scholarship Council, respectively, for grants. Thanks are also extended to the Ramón y Cajal program (by E.P.) and the “Subprograma atracció de talentcontractes postdoctorals de la Universitat de Valenci” (by J.F.S.). We also acknowledge SOLEIL for the provision of synchrotron radiation facilities and thank Dr. Pierre Fertey for his assistance at CRISTAL beamline.

■

REFERENCES

(1) Cotton, S. Lanthanide and Actinide Chemistry; John Wiley & Sons, Ltd.: Chichester, U.K., 2006. (2) McGill, I. Rare Earth Elements. In Ullmann’s Encyclopedia of Industrial Chemistry; Wiley-VCH Verlag GmbH & Co. KGaA: Weinheim, Germany, 2000. (3) Nash, K. L. A Review of the Basic Chemistry and Recent Developments in Trivalent F-Elements Separations. Solvent Extr. Ion Exch. 1993, 11 (4), 729−768. (4) Krättli, M.; Mü ller-Späth, T.; Ulmer, N.; Strö hlein, G.; Morbidelli, M. Separation of Lanthanides by Continuous Chromatography. Ind. Eng. Chem. Res. 2013, 52, 8880−8886. (5) Shiokawa, J. Separation and Purification of Rare Earth Elements by Fractional Crystallization. IV. Purifications of Cerium Group Elements by Fractional Crystallizations of Double Salts of Nitrates. J. Soc. Chem. Ind. Japan 1963, 66, 765−769. (6) Sholl, D. S.; Lively, R. P. Seven Chemical Separations to Change the World. Nature 2016, 532, 435−437. (7) Cui, Y.; Li, B.; He, H.; Zhou, W.; Chen, B.; Qian, G. Metal− Organic Frameworks as Platforms for Functional Materials. Acc. Chem. Res. 2016, 49, 483−493. (8) Farha, O. K.; Hupp, J. T. Rational Design, Synthesis, Purification, and Activation of Metal−Organic Framework Materials. Acc. Chem. Res. 2010, 43, 1166−1175. (9) Furukawa, H.; Cordova, K. E.; O’Keeffe, M.; Yaghi, O. M. The Chemistry and Applications of Metal-Organic Frameworks. Science 2013, 341, 1230444. (10) Long, J. R.; Yaghi, O. M. The Pervasive Chemistry of MetalOrganic Frameworks. Chem. Soc. Rev. 2009, 38, 1213−1214. (11) Férey, G. Hybrid Porous Solids: Past, Present, Future. Chem. Soc. Rev. 2008, 37, 191−214. (12) Maspoch, D.; Ruiz-Molina, D.; Veciana, J. Old Materials with New Tricks: Multifunctional Open-Framework Materials. Chem. Soc. Rev. 2007, 36, 770−818. (13) Grancha, T.; Ferrando-Soria, J.; Castellano, M.; Julve, M.; Pasán, J.; Armentano, D.; Pardo, E. Oxamato-Based Coordination Polymers: Recent Advances in Multifunctional Magnetic Materials. Chem. Commun. 2014, 50, 7569−7585. (14) Li, J.; Sculley, J.; Zhou, H. Metal−Organic Frameworks for Separations. Chem. Rev. 2012, 112, 869−932. (15) Mon, M.; Tiburcio, E.; Ferrando-Soria, J.; Gil San Millán, R.; Navarro, J. A. R.; Armentano, D.; Pardo, E. A Post-Synthetic Approach Triggers Selective and Reversible Sulphur Dioxide Adsorption on a Metal−organic Framework. Chem. Commun. 2018, 54, 9063−9066. (16) Ferrando-Soria, J.; Serra-Crespo, P.; de Lange, M.; Gascon, J.; Kapteijn, F.; Julve, M.; Cano, J.; Lloret, F.; Pasán, J.; Ruiz-Pérez, C.; E

DOI: 10.1021/acs.inorgchem.8b02409 Inorg. Chem. XXXX, XXX, XXX−XXX

Article

Inorganic Chemistry (33) Bloch, W. M.; Champness, N. R.; Doonan, C. J. X-Ray Crystallography in Open-Framework Materials. Angew. Chem., Int. Ed. 2015, 54, 12860−12867. (34) Mon, M.; Bruno, R.; Ferrando-Soria, J.; Bartella, L.; Di Donna, L.; Talia, M.; Lappano, R.; Maggiolini, M.; Armentano, D.; Pardo, E. Crystallographic Snapshots of Host−guest Interactions in Drugs@ metal−organic Frameworks: Towards Mimicking Molecular Recognition Processes. Mater. Horiz. 2018, 5, 683−690. (35) Mon, M.; Rivero-Crespo, M. A.; Ferrando-Soria, J.; VidalMoya, A.; Boronat, M.; Leyva-Pérez, A.; Corma, A.; HernándezGarrido, J. C.; López-Haro, M.; Calvino, J. J.; Ragazzon, G.; Credi, A.; Armentano, D.; Pardo, E. Synthesis of Densely Packaged, Ultrasmall Pt02 Clusters within a Thioether-Functionalized MOF: Catalytic Activity in Industrial Reactions at Low Temperature. Angew. Chem., Int. Ed. 2018, 57, 6186−6191. (36) Mon, M.; Ferrando-Soria, J.; Grancha, T.; Fortea-Pérez, F. R.; Gascon, J.; Leyva-Pérez, A.; Armentano, D.; Pardo, E. Selective Gold Recovery and Catalysis in a Highly Flexible Methionine-Decorated Metal−Organic Framework. J. Am. Chem. Soc. 2016, 138, 7864−7867. (37) Mon, M.; Lloret, F.; Ferrando-Soria, J.; Martí-Gastaldo, C.; Armentano, D.; Pardo, E. Selective and Efficient Removal of Mercury from Aqueous Media with the Highly Flexible Arms of a BioMOF. Angew. Chem., Int. Ed. 2016, 55, 11167−11172. (38) Liang, L.; Chen, Q.; Jiang, F.; Yuan, D.; Qian, J.; Lv, G.; Xue, H.; Liu, L.; Jiang, H.-L.; Hong, M. In Situ Large-Scale Construction of Sulfur-Functionalized Metal−organic Framework and Its Efficient Removal of Hg(II) from Water. J. Mater. Chem. A 2016, 4, 15370− 15374. (39) Holcroft, J. M.; Hartlieb, K. J.; Moghadam, P. Z.; Bell, J. G.; Barin, G.; Ferris, D. P.; Bloch, E. D.; Algaradah, M. M.; Nassar, M. S.; Botros, Y. Y.; Thomas, K. M.; Long, J. R.; Snurr, R. Q.; Stoddart, J. F. Carbohydrate-Mediated Purification of Petrochemicals. J. Am. Chem. Soc. 2015, 137, 5706−5719. (40) Urban, S.; Brkljača, R.; Hoshino, M.; Lee, S.; Fujita, M. Determination of the Absolute Configuration of the PseudoSymmetric Natural Product Elatenyne by the Crystalline Sponge Method. Angew. Chem., Int. Ed. 2016, 55, 2678−2682. (41) Zhao, X.; Wong, M.; Mao, C.; Trieu, T. X.; Zhang, J.; Feng, P.; Bu, X. Size-Selective Crystallization of Homochiral Camphorate Metal−Organic Frameworks for Lanthanide Separation. J. Am. Chem. Soc. 2014, 136, 12572−12575. (42) Tasaki-Handa, Y.; Abe, Y.; Ooi, K.; Narita, H.; Tanaka, M.; Wakisaka, A. Selective Crystallization of Phosphoester Coordination Polymer for the Separation of Neodymium and Dysprosium: A Thermodynamic Approach. J. Phys. Chem. B 2016, 120, 12730− 12735. (43) Hu, Y.-Q.; Zhang, T.; Li, M.-Q.; Wang, Y.; Zheng, Z.; Zheng, Y.-Z. Copper(I)/(II)-Redox Triggered Efficient and Green RareEarth Separation Using a Heterometallic Metal−organic Framework. Green Chem. 2017, 19, 1250−1254. (44) Ya Gao, H.; Li Peng, W.; Pan Meng, P.; Feng Feng, X.; Qiang Li, J.; Qiong Wu, H.; Sheng Yan, C.; Yang Xiong, Y.; Luo, F. Lanthanide Separation Using Size-Selective Crystallization of LnMOFs. Chem. Commun. 2017, 53, 5737−5739. (45) Lu, Q.; Ma, Y.; Li, H.; Guan, X.; Yusran, Y.; Xue, M.; Fang, Q.; Yan, Y.; Qiu, S.; Valtchev, V. Postsynthetic Functionalization of Three-Dimensional Covalent Organic Frameworks for Selective Extraction of Lanthanide Ions. Angew. Chem., Int. Ed. 2018, 57, 6042−6048.

F

DOI: 10.1021/acs.inorgchem.8b02409 Inorg. Chem. XXXX, XXX, XXX−XXX