Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 120 (2014) 401–404
Contents lists available at ScienceDirect
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy journal homepage: www.elsevier.com/locate/saa
A novel cobalt (I) coordination polymer with mixed thiocyanate and quinoline ligands: Crystal structure, magnetism and luminescent properties Lei Li, Shuai Chen, Rui-Min Zhou, Yan Bai ⇑, Dong-Bin Dang ⇑ Institute of Molecular and Crystal Engineering, School of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004, PR China
h i g h l i g h t s
g r a p h i c a l a b s t r a c t
Synthesized a new Co(I) 1D
coordination polymer. Crystal structure analyses and
discussion for the compound. The luminescent properties and
magnetic properties were investigated.
a r t i c l e
i n f o
Article history: Received 26 August 2013 Received in revised form 2 October 2013 Accepted 9 October 2013 Available online 19 October 2013 Keywords: Co(I) Thiocyanato bridged Crystal structure Luminescent properties Magnetic properties
a b s t r a c t A new Co(I) one-dimensional coordination polymer [Co(SCN)(ql)]n (ql = quinoline) (1) has been synthesized and characterized by IR, elemental analysis, TG technique and X-ray crystallography. Co(I) atom has a distorted trigonal pyramidal N2S2 (1) environment with two S atoms and one N atom from three l-1,1,3-thiocyanate bridge ligands and one N atom from ql ligand. Two S atoms from two l-1,1,3-SCN bridging ligands bridge two centers to obtain bimetallic 4-membered ring. Adjacent 4-membered rings are linked by a pair of l-1,1,3-SCN bridging ligands to form a 1D stair-case like chain. The luminescent properties and magnetic properties of the polymer 1 were investigated in the solid state. Ó 2013 Elsevier B.V. All rights reserved.
Introduction The design and construction of the coordination polymeric multifunctional materials have attracted great interest in coordination chemistry and material science due to not only the varieties of topologies and intriguing frameworks, but also their interesting electric, magnetic, catalytic and optical properties [1–7]. The most ⇑ Corresponding authors. Tel./fax: +86 378 3881589. E-mail addresses: [email protected] (Y. Bai), [email protected] (D.-B. Dang). 1386-1425/$ - see front matter Ó 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.saa.2013.10.051
intriguing feature of multifunctional materials is that the synergy between different functionalities provides new opportunity and possibility in finding interesting physical properties and developing new materials. Among them, luminescent and magnetic dual functional coordination polymers have been one kind of important functional materials in recent years. However, the synthesis of this type of dual functional coordination polymers is still rare and lacking due to the diversity of coordination and the complicated natures of luminescent and magnetic behaviors [8–12]. As a part of our continuing investigations on thiocyanato bridged Cd(II)-containing coordination polymers and their
402
L. Li et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 120 (2014) 401–404
photoluminescent properties [13–20], herein we chose paramagnetic cobalt center and thiocyanate ligand with multiform coordination bridging configuration to assemble luminescent and magnetic dual functional coordination polymers. Using this strategy to synthesize dual functional coordination polymer with intriguing structure and interesting physical properties is doable given the following considerations: (i) The linear triatomic pseudohalide, SCN, is one of the best bridging ligands with an ambidentate ability, which may link two or three metal centers through 1,1-l-SCN, 1,3-l-SCN or l-1,1,3-SCN bridging modes to lead one dimensional chains, two dimensional layers, and three dimensional networks [21–25]. (ii) The thiocyanate group is a good electron supplier and the electron transfer from SCN to metal ion. (iii) The thiocyanate ligand may act as an efficient mediator for the magnetic interaction between the paramagnetic metal ion centers [26–29]. Furthermore, there are only a few literature citations reported on the Co(I) complexes [30,31]. In this present, we report the synthesis and crystal structure of one novel cobalt(I) onedimensional coordination polymer [Co(SCN)(ql)]n (ql = quinoline) (1) displaying strong luminescent emission at room temperature, in which contains the bridging mode of l-1,1,3-SCN. The magnetic properties of polymer 1 have been investigated. Experimental Physical measurements Elemental analyses (C, H and N) were carried out on a PerkinElmer 240C analytical instrument. IR spectra were recorded in KBr pellets with a Nicolet 170 S spectrophotometer in the 4000– 400 cm1 region. The luminescent spectra were performed on a XFT-IR Hitachi F-7000 fluorescence spectrophotometer. The thermo gravimetric analysis was carried out under nitrogen condition on a Perkin–Elmer-7 thermal analyzer at a heating rate of 10 °C/min from 25 to 1000 °C. Magnetic susceptibility data on crushed single crystals were collected over the temperature range 2–300 K using a Quantum Design MPMS-5S super-conducting quantum interference device (SQUID) magnetometer, and the experimental data were corrected for diamagnetism of the constituent atoms estimated from Pascal’s constants. Materials All the chemicals were reagent grade quality obtained from commercial sources and used without further purification. Preparation of the polymer 1 A 15 mL aqueous solution of Co(NO3)26H2O (0.087 g, 0.3 mmol) and KSCN (0.291 g, 3 mmol) were mixed. The obtained solution was slowly added to a 20 mL CH3CN solution of quinoline (0.130 g, 1 mmol). After stirring for 30 min, the resulting blue solution was filtered and left for slowly evaporating at room temperature to obtain blue block crystals suitable for single crystal X-ray structure determination. Yield: 71%. Anal. Calc. For C10H7CoN2S(%): C, 48.79; H, 2.87; N, 11.38. Found (%): C, 40.81; H, 2.85; N, 11.20. IR (KBr pellet, cm1): 2364(w), 2059(vs), 2048(vs), 1621(w), 1596(m), 1585(m), 1509(s), 1438(w), 1401(w), 1376(m), 1310(m), 1239(m), 1059(w), 1022w(m), 957(s), 843(w), 804(s), 778(s), 734(m), 637(m), 622(w), 530(w), 478(m), 467(w). Crystallographic data collection and refinement A suitable sample of size 0.14 mm 0.18 mm 0.22 mm for 1 was chosen for the crystallographic study and then mounted on
a BRUKER SMART APEX CCD diffractometer with x and u scan mode in the range of 1.91° < h < 25.25°. All diffraction measurements were performed at room temperature using graphite monochromatized Mo Ka radiation (k = 0.71073 Å). A total of 4067 (1736 independent, Rint = 0.025) reflections were measured. The structure was solved by direct methods and refined by full-matrix leastsquares on F2 using SHELXL 97 program [32]. All non-hydrogen atoms were refined anisotropically by full-matrix least-squares techniques and all hydrogen atoms were geometrically fixed to allow riding on the parent atoms to which they are attached. CCDC reference number: 847022 (1). Space group, lattice parameters and other relevant information are listed in Table 1. The relevant bond lengths and bond angles are listed in Table 2.
Results and discussion IR and UV spectra In the IR spectra of the coordination polymer 1, the strong absorption bands at 2059 and 2048 cm1 are assigned as the coordination of SCN anion with both N and S atoms. Its identity was finally confirmed by X-ray crystallography [13–15]. The UV spectra of the polymer 1 in H2O solution displays three absorption peaks at 208, 221 and 286 nm, respectively, which can be assigned as the p–p* and n–p* transition of quinoline [19,20,33].
Description of the crystal structure of polymer 1 The coordination polymer 1 crystallizes in the monoclinic space group C2/c. Single crystal X-ray diffraction analysis revealed that the structure of 1 exhibits a new crystalline 1D coordination polymer constructed through double l-1,1,3-SCN bridges between adjacent Co(I) centers [34]. An ORTEP diagram of the polymer 1 with the atomic numbering scheme and the coordination environment of Co(I) atom is depicted in Fig. 1. Each Co center is surrounded by two S atoms and one N atom from three l-1,1, 3-thiocyanate bridge ligands and one N atom from ql ligand. The value of the topological parameter s of ca. 0.78 indicates a distorted trigonal pyramidal geometry [35]. The average distances of CoAS and CoAN are 2.535 Å and 1.972 Å, respectively, and the bond angles around Co center range from 99.15° to 141.31°. The thiocyanate groups are almost linear with the SACAN bond angle of 178.9(4)°. The distances of SAC and CAN at 1.660(4) and
Table 1 Crystallographic data and structure refinement parameters for polymer 1. Crystal data
1
Chemical formula Formula weight Crystal system Space group a (Å) b (Å) c (Å) b (°) Volume (Å3) Z Dc (Mg m3) Crystal size (mm) Radiation (Å) Theta min–max (°) Tot., Uniq. Data, R(int) Observed data [I > 2.0 sigma(I)] Nref, Npar R, wR2, S Min. and max. resd. Dens. [e/Å3]
C10H7CoN2S 246.17 Monoclinic C2/c 26.148(5) 5.6860(11) 15.827(3) 125.196(3) 1923.0(6) 8 1.701 0.22 0.18 0.14 MoKa 0.71073 1.91–25.25 4067, 1736, 0.025 1401 1736, 127 0.0422, 0.1288, 1.002 0.878/0.457
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L. Li et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 120 (2014) 401–404 Table 2 Selected bond distances (Å) and bond angles (°) for polymer 1. Bond length (Å) Co1AN1 Co1AS1b N1AC1
1.929(3) 2.5327(12) 1.162(4)
Co1AN2 Co1AS1c C1AS1
2.014(3) 2.5473(11) 1.660(4)
Bond length (°) N1ACo1AN2 N2ACo1AS1b N2ACo1AS1c N1AC1AS1
141.31(13) 99.64(9) 103.17(10) 178.9(4)
N1ACo1AS1b N1ACo1AS1c S1bACo1AS1c Co1aAS1cACo1
99.15(11) 102.28(10) 108.82(3) 71.18(3)
Symmetry codes, a x, 1y, z. b x, 1 + y, z. c x, y, z.
ligands bridge Co(1A) and Co(1B) centers to obtain bimetallic 8membered ring through S and N atom from each l-1,1,3-SCN anion with the CASACo angle of 95.46(13)° and the NACoAS angle of 102.28(10)°. These structure features are similar to those found in related polymer [(AgSCN)2tbpe] (tbpe = tran-1,2-bis(4-pyridyl)ethylene) [35]. Therefore, the polymer 1 represents the novel onedimensional stair-case like structure containing above two types of dinuclear metallocyclic rings Co2S2 and Co2(SCN)2 in which the minicycle Co2S2 subunit represents the steps (Fig. S1). This ladder-type chain exhibits average angle of 79° between adjacent subunits. Thermal analysis In order to study the thermal stability of the title complex, the thermal gravimetric analysis (TGA) measurements were carried out at the temperature range of 25–700 °C (Fig. S2). The TGA curve of 1 suggests that the first weight loss of 76.99% in the region of 110–560 °C corresponds to the expulsion of one thiocyanate and ql ligand (calculated 76.06%). The final residue after 700 °C should be Co elementray substance (found: 22.61%, calcd: 23.94%). Luminescence properties The solid state excitation and emission spectrum of coordination polymer 1 were investigated at room temperature. As shown in Fig. 2, the coordination polymer 1 shows the main emission peak at 415 nm and a shoulder emission at 435 nm using excitation wavelengths at 272 nm. Since the ql ligand shows a similar emission at 375 nm, the strong emission band of polymer 1 is obviously red-shifted of 40 nm and would be assigned to the intraligand p–p* transitions from the ql ligand [19,20,33].
Fig. 1. ORTEP drawing of the polymer 1 with the atom numbering scheme and the coordination geometry of Co. The atoms are represented by 30% probability thermal ellipsoids (symmetry codes: A: x, 1 y, z; B: x, 1 + y, z; C: x, y, z).
1.162(4) Å are in accordance with the values observed in other thiocyanato bridges metal complexes [13–25]. Each l-1,1,3-SCN bridging ligand links three Co centers Co(1), Co(1A) and Co(1B) with the distances of 2.96 Å for Co(1) Co(1A), 5.69 Å for Co(1) Co(1B) and 5.27 Å for Co(1A) Co(1B), respectively (Fig. 2). Two S atoms from two l-1,1,3-SCN bridging ligands bridge Co(1) and Co(1A) centers to obtain bimetallic 4-membered ring with the Co(1)ASACo(1A) angle of 71.18(3)° and the SACoAS angle of 108.82(3)°. Meanwhile, a pair of l-1,1,3-SCN bridging
Magnetic properties The magnetic properties of polymer 1 have been investigated at a field of 1 kOe in the temperature range 2–300 K. As illustrated in Fig. 3, the vmT value of 1 at room temperature is 1.27 emu mol1 K (vm is the molar magnetic susceptibility per Co(III) ions), which is slightly larger than the spin-only value of a Co(III)2 unit (1 emu mol1 K for S = 1 and g = 2). With decreasing temperature, the vmT value first decreases smoothly till reaching 1.15 emu mol1 K at 16 K, and then decreases rapidly below this temperature till reaching 0.73 emu mol1 K at 2 K. The v1 m versus T plot follows the Curie–Weiss law with C = 1.27 emu mol1 K and h = 2.38 K. The negative value of Weiss temperature indicates that the antiferromagnetic exchange coupling between Co(III) ions dominates the magnetic properties of the complex.
1.3
250
1.2
K −1
χmT / emu mol
50
0.8
0
0.7 0 Fig. 2. The emission spectrum (kex = 272 nm) and excitation spectrum (inset, kem = 415 nm) of polymer 1 in solid state at room temperature.
50
100
150
200
250
300
Fig. 3. Temperature variation of the magnetic susceptibility of 1.
−1
100
0.9
−1
150
1.0
χm / emu mol
200
1.1
404
L. Li et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 120 (2014) 401–404
Conclusion In summary, we presented a new one-dimension Co(I) coordination polymer [Co(SCN)(ql)]n (ql = quinoline) (1). The structure of the polymer 1 has been established by single-crystal X-ray diffraction analysis and also characterized by IR, elemental analysis, TG technique and luminescent properties. Adjacent Co(I) atoms interconnect with l-1,1,3-SCN bridging ligands to form one dimension stair-case like structure containing two types of dinuclear 4-membered and 8-membered metallocyclic rings. The fluorescence spectra of polymer 1 shows solid-state emission peaks at 415 nm and a shoulder emission at 435 nm. Acknowledgements This work was supported by the Natural Science Foundation of Henan Province of China, the Foundation for University Youth Key Teacher of Henan Province of China, the Foundation of Henan Educational Committee of China and the Foundation Co-established by the Province and the Ministry of Henan University. Appendix A. Supplementary material CCDC-847022 (1) contains the supplementary crystallographic data for this paper. These data can be obtained free of charge at http://www.ccdc.cam.ac.uk/conts/retrieving.html (or from the Cambridge Crystallographic Data Centre (CCDC), 12 Union Road, Cambridge CB2 1EZ, UK; fax: +44 (0)1223 336033; email: [email protected]). Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/ 10.1016/j.saa.2013.10.051. References [1] A. Gallego, C. Hermosa, O. Castillo, I. Berlanga, C.J. Go9 mez-García, E. MateoMartí, J.I. Martínez, F. Flores, C. Go9 mez-Navarro, J. Go9 mez-Herrero, S. Delgado, F. Zamora, Adv. Mater. 25 (2013) 2141–2146. [2] M. Clemente-Leon, E. Coronado, M. Lopez-Jorda, J.C. Waerenborgh, Inorg. Chem. 50 (2011) 9122–9130. [3] M. Cortijo, S. Herrero, R. Jiménez-Aparicio, E. Matesanz, Inorg. Chem. 52 (2013) 7087–7093. [4] P.Y. Wu, J. Wang, Y.M. Li, C. He, Z. Xie, C.Y. Duan, Adv. Funct. Mater. 21 (2011) 2788–2794.
[5] L. Yi, X.Y. Wang, J. Lumin. 131 (2011) 2083–2088. [6] A. Lee, S. Dubinsky, E. Tumarkin, M. Moulin, A.A. Beharry, E. Kumacheva, Adv. Funct. Mater. 21 (2011) 1959–1969. [7] F. Artizzu, P. Deplano, L. Pilla, A. Serpe, L. Marchio, K. Bernot, M.L. Mercuri, Inorg. Chim. Acta 370 (2011) 474–481. [8] X.L. Zhang, X. Jing, T. Liu, G. Han, H.Q. Li, C.Y. Duan, Inorg. Chem. 51 (2012) 2325–2331. [9] C.Y. Niu, Z.L. Pan, Y.L. Dang, C.L. Feng, C.H. Kou, J. Inorg. Organomet. Polym. 21 (2011) 611–618. [10] X.H. Yan, Y.F. Li, Q. Wang, X.G. Huang, Y. Zhang, C.J. Gao, W.S. Liu, Y. Tang, H.R. Zhang, Y.L. Shao, Cryst. Growth Des. 11 (2011) 4205–4212. [11] T.D. Pasatiu, C. Tiseanu, A.M. Madalan, B. Jurca, C. Duhayon, J.P. Sutter, M. Andruh, Inorg. Chem. 50 (2011) 5879–5889. [12] S.Y. Zhang, J.G. Mao, Inorg. Chem. 50 (2011) 4934–4943. [13] Y. Bai, W.L. Shang, D.B. Dang, J.D. Sun, H. Gao, Spectrochim. Acta, Part A, Mol. Biomol. Spectrosc. 72 (2009) 407–411. [14] D.B. Dang, W.L. Shang, Y. Bai, J.D. Sun, H. Gao, Inorg. Chim. Acta 362 (2009) 2391–2395. [15] Y. Bai, W.L. Shang, D.B. Dang, H. Gao, X.F. Niu, Y.F. Guan, Inorg. Chem. Commun. 11 (2008) 1470–1473. [16] D.B. Dang, J.D. Sun, Y. Bai, H. Gao, W.L. Shang, J Chem. Crystallogr. 39 (2009) 683–687. [17] Y. Bai, H. Gao, D.B. Dang, W.L. Shang, X.J. Pan, J. Mol. Struct. 934 (2009) 53–56. [18] Y. Bai, H. Gao, D.B. Dang, X.F. Hu, X.Y. Guo, Synth. React. Inorg. Met.-Org. NanoMet. Chem. 39 (2009) 512–515. [19] D.B. Dang, X.Y. Guo, Y. Bai, H. Gao, G.Q. Zhang, Synth. React. Inorg. Met.-Org. Nano-Met. Chem. 40 (2010) 195–199. [20] D.B. Dang, M.M. Li, Y. Bai, R.Q. Ning, Synth. React. Synthetic Metals 162 (2012) 2075–2080. [21] H.G. Zhu, M. Ströbele, Z. Yu, Z. Wang, H. Meyer, X.Z. You, Inorg. Chem. Commun. 4 (2001) 577–581. [22] L. Shen, X.W. Feng, Struct. Chem. 13 (2002) 437–441. [23] D.P. Martin, W.R. Knapp, R.M. Supkowski, R.L. LaDuca, Inorg. Chim. Acta 362 (2009) 1559–1564. [24] C. Merz, M. Desciak, C. O0 Brien, R.L. LaDuca, R.C. Finn, R.S. Rarig, J.A. Zubieta, Inorg. Chim. Acta 357 (2004) 3331–3335. [25] J.M. Shi, Z. Liu, Y.M. Sun, L. Yi, L.D. Liu, Chem. Phys. 325 (2006) 237–242. [26] P.P. Liu, Y.Q. Wang, C.Y. Tian, H.Q. Peng, E.Q. Gao, J. Mol. Struct. 920 (2009) 459–465. [27] J. Mrozin´ski, J. Kłak, R. Kruszyn´ski, Polyhedron 27 (2008) 1401–1407. [28] A. Karadag, V.T. Yilmaz, C. Thoene, Polyhedron 20 (2001) 635–641. [29] P. Sobczak, A. Barasin´ski, A. Drzewin´ski, G. Kamieniarz, J. Kłak, A. Bien´ko, J. Mrozin´ski, Polyhedron 28 (2009) 1838–1841. [30] M.D. Liptak, T.C. Brunold, J Am. Chem. Soc. 128 (2006) 9144–9156. [31] J.A. DuPont, G.P.A. Yap, C.G. Riordan, Inorg. Chem. 47 (2008) 10700–10707. [32] G.M. Sheldrick, SHELXL-97 and SHELXS-97, Program for X-ray Crystal Structure Solution and Refinement, University of Göttingen, 1997. [33] D.Y. Chen, H. Gao, X.F. Hu, X.Y. Guo, F. Yang, Y. Bai, Synth. React. Inorg. Met.Org. Nano-Met. Chem. 40 (2010) 112–115. [34] L. Yang, D.R. Powell, R.P. Houser, J. Chem. Soc., Dalton Trans. (2007) 955–964. [35] S.E.H. Etaiw, D.M.A. El-Aziz, M.S. Ibrahim, A.S.B. El-din, Polyhedron 28 (2009) 1001–1009.
Contents lists available at ScienceDirect
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy journal homepage: www.elsevier.com/locate/saa
A novel cobalt (I) coordination polymer with mixed thiocyanate and quinoline ligands: Crystal structure, magnetism and luminescent properties Lei Li, Shuai Chen, Rui-Min Zhou, Yan Bai ⇑, Dong-Bin Dang ⇑ Institute of Molecular and Crystal Engineering, School of Chemistry and Chemical Engineering, Henan University, Kaifeng 475004, PR China
h i g h l i g h t s
g r a p h i c a l a b s t r a c t
Synthesized a new Co(I) 1D
coordination polymer. Crystal structure analyses and
discussion for the compound. The luminescent properties and
magnetic properties were investigated.
a r t i c l e
i n f o
Article history: Received 26 August 2013 Received in revised form 2 October 2013 Accepted 9 October 2013 Available online 19 October 2013 Keywords: Co(I) Thiocyanato bridged Crystal structure Luminescent properties Magnetic properties
a b s t r a c t A new Co(I) one-dimensional coordination polymer [Co(SCN)(ql)]n (ql = quinoline) (1) has been synthesized and characterized by IR, elemental analysis, TG technique and X-ray crystallography. Co(I) atom has a distorted trigonal pyramidal N2S2 (1) environment with two S atoms and one N atom from three l-1,1,3-thiocyanate bridge ligands and one N atom from ql ligand. Two S atoms from two l-1,1,3-SCN bridging ligands bridge two centers to obtain bimetallic 4-membered ring. Adjacent 4-membered rings are linked by a pair of l-1,1,3-SCN bridging ligands to form a 1D stair-case like chain. The luminescent properties and magnetic properties of the polymer 1 were investigated in the solid state. Ó 2013 Elsevier B.V. All rights reserved.
Introduction The design and construction of the coordination polymeric multifunctional materials have attracted great interest in coordination chemistry and material science due to not only the varieties of topologies and intriguing frameworks, but also their interesting electric, magnetic, catalytic and optical properties [1–7]. The most ⇑ Corresponding authors. Tel./fax: +86 378 3881589. E-mail addresses: [email protected] (Y. Bai), [email protected] (D.-B. Dang). 1386-1425/$ - see front matter Ó 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.saa.2013.10.051
intriguing feature of multifunctional materials is that the synergy between different functionalities provides new opportunity and possibility in finding interesting physical properties and developing new materials. Among them, luminescent and magnetic dual functional coordination polymers have been one kind of important functional materials in recent years. However, the synthesis of this type of dual functional coordination polymers is still rare and lacking due to the diversity of coordination and the complicated natures of luminescent and magnetic behaviors [8–12]. As a part of our continuing investigations on thiocyanato bridged Cd(II)-containing coordination polymers and their
402
L. Li et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 120 (2014) 401–404
photoluminescent properties [13–20], herein we chose paramagnetic cobalt center and thiocyanate ligand with multiform coordination bridging configuration to assemble luminescent and magnetic dual functional coordination polymers. Using this strategy to synthesize dual functional coordination polymer with intriguing structure and interesting physical properties is doable given the following considerations: (i) The linear triatomic pseudohalide, SCN, is one of the best bridging ligands with an ambidentate ability, which may link two or three metal centers through 1,1-l-SCN, 1,3-l-SCN or l-1,1,3-SCN bridging modes to lead one dimensional chains, two dimensional layers, and three dimensional networks [21–25]. (ii) The thiocyanate group is a good electron supplier and the electron transfer from SCN to metal ion. (iii) The thiocyanate ligand may act as an efficient mediator for the magnetic interaction between the paramagnetic metal ion centers [26–29]. Furthermore, there are only a few literature citations reported on the Co(I) complexes [30,31]. In this present, we report the synthesis and crystal structure of one novel cobalt(I) onedimensional coordination polymer [Co(SCN)(ql)]n (ql = quinoline) (1) displaying strong luminescent emission at room temperature, in which contains the bridging mode of l-1,1,3-SCN. The magnetic properties of polymer 1 have been investigated. Experimental Physical measurements Elemental analyses (C, H and N) were carried out on a PerkinElmer 240C analytical instrument. IR spectra were recorded in KBr pellets with a Nicolet 170 S spectrophotometer in the 4000– 400 cm1 region. The luminescent spectra were performed on a XFT-IR Hitachi F-7000 fluorescence spectrophotometer. The thermo gravimetric analysis was carried out under nitrogen condition on a Perkin–Elmer-7 thermal analyzer at a heating rate of 10 °C/min from 25 to 1000 °C. Magnetic susceptibility data on crushed single crystals were collected over the temperature range 2–300 K using a Quantum Design MPMS-5S super-conducting quantum interference device (SQUID) magnetometer, and the experimental data were corrected for diamagnetism of the constituent atoms estimated from Pascal’s constants. Materials All the chemicals were reagent grade quality obtained from commercial sources and used without further purification. Preparation of the polymer 1 A 15 mL aqueous solution of Co(NO3)26H2O (0.087 g, 0.3 mmol) and KSCN (0.291 g, 3 mmol) were mixed. The obtained solution was slowly added to a 20 mL CH3CN solution of quinoline (0.130 g, 1 mmol). After stirring for 30 min, the resulting blue solution was filtered and left for slowly evaporating at room temperature to obtain blue block crystals suitable for single crystal X-ray structure determination. Yield: 71%. Anal. Calc. For C10H7CoN2S(%): C, 48.79; H, 2.87; N, 11.38. Found (%): C, 40.81; H, 2.85; N, 11.20. IR (KBr pellet, cm1): 2364(w), 2059(vs), 2048(vs), 1621(w), 1596(m), 1585(m), 1509(s), 1438(w), 1401(w), 1376(m), 1310(m), 1239(m), 1059(w), 1022w(m), 957(s), 843(w), 804(s), 778(s), 734(m), 637(m), 622(w), 530(w), 478(m), 467(w). Crystallographic data collection and refinement A suitable sample of size 0.14 mm 0.18 mm 0.22 mm for 1 was chosen for the crystallographic study and then mounted on
a BRUKER SMART APEX CCD diffractometer with x and u scan mode in the range of 1.91° < h < 25.25°. All diffraction measurements were performed at room temperature using graphite monochromatized Mo Ka radiation (k = 0.71073 Å). A total of 4067 (1736 independent, Rint = 0.025) reflections were measured. The structure was solved by direct methods and refined by full-matrix leastsquares on F2 using SHELXL 97 program [32]. All non-hydrogen atoms were refined anisotropically by full-matrix least-squares techniques and all hydrogen atoms were geometrically fixed to allow riding on the parent atoms to which they are attached. CCDC reference number: 847022 (1). Space group, lattice parameters and other relevant information are listed in Table 1. The relevant bond lengths and bond angles are listed in Table 2.
Results and discussion IR and UV spectra In the IR spectra of the coordination polymer 1, the strong absorption bands at 2059 and 2048 cm1 are assigned as the coordination of SCN anion with both N and S atoms. Its identity was finally confirmed by X-ray crystallography [13–15]. The UV spectra of the polymer 1 in H2O solution displays three absorption peaks at 208, 221 and 286 nm, respectively, which can be assigned as the p–p* and n–p* transition of quinoline [19,20,33].
Description of the crystal structure of polymer 1 The coordination polymer 1 crystallizes in the monoclinic space group C2/c. Single crystal X-ray diffraction analysis revealed that the structure of 1 exhibits a new crystalline 1D coordination polymer constructed through double l-1,1,3-SCN bridges between adjacent Co(I) centers [34]. An ORTEP diagram of the polymer 1 with the atomic numbering scheme and the coordination environment of Co(I) atom is depicted in Fig. 1. Each Co center is surrounded by two S atoms and one N atom from three l-1,1, 3-thiocyanate bridge ligands and one N atom from ql ligand. The value of the topological parameter s of ca. 0.78 indicates a distorted trigonal pyramidal geometry [35]. The average distances of CoAS and CoAN are 2.535 Å and 1.972 Å, respectively, and the bond angles around Co center range from 99.15° to 141.31°. The thiocyanate groups are almost linear with the SACAN bond angle of 178.9(4)°. The distances of SAC and CAN at 1.660(4) and
Table 1 Crystallographic data and structure refinement parameters for polymer 1. Crystal data
1
Chemical formula Formula weight Crystal system Space group a (Å) b (Å) c (Å) b (°) Volume (Å3) Z Dc (Mg m3) Crystal size (mm) Radiation (Å) Theta min–max (°) Tot., Uniq. Data, R(int) Observed data [I > 2.0 sigma(I)] Nref, Npar R, wR2, S Min. and max. resd. Dens. [e/Å3]
C10H7CoN2S 246.17 Monoclinic C2/c 26.148(5) 5.6860(11) 15.827(3) 125.196(3) 1923.0(6) 8 1.701 0.22 0.18 0.14 MoKa 0.71073 1.91–25.25 4067, 1736, 0.025 1401 1736, 127 0.0422, 0.1288, 1.002 0.878/0.457
403
L. Li et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 120 (2014) 401–404 Table 2 Selected bond distances (Å) and bond angles (°) for polymer 1. Bond length (Å) Co1AN1 Co1AS1b N1AC1
1.929(3) 2.5327(12) 1.162(4)
Co1AN2 Co1AS1c C1AS1
2.014(3) 2.5473(11) 1.660(4)
Bond length (°) N1ACo1AN2 N2ACo1AS1b N2ACo1AS1c N1AC1AS1
141.31(13) 99.64(9) 103.17(10) 178.9(4)
N1ACo1AS1b N1ACo1AS1c S1bACo1AS1c Co1aAS1cACo1
99.15(11) 102.28(10) 108.82(3) 71.18(3)
Symmetry codes, a x, 1y, z. b x, 1 + y, z. c x, y, z.
ligands bridge Co(1A) and Co(1B) centers to obtain bimetallic 8membered ring through S and N atom from each l-1,1,3-SCN anion with the CASACo angle of 95.46(13)° and the NACoAS angle of 102.28(10)°. These structure features are similar to those found in related polymer [(AgSCN)2tbpe] (tbpe = tran-1,2-bis(4-pyridyl)ethylene) [35]. Therefore, the polymer 1 represents the novel onedimensional stair-case like structure containing above two types of dinuclear metallocyclic rings Co2S2 and Co2(SCN)2 in which the minicycle Co2S2 subunit represents the steps (Fig. S1). This ladder-type chain exhibits average angle of 79° between adjacent subunits. Thermal analysis In order to study the thermal stability of the title complex, the thermal gravimetric analysis (TGA) measurements were carried out at the temperature range of 25–700 °C (Fig. S2). The TGA curve of 1 suggests that the first weight loss of 76.99% in the region of 110–560 °C corresponds to the expulsion of one thiocyanate and ql ligand (calculated 76.06%). The final residue after 700 °C should be Co elementray substance (found: 22.61%, calcd: 23.94%). Luminescence properties The solid state excitation and emission spectrum of coordination polymer 1 were investigated at room temperature. As shown in Fig. 2, the coordination polymer 1 shows the main emission peak at 415 nm and a shoulder emission at 435 nm using excitation wavelengths at 272 nm. Since the ql ligand shows a similar emission at 375 nm, the strong emission band of polymer 1 is obviously red-shifted of 40 nm and would be assigned to the intraligand p–p* transitions from the ql ligand [19,20,33].
Fig. 1. ORTEP drawing of the polymer 1 with the atom numbering scheme and the coordination geometry of Co. The atoms are represented by 30% probability thermal ellipsoids (symmetry codes: A: x, 1 y, z; B: x, 1 + y, z; C: x, y, z).
1.162(4) Å are in accordance with the values observed in other thiocyanato bridges metal complexes [13–25]. Each l-1,1,3-SCN bridging ligand links three Co centers Co(1), Co(1A) and Co(1B) with the distances of 2.96 Å for Co(1) Co(1A), 5.69 Å for Co(1) Co(1B) and 5.27 Å for Co(1A) Co(1B), respectively (Fig. 2). Two S atoms from two l-1,1,3-SCN bridging ligands bridge Co(1) and Co(1A) centers to obtain bimetallic 4-membered ring with the Co(1)ASACo(1A) angle of 71.18(3)° and the SACoAS angle of 108.82(3)°. Meanwhile, a pair of l-1,1,3-SCN bridging
Magnetic properties The magnetic properties of polymer 1 have been investigated at a field of 1 kOe in the temperature range 2–300 K. As illustrated in Fig. 3, the vmT value of 1 at room temperature is 1.27 emu mol1 K (vm is the molar magnetic susceptibility per Co(III) ions), which is slightly larger than the spin-only value of a Co(III)2 unit (1 emu mol1 K for S = 1 and g = 2). With decreasing temperature, the vmT value first decreases smoothly till reaching 1.15 emu mol1 K at 16 K, and then decreases rapidly below this temperature till reaching 0.73 emu mol1 K at 2 K. The v1 m versus T plot follows the Curie–Weiss law with C = 1.27 emu mol1 K and h = 2.38 K. The negative value of Weiss temperature indicates that the antiferromagnetic exchange coupling between Co(III) ions dominates the magnetic properties of the complex.
1.3
250
1.2
K −1
χmT / emu mol
50
0.8
0
0.7 0 Fig. 2. The emission spectrum (kex = 272 nm) and excitation spectrum (inset, kem = 415 nm) of polymer 1 in solid state at room temperature.
50
100
150
200
250
300
Fig. 3. Temperature variation of the magnetic susceptibility of 1.
−1
100
0.9
−1
150
1.0
χm / emu mol
200
1.1
404
L. Li et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 120 (2014) 401–404
Conclusion In summary, we presented a new one-dimension Co(I) coordination polymer [Co(SCN)(ql)]n (ql = quinoline) (1). The structure of the polymer 1 has been established by single-crystal X-ray diffraction analysis and also characterized by IR, elemental analysis, TG technique and luminescent properties. Adjacent Co(I) atoms interconnect with l-1,1,3-SCN bridging ligands to form one dimension stair-case like structure containing two types of dinuclear 4-membered and 8-membered metallocyclic rings. The fluorescence spectra of polymer 1 shows solid-state emission peaks at 415 nm and a shoulder emission at 435 nm. Acknowledgements This work was supported by the Natural Science Foundation of Henan Province of China, the Foundation for University Youth Key Teacher of Henan Province of China, the Foundation of Henan Educational Committee of China and the Foundation Co-established by the Province and the Ministry of Henan University. Appendix A. Supplementary material CCDC-847022 (1) contains the supplementary crystallographic data for this paper. These data can be obtained free of charge at http://www.ccdc.cam.ac.uk/conts/retrieving.html (or from the Cambridge Crystallographic Data Centre (CCDC), 12 Union Road, Cambridge CB2 1EZ, UK; fax: +44 (0)1223 336033; email: [email protected]). Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/ 10.1016/j.saa.2013.10.051. References [1] A. Gallego, C. Hermosa, O. Castillo, I. Berlanga, C.J. Go9 mez-García, E. MateoMartí, J.I. Martínez, F. Flores, C. Go9 mez-Navarro, J. Go9 mez-Herrero, S. Delgado, F. Zamora, Adv. Mater. 25 (2013) 2141–2146. [2] M. Clemente-Leon, E. Coronado, M. Lopez-Jorda, J.C. Waerenborgh, Inorg. Chem. 50 (2011) 9122–9130. [3] M. Cortijo, S. Herrero, R. Jiménez-Aparicio, E. Matesanz, Inorg. Chem. 52 (2013) 7087–7093. [4] P.Y. Wu, J. Wang, Y.M. Li, C. He, Z. Xie, C.Y. Duan, Adv. Funct. Mater. 21 (2011) 2788–2794.
[5] L. Yi, X.Y. Wang, J. Lumin. 131 (2011) 2083–2088. [6] A. Lee, S. Dubinsky, E. Tumarkin, M. Moulin, A.A. Beharry, E. Kumacheva, Adv. Funct. Mater. 21 (2011) 1959–1969. [7] F. Artizzu, P. Deplano, L. Pilla, A. Serpe, L. Marchio, K. Bernot, M.L. Mercuri, Inorg. Chim. Acta 370 (2011) 474–481. [8] X.L. Zhang, X. Jing, T. Liu, G. Han, H.Q. Li, C.Y. Duan, Inorg. Chem. 51 (2012) 2325–2331. [9] C.Y. Niu, Z.L. Pan, Y.L. Dang, C.L. Feng, C.H. Kou, J. Inorg. Organomet. Polym. 21 (2011) 611–618. [10] X.H. Yan, Y.F. Li, Q. Wang, X.G. Huang, Y. Zhang, C.J. Gao, W.S. Liu, Y. Tang, H.R. Zhang, Y.L. Shao, Cryst. Growth Des. 11 (2011) 4205–4212. [11] T.D. Pasatiu, C. Tiseanu, A.M. Madalan, B. Jurca, C. Duhayon, J.P. Sutter, M. Andruh, Inorg. Chem. 50 (2011) 5879–5889. [12] S.Y. Zhang, J.G. Mao, Inorg. Chem. 50 (2011) 4934–4943. [13] Y. Bai, W.L. Shang, D.B. Dang, J.D. Sun, H. Gao, Spectrochim. Acta, Part A, Mol. Biomol. Spectrosc. 72 (2009) 407–411. [14] D.B. Dang, W.L. Shang, Y. Bai, J.D. Sun, H. Gao, Inorg. Chim. Acta 362 (2009) 2391–2395. [15] Y. Bai, W.L. Shang, D.B. Dang, H. Gao, X.F. Niu, Y.F. Guan, Inorg. Chem. Commun. 11 (2008) 1470–1473. [16] D.B. Dang, J.D. Sun, Y. Bai, H. Gao, W.L. Shang, J Chem. Crystallogr. 39 (2009) 683–687. [17] Y. Bai, H. Gao, D.B. Dang, W.L. Shang, X.J. Pan, J. Mol. Struct. 934 (2009) 53–56. [18] Y. Bai, H. Gao, D.B. Dang, X.F. Hu, X.Y. Guo, Synth. React. Inorg. Met.-Org. NanoMet. Chem. 39 (2009) 512–515. [19] D.B. Dang, X.Y. Guo, Y. Bai, H. Gao, G.Q. Zhang, Synth. React. Inorg. Met.-Org. Nano-Met. Chem. 40 (2010) 195–199. [20] D.B. Dang, M.M. Li, Y. Bai, R.Q. Ning, Synth. React. Synthetic Metals 162 (2012) 2075–2080. [21] H.G. Zhu, M. Ströbele, Z. Yu, Z. Wang, H. Meyer, X.Z. You, Inorg. Chem. Commun. 4 (2001) 577–581. [22] L. Shen, X.W. Feng, Struct. Chem. 13 (2002) 437–441. [23] D.P. Martin, W.R. Knapp, R.M. Supkowski, R.L. LaDuca, Inorg. Chim. Acta 362 (2009) 1559–1564. [24] C. Merz, M. Desciak, C. O0 Brien, R.L. LaDuca, R.C. Finn, R.S. Rarig, J.A. Zubieta, Inorg. Chim. Acta 357 (2004) 3331–3335. [25] J.M. Shi, Z. Liu, Y.M. Sun, L. Yi, L.D. Liu, Chem. Phys. 325 (2006) 237–242. [26] P.P. Liu, Y.Q. Wang, C.Y. Tian, H.Q. Peng, E.Q. Gao, J. Mol. Struct. 920 (2009) 459–465. [27] J. Mrozin´ski, J. Kłak, R. Kruszyn´ski, Polyhedron 27 (2008) 1401–1407. [28] A. Karadag, V.T. Yilmaz, C. Thoene, Polyhedron 20 (2001) 635–641. [29] P. Sobczak, A. Barasin´ski, A. Drzewin´ski, G. Kamieniarz, J. Kłak, A. Bien´ko, J. Mrozin´ski, Polyhedron 28 (2009) 1838–1841. [30] M.D. Liptak, T.C. Brunold, J Am. Chem. Soc. 128 (2006) 9144–9156. [31] J.A. DuPont, G.P.A. Yap, C.G. Riordan, Inorg. Chem. 47 (2008) 10700–10707. [32] G.M. Sheldrick, SHELXL-97 and SHELXS-97, Program for X-ray Crystal Structure Solution and Refinement, University of Göttingen, 1997. [33] D.Y. Chen, H. Gao, X.F. Hu, X.Y. Guo, F. Yang, Y. Bai, Synth. React. Inorg. Met.Org. Nano-Met. Chem. 40 (2010) 112–115. [34] L. Yang, D.R. Powell, R.P. Houser, J. Chem. Soc., Dalton Trans. (2007) 955–964. [35] S.E.H. Etaiw, D.M.A. El-Aziz, M.S. Ibrahim, A.S.B. El-din, Polyhedron 28 (2009) 1001–1009.
