CuI Cluster-Based Organic Frameworks with Unusual 4- and 5

Dec 9, 2010 - Compound 1 displays an unprecedented 4-connected network based on Cu4I4 and Cu6I6 clusters, respectively, as tetrahedral and pseudosquar...
1 downloads 10 Views 3MB Size
Download PDF
DOI: 10.1021/cg101321u

CuI Cluster-Based Organic Frameworks with Unusual 4- and 5-Connected Topologies

2011, Vol. 11 29–32

Ying Zhang,†,§ Xinwei He,†,‡ Jian Zhang,*,‡ and Pingyun Feng*,§ † The State Key Laboratory of Heavy Oil Processing, China University of Petroleum (Beijing), 102249 Beijing, China, ‡State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China, and § Department of Chemistry, University of California, Riverside, California 92521, United States

Received October 8, 2010; Revised Manuscript Received December 7, 2010

ABSTRACT: Reported here are two three-dimensional CuI cluster-based organic frameworks, (Cu4I4)2(Cu6I6)(DABCO)6 (1) and (Cu4I3)2(CN)2(DABCO)3 (2) (DABCO=1,4-diazabicyclo[2.2.2]octane) constructed from mixed CuI clusters and mixed linear ligands, respectively. Compound 1 displays an unprecedented 4-connected network based on Cu4I4 and Cu6I6 clusters, respectively, as tetrahedral and pseudosquare planar 4-connected nodes, while 2 displays a novel 5-connected BN-type network composed of 5-connected cationic Cu4I3þ clusters linked by mixed cyanide anion CN- and DABCO ligands. The CN- in 2 derives from the solvent CH3CN and adopts a rare μ4-bridging mode. 1 shows chiral symmetry and photoluminescence at 298 K. The mixed strategies prove to be a useful fool to enrich the synthetic chemistry and structural diversity of cluster organic frameworks.

*To whom correspondence should be addressed. E-mail: [email protected] (J.Z.).

analysis of compound 2 reveals the appearance of cyanide anion CN- acting as a linear linker. The solvent CH3CN is thus supposed to release CN- in the basic synthetic mixture under thermal conditions.8 Generally, solid KCN, NaCN, CuCN, and K3Fe(CN)6 are used as cyanide anion precursors.9 A single-crystal X-ray diffraction study performed on compound 1 reveals the formation of a 3-D 4-connected network which crystallizes in the chiral space group P6422. The structure of 1 is constructed from Cu4I4 and Cu6I6 clusters connected by DABCO ligands. The Cu4I4 cluster (Figure 1) is a typical cubane unit, wherein each Cu(I) cation connects three neighboring iodide anions and uses a coordination sphere pointing outward of the cube to bond a DABCO ligand. The bond distances of the Cu-I and Cu-N bonds are respectively 2.6494(8)-2.7772(8) A˚ and 2.0661(6)-2.0789(6) A˚, both within rational ranges. Each Cu4I4 cluster is tetrahedrally connected to two other Cu4I4 clusters and two Cu6I6 clusters through four DABCO linkers, serving as a tetrahedral 4-connected node. The DABCO linked Cu4I4 clusters form zigzag chains oriented along the c-axis direction. The Cu6I6 cluster (Figure 1) is composed of four tetrahedrally coordinated Cu atoms and two three-coordinated Cu atoms in a trigonal pyramidal geometry. The hexanuclear Cu6I6 cluster is rare in the CuI system, and until now only a few compounds with a Cu6I6 cluster have been reported.2g,3c,4a,5b Usually, the “hexagonal” prism-shaped Cu6I6 cluster is constructed by the combination of two six-membered Cu3I3 units through bonding between six iodine anions with six tetrahedrally coordinated copper(I) atoms. The Cu6I6 cluster reported here is an unusual example of the Cu6I6 “hexagonal” prismatic cluster with two Cu atoms in a trigonal pyramidal geometry. The other four Cu atoms are respectively coordinated to three iodide atoms and a nitrogen atom from DABCO, creating four points of connectivity to four Cu4I4 clusters. These four Cu atoms are approximately coplanar with Cu-Cu-Cu angles of 89.300(3)°, 89.287(3)°, 89.287(3)°, and 89.300(3)°, and thus, every Cu6I6 cluster acts as a pseudosquare planar 4-connected node. The 3-D framework of compound 1 (Figure 2) can be conceptually envisioned as being built up from the zigzag Cu4I4 cluster chains cross-linked by Cu6I6 clusters via DABCO bridges. First, the zigzag Cu4I4 cluster chains are parallelly arrayed along the b-axis direction to form a zigzag Cu4I4 cluster sheet. Second, two such zigzag sheets are arranged face to face and partly crosslinked by Cu6I6 clusters resulting in a zigzag double-layer Cu4I4

r 2010 American Chemical Society

Published on Web 12/09/2010

Organic-inorganic hybrid architectures have attracted contemporary interests because they promise both diverse structural chemistry and multifunctional properties due to the combination of the characteristics of the organic and inorganic components.1 To construct hybrid architectures, cuprous halides have been widely used as inorganic components owing to their structural diversity and interesting photochemical and photophysical properties.2-5 The cuprous halide skeletons generally exhibit rich structural motifs ranging from discrete oligomers2 to polymeric chains3 and two-dimensional layers.4 Among them, discrete neutral CunIn clusters such as Cu2I2 rhomboid dimers, Cu4I4 cubane tetramers, and Cu6I6 hexagonal prisms, are facile acting as secondary building units (SBUs) for constructing extended organic-inorganic hybrid architectures varying from one to three dimensions.2a-h,5 In these cuprous halide hybrid structures, the organic components acting as linkers are usually multidentate nitrogen-donor ligands focusing on polypyridine and polyazaheteroaromatic compounds including pyrazole, imidazole, triazole, tetrazole, and benzotriazole,6 and linear bidentate ligands such as cyanide7 and 1,4-diazabicyclo[2.2.2]octane (DABCO).5b-d However, most of these cuprous halide hybrid architectures are lowdimensional. A few three-dimensional (3-D) frameworks include one rare chiral triple-interpenetrated quartz net, constructed with tetrahedrally connected Cu4I4 cluster and flexible 1,3-bis-(4pyridyl)propane,5a and four photoluminescent copper halide frameworks composed of cuprous iodide clusters and DABCO linkers.5b-d We have been interested in constructing 3-D CuI cluster-based organic frameworks from diverse cuprous halide skeletons, and recently three photoluminescent cuprous halide frameworks have been successfully constructed from size-tunable CuI clusters.5e As an extension of our previous work, here we report two new hybrid cuprous iodide frameworks, (Cu4I4)2(Cu6I6)(DABCO)6 (1) and (Cu4I3)2(CN)2(DABCO)3 (2), obtained by adopting mixed-CuI cluster and mixed-linear ligand strategies, respectively. The crystallographic and structural refinement data for 1 and 2 are listed in the Supporting Information (Table S1). Compound 1 was prepared through the reaction of CuI and DABCO in the mixed water/ethylene glycol solvents, while compound 2 was synthesized in the mixed DMF/CH3CN solvent (see Supporting Information). Interestingly, a single-crystal X-ray diffraction

pubs.acs.org/crystal

30

Crystal Growth & Design, Vol. 11, No. 1, 2011

sheet (Figure 2a). Finally, these double-layer sheets interpenetrate with each other (Figure 2b) and are further cross-linked with each other by Cu6I6 clusters through DABCO linkers (Figure 2c) to form the 3-D framework of compound 1. This further crosslinking (see the gray lines in Figure 2c) generates two new types of layers in compound 1. The arrays of Cu6I6 and Cu4I4 clusters in the two types of layers are respectively shown in Figure 2d,e. Both types of arrays show the same pattern but different orientations. A view along the c-axis direction shown in Figure 2f shows that compound 1 has one-dimensional (1-D) honeycomb channels. If the Cu4I4 and Cu6I6 building blocks are assigned as nodes and the DABCO ligand as a linker, compound 1 has an unprecedented topology with a Schl€afli symbol of (4.105)2(42.104), which is still unknown in other 4-connected metal organic frameworks (Figure 2c,f). Remarkably, such a topological network is also a self-interpenetrating net.

Figure 1. The Cu4I4 (a) and Cu6I6 (b) clusters and their connectivity in compound 1.

Zhang et al. Four-connected topology is among the mostly investigated net topologies in crystal engineering because of the importance of the materials with four connectivity, which has been shown by the large-scale industrial applications of zeolites in catalysis, gas separation, etc.10 A large number of 4-connected organicinorganic hybrid frameworks have been constructed based on the nets with tetrahedral geometries such as diamond (66), SrAl2 (42638), quartz (6482), and zeolite related nets.11 Relatively rare are those 4-connected networks based solely upon square planar nodes, for instance, tetragonal CdSO4 (658), cubic NbO (6482), quartz dual (759), and lvt (4284), and those based upon square planar/tetrahedral mixed nodes such as pts, ptt, mog, and asv.12 Among them, the pts(4284) net with equal numbers of squareplanar and tetrahedral centers provides especially attractive targets because of its intrinsic simplicity and open channel structure. Networked materials with this net topology have been assembled by using tetrahedral centers such as Cu(I) ions, [M(CN)4]2- (M=Cd, Hg, Zn) moieties, 1,5,9,13-tetrathiacyclohexadecane, polyoxomolybdate cluster [Mo8O26]4-, and cadmium thiophenolate cluster [Cd8(SPh)12]4þ together with square-planar metal centers, such as [Pt(CN)4]2-, metalloporphyrins, tetranuclear copper-organonitrogen complex [Cu4(S-py2)4]4þ, as well as suitable organic molecules such as 1,2,4,5-tetra(4-pyridyl)-benzene, 7,7,8,8-tetracyano-p-quinodimethane (TCNQ), and 1,2,4,5tetracyanobenzene (TCNB).13 In the present study, the construction of compound 1 was based on versatile neutral cuprous iodide clusters, that is, Cu4I4 and Cu6I6, respectively, as tetrahedral and pseudosquare planar 4-connected nodes. The unique 4-connected network of 1, we believe, is a significant addition to existing 3D

Figure 2. The structure of compound 1: (a) a double-layer (black dot: Cu4I4 cluster; yellow dot: Cu6I6 cluster); (b) the interpenetrated doublelayers; (c) perspective view of the 3D net; (d) array of Cu4I4 and Cu6I6 clusters in one type of layer; (e) array of Cu4I4 and Cu6I6 clusters in the neighboring layer; (f) view of the 3D net along the c-axis direction.

Communication

Crystal Growth & Design, Vol. 11, No. 1, 2011

31

Figure 3. (a) The molecular structure of compound 2; (b) the 3D structure of 2.

organic-inorganic frameworks with mixed square planar/tetrahedral geometries. A single-crystal X-ray diffraction study performed on compound 2 reveals the formation of a 3-D 5-connected BN-type network, which is composed of Cu4I3þ clusters linked by mixed CN- and DABCO ligands (Figure 3). The Cu4I3þ cluster is composed of four tetrahedrally coordinated copper(I) atoms and three three-coordinated iodine anions (Figure 3a). The four tetrahedral copper(I) atoms can be divided into two types: three of them represent type I, each of which is coordinated to two iodide atoms, one nitrogen atom from DABCO and one-third nitrogen atom from a CN- group; the last one Cu atom represents type II, which is coordinated to three iodide atoms and one carbon atom from another CN- group. Overall, each Cu4I3þ cluster is coordinated to three DABCO molecules and two CNgroups, serving as a 5-connected node. These 5-connected Cu4I3þ clusters are first bridged by CN- linkers to form cuprous iodide chains along the c-axis direction, and then each cuprous iodide chain is cross-linked with three neighboring cuprous iodide chains through DABCO ligands to form the 3-D framework (Figure 3b). A view along the c-axis direction reveals that 2 possesses 1-D hexagonally arranged channels. The whole framework of 2 can be represented as the 5-connected bnn topology (short vertex symbol 4664) by reducing the Cu4I3þ clusters as the 5-connected nodes. Interestingly, the bidentate CN- ligand adopts a rare μ4bridging mode in compound 2; that is, the nitrogen atom is simultaneously coordinated to three type I Cu atoms from one Cu4I3þ cluster and the carbon atom is coordinated to one type II Cu atom from another Cu4I3þ cluster. The bond distances of the Cu-N, Cu-C, and triple C-N bonds are 2.1434(1) A˚, 1.9368(1) A˚ and 1.10961(1) A˚, respectively. For crystallographically characterized cyanocuprates, Cu(I)-C/N distances are found to range from 1.80 to 1.86 A˚ in nearly linear dicoordinated systems, increasing to 1.92-1.96 A˚ in three-coordinated complexes and further to 1.94-2.0 A˚ for four-coordinated cynocuprates.9b Here the seemingly unusually long bond distances of Cu-C/N can be reasonable when the four-coordination mode of cyanide ion is taken into consideration. The ν(CN) stretching vibration in FTIR spectrum is known to be sensitive to Cu-C/N bond lengths in Cu(I)-cyanide complexes and a correlation exists between ν(CN) and Cu(I)-C/N bond lengths; that is, ν(CN) decreases with increasing Cu-C/N bond length. So the FTIR spectrum of compound 2 was recorded (Figure 4) and the adsorption band corresponding to the CN- stretching vibration appeared at 2038 cm-1, which is much lower than the typical wavenumber 2080-2158 cm-1 for the μ2-bridging cyanide groups.9d For compound 2, the CN- group adopts a rare μ4-bridging mode, and the Cu-C/N bond lengths are as long as about 2.0 A˚, so it is reasonable that the ν(CN) stretching vibration is decreased

Figure 4. FTIR spectrum of compound 2.

dramatically. Notably, the μ4-bridging mode of cyanide group is very rare. As far as we know, only two examples are reported in the literature.14 For one example, the nitrogen atom of CN- is simultaneously coordinated to three potassium atoms and the carbon atom to one copper atom;14a for the other example, the nitrogen atom is simultaneously coordinated to three mercury atoms and the carbon atom to one iron atom.14b The powder X-ray diffraction pattern and the IR spectra of 1 are provided in the Supporting Information (Figures S1 and S2). Thermal analysis performed under nitrogen atmosphere from 30 to 1000 °C (Figure S3, Supporting Information) shows that compound 1 is stable up to ca. 230 °C. Similar to other Cu-I cluster compounds,5b-d compound 1 shows photoluminescence at room temperature in the solid state. The spectrum displays a single excitation peak with a maximum at 365 nm that leads to yellow emission at 585 nm (Figure S4, Supporting Information). The mechanism of the photoluminescence is expected to be similar to that of other Cu-I clusters.5b-d The emission band might be assigned to a combination of iodide-to-copper charge transfer (LMCT) and d-s transitions via Cu 3 3 3 Cu interaction. In summary, described here are two CuI cluster-based organic frameworks constructed from mixed CuI clusters and mixed linear ligands, respectively. The results clearly show that the mixed strategies can act as a useful tool to enrich structural characteristics of hybrid cuprous iodide frameworks, which has been exemplified by the unpredicted 4-connected topology, peculiar five-connected Cu4I3þ cationic cluster, and four-coordination mode of cyanide ion. Acknowledgment. We acknowledge the support of this work by the DOE (P.F.), 973 Program 2011CB932504 (J.Z.), Beijing Natural Science Foundation (Grant No. 2093043), and NSFC (21073191, 51072230).

32

Crystal Growth & Design, Vol. 11, No. 1, 2011

Zhang et al.

Supporting Information Available: Crystal structure information (CIF) and more experimental details and data (PDF). This material is available free of charge via the Internet at http://pubs.acs.org.

References (1) (a) Chujo, Y. Curr. Opin. Solid State Mater. Sci. 1996, 1, 806. (2) (a) Victoriano, L. I.; Garland, M. T.; Vega, A.; Lopez, C. Inorg. Chem. 1998, 37, 2060. (b) Victoriano, L. I.; Garland, M. T.; Vega, A.; Lopez, C. J. Chem. Soc., Dalton Trans. 1998, 1127. (c) Lobana, T. S.; Kaur, P.; Nishioka, T. Inorg. Chem. 2004, 43, 3766. (d) Araki, H.; Tsuge, K.; Sasaki, Y.; Ishizaka, S.; Kitamura, N. Inorg. Chem. 2005, 44, 9667. (e) Lobana, T. S.; Rekha; Butcher, R. J.; Castineiras, A.; Bermejo, E.; Bharatam, P. V. Inorg. Chem. 2006, 45, 1535. (f ) Angelis, F. D.; Fantacci, S.; Sgamellotti, A.; Cariati, E.; Ugo, R.; Ford, P. C. Inorg. Chem. 2006, 45, 10576. (g) Ohi, H.; Tachi, Y.; Kunimoto, T.; Itoh, S. Dalton Trans. 2005, 3146. (h) Chandrasekaran, P.; Mague, J. T.; Balakrishna, M. S. Inorg. Chem. 2006, 45, 6678. (i) Xue, X.; Wang, X. S.; Xiong, R. G.; You, X. Z.; Abrahams, B. F.; Che, C. M.; Ju, H. X. Angew. Chem., Int. Ed. 2002, 41, 2944. (3) (a) N€ ather, C.; Wriedt, M.; Jess, I. Inorg. Chem. 2003, 42, 2391. (b) Lobana, T. S.; Sharma, R.; Bermejo, E.; Castineiras, A. Inorg. Chem. 2003, 42, 7728. (c) Li, G.; Shi, Z.; Liu, X.; Dai, Z.; Feng, S. Inorg. Chem. 2004, 43, 6884. (d) Cariati, E.; Roberto, D.; Ugo, R.; Ford, P. C.; Galli, S.; Sironi, A. Inorg. Chem. 2005, 44, 4077. (e) Lobana, T. S.; Sharma, R.; Hundal, G.; Butcher, R. J. Inorg. Chem. 2006, 45, 9402. (4) (a) Wu, T.; Li, M.; Li, D.; Huang, X. C. Cryst. Growth Des. 2008, 8, 568. (b) Blake, A. J.; Brooks, N. R.; Champness, N. R.; Cooke, P. A.; Deveson, A. M.; Fenske, D.; Hubberstey, P.; Li, W.-S.; Schr€oder, M. J. Chem. Soc., Dalton Trans. 1999, 2103. (c) Cariati, E.; Ugo, R.; Cariati, F.; Roberto, D.; Masciocchi, N.; Galli, S.; Sironi, A. Adv. Mater. 2001, 13, 1665. (d) Wu, T.; Li, D.; Ng, S. W. CrystEngComm 2005, 7, 514. (5) (a) Hu, S.; Tong, M. L. Dalton Trans. 2005, 1165. (b) Bi, M. H.; Li, G. H.; Zou, Y. C.; Shi, Z.; Feng, S. H. Inorg. Chem. 2007, 46, 604. (c) Bi, M. H.; Li, G. H.; Hua, J.; Liu, Y. L.; Liu, X. M.; Hu, Y. W.; Shi, Z.; Feng, S. H. Cryst. Growth Des. 2007, 7, 2066. (d) Bi, M. H.; Li, G. H.; Hua, J.; Liu, X. M.; Hu, Y. W.; Shi, Z.; Feng, S. H. CrystEngComm 2007, 9, 984. (e) Zhang, Y.; Wu, T.; Liu, R.; Dou, T.; Bu, X. H.; Feng, P. Y. Cryst. Growth Des. 2010, 10, 2047. (f ) Zhai, Q. G.; Lu, C. Z.; Chen, S. M.; Xu, X. J.; Yang, W. B. Inorg. Chem. Commun. 2006, 9, 819. (g) Wang, X. L.; Qin, C.; Wang, E. B.; Su, Z. M.; Li, Y. G.; Xu, L. Angew. Chem., Int. Ed. 2006, 45, 7411. (6) (a) Haasnoot, J. G. Coord. Chem. Rev. 2000, 200-202, 131. (b) Beckmann, U.; Brooker, S. Coord. Chem. Rev. 2003, 245, 17. (c) Klingele, M. H.; Brooker, S. Coord. Chem. Rev. 2003, 241, 119.

(7)

(8) (9)

(10)

(11) (12) (13)

(14)

(d) Zhang, J. P.; Zhang, S. L.; Huang, X. C.; Chen, X. M. Angew. Chem., Int. Ed. 2004, 43, 206. (e) Zhang, J. P.; Lin, Y. Y.; Huang, X. C.; Chen, X. M. J. Am. Chem. Soc. 2005, 127, 5495. (f ) Zhou, J. H.; Cheng, R. M.; Song, Y.; Li, Y. Z.; Yu, Z.; Chen, X. T.; Xue, Z. L.; You, X. Z. Inorg. Chem. 2005, 44, 8011. (g) Zhang, J. P.; Chen, X. M. Chem. Commun. 2006, 1689. (h) Carlucci, L.; Ciani, G.; Gramaccioli, A.; Proserpio, D. M.; Rizzato, S. CrystEngComm 2000, 2, 154. (a) Rath, N. P.; Holt, E. M.; Tanimura, K. Inorg. Chem. 1985, 24, 3934. (b) Healy, P. C.; Kildea, J. D.; White, A. H. J. Chem. Soc., Dalton Trans. 1988, 1637. (c) Domasevitch, K. V.; Rusanova, J. A.; Vassilyeva, O. Y.; Kokozay, V. N.; Squattrito, P. J.; Sieler, J.; Raithby, P. R. J. Chem. Soc., Dalton Trans. 1999, 3087. (d) Lobana, T. S.; Mahajan, P.; Pannu, A. S.; Hundal, G.; Butcher, R. J. J. Coord. Chem. 2007, 60, 733. (e) Vogel, U.; Nixon, J. F.; Scheer, M. Chem. Commun. 2007, 5055. (f ) Liu, X.; Guo, G. C. Cryst. Growth Des. 2008, 8, 776. (a) Li, D.; Wu, T.; Zhou, X.-P.; Zhou, R.; Huang, X.-C. Angew. Chem., Int. Ed. 2005, 44, 4175. (b) Zhang, X.; Fang, R.; Wu, H. J. Am. Chem. Soc. 2005, 127, 7670. (a) Lin, J.; Li, Z.; Li, T.; Li, J.; Du, S. Inorg. Chem. Commun. 2006, 9, 675. (b) Colacio, E.; Kivek€as, R.; Lloret, F.; Sunberg, M.; SuarezVarela, J.; Bardají, M.; Laguna, A. Inorg. Chem. 2002, 41, 5141. (c) Park, K.; Lee, S.; Kang, Y.; Moon, S.; Lee, S. Dalton Trans. 2008, 6521. (d) He, X.; Lu, C.; Wu, C.; Chen, L. Eur. J. Inorg. Chem. 2006, 2491. (e) Liu, X.; Guo, G. Aust. J. Chem. 2008, 61, 481. Flanigen, E. M. In Introduction to Zeolite Science and Practice; Bekkum, H., Flanigen, E. M., Jansen, J. C., Eds.; Elsevier, New York, 1991; pp 13-34. Wells, A. F. In Three-Dimensional Nets and Polyhedra; John Wiley & Sons: New York, 1977. Ockwig, N. W.; Delgado-Friedrichs, O.; O’Keeffe, M.; Yaghi, O. M. Acc. Chem. Res. 2005, 38, 176. (a) Heintz, R. A.; Zhao, H.; Ouyang, X.; Grandinetti, G.; Cowen, J.; Dunbar, K. R. Inorg. Chem. 1999, 38, 144. (b) Brooks, N. R.; Blake, A. J.; Champness, N. R.; Cooke, P. A.; Hubberstey, P.; Proserpio, D. M.; Wilson, C.; Schr€oder, M. J. Chem. Soc., Dalton Trans. 2001, 456. (c) Soma, T.; Yuge, H.; Iwamoto, T. Angew. Chem., Int. Ed. 1994, 33, 1665. (d) Carlucci, L.; Ciani, G.; Gudenberg, D. W. V.; Proserpio, D. M. New J. Chem. 1999, 23, 397. (e) Gable, R. W.; Hoskins, B. F.; Robson, R. J . Chem. Soc., Chem. Commun. . 1990, 762. (f ) Munakata, M.; Ning, G. L.; Kuroda-Sowa, T.; Maekawa, M.; Suenaga, Y.; Horino, T. Inorg. Chem. 1998, 37, 5651. (g) Zheng, N.; Bu, X.; Feng, P. J. Am. Chem. Soc. 2002, 124, 9688. (a) Eaborn, C.; Hill, M. S.; Hitchcock, P. B.; Smith, J. D. Organometallics 2000, 19, 5780. (b) Tikhonova, I. A.; Dolgushin, F. M.; Tugashov, K. I.; Ellert, O. G.; Novotortsev, V. M.; Furin, G. G.; Antipin, M. Y.; Shur, V. B. J. Organomet. Chem. 2004, 689, 82.