ARTICLE pubs.acs.org/crystal
External Template-Assisted Self-Assembly:Design and Synthesis of 4,40 -bipy-Based Mo(W)/Cu/S Heterothiometallic Polymeric Clusters Directed by 1,10-Bis(pyridinium)methylene Cation Yi Han, Zhenhua Zhang, Yanyan Liu, Yunyin Niu,* Degang Ding, Benlai Wu, Hongwei Hou,* and Yaoting Fan Department of Chemistry, Zhengzhou University, Henan 450052, People's Republic of China
bS Supporting Information ABSTRACT: Organic cation-templated self-assembly of 4,40 -bipy (4,40 -bipy = bpy) with [NH4]2MS2O2 (M = Mo, W) and CuX (X = Cl, NCS) in the present of 1,1-bis(pyridinium)methylene [bpm = 1, 10 -bis(pyridinium)methylene] resulted in four novel neutral heterothiometallic cluster polymers based on tetranuclear [Mo/WOS3Cu3] unit: [MOS3Cu3Cl(μ-bpy)2 3 Sol]n (M = Mo, Sol = 1.3DMF 3 5.5H2O 1; M = W, Sol = 1.5DMF 3 8.2H2O 2), [MoOS3Cu3(NCS)(bpy)(μbpy)2 3 DMF]n (3), and [WOS3Cu3(NCS)(μ-bpy)2.5 3 3DMF]n (4). Polymer 1 or 2 crystallizes in the Fddd space group with a 2-fold interpenetrating (10,3)-b net, which presents a 3-connected 3D heterothiometallic polymer assembled with bidentate organic bridging ligands. Polymer 3 crystallizes in the space group P1 with a 2D noninterpenetrating network with (6,3) topology in which [MoOS3Cu3(bpy)] units are interconnected via three single or double Cu-μ-bpy-Cu bridges. Polymer 4 crystallizes in the space group C2/c with a (64 82) net, which displays the first self-interpenetrating network in heterothiometallic chemistry. All of these results confirm the ideal template effect and correct choice of bpm.
’ INTRODUCTION In the past decades, Mo(W)/Cu/S clusters have received a great deal of attention not only for the integrity during the synthesis and the resulting assembled network1 but also for their comprehensive applications in biological systems and material science.2 To date, many intriguing 3D heterothiometallic cluster polymers have been reported.3 The {[WS4Cu4(4,40 -bpy)4][WS4Cu4I4(4,40 -bpy)2]}n coordination polymer,3a,b which is the first example of containing interpenetrating cationic and anionic 3D diamondoid cluster coordination polymer, enriches the structural characterization in coordination chemistry; the 8-connected 3D [MoS4Cu4(bpp)2(CN)2] 3 1.5(aniline) polymer3c [bpp = bis(4-pyridyl)propane] contains the highest-connected nodes in heterothiometallic chemistry; two coordination polymers of {[(MoOS3Cu3)2(NCS)(μ-NCS)(4,40 -bipy)4.5] 3 7 (aniline)}n3d and [WS4Cu6I4(timtz)8/3(H2O)12]n3e [timtz = (2, 4, 6-tri(1H-imidazol-1-yl)-1,3,5-triazine)] were obtained, which feature (4,5)-connected and (3,4)-connected 3D frameworks, respectively, and the coexistence of such mixed connecting nodes in one structure is unprecedented in the cluster-based supramolecular chemistry. Among the 3D heterothiometallic cluster polymers,3 we found all of them are highly connected noninterpenetrating or mutual interpenetrating structures. However, only one low connected (3-connected) 3D network is involved,3f and no self-interpenetrating examples have been r 2011 American Chemical Society
Scheme 1
reported. This may be due to the fact that Mo(W)/Cu/S units have more coordination Cu atoms or bridging organic ligands are generally sufficiently long, which makes such cluster polymers have the necessary space to interpenetrate. The most widespread approach for the preparation of heterothiometallic cluster polymers is the reaction of certain cluster precursors with various multitopic ligands in common organic solvents or induced by smaller NH4+, [NEt4]+, [NMe4]+, or [PPh4]+.3 Is it possible to obtain desired novel crystal architectures by introducing larger organic cations as the templates to the construction of Mo(W)/Cu/S clusters? Recently, we found that the bpm dication (Scheme 1) possesses the ideal size and flexibility for structure-directing and construction of the Received: February 25, 2011 Revised: May 21, 2011 Published: June 08, 2011 3448
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Table 1. Crystal Data and Structure Refinement Details for 14 1
a
2
3
4
formula
C20H16N4OCl S3Cu3Mo
C20H16N4OClS3Cu3W
C34H31N8O2S4Cu3Mo
C35H41N9O4S4Cu3W
Fw
746.56
834.47
998.47
1154.48
temperature (K)
293(2)
296(2)
296(2)
296(2)
crystal system
orthorhombic
orthorhombic
triclinic
monoclinic
space group
Fddd
Fddd
P1
C2/c
a (Å)
25.585(15)
25.569(4)
9.783(11)
40.669(3)
b (Å)
29.620(18)
29.638(4)
11.321(9)
9.7097(7)
c (Å) R (deg)
58.413(4) 90.00
58.594(9) 90.00
23.143(19) 72.595(14)
24.7394(19) 90.00
β (deg)
90.00
90.00
78.897(14)
105.0230(10)
γ (deg)
90.00
90.00
87.935(14)
90.00
V (Å3)
44267(5)
44404(11)
2550(5)
9435.4(12)
Z
32
32
2
8
Dc (mg m3)
0.896
0.999
1.300
1.625
μ (mm1)
1.530
3.370
1.670
3.985
F (000) rflns collected
11712 86138
12736 82768
1000 29007
4568 34958
unique rflns
10882
10347
19330
7492
R(int)
0.0555
0.0614
0.0433
0.0327
GOF on F2
1.016
1.011
0.958
1.009
R1a (I > 2σI)
0.0530
0.0526
0.0547
0.0358
wR2a
0.1116
0.0945
0.1002
0.0473
R1 = ||Fo| |Fc||/|Fo|. wR2 = [w(|Fo2| |Fc2|)2/w|Fo2|2]1/2.
organicinorganic hybrid polymers,4 so in this contribution, we select bpm as a high efficient template and successfully synthesized four novel [Mo/WOS3Cu3]-based polymers [MOS3Cu3Cl(μ-bpy)2 3 Sol ]n [M = Mo, Sol = 1.3DMF 3 5.5H2O (1); M = W, Sol = 1.5DMF 3 8.2H2O) (2)], [MoOS3Cu3(NCS)(bpy)(μ-bpy)2 3 DMF]n (3), and [WOS3Cu3(NCS)(μ-bpy)2.5 3 3DMF]n (4). Fortunately, both 1 and 2 present 3-connected 3D 2-fold interpenetrating frameworks with (10,3)-b net, 3 features a 2D noninterpenetrating network with (6,3) topology, and 4 displays with a 3D self- interpenetrating (64 82) network; all of these results confirm the ideal template effect and correct choice of bpm.
’ EXPERIMENTAL SECTION Materials and Methods. The compounds [NH4]2MS2O25a (M = Mo, W) and the dications 1,1-bis(pyridinium)alkanes5b were prepared as described in the literature. Other chemicals were obtained from commercial sources and used as received without further purification. Infrared spectra were recorded on a Shimadzu IR435 spectrometer as KBr disk (4000 400 cm1). Elemental analyses (C, H, and N) were carried out on a FLASH EA 1112 elemental analyzer. Thermal analyses were performed on a Netzsch STA 449C thermal analyzer from 30 to 600 °C at a heating rate of 10 °C min1 in air. Powder X-ray diffraction (XRD) patterns were recorded using Cu KR1 radiation on a PAN alytical X'Pert PRO diffractometer. The UVvis spectra were measured on a Lambda 35 UVvisible spectrophotometer. Synthesis of [MoOS3Cu3Cl(μ-bpy)2 3 1.3DMF 3 5.5H2O]n (1).
A mixture of [NH4]2MoS2O2 (0.114 g, 0.5 mmol), 4,40 -bipy (0.078 g, 0.5 mmol), bpm 3 Cl2 (0.243 g, 1 mmol), and CuCl (0.149 g, 1.5 mmol) in DMF was stirring at room temperature for 9 h in the air. The final reaction solution was filtered and left to stand in darkness. Several days later, dark red crystals were obtained. Yield: 0.0536 g (47% based on Mo). Anal. calcd (%) for C23.9H36.1N5.3O7.8ClS3Cu3Mo: C, 30.49; H, 3.84; N, 7.89. Found: C, 30.61; H, 3.76; N, 7.93. IR (KBr, cm1): 3454
(w), 3050 (w), 1662 (s), 1601 (s), 1530 (m), 1485 (s), 1410 (s), 1066 (m), 908 (s), 808 (s), 629 (m), 571 (w), 487 (w), 442 cm (s).
Synthesis of [WOS3Cu3Cl(μ-bpy)2 3 1.5DMF 3 8.2H2O]n (2).
Red crystals were obtained under conditions similar to those for 1 only with [NH4]2WS2O2 (0.158 g, 0.5 mmol) instead of [NH4]2MoS2O2. Yield: 0.0553 g (35% based on W). Anal. calcd (%) for C24.5H42.9N5.5O10.7ClS3Cu3W: C, 26.93; H, 3.93; N, 7.05. Found: C, 27.08; H, 3.86; N, 7.12. IR (KBr, cm1): 3440 (w), 3051 (w), 2924 (w), 1665 (s), 1601 (s), 1531 (w), 1486 (m), 1410 (s), 1217 (m), 1094 (mw), 1067 (m), 920 (s), 810 (s), 630 (m), 428 (s).
Synthesis of [MoOS3Cu3(NCS)(bpy)(μ-bpy)2 3 DMF]n (3).
Dark red crystals were obtained under conditions similar to those for 1 only with CuSCN (0.182 g, 1.5 mmol) instead of CuCl. Yield: 0.0433 g (38% based on Mo). Anal. calcd (%) for C34H31N8O2S4Cu3Mo: C, 40.86; H, 3.10; N, 11.22. Found: C, 40.93; H, 3.14; N, 11.14. IR (KBr, cm1): 3439 (w), 3046 (w), 2085 (m), 1667(s), 1601 (s), 1410(s), 1213 (w), 906 (m), 806 (s), 626 (w), 435 (w). Synthesis of [WOS3Cu3(NCS)(μ-bpy)2.5 3 3DMF]n (4). Yellow crystals were obtained under conditions similar to those for 2 only with [NH4]2WS2O2 (0.158 g, 0.5 mmol) instead of [NH4]2MoS2O2. Yield: 0.0679 g (43% based on Mo). Anal. calcd (%) for C35H41N9O4S4Cu3W: C, 36.41; H, 3.55; N, 10.92. Found: C, 36.49; H, 3.59; N, 10.88. IR (KBr, cm1): 3438 (w), 3124 (w), 3054 (s), 1659 (s), 1632 (m), 1603 (s), 1531 (w), 1486 (s), 1409 (s), 1217 (m), 1097 (w), 1067 (w), 908 (s), 807 (s), 681 (m), 442 (m). Crystal Structure Analyses. The intensity data sets for compounds 14 were collected on a Bruker SMART CCD diffractometer with graphite-monochromated Mo KR radiation (λ = 0.71073 Å) at 293 K. Absorption corrections were applied by using SADABS. The structures were solved by direct methods with the SHELXS-97 program.6 All of the nonhydrogen atoms were refined anisotropically. The hydrogen atoms were assigned with common isotropic displacement factors and included in the final refinement by using geometrical restrains. Crystal data for 14 are summarized in detail in Table 1. Selected bond lengths are put in Table 2. 3449
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Table 2. Selected Bond Distances (Å) for 14
Scheme 2. Schematic Showing Novel 3-Connected or SelfPenetrating Crystal Architectures Based on Mo(W)/Cu/S Clusters Directed by bpm Cationa
compound 1 Cu(2)N(4)
2.015(9)
Cu(2)N(3)
2.088(9)
Cu(2)S(1)
2.270(3)
Cu(2)S(2)
2.272(3) 1.705(6)
Cu(2)Mo(1)
2.6679(15)
Mo(1)O(1)
Mo(1)S(3)
2.258(4)
Mo(1)S(2)
2.258(3)
Mo(1)S(1) Mo(1)Cu(3)
2.260(3) 2.6671(15)
Mo(1)Cu(1) Cu(3)N(2)
2.6511(19) 2.038(9)
Cu(3)N(1)
2.092(8)
Cu(3)S(2)
2.268(3)
Cu(3)S(3)
2.268(4)
S(1)Cu(1)
2.253(3)
S(3)Cu(1)
2.242(3)
Cu(1)Cl(1)
2.261(4)
W(1)O(1)
1.720(9)
W(1)S(1)
2.239(5)
W(1)S(2)
2.248(4)
W(1)S(3)
2.254(4)
compound 2
W(1)Cu(2)
2.660(2)
W(1)Cu(1)
2.6808(18)
W(1)Cu(3) Cu(1)N(4)
2.6818(18) 2.090(10)
Cu(1)N(2) Cu(1)S(2)
2.018(11) 2.272(5)
Cu(1)S(1)
2.283(5)
Cu(2)S(3)
2.256(5)
Cu(2)S(1)
2.265(5)
Cu(2)Cl(1)
2.303(5)
Cu(3)N(3)
2.015(13)
Cu(3)N(1)
2.081(11)
Cu(3)S(3)
2.290(4)
Cu(3)S(2)
2.290(4)
N(2)Cu(1)
2.018(11)
Cu(3)N(3) Mo(1)O(1)
2.152(5) 1.706(4)
Cu(1)N(5) Mo(1)S(2)
Mo(1)S(1)
2.272(2)
Mo(1)S(3)
2.274(2)
Mo(1)Cu(3)
2.684(3)
Mo(1)Cu(1)
2.692(3)
compound 3 2.108(5) 2.271(2)
Mo(1)Cu(2)
2.694(3)
Cu(3)N(4)
2.016(5)
Cu(3)S(1)
2.275(2)
Cu(3)S(2)
2.291(2)
Cu(1)N(1)
2.044(5)
Cu(1)N(5)
2.108(5)
Cu(1)S(3)
2.276(2)
Cu(1)S(1)
2.277(2)
Cu(2)N(7) Cu(2)S(3)
1.973(6) 2.285(3)
Cu(2)N(2) Cu(2)S(2)
2.175(6) 2.297(3)
W(1)O(1)
1.723(4)
W(1)S(1)
2.2559(16)
W(1)S(2)
2.2661(14)
W(1)S(3)
2.2572(14)
compound 4
W(1)Cu(2)
2.7011(7)
W(1)Cu(1)
2.7114(8)
W(1)Cu(3)
2.6848(7)
Cu(1)N(1)
1.976(6)
Cu(1)N(2)
2.114(5)
Cu(1)S(3)
2.2936(17)
Cu(1)S(1)
2.3158(16)
Cu(2)N(5)
2.036(4)
Cu(2)N(4) Cu(2)S(1)
2.078(4) 2.3065(16)
Cu(2)S(2) Cu(3)N(3)
2.3034(17) 2.047(5)
Cu(3)N(6)
2.091(5)
Cu(3)S(2)
2.2837(15)
Cu(3)S(3)
2.3005(16)
N(3)Cu(3)
2.047(5)
N(6)Cu(3)
2.091(5)
’ RESULTS AND DISCUSSION Synthesis. In this work, we are devoted to obtaining lowconnected 3D and self-interpenetrating structures directed by bpm depending on the distinctive [NH4]2MS2O2 (M = Mo, W), copper(I) sources, and 4,40 -bipy linkers (Scheme 2). Because the [Mo/WOS3Cu3] unit has less coordination Cu atoms and larger halogen atoms possess strong steric hindrance to reduce the connectivity of the tetranuclear cores, we decided to introduce MOS32 (M = Mo, W) and CuCl into the assembly
a
Black balls, Mo(W)/Cu/S clusters; colorful sticks, 4,40 -bipy lgands.
to obtain low-connected 3D structure. In fact, heterothiometallic [Mo/WOS3Cu3]-based polymeric clusters could be formed directly from the reaction of (MOS3)2, copper salts, and the template.3g,7 However, as compared to the preparation of (NH4)2MOS3, the starting reagent (NH4)2MS2O2 exhibited in higher yield, stability, and simpler synthetic procedure.5a In addition, according to the previous works, in the assembly process, [MS2O2]2 could be transformed to [MS3O]2.3e,h,j,8 Advisedly, we chose (NH4)2(MS2O2) (M = Mo, W) instead of (NH4)2(MS3O) as the starting reagents for the assembly of title heterothiometallic [Mo/WOS3Cu3]-based polymers. Polymer 1 was obtained by the treatment of bpm with [NH4]2MoS2O2 and CuCl in the presence of bpy, and under the same conditions, just using [NH4]2WS2O2 instead of [NH4]2MoS2O2, polymer 2 was obtained. Fortunately, both 1 and 2 are isomorphous 3D polymers with a 3-connected 2-fold interpenetrating network. In 1 or 2, the coordination environment of three Cu atoms is different: Two Cu atoms are coordinated by N atoms from two bridging bpy ligands, whereas another Cu atom is only coordinated by one terminal Cl atom. Remarkably, the free void volume estimated by PLATON9 is 60.6 (in 1) and 61.7% (in 2) of the total volume, which are filled with disorder DMF and H2O solvent molecules. From XRD results of 1 and 2, we concluded that the smaller size of the voids containing less solvent molecules in 1 may cause it remaining intact upon loss of solvent from the channels. If we wish to further obtain self-interpenetrating structures, it is necessary to increase the connection of the tetranuclear cores and try to reduce the inner space of the polymer to overcome mutual interpenetration. When we used CuSCN as the replacement reagent, the reactions similar to the preparations of 1 and 2 gave two different types of polymers, namely, polymer 3 and 4, respectively. Compound 3 features a 2D noninterpenetrating network. Surprisingly, 4 displays a 3D self-interpenetrating framework. XRD results display that 3 but not 4 remains intact upon loss of solvent from the channels. Furthermore, to prove that single crystal XRD structure is representative of the isolated crystalline sample, characteristic d-spacings (experimental and calculated) of each phase are presented. Agreement is observed for the strongest reflections at d-spacings of 1 and 3 but not in 2 3450
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Figure 1. (a) Asymmetric unit of 1. (b) Perspective view of the 3D network in 1 along the bc plane. Color code: Mo, teal; S, yellow; Cu, bright blue; Cl, bright green; N, blue; O, red; and C, gray. (c) Infinite zigzag chains along the ab plane. (d) Perspective view of the extension of each adjacent [MoOS3Cu3Cl] clusters of zigzag chains in the ab plane in the opposite direction along the c-axis. Zigzag chains and 4,40 -bipy ligands are highlighted in pink and violet, respectively. (e) Perspective view of the 10-membered ring along the b-axis. All hydrogen atoms are omitted for clarity. (f) Schematic view of the 2-fold interpenetration network. Each node and rod represents a cluster fragment [MoOS3Cu3Cl] and 4,40 -bipy ligand, respectively.
and 4. The results of 1 and 3 ensure that the single crystal studied was representative of the bulk materials (Table S1 in the Supporting Information). It is noticed that the bpm counterions do not exist in all compounds 14. In case the reaction was conducted in the absence of bpm, no desirable crystals were obtained. So, the presence of bpm in reaction system is crucial to the assembly, although it left the products at last. A template is described as temporary or external if it is not incorporated into the end product.10 However, the reported external template had to encounter an
elimination process such as pyrolysis or hydrolysis.11 From this point of view, the bpm used here is a real external template without elimination workup procedure. Crystal Structures of 1 and 2. Polymers 1 and 2 have a common chemical formula [MOS3Cu3Cl(μ-bpy)2]n (1, M = Mo; 2, M = W), and their cell parameters are essentially identical, as are their structures. Therefore, only the structure of 1 is shown in Figure 1. X-ray single-crystal structure determination reveals that 1 is a novel 3D structure that crystallizes in the Fddd space group. The asymmetric unit of 1 is composed of the nest-shaped 3451
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Figure 2. (a) Asymmetric unit of 3. (b) Perspective view along the ab plane of the 2D network in [MoOS3Cu3(NCS)(bpy)(μ-bpy)2]∞, showing the cavities. All hydrogen atoms and DMF solvated molecules are omitted for clarity. Color code: Mo, teal; S, yellow; Cu, bright blue; Cl, bright green; N, blue; O, red; and C, gray.
secondary building units (SBUs) [MoOS3Cu3], two molecules of bridging bpy, and one terminal Cl atom (Figure 1a). As indicated in Figure 1b,c, each [MoOS3Cu3Cl] cluster is alternately linked by single or double bridging bpy ligands to form many interesting parallel infinite zigzag chains along the ab plane and further generate a 3D framework with bpy ligands, in which the extension in the c-axis of each adjacent [MoOS3Cu3Cl] cluster units of zigzag chains is in the opposite direction (Figure 1d). It is noticed that, from Figure 1c, there are no interchain interactions between parallel infinite zigzag chains along the ab plane. However, as shown in Figured 1e, two [(MoOS3Cu3)2(μ-bpy)2Cl2] (highlighted in orange and teal, respectively) are parts of two adjacent parallel zigzag chains in the ab plane, they could connect each other with bpy along the c-axis or connect [(MoOS3Cu3)2(μ-bpy)2Cl2] and bpy ligands in neighboring layers; thus, a 10-membered circuit was formed (Figure 1e). A consequence of this packing arrangement is that giant channels are created along the crystallographic a direction with the large dimension of 26.7 Å 16.4 Å (Figure 1b). The large void generated in this net is partly reduced by the formation of a 2-fold interpenetration. Interestingly, the interpenetration of the networks does not interfere in channel formation as the channels run in the a-axis overlapping that of the two nets (Figure S1a in the Supporting Information). The two independent networks stack parallel to a direction to afford distorted square-shaped channels with a cross-section of approximately 20.4 Å 15.2 Å (Figure S1b in the Supporting Information). Remarkably, in spite of 2-fold interpenetration of 1, the size of the voids occupied by the solvent molecules is still about 26809 Å3, which is 60.6% of the unit cell volume.7 From a topological perspective, the 3D framework can be classified as a 3-connected (10,3)-b net (Figure 1f), which is remarkably different from the previously reported 3-connected examples containing the cube, 1D folded ladder type chain, and 2D brick-wall network observed in [(η5-C5Me5)WS3Cu3]-based heterothiometallic compounds.3k To the best of our knowledge, 1 features the first 3-connected 3D heterothiometallic polymer assembled with bidentate organic bridges, comparable to the only one known 3-connected 3D example: {[WS4Cu2(titb)] 3 0.5H2O}n, in which titb is a tridentate organic ligand.3e
Crystal Structure of 3. The crystal structure of 3 reveals an infinite 2D coordination network that crystallizes in a triclinic system with the space group P1. As indicated in Figure 2a, the asymmetric unit contains a solvated DMF molecule and a [MoOS3Cu3(NCS)(bpy)(μ-bpy)2] molecule, which is further interconnected via three single or double Cu-μ-bpy-Cu bridges to form a 2D layer extending structure along the ab plane (Figure 2b). There are no evident interactions between the layers and the DMF molecules. Each hexagonal cavity is estimated to have dimensions of 25.7 Å 21.2 Å. Topologically, each [MoOS3Cu3] core in 3 serves as a 3-connected node, and bpy bridges are attached to each copper atom, forming an extended 2D sheet with (6,3) topology. In 2001, we reported a 2D network [Mo2O2S6Cu6I3(4,40 -bipy)5]∞ anion, which is topologically the same as 3 but not neutral.12 Crystal Structure of 4. Polymer 4 crystallizes in the monoclinic space group C2/c, and the asymmetric unit consists of one [WOS3Cu3(NCS)(μ-bpy)2.5] molecule and three DMF solvent molecules. As shown in Figure 3a, [WOS3Cu3] cluster is connected by two and a half bridging bpy molecules and one terminal NCS anion via three Cu atoms, which further links four crystallographically equivalent clusters via four bridging bpy molecules to form a 3D network, in which two types of 6-membered and 8-membered circuits are included. It is noticed that the 6-membered ring is constructed by repeating [MoOS3Cu3] clusters and single bridging bpy ligands, while in 8-membered circuit, apart from the similarities, it also contains double bridging bpy ligands. This packing arrangement results in large channels created along the ac plane with the dimension of 11.1 Å 11.2 Å (Figure 3b), which are occupied by solvent molecules. The total void value of the channels is estimated to be 4203.6 Å3, approximately 44.6% of the total crystal volume.9 To be a better insight into the structure of compound 4, the 3D framework can be reduced to a 4-connected (64 82) net. This framework is obviously different from the well-known 4-connected twisted dia, nbo, pts, and qtz nets.13 The biggest difference is that 4 exhibits a self-penetrating network topology, in which the shortest 6-membered circuit interpenetrated by a second identical one is observed (two rings highlighted in blue and green in Figure 3c). Generally, 4-connected 3D nets will lead to large voids and may further result in multifold interpenetrating structures, espesically in heterothiometallic chemistry.3a,b,d,fj In 3452
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Figure 3. (a) Aasymmetric unit of 4. (b) Perspective view of the 3D network in 4 along the ac plane, which contains 6-membered and 8-membered rings. All hydrogen atoms and DMF solvated molecules are omitted for clarity. (c) Overall (64 82) topology of polymer 4. Each node and rod represents a cluster fragment [WOS3Cu3(NCS)] and 4,40 -bipy ligand, respectively. Color code: W, teal; S, yellow; Cu, bright blue; Cl, bright green; N, blue; O, red; and C, gray.
this report, [MoOS3Cu3] clusters and NCS anions prohibit the interpenetration of the 3D framework by steric hindrance, and an interesting self-penetration occurred. To the best of our knowledge, polymer 4 displays the first self-penetrating network in heterothiometallic chemistry. It should be noted that 4 is very similar to the 3D example {[MoOS3Cu3(NCS)(4,40 -bipy)2.5] 3 3 (ani)}n on chemical formula.3d However, the latter polymer holds a 3-fold interpenetrated 3D diamondoid net in which each cluster [MoOS3Cu3] core also works as a tetrahedral 4-connecting node and is coordinated by five bridging bpy ligands. The voids of the unit cell are occupied by the aniline solvent molecules. Thermogravimetric Analysis and XRD Results. The TGA curves for compounds 14 are shown in Figures S25 in the Supporting Information. Although it was not possible to identify
solvent molecules in compounds 1 and 2, they were considered likely that large inner regions are occupied by solvent molecule. From the elemental analysis and thermal analysis, the formulas of the above compounds were estimated as 1 3 1.3DMF 3 5.5H2O and 2 3 1.5DMF 3 8.2H2O. Thermogravimetric analysis (TGA) of the compound 1 reveals a weight loss of 10.53 and 9.88% in the region 30189 °C, consistent with the loss of lattice H2O and DMF molecules from the channels; above this temperature, a series of decomposition steps commence. In 2, the weight loss of 13.49 and 9.70% in the range 30219 °C could be assigned to the loss of H2O and DMF molecules; above this temperature, the second step of weight loss is due to the decomposition of organic components. For 3, the weight loss before 165 °C (observed, 8.74%; calculated, 7.32%) could be assigned to the escape of DMF molecules; above this temperature, the second step of 3453
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cation structure modifications on the resulting supramolecular polymeric structures, and to elucidate the mechanism of inorganic polymeric framework formation.
’ ASSOCIATED CONTENT
bS
Supporting Information. X-ray crystallographic files in CIF format of 14 and d-spacings (experimental and calculated) of each phase of 14, the TGA curves, XRD patterns of 14, and the hexagonal channels of 1 formed from the interpenetration along bc plane. This material is available free of charge via the Internet at http://pubs.acs.org.
’ AUTHOR INFORMATION Figure 4. UVvis curves for the DMSO solutions of 105 M for 14.
weight loss begins, from which the organic components were burnt. In the TGA curve of 4, the initial weight loss between 30 and 198 °C corresponds to the release of DMF molecules. The observed weight loss of ca.19.00% is close to the theoretical value (20.55%). The second step of weight loss begins at 215 °C, from which the organic groups were burnt. When the crystals are dried in vacuo, they fail to diffract as single crystals. Analysis of the powder diffraction pattern reveals that the framework of 1 and 3 still remains intact upon loss of solvent from the channels. However, the main peaks of experimental XRD spectra of 2 and 4 are not consistent with their simulated spectra (Figures S6S9 in the Supporting Information). In addition, we tried to investigate the porosity of compounds 1 by N2 adsorption, but no ideal experimental result was obtained. UVvis Absorption Spectra of 14. The UVvis absorption spectra of 14 in DMSO solution are shown in Figure 4. The electronic spectra of 1, 3, and 4 showed similar bands at 417 (1), 418 (3), and 357 nm (4). These bands are probably dominated by the S f Mo (1 and 3) or S f W (4) charge transfers in the [Mo/WOS3] moieties.14a However, in the spectra of 2 and 3, the similar shoulder bands feature absorption at 284 (2) and 288 nm (3), which are tentatively assumed as the metal-to-ligand charge transfer transition.14b
’ CONCLUSIONS In this paper, we dedicated our efforts to exploring how the [NH4]2MS2O2 (M = Mo, W), and copper sources affected the formation of cluster-based structures and demonstrated a larger organic cation as a template to the construction of novel 2D or 3D [Mo/WOS3Cu3]-based heterothiometallitic polymers. Compound 1 (or 2) features a 3-connected 3D 2-fold interpenetrating frameworks with (10,3)-b net. Compound 3 consists of a 2D noninterpenetrating network with (6,3) topology. Compound 4 displays the first self-penetrating example in heterothiometallic chemistry with (64 82) net. It is noteworthy that the striking structural difference among compounds 14 is simply caused by one identical organic cation, which is mainly attributed to the template effects during the assembly process. This presentation summarizes the newest and the most important results on the use of the organic cation template for the syntheses of cluster-based assemblies. Further efforts are in progress to extend this novel method to other metal polymeric species, to evaluate the influences of
Corresponding Author
*Fax: +86-371-67767627. E-mail:
[email protected] (Y.N.). Fax: +86-371-67761744. E-mail:
[email protected] (H.H.).
’ ACKNOWLEDGMENT We gratefully acknowledge the financial support by the National Natural Science Foundation (Nos. 20971110 and 91022013), Program for New Century Excellent Talents of Ministry of Education of China (NCET-07-0765), the Ministry of Science and Technology of China for the International Science Linkages Program (2009DFA50620), and the Outstanding Talented Persons Foundation of Henan Province. ’ REFERENCES (1) Yaghi, O. M.; Li, H. L.; Davis, C.; Richardson, D.; Groy, T. L. Acc. Chem. Res. 1998, 31, 474. (2) (a) George, G. N.; Pickering, I. J.; Yu, E. Y.; Prince, R. C.; Bursakov, S. A.; Gavel, O. Y.; Moura, I.; Moura, J. J. G. J. Am. Chem. Soc. 2000, 122, 8321. (b) Shi, S.; Ji, W.; Tang, S. H.; Lang, J. P.; Xin, X. Q. J. Am. Chem. Soc. 1994, 116, 3615. (c) Che, C. M.; Xia, B. H.; Huang, J. S.; Chan, C. K.; Zhou, Z. Y.; Cheung, K. K. Chem.—Eur. J. 2001, 7, 3998. (3) Niu, Y. Y.; Zheng, H. G.; Hou, H. W.; Xin, X. Q. Coord. Chem. Rev. 2004, 248, 169. Recent examples:(a) Liang, K.; Zheng, H. G.; Song, Y. L.; Lappert, M. F.; Li, Y. Z.; Xin, X. Q.; Huang, Z. X.; Chen, J. T.; Lu, S. F. Angew. Chem., Int. Ed. Engl. 2004, 43, 5776. (b) Lang, J. P.; Xu, Q. F.; Yuan, R. X.; Abrahams, B. F. Angew. Chem., Int. Ed. 2004, 43, 4741. (c) Zhang, W. H.; Lang, J. P.; Zhang, Y.; Abrahams, B. F. Cryst. Growth Des. 2008, 8, 399. (d) Chen, J. X.; Tang, X. Y.; Chen, Y.; Zhang, W. H.; Li, L. L.; Yuan, R. X.; Zhang, Y.; Lang, J. P. Cryst. Growth Des. 2009, 9, 1461. (e) Pan, Z. R.; Xu, J.; Zheng, H. G.; Huang, K. X.; Li, Y. Z.; Guo, Z. J.; Batten, S. R. Inorg. Chem. 2009, 48, 5772. (f) Huang, Y. J.; Song, Y. L.; Chen, Y.; Li, H. X.; Zhang, Y.; Lang, J. P. Dalton Trans. 2009, 1411. (g) Song, L.; Li, J. R.; Lin, P.; Li, Z. H.; Li, T.; Du, S. W.; Wu, X. T. Inorg. Chem. 2006, 45, 10155. (h) Huang, K. X.; Song, Y. L.; Pan, Z. R.; Li, Y. Z; Zhuo, X.; Zheng, H. G. Inorg. Chem. 2007, 46, 6233. (i) Zhang, W. H.; Song, Y. L.; Ren, Z. G.; Li, H. X.; Li, L. L.; Zhang, Y.; Lang, J. P. Inorg. Chem. 2007, 46, 6647. (j) Liang, K.; Zheng, H. G.; Song, Y. L.; Li, Y. Z.; Xin, X. Q. Cryst. Growth Des. 2007, 7, 373. (k) Xu, Q. F.; Chen, J. X.; Zhang, W. H.; Ren, Z. G.; Li, H. X.; Zhang, Y.; Lang, J. P. Inorg. Chem. 2006, 45, 4055. (4) Niu, Y. Y.; Wu, B. L.; Guo, X. L.; Song, Y. L.; Liu, X. C.; Zhang, H. Y.; Hou, H. W.; Niu, C. Y.; Ng, S. W. Cryst. Growth Des. 2008, 8, 2393. (5) (a) McDonald, J. W.; Frieson, G. D.; Rosenhein, C. D.; Newton, W. E. Inorg. Chim. Acta 1983, 72, 205. (b) Almarzoqi, B.; George, A. V.; Isaacs, N. S. Tetrahedron 1986, 42, 601. (6) Sheldrick, G. M. SHELXL93; University of G€ottingen: G€ottingen, Germany, 1993. 3454
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