Synthesis, structure and hydrogen sorption properties of a pyrazine-bridged copper(I) nitrate metal-organic framework European Journal of Chemistry 10 (3) (2019) 195-200 European Journal of Chemistry View Journal Online View Article Online Synthesis, structure and hydrogen sorption properties of a pyrazine-bridged copper(I) nitrate metal-organic framework Emmanuel Ngwang Nfor 1,2,*, Andrew David Burrows 2, Bridget Ndoye Ndosiri 3, Luke Lawrence Keenan 4 and Offiong Efanga Offiong 5 1 Department of Chemistry, Faculty of Science, University of Buea, Buea, Cameroon nfor.emmanuel@ubuea.cm (E.N.N.) 2 Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom a.d.burrows@bath.ac.uk (A.D.B.) 3 Inorganic Chemistry Department, Faculty of Science, University of Yaounde 1, Yaounde, Cameroon ndosirin@yahoo.com (B.N.N.) 4 Diamond Light Source, Didcot, Oxfordshire, OX11 0DE, United Kingdom luke.keenan@diamond.ac.uk (L.L.K.) 5 Department of Pure and Applied Chemistry, University of Calabar, PMB 1115, Calabar, CRS, Nigeria offiongeo@yahoo.com (O.E.O.) * Corresponding author at: Department of Chemistry, Faculty of Science, University of Buea, Buea, Cameroon. Tel: +237.67.4519817 Fax: +237.33.322272 e-mail: nfor.emmanuel@ubuea.cm (E.N. Nfor). 10.5155/eurjchem.10.3.195-200.1888 Received: 03 May 2019 Received in revised form: 10 June 2019 Accepted: 14 June 2019 Published online: 30 September 2019 Printed: 30 September 2019 A new copper(I) pyrazine-bridged coordination polymer [Cu2(pyz)3(NO3)2]·2DMF] (pyz = pyrazine) (1) has been synthesized and characterized by FT-IR, TG/DTG, DSC and single crystal X-ray diffraction techniques. The X-ray crystallographic result reveals a two- dimensional network structure containing hexagonal pores. Thermal analysis of compound 1 reveals it is stable to 380 °C, and gas sorption studies showed that it adsorbs 1.04 wt% hydrogen at 1 atm and 77 K. Compound 1 crystallizes in a triclinic system, space group P-1 (no. 2), a = 7.9550(2) Å, b = 7.9810(2) Å, c = 11.0660(3) Å, α = 76.328(1)°, β = 71.115(1)°, γ = 84.577(1)°, V = 645.79(3) Å3, Z = 2, T = 150(2) K, μ(MoKα) = 1.709 mm-1, Dcalc = 1.639 g/cm3, 11111 reflections measured (7° ≤ 2Θ ≤ 54.96°), 2951 unique (R int = 0.0539) which were used in all calculations. The final R1 was 0.0346 (>2σ(I)) and wR2 was 0.0727 (all data). Copper Pyrazine Hydrogen sorption X-ray crystallography Single crystal structure Metal-organic framework Cite this: Eur. J. Chem. 2019, 10(3), 195-200 Journal website: www.eurjchem.com 1. Introduction The design and synthesis of metal-organic frameworks (MOFs) have received increasing attention due to their wide variety of fascinating topologies and potential applications in the fields of magnetism, catalysis, gas storage, conductivity, luminescence, non-linear optics [1-9] and drug delivery systems [10-12]. For many applications, optimal implement- tation requires: (a) large pore volumes (b) phase purity, and (c) retention of porosity upon removal of guest molecules [13]. The construction of MOFs is dependent on several factors, such as the choice of ligands and metal ions, as well as the solvent, temperature and the ratio of the ligands to metal ions used in the synthesis [9,14-16]. The most interesting versions of these materials display permanent nanoscale porosity, a feature that can translate into large internal surface areas, ultralow densities, and the availability of uniformly structured cavities and portals of molecular dimensions. Importantly, the crystalline nature of MOF materials allows for unambiguous structure determination by X-ray diffraction methods. The resulting knowledge of atomic coordinates makes possible the application of high-quality computational modelling of static and dynamic interactions of MOFs with potential sorbents (i.e., predictive or explanative modelling of atomic and molecular isotherms, binding energies, and transport behaviour) [17-19]. Some of these properties are shared by other porous materials such as zeolites; however, MOFs diverge from zeolites in important ways. Perhaps the most significant difference lies in the element of chemical tunability embedded in the organic components of MOFs, which provides considerably greater structural diversity than is possible in zeolites [19]. Ligands with rigid backbones are often preferred in MOF synthesis ABSTRACT RESEARCH ARTICLE KEYWORDS European Journal of Chemistry ISSN 2153-2249 (Print) / ISSN 2153-2257 (Online) – Copyright © 2019 The Authors – Atlanta Publishing House LLC – Printed in the USA. This work is published and licensed by Atlanta Publishing House LLC – CC BY NC – Some Rights Reserved. http://dx.doi.org/10.5155/eurjchem.10.3.195-200.1888 http://dx.doi.org/10.5155/eurjchem.10.3.195-200.1888 https://crossmark.crossref.org/dialog/?doi=10.5155/eurjchem.10.3.195-200.1888&domain=pdf&date_stamp=2019-09-30 http://www.eurjchem.com/ http://dx.doi.org/10.5155/eurjchem.10.3.195-200.1888 mailto:nfor.emmanuel@ubuea.cm mailto:a.d.burrows@bath.ac.uk mailto:ndosirin@yahoo.com mailto:luke.keenan@diamond.ac.uk mailto:offiongeo@yahoo.com mailto:nfor.emmanuel@ubuea.cm http://www.eurjchem.com/ https://crossmark.crossref.org/dialog/?doi=10.5155/eurjchem.10.3.195-200.1888&domain=pdf&date_stamp=2019-09-30� 196 Nfor et al. / European Journal of Chemistry 10 (3) (2019) 195-200 because, their rigidity makes it easier to predict the network geometry in advance of synthesis, and rearrangement to a denser phase on solvent removal is less favourable. Among neutral ligands, pyrazines are especially useful as pillars in the construction of pillared-layer in 2D/3D network and pyrazine is a well-known bridging ligand that has been used in the preparation of MOFs [20,21]. Pyrazines have nitrogen lone electron pairs that are highly directional and have attracted much attention in the construction of supra- molecular structures such as porous materials [22,23] and molecular grids [24,25]. Herein, we report on the unantici- pated reaction of pyrazine with copper(II) nitrate to form a copper(I) metal-organic framework. 2. Experimental 2.1. Materials and physical measurements Cu(NO3)2·2.5H2O, pyrazine and the solvents were all used as purchased, without any further purification. The IR spectra were recorded on a Perkin-Elmer System 2000 FT-IR spectrometer scanning in the range of 4000-400 cm-1 using KBr pellets. The following indications are used to characterize absorption bands: very strong (vs), strong (s), medium (m), weak (w), shoulder (sh), and broad (br). Elemental analyses were performed on Perkin Elmer CHN-analyser. Thermogravi- metric analysis (TGA) experiments were performed on a Shimadzu simultaneous TGA/DTG-60A compositional analysis instrument from room temperature to 800 °C in N2 atmos- phere at a heating rate of 5 °C/min and DSC analyses were recorded on a TA instrument, DSC-Q200, under dry nitrogen flow of 60 mL/min. Variable temperature PXRD analyses were conducted using the Bruker D8 Advance diffractometer equipped with a Lynx Eye detector using CuKα (λ = 1.5406 Å) at 298 K. The hydrogen adsorption measurements were performed using a Quantochrome iSorb-HP gas analyser at 77 and 87 K. Prior to the sorption experiments the sample of compound 1 was degassed by heating at 150 °C for 1.5 hours under dynamic vacuum. 2.2. Single crystal X-ray diffraction analysis and structure determination The crystallographic data were collected on a Gemini diffractometer (Agilent Technologies) using MoKα radiation (λ=0.71073 Å), ω-scan rotation. Data reduction was performed with the CrysAlis Pro [26] including the program SCALE3 ABSPACK [27] for empirical absorption correction. The structure was solved by direct methods (SHELXS-97 and SIR- 92) and the refinement of all non-hydrogen atoms was performed with SHELXL-97 [28]. All non-hydrogen atoms were refined with anisotropic thermal parameters. For compound 1, a difference-density Fourier map was used to locate all hydrogen atoms. The molecular graphics were done with ORTEP-3 [29] and Mercury (Version 3) [30]. 2.3. Synthesis of the copper(I) MOF (1) A mixture of Cu(NO3)2·2.5H2O (0.696 g, 3 mmol) and pyrazine (0.240 g, 3 mmol), in 10 mL of DMF, 2 mL of ethanol was sealed in a 18 mL Teflon-lined autoclave and heated in an oven at 100 °C for 24 h. After slow cooling to room tempe- rature, red acicular crystals of compound 1 were separated by filtration, washed repeatedly with DMF and soaked in anhydrous chloroform for 5 h. The resulting solid product was dried under vacuum at 120 °C for 4 h. Yield: 48%, based on Cu. Anal. calcd. for C9H13CuN5O4: C, 33.88; H, 4.78; N, 21.95. Found: C, 34.20; H, 3. 95; N, 22.52%. FT-IR (KBr, ν, cm−1): 3458 (br), 3091 (m), 2932 (m), 2341 (m), 1657 (s), 1483 (s), 1427 (s), 1411 (s), 1304(s), 1093(s), 1038(s), 793(sh), 493(s), 417(s). 3. Results and discussion The reaction between hydrated copper (II) nitrate and pyrazine in a 1:1 molar ratio in DMF:ethanol mixture at 100 °C for 24 hours, produced red acicular crystals in a 48% yield. The red colouration suggested the reduction of the Cu(II) metal centre to Cu(I) as corroborated by X-ray diffraction analysis. At high temperatures, nitrogen-rich organic ligands are well known to serve as effective reducing agents for such process [31]. 3.1. Infrared spectra The infrared spectrum of the uncoordinated pyrazine ligand exhibited a band at 417 cm–1 which shifted to higher frequency at 493 cm–1 in compound 1 upon coordination of the ligand to the metal centre [32]. The IR spectrum of compound 1 further exhibited strong vibrational bands at 1411, 1427 and 1488 cm–1 that were attributed to NO stretching vibrations for the monodentate nitrate group [33]. 3.2. Crystal structure of compound 1 The structure of compound 1 with atomic numbering scheme is shown in Figure 1. The crystal structure refinement data of compound 1 is shown in Table 1, while selected bond lengths and bond angles are listed in Table 2. The asymmetric unit of compound 1 consists of one Cu(I) centre, three independent pyrazine halves, each of which straddles a crystallographic inversion centre, one nitrate anion and one guest DMF molecule. The coordination geometry about each copper(I) ion is that of a distorted tetrahedron, with the coordination sphere containing three nitrogen atoms from pyrazine ligands and one oxygen atom from the nitrate ion. The Cu-N bond lengths involving the bridging pyrazine ligands are between 1.9721(17)-2.0445(18) Å. The oxygen atoms of the nitrate groups are considerably further from the copper(I) ion with a Cu-O bond length of 2.1660(16) Å. The Cu-N bond lengths within compound 1 are comparable to those observed for the equatorially bound pyrazine ligands in previously reported compounds [34-37], but shorter than those observed for the axially bound pyrazine ligands in Cu(pyz)2(CH3SO3)2 (2.692(3) Å) [37] and Cu(pyz)(hfac)2 (2.529(3) Å) [38]. The Cu···Cu separation across the bridging pyrazine group is 6.825 Å. Overall, the pyrazine linkers connect the copper(I) centres into sheets with 63 topology, with each Cu6(pyz)6 ring being in the chair conformation (Figure 2a). The sheets are packed in an offset manner so that channels are present along the crystallographic b axis (Figure 2b), and the included DMF molecules reside in these. Despite the ubiquity of pyrazine as a linker in MOF chemistry, the two-dimensional network struc- ture observed in compound 1 is unusual, with only one previous report. The compound [Cu2(pyz)3(ClO4)2], prepared from the reaction of Cu(ClO4)2·6H2O with pyrazine in the presence of 2,3-dihydroxyfumaric acid, forms a similar topo- logy network to compound 1, though the sheets are conside- rably more puckered [39]. Notably, when this reaction was carried out using Cu(NO3)2·2.5H2O as the copper source, it yielded a different product to compound 1, and the compound [Cu(pyz)(NO3)] has a structure in which copper(I)-pyrazine chains are cross-linked into sheets by bridging nitrate ions [40]. The related ligands 2-methyl pyrazine and 2,3-dimethyl pyrazine form similar topology networks to compound 1 with copper(I), though in this case the pores are filled with polyoxometallate anions [41]. 2019 – European Journal of Chemistry – CC BY NC – DOI: 10.5155/eurjchem.10.3.195-200.1888 Nfor et al. / European Journal of Chemistry 10 (3) (2019) 195-200 197 Table 1. Crystal data and details of the structure refinement for compound 1. Parameters Compound1 Empirical formula C 9H13CuN5O4 Formula weight 318.78 Temperature (K) 150(2) Crystal system Triclinic Space group P-1 a (Å) 7.9550(2) b (Å) 7.9810(2) c (Å) 11.0660(3) α (°) 76.328(1) β (°) 71.115(1) γ (°) 84.577(1) Volume (Å3) 645.79(3) Z 2 ρ calc (g/cm3) 1.639 μ (mm–1) 1.709 F(000) 326 Crystal size (mm3) 0.20 × 0.10 × 0.05 Radiation MoKα (λ = 0.71073) 2θ range for data collection (°) 3.50 to 27.48 Index ranges –10 ≤ h ≤ 10, –10 ≤ k ≤ 10, –14 ≤ l ≤ 14 Reflections collected 11111 Independent reflections 2951 [R(int) = 0.0539] Data/restraints/parameters 2951 / 0 / 174 Goodness-of-fit on F2 1.054 Final R indexes [I≥2σ(I)] R1 = 0.0346 wR2 = 0.0669 Final R indexes [all data] R1 = 0.0524 wR2 = 0.0727 Largest diff. peak/hole (e.Å–3) 0.316 and -0.649 Flack parameter -0.6(10) Table 2. Selected bond lengths [Å] and angles [°] for compound 1. Bond lengths Cu(1)-N(1) 1.9720(17) Cu(1)-N(3) 2.0108(17) Cu(1)-N(2) 2.0443(18) Cu(1)-O(1) 2.1660(16) O(1)-N(4) 1.274(2) O(2)-N(4) 1.237(2) O(3)-N(4) 1.246(2) O(4)-C(7) 1.227(3) N(5)-C(8) 1.452(3) C(1)-C(2)#1 1.380(3) C(2)-C(1)#1 1.380(3) C(3)-C(4)#2 1.382(3) C(4)-C(3)#2 1.382(3) C(5)-C(6)#3 1.380(3) C(6)-C(5)#3 1.380(3) Bond angles N(1)-Cu(1)-N(3) 125.60(7) N(1)-Cu(1)-N(2) 111.52(7) N(3)-Cu(1)-N(2) 105.15(7) N(1)-Cu(1)-O(1) 112.54(7) N(3)-Cu(1)-O(1) 101.48(7) N(2)-Cu(1)-O(1) 96.28(7) N(4)-O(1)-Cu(1) 115.53(13) C(1)-N(1)-C(2) 115.77(17) O(2)-N(4)-O(3) 121.20(19) O(2)-N(4)-O(1) 119.75(19) O(3)-N(4)-O(1) 119.05(19) C(7)-N(5)-C(9) 120.7(2) N(1)-C(1)-C(2)#1 122.22(19) N(1)-C(2)-C(1)#1 122.01(19) N(2)-C(3)-C(4)#2 121.7(2) N(2)-C(4)-C(3)#2 121.8(2) N(3)-C(5)-C(6)#3 121.9(2) N(3)-C(6)-C(5)#3 122.22(19) Symmetry codes: #1 –x + 1,–y + 1,–z + 1, #2 –x,–y + 1,–z + 2, #3 –x + 1,–y,–z + 2. Figure 1. Asymmetric unit of compound 1 with atom numbering scheme at 50% probability level. 2019 – European Journal of Chemistry – CC BY NC – DOI: 10.5155/eurjchem.10.3.195-200.1888 198 Nfor et al. / European Journal of Chemistry 10 (3) (2019) 195-200 (a) (b) Figure 2. (a) View of the two-dimensional polymeric structure of compound 1. DMF molecules in the pores have been omitted for clarity; (b) Space-filling representation of the structure of compound 1 showing the pores that are occupied by DMF molecules in the crystal structure. These molecules have been removed for clarity. Figure 3. DSC curve of compound 1. 3.3. Thermal behaviour of compound 1 The thermal stability of compound 1 was analyzed by TG/DTG and DSC experiments as depicted in Figures 3 and 4, respectively. The DSC curve reveals a weak endothermic peak at approximately 200 °C and two exothermic peaks at 370 and 380 °C. The TGA results indicate that compound 1 is stable to 380 °C when decomposition of the framework starts. This is confirmed by the DTG curve with a characteristic intense exothermic peak at 370 °C followed by another weak exothermic peak at 392 °C. Overall the thermal analysis of the synthesized complex indicated an intense exothermic decomposition occurring between 350-400 °C. 3.4. Powder X-ray diffraction The phase purity of compound 1 was confirmed by PXRD analysis, in which the experimental PXRD pattern was consistent with the simulated PXRD pattern calculated from the single crystal data (Figure 5). 3.5. Activation A three step activation process was carried out on the as- synthesized MOF 1 as follows. It was washed three times with DMF/DEF and the solvent exchange of DMF/DEF for CHCl3 was carried out in which the samples was washed with lower boiling point solvent for removal of the first solvent from the pore. For implementing this exchange, the mixture was immersed in CHCl3 for 4 days and then the solvent removed under mild conditions after which the sample was filtered under vacuum at 120 °C for 8 hours [42]. The chemical stability of the thermally activated sample (0.05 g) of compound 1 was assessed by stirring it in ethanol under ambient condition for 5 hrs. 2019 – European Journal of Chemistry – CC BY NC – DOI: 10.5155/eurjchem.10.3.195-200.1888 Nfor et al. / European Journal of Chemistry 10 (3) (2019) 195-200 199 Figure 4. TG-DTG curve of compound 1. Figure 5. The experimental and simulated PXRD pattern of compound 1. Figure 6. H2 adsorption and desorption curves for compound 1 at 77 K (red) and 87 K (blue). After collecting the samples by filtration, the crystallinity was examined by PXRD (Figure 5). Compound 1 retained its crystallinity following this treatment, confirmed by PXRD. 3.6. Gas adsorption properties of compound 1 Gas sorption experiments were performed in order to estimate the effect of the removal of DMF on the microporosity and on the accessible internal surface area of the metal- organic framework. To evaluate the porous properties of the framework, the desolvated solid of compound 1 was investigated for H2 gas sorption measurements with the result suggesting reasonably porous properties and gas adsorption capability. The adsorption curve of compound 1, revealed a type 1 isotherm, typical of microporous material [43]. The apparent BET surface areas for compound 1 of 512 m2/g and pore volume of 0.203 mL/g were determined based on the Ar adsorption isotherm at 77 K. The H2 adsorption isotherms were carried out on compound 1 at both 77 and 87 K from 0 to 1.0 atm (Figure 6). The isotherm at 77 K displayed a maximum uptake of 1.04 wt% H2 at 1.0 atm. 4. Conclusion In conclusion, we report the synthesis and charac- terization, of a new copper(I) pyrazine-bridged coordination network structure. The material has been shown to be porous and able to absorb 1.04 wt% hydrogen gas at 77 K and 1 atm. 2019 – European Journal of Chemistry – CC BY NC – DOI: 10.5155/eurjchem.10.3.195-200.1888 200 Nfor et al. / European Journal of Chemistry 10 (3) (2019) 195-200 Acknowledgements Emmanuel Ngwang Nfor is thankful to the Commonwealth Scholarship Commission (CSC) for Research Fellowship and Department of Chemistry, University of Bath, United Kingdom for hosting the fellowship Supporting information CCDC-1547134 contains the supplementary crystallo graphic data for this paper. These data can be obtained free of charge via https://www.ccdc.cam.ac.uk/structures/, or by e- mailing data_request@ccdc.cam.ac.uk, or by contacting The Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax: +44(0)1223-336033. Disclosure statement Conflict of interests: The authors declare that they have no conflict of interest. Author contributions: All authors contributed equally to this work. Ethical approval: All ethical guidelines have been adhered. Sample availability: Samples of the compounds are available from the author. ORCID Emmanuel Ngwang Nfor http://orcid.org/0000-0003-4941-3917 Andrew David Burrows http://orcid.org/0000-0002-9268-4408 Bridget Ndoye Ndosiri http://orcid.org/0000-0001-7969-8963 Luke Lawrence Keenan http://orcid.org/0000-0001-9892-7864 Offiong Efanga Offiong http://orcid.org/0000-0002-7784-4821 References [1]. Batten, S. R.; Robson, R. Angew. Chem. Int. Ed. 1998, 37, 1460-1494. [2]. Eddaoudi, M.; Kim, J.; Rosi, N.; Vodak, D.; Wachter, J.; O’Keeffe, M.; Yaghi, O. M. Science 2002, 295, 469-472. [3]. Farrusseng, D.; Aguado, S.; Pinel, C. Angew. Chem. Int. Ed. 2009, 48, 7502-7513. [4]. Rowsel, J. L. C.; Yaghi, O. M. Angew. Chem. Int. Ed. 2005, 44, 4670- 4679. [5]. Leininger, S.; Olenyuk, B.; Stang, P. J. Chem. Rev. 2000, 100, 853-908. [6]. Cheng, X.; Liu, T.; Duan, X.; Wang, F.; Meng, Q.; Lu, C.; Cryst. Eng. Comm. 2011, 13, 1314-1321. [7]. Zang, S.; Su, Y.; Li, S.; Ni, Z.; Meng, Q. Inorg. Chem. 2006, 45(1), 174- 180. [8]. Hasegawa, S.; Horike, S.; Matsuda, R.; Furukawa, S.; Mochizuki, K.; Kinoshita, Y.; Kitagawa, S. J. Am. Chem. Soc. 2007, 129, 2607-2614. [9]. Arici, M.; Yesilel, O. Z.; Keskin, S.; Tas, M. Polyhedron 2012, 45, 103- 106. [10]. Horcajada, P.; Serre, C.; Vallet-Regi, M.; Sebban, M.; Taulelle, F.; Ferey, G. Angew. Chem. Int. Ed. 2006, 118, 6120-6124. [11]. An, J.; Geib, S. J.; Rosi, N. L. J. Am. Chem. Soc. 2009, 131, 8376-8377. [12]. Taylor-Pashow, K. M. L.; Rocca, J. D.; Xie, Z.; Tran, S.; Lin, W. J. Am. Chem. Soc. 2009, 131, 14261-14263. [13]. Sethi, N. K. PhD Thesis, Preparation of Heterobimetallic catalyst, York University, 2013. [14]. Wen, G. L.; Wang, Y. Y.; Zhang, W. H.; Ren, C.; Liu, R. T.; Shi, Q. Z. Cryst. Eng. Comm. 2010, 12, 1238-1251. [15]. Sun, D.; Luo, G. G.; Zhang, N.; Chen, J. H.; Huang, R. B.; Lin, L. R.; Zhang, L. S. Polyhedron 2009, 28, 2983-2988. [16]. Munakata, M.; Wu, L. P.; Kuroda-Sowa, T.; Maekawa, M.; Moriwaki, K.; Kitagawa, S. Inorg. Chem. 1997, 36(23), 5416-5418. [17]. Duren, T.; Bae, Y. S.; Snurr, R. Q. Chem. Soc. Rev. 2009, 38, 1237-1247. [18]. Han, S. S.; Mendoza-Cortes, J. L.; Goddard, W. A. Chem. Soc. Rev. 2009, 38, 1460-1476. [19]. Farha, O. K; Hupp. J. T. Accoun. Chem. Res. 2010, 43(8), 1166-1175. [20]. Real, J. A.; Munno, G. D.; Munoz, M. C.; Julve, M. Inorg. Chem. 1991, 30, 2701-2704. [21]. Otieno, T.; Gipson, A. M.; Parkin, S. J. Chem. Crystallogr. 2002, 2(3-4), 81-85. [22]. Kitagawa, S.; Kitaura, R.; Noro, S. Angew. Chem., Int. Ed. 2004, 43(18), 2334-2375. [23]. Navarro, J. A. R.; Barea, E.; Galindo, M. A.; Salas, J. M.; Romero, M. A.; Quiros, M.; Masciocchi, N.; Galli, S.; Sironi, A.; Lippert, B. J. Solid State Chem. 2005, 178, 2436-2451. [24]. Ruben, M.; Rojo, J.; Romero-Salquero, F. J.; Uppadine, I. H.; Lehn, J. M. Angew. Chem. Int. Ed. 2004, 43(28), 3644-3662. [25]. Lehn, J. M. Supramolecular Chemistry. Concept and Perspectives, VCH, Weinheim, Germany, 1995. [26]. CrysAlis Pro: Data collection and data reduction software package, Agilent Technologies. [27]. SCALE3 ABSPACK: Empirical absorption correction using spherical harmonics. [28]. Sheldrick, G. M. Acta Crystallogr. A 2008, 64, 112-122. [29]. Farrugia, L. J. J. Appl. Crystallogr. 1997, 30, 565-565. [30]. Macrae, C. F.; Bruno, I. J.; Chisholm, J. A.; Edgington, P. R.; McCabe, P.; Pidcock, E.; Rodriguez-Monge, L.; Taylor, R.; Van de Streek, J.; Wood, P. A. J. Appl. Crystallogr. 2008, 411, 466-470. [31]. Otieno, T.; Rettig, S. J.; Thompson, R. C.; Trotter, B. Can. J. Chem. 1989, 67(11), 1964-1969. [32]. Nakamoto, K. Infrared and Raman Spectra of Inorganic and Coordination Compounds, Wiley-Interscience: New York, 1986. [33]. Lo, S. M. F.; Chu, S. S. Y.; Shek, L. Y.; Lin, Z.; Zhang, X. X.; Wen, G. H.; Williams, I. D. J. Am. Chem. Soc. 2000, 122, 6293-6294. [34]. Santoro, A.; Mighell, A. D.; Reimann, M. R. Acta Crystallogr. B 1970, 26, 979-984. [35]. Kuhlman, R.; Sehimek, G. L.; Kolis, J. W. Polyhedron 1999, 18, 1379- 1389. [36]. Darriet, J.; Haddad, M. D.; Duesler, E. N.; Hendrickson, D. N. Inorg. Chem. 1979, 18(10), 2679-2682. [37]. Haynes, J. S.; Rettig, S. J.; Sams, J. R.; Thompson, R. C.; Trotter, J. Can. J. Chem. 1987, 65, 420-426. [38]. Belford, R. C. E.; Fenton, D. E.; Truter, M. R. J. Chem. Soc. Dalton Trans. 1974, 17-24. [39]. The Cambridge Structural Database, Ref. code HUTWOJ; Groom, C. R.; Bruno, I. J.; Lightfoot, M. P.; Ward, S. C. Acta Crystallogr. B 2016, 72, 171-179. [40]. Mohapatra, S.; Maji, T. K. Dalton Trans. 2010, 39, 3412-3419. [41]. Kong, X. J.; Ren, Y. P.; Zheng, P. Q.; Long, L. S.; Huang, R. B.; Zheng, L. S. Inorg. Chem. 2006, 45, 10702-10711. [42]. Aghajanloo, M.; Rashidi, A. M.; Moosavian, M. A. J. Chem. Eng. Process. Technol. 2014, 5, 1-6. [43]. Hulvey, Z.; Sava, D. A; Eckert, J.; Cheetham. A. K. Inorg. Chem. 2011, 50, 403-405. Copyright © 2019 by Authors. This work is published and licensed by Atlanta Publishing House LLC, Atlanta, GA, USA. The full terms of this license are available at http://www.eurjchem.com/index.php/eurjchem/pages/view/terms and incorporate the Creative Commons Attribution-Non Commercial (CC BY NC) (International, v4.0) License (http://creativecommons.org/licenses/by-nc/4.0). By accessing the work, you hereby accept the Terms. This is an open access article distributed under the terms and conditions of the CC BY NC License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited without any further permission from Atlanta Publishing House LLC (European Journal of Chemistry). No use, distribution or reproduction is permitted which does not comply with these terms. Permissions for commercial use of this work beyond the scope of the License (http://www.eurjchem.com/index.php/eurjchem/pages/view/terms) are administered by Atlanta Publishing House LLC (European Journal of Chemistry). 2019 – European Journal of Chemistry – CC BY NC – DOI: 10.5155/eurjchem.10.3.195-200.1888 https://www.ccdc.cam.ac.uk/structures/ mailto:data_request@ccdc.cam.ac.uk http://orcid.org/0000-0003-4941-3917 http://orcid.org/0000-0002-9268-4408 http://orcid.org/0000-0001-7969-8963 http://orcid.org/0000-0001-9892-7864 http://orcid.org/0000-0002-7784-4821 http://www.eurjchem.com/index.php/eurjchem/pages/view/terms http://creativecommons.org/licenses/by-nc/4.0 http://www.eurjchem.com/index.php/eurjchem/pages/view/terms 1. Introduction 2. Experimental 2.1. Materials and physical measurements 2.2. Single crystal X-ray diffraction analysis and structure determination 2.3. Synthesis of the copper(I) MOF (1) 3. Results and discussion 3.1. Infrared spectra 3.2. Crystal structure of compound 1 3.3. Thermal behaviour of compound 1 3.4. Powder X-ray diffraction 3.5. Activation 3.6. Gas adsorption properties of compound 1 4. Conclusion Acknowledgements Supporting information Disclosure statement ORCID References PrintField10: PrintField11: PrintField12: PrintField13: PrintField14: PrintField15: PrintField20: PrintField21: PrintField22: PrintField23: PrintField24: PrintField25: