Amine-Templated Assembly of Metal–Organic Frameworks with

Dec 14, 2007 - (44) topology (1), [Cd2(BTC)2(H2O)2]·2(HCHA)·2(EtOH)·. 2(H2O) with (4·62)2(42 ·610 ·83) topology (2), [Cd5(BTC)4Cl4]·. 4(HTEA)·...
0 downloads 0 Views 2MB Size
Download PDF
Amine-Templated Assembly of Metal–Organic Frameworks with Attractive Topologies Qianrong Fang, Guangshan Zhu,* Ming Xue, Zhuopeng Wang, Jinyu Sun, and Shilun Qiu* State Key Lab of Inorganic Synthesis & PreparatiVe Chemistry, Jilin UniVersity, Changchun 130012, People’s Republic of China

CRYSTAL GROWTH & DESIGN 2008 VOL. 8, NO. 1 319–329

ReceiVed June 30, 2007; ReVised Manuscript ReceiVed September 2, 2007

ABSTRACT: Seven new metal–organic frameworks (MOFs) have been synthesized using different organic amines as templates: [Cd(HBTC)2] · 2(HDETA) · 4(H2O) (1) (BTC ) 1,3,5-benzenetricarboxylate and DETA ) diethylenetriamine), [Cd2(BTC)2(H2O)2] · 2(HCHA) · 2(EtOH) · 2(H2O) (CHA ) cyclohexylamine) (2), [Cd5(BTC)4Cl4] · 4(HTEA) · 2(H3O) (TEA ) triethylamine) (3), [Cd3(BTC)3(H2O)] · (HTEA) · 2(H3O) (4), [Zn(BTC)(H2O)] · (HTPA) · (H2O) (TPA ) tri-n-propylamine) (5), [Cd(BTC)] · (HTPA) · (H2O) (6), and [Cd2(BTC)(HBTC)] · (HTBA) · (H2O) (TBA ) tri-n-butylamine) (7). Topologically, the polymer 1 exhibits a twodimensional (2D) Cd-HBTC network with (44) topology, which is a sql structure; the polymer 2 possesses a three-dimensional (3D) porous Cd-BTC framework with (4 · 62)2(42 · 610 · 83) topology, which is a contorted rutile structure; polymer 3 exhibits a 3D open Cd-BTC architecture with (62 · 82 · 102)2(62 · 84)(63)4 topology; polymer 4 is a 3D porous Cd-BTC network with new (4 · 62)2(42 · 64 · 86 · 103)(6 · 82)2(62 · 84)(62 · 84)2(62 · 8)2 topology; similar to 1, polymer 5 is a 2D Zn-BTC framework with (4 · 82) topology; interestingly, polymer 6 possesses a 3D porous Cd-BTC architecture with the same topology as 2; polymer 7 shows a 3D open Cd-BTC framework with (63)(65 · 10) topology. In addition to the structures of polymers 1–7, their thermal stabilities, ion exchange properties, and nonbonding interaction energies, including H-bonding and van der Waals, have also been studied. Remarkably, those organic amine cations reside in the interlayer or channel space, playing important roles such as templating, space-filling, and charge-balancing agents. These studies would facilitate the exploration of novel MOFs with charming molecular topologies and multifunctional properties. Introduction Metal–organic frameworks (MOFs) have recently attracted much attention owing to their intriguing molecular topologies1 and potential applications as functional materials, such as in porosity,2 catalysis,3 ion exchange,4 chirality,5 luminescence,6 nonlinear optics (NLO),7 conductivity,8 optoelectronic effects,9 magnetism,10 and spin-transition behavior.11 However, it is still a challenging task to explore successful synthetic strategies for the preparation of the MOFs that have expected applications and intriguing structures. These preparations are affected by all kinds of factors, such as the structural characteristic of the ligand,12 coordination nature of the metal ion,13 solvent system,14 template,15 pH value of the solution,16 steric requirement of the counterion,17 reaction temperature,18 and the metal-to-ligand ratio.19 Employing different solvents and organic bases, Yaghi et al. successfully synthesized a series of Zn-BTC (BTC ) 1,3,5benzenetricarboxylate) frameworks and found that the dimensionality of the resulting Zn-BTC framework is mainly dependent on the solvent media and the strength of organic base.20 Recently, Zaworotko et al. presented two very interesting ZnBTC compounds by self-assembly of triangular, square, and tetrahedral molecular building blocks (MBBs) in the presence of different solvents, benzene and chlorobenzene.21 In previous studies, our interest mainly focused on the effect of various organic bases.22 The organic bases were found to play different roles in the formation of various types of structures: an agent to deprotonate O-donor ligands,23 a structure-directing agent or template to construct new architectures,24 and a ligand to coordinate to the metal ion.25 As a sequel, we apply the same strategy to prepare novel MOFs structures with charming topologies and further study the effects of different organic * To whom correspondence should be addressed. E-mail: [email protected] (S.Q.), [email protected] (G.Z.); fax: +86-431-5168887; tel: +86-4315168589.

amines as templates. Such amines include diethylenetriamine (DETA), cyclohexylamine (CHA), triethylamine (TEA), tri-npropylamine (TPA), and tri-n-butylamine (TBA) (Scheme 1). As is well-known, MOFs are formed between metal centers with well-defined coordination geometries and multidentate organic ligands containing O- or N-donors. The structures of some minerals, such as quartz,26 diamond,27 perovskite,28 rutile,29 PtS,30 and paracelsian,31 have been reproduced synthetically. By reducing multidimensional frameworks to simple nodeand-linker reference nets, a topological approach plays a significant role in structural simplification and subsequent systematization.32 Network topologies of coordination polymers have been described in some detailed reviews.33 Recently, O’Keeffe, Yaghi and co-workers have systematically analyzed the underlying topologies of all 1127 three-dimensional (3D) MOFs reported in the Cambridge Structure Database (CSD), and the statistical results show that only 353 (31.3%) MOFs out of the 1127 examples have different connectivity (3,4; 3,5; 4,5; 3,6; 4,6; 5,6).34 As a result, further investigation on the self-assemblies of MOFs with mixed nodes will not only help explore novel topologies but also enrich the database of coordination polymers. To address the above issue, we present here the syntheses and crystal structures of seven compounds constructed from the BTC ligand coordinated to Cd(II) or Zn(II) in the presence of various organic amines: [Cd(HBTC)2] · 2(HDETA) · 4(H2O) with (44) topology (1), [Cd2(BTC)2(H2O)2] · 2(HCHA) · 2(EtOH) · 2(H2O) with (4 · 62)2(42 · 610 · 83) topology (2), [Cd5(BTC)4Cl4] · 4(HTEA) · 2(H3O) with (62 · 82 · 102)2(62 · 84)(63)4 topology (3), [Cd3(BTC)3(H2O)] · (HTEA) · 2(H3O) with (4 · 62)2(42 · 64 · 86 · 103) (6 · 82)2(62 · 84)(62 · 84)2(62 · 8)2 topology (4), [Zn(BTC)(H2O)] · (HTPA) · (H2O) with (4 · 82) topology (5), [Cd(BTC)] · (HTPA) · (H2O) with (4 · 62)2(42 · 610 · 83) topology (6), and [Cd2(BTC)(HBTC)] · (HTBA) · (H2O) with (63)(65 · 10) topology (7). Moreover, their thermal stabilities, ion exchange properties, and nonbonding

10.1021/cg070604f CCC: $40.75  2008 American Chemical Society Published on Web 12/14/2007

320 Crystal Growth & Design, Vol. 8, No. 1, 2008

Fang et al.

Scheme 1. Representation of organic amines: (a) diethylenetriamine (DETA), (b) cyclohexylamine (CHA), (c) triethylamine (TEA), (d) tri-n-propylamine (TPA) and (e) tri-n-butylamine (TBA)

interaction energies, including H-bonding and van der Waals, have also been examined. Of particular interest is that those protonated organic amines reside in the interlayer or channel space, playing important roles such as templating, space-filling, and chargebalancing agents. Experimental Section Materials and Measurements. All chemicals were reagent grade and were used as received. A Perkin-Elmer TGA 7 thermogravimetric analyzer was used to obtain thermogravimetric analysis (TGA) curves in air with a heating rate of 10 °C per min. Powder X-ray diffraction (XRD) data were collected on a Siemens D5005 diffractometer with CuKa radiation (λ ) 1.5418 Å). The elemental analyses were carried out on a Perkin-Elmer 240C element analyzer. Inductively coupled plasma (ICP) analyses were carried out on a Perkin-Elmer Optima 3300 DV ICP spectrometer. The infrared (IR) spectra were recorded (400–4000 cm-1 region) on a Nicolet Impact 410 FTIR spectrometer using KBr pellets. Energy calculations were accomplished using the Burchart 1.01-Dreding2.21 force field with the Cerius2 software package,35 and the processing procedure was according to ref 36. Synthesis of [Cd(HBTC)2] · 2(HDETA) · 4(H2O) (1). A mixture of CdCl2 · 2.5H2O (0.046 g, 0.2 mmol), H3BTC (0.105 g, 0.5 mmol), DMF (8.0 mL), CHO (3.0 mL), and H2O (2.0 mL) was stirred in a 25-mL beaker in air for 4 h, and then was transfered into a tube (dimensions of 10 × 150 mm). A DMF solution (0.3 mL) containing DETA (0.2 mL) was placed in a small vial. The vial was sealed with a stopper that had been pierced with a pinprick to allow slow emergence of the contents. This vial was then placed in a large solution tube. The outer tube was then sealed and left to stand at 60 °C in an oven for a week. The resulting colorless block-shaped single crystals of 1 were collected in 72% yield based on cadmium. The complex was stable in air and insoluble in common organic solvents such as acetone, methanol, ethanol, dichloromethane, acetonitrile, chloroform, DMF, and DMSO. Elemental analysis and ICP analysis for C26H44N6O16Cd (809.08): C 38.51, H 5.42, N 10.29, Cd 13.83% (calcd: C 38.60, H 5.48, N 10.39, Cd 13.89%). FT-IR (KBr) ) 3429 (m), 3309 (m), 2935 (m), 2877 (m), 2063 (s), 1701 (w), 1664 (s), 1624 (s), 1558 (s), 1435 (s), 1365 (s), 1254 (m), 1101 (s), 1032 (m), 974 (w), 928 (m), 835 (m), 758 (m), 731 (m), 663 (m), 604 (w), 513 (m) cm-1. Synthesis of [Cd2(BTC)2(H2O)2] · 2(HCHA) · 2(EtOH) · 2(H2O) (2). The procedure was the same as that for 1 except substituting a DMF (0.2 mL) and EtOH (0.1 mL) solution of CHA (0.2 mL) for a DMF solution of DETA. The yield is 75% based on cadmium. The resulting colorless block-shaped single crystals of 2 were stable in air and insoluble in common organic solvents such as acetone, methanol, ethanol, dichloromethane, acetonitrile, chloroform, DMF, and DMSO. Elemental analysis and ICP analysis for C34H54N2O18Cd2 (1003.63): C 40.61, H 5.40, N 2.72, Cd 22.42% (calcd: C 40.69, H 5.42, N 2.79, Cd 22.40%). FT-IR (KBr) ) 3425 (m), 2927 (m), 2860 (w), 2810 (w), 2476 (w), 2071 (m), 1658 (s), 1612 (s), 1558 (s), 1439 (s), 1365 (s), 1252 (w), 1099 (m), 767 (m), 731 (s), 661 (m), 517 (m) cm-1. Synthesis of [Cd5(BTC)4Cl4] · 4(HTEA) · 2(H3O) (3). The procedure was the same as that for 1 except substituting TEA (0.2 mL) for DETA.

The yield is 68% based on cadmium. The resulting colorless blockshaped single crystals of 3 were stable in air and insoluble in common organic solvents such as acetone, methanol, ethanol, dichloromethane, acetonitrile, chloroform, DMF and DMSO. Elemental analysis and ICP analysis for C60H82N4O26Cl4Cd5 (1979.18): C 36.33, H 4.12, N 2.79, Cd 28.36% (calcd: C 36.41, H 4.18, N 2.83, Cd 28.40%). FT-IR (KBr) ) 3421 (m), 2987 (w), 2931 (w), 2873 (w), 2808 (w), 2706 (w), 2505 (w), 2073 (m), 1656 (s), 1610 (s), 1558 (s), 1431 (s), 1369 (s), 1254 (w), 1101 (m), 767 (m), 725 (s), 661 (m), 518 (w) cm-1. Synthesis of [Cd3(BTC)3(H2O)] · (HTEA) · 2(H3O) (4). The procedure was the same as that for 1 except substituting TEA (0.2 mL) for DETA and Cd(NO3)2 for CdCl2. The yield is 81% based on cadmium. The resulting colorless block-shaped single crystals of 4 were stable in air and insoluble in common organic solvents such as acetone, methanol, ethanol, dichloromethane, acetonitrile, chloroform, DMF, and DMSO. Elemental analysis and ICP analysis for C33H33NO21Cd3 (1116.85): C 35.36, H 2.91, N 1.22, Cd 30.15% (calcd: C 35.49, H 2.98, N 1.25, Cd 30.19%). FT-IR (KBr) ) 3386 (m), 3299 (m), 2927 (w), 2875 (w), 2810 (w), 2505 (w), 2071 (m), 1660 (s), 1622 (s), 1558 (s), 1433 (s), 1371 (s), 1253 (w), 1099 (s), 931 (w), 768 (m), 729 (s), 661 (w), 517 (w) cm-1. Synthesis of [Zn(BTC)(H2O)] · (HTPA) · (H2O) (5). The procedure was the same as that for 1 except substituting TPA (0.2 mL) for DETA and ZnCl2 for CdCl2. The yield is 76% based on zinc. The resulting colorless block-shaped single crystals of 5 were stable in air and insoluble in common organic solvents such as acetone, methanol, ethanol, dichloromethane, acetonitrile, chloroform, DMF, and DMSO. Elemental analysis and ICP analysis for C18H29NO8Zn (452.81): C 47.69, H 6.41, N 3.01, Zn 14.40% (calcd: C 47.75, H 6.46, N 3.09, Zn 14.44%). FT-IR (KBr) ) 3392 (m), 3292 (m), 2925 (w), 2490 (w), 2073 (m), 1670 (w), 1624 (s), 1558 (s), 1429 (s), 1365 (s), 1277 (w), 1101 (m), 926 (w), 766 (m), 723 (m), 690 (m), 519 (w) cm-1. Synthesis of [Cd(BTC)] · (HTPA) · (H2O) (6). The procedure was the same as that for 1 except substituting TPA (0.2 mL) for DETA. The yield is 70% based on cadmium. The resulting colorless blockshaped single crystals of 6 were stable in air and insoluble in common organic solvents such as acetone, methanol, ethanol, dichloromethane, acetonitrile, chloroform, DMF, and DMSO. Elemental analysis and ICP analysis for C18H27NO7Cd (481.82): C 44.81, H 5.59, N 2.93, Cd 23.28% (calcd: C 44.87, H 5.65, N 2.91, Cd 23.33%). FT-IR (KBr) ) 3392 (m), 3298 (m), 3028 (w), 2972 (m), 2933 (w), 2879 (w), 2744 (w), 2673 (w), 2557 (w), 2067 (s), 1657 (s), 1614 (s), 1558 (s), 1437 (s), 1371 (s), 1099 (m), 964 (w), 766 (s), 725 (s), 663 (w), 521 (w) cm-1. Synthesis of [Cd2(BTC)(HBTC)] · (HTBA) · (H2O) (7). The procedure was similar to that for 1 except substituting TBA (0.1 mL) for DETA, which was added dropwise into the mixture solution. The yield is 66% based on cadmium. The resulting colorless block-shaped single crystals of 7 were stable in air and insoluble in common organic solvents such as acetone, methanol, ethanol, dichloromethane, acetonitrile, chloroform, DMF, and DMSO. Elemental analysis and ICP analysis for C30H37NO13Cd2 (844.44): C 42.59, H 4.41, N 1.61, Cd 26.66% (calcd: C 42.67, H 4.42, N 1.66, Cd 26.62%). FT-IR (KBr) ) 3404 (m), 2933 (w), 2852 (w), 2491 (w), 1705 (s), 1612 (s), 1560 (s), 1433

Amine-Templated Assembly of MOFs

Crystal Growth & Design, Vol. 8, No. 1, 2008 321

Table 1. Crystal Data and Details of Structure Solution and Refinement for 1–7

formula Mw crystal system space group a [Å] b [Å] c [Å] R [°] β [°] γ [°] V [Å3] Z Fcalcd [g cm-3] µ (Mo KR) [cm-1] measured data uique data observed data R [I > 2 σ(I)] Rw

1

2

3

4

5

6

7

C26H36N6O16Cd 801.01 orthorhombic Fdd2 15.8227(10) 45.308(3) 12.7105(8) 90.00 90.00 90.00 9112.1(10) 8 1.168 0.539 11466 2886 2586 0.0573 0.1539

C34H24N2O18Cd2 973.35 monoclinic P21/c 16.0984(16) 14.6070(14) 16.1257(16) 90.00 101.479(2) 90.00 3716.1(6) 4 1.740 1.226 12454 3913 3231 0.0933 0.2106

C60H76N4O24Cl4Cd5 1941.05 tetragonal P4212 20.1824(14) 20.1824(14) 12.6052(18) 90.00 90.00 90.00 5134.5(9) 2 1.256 1.177 26806 4524 4373 0.0380 0.1255

C33H25NO19Cd3 1076.74 monoclinic P21/c 10.243(2) 36.485(8) 17.971(4) 90.00 99.753(4) 90.00 6619(2) 4 1.080 1.001 33044 11411 9176 0.0576 0.1722

C18H25NO7Zn 432.76 monoclinic P21/c 11.061(2) 16.136(3) 12.343(3) 90.00 102.48(3) 90.00 2150.9(7) 4 1.336 1.177 5005 3512 2918 0.0496 0.1518

C18H25NO6Cd 463.79 monoclinic P21/c 10.0355(5) 12.8190(6) 15.4797(7) 90.00 102.4860(10) 90.00 1944.29(16) 4 1.584 1.156 9854 3422 3189 0.0290 0.0872

C30H34NO13Cd2 841.38 monoclinic P21/c 10.2235(11) 12.9894(13) 30.487(3) 90.00 91.993(2) 90.00 4046.1(7) 4 1.381 1.104 20697 7089 5461 0.0943 0.2811

Scheme 2. Representation of synthesis of polymers 1–7.

(s), 1367 (s), 1097 (m), 1022 (w), 931 (w), 889 (w), 766 (s), 729 (s), 528 (w) cm-1. X-ray Crystallography. Diffraction data for 1–7 were collected at 293 K on a Bruker SMART CCD diffractometer equipped with graphite-monochromated MoKa radiation (λ ) 0.71073 Å) by using the ω scan technique. The structures of 1–7 were solved by direct methods and refined with the full-matrix least-squares technique by means of the SHELX-97 program.37 Nonhydrogen atoms were located by direct phase determination and subjected to anisotropic refinement (excluding disordered guest HTBA molecule of 7). In 2, the guest HCHA molecules are disordered. In 7, besides a disordered guest HTBA molecule, one oxygen atom of a carboxylate group is split into two oxygen atoms (each having half-occupancy). All H atoms were placed geometrically. The crystallographic data for 1–7 are listed in Table 1. Crystal drawings were produced by Cerius2 software. Crystallographic Data for polymers 1–7 reported in this paper have been deposited at the Cambridge Crystallographic Data Centre as supplementary publication no. CCDC-602483 to 602489. These data can be obtained free of charge from the Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.

Results and Discussion Synthesis Chemistry. The polymers 1–6 were obtained by slow diffusion of different organic amines into a DMF/CHO (cyclohexanol)/H2O mixture solutions of M(II) (Cd(II) or Zn(II)) and BTC ligand in a molar ratio of 2:5 at 60 °C for 7 days. However, the polymer 7 was obtained by slow evaporation of DMF/CHO/H2O solutions with Cd(II) and BTC ligand, in the same molar ratio as above, in the presence of TBA. As shown in Scheme 2, the polymer 1 exhibits a twodimensional (2D) Cd-HBTC network with (44) topology by

using organic amine, DETA, as a template; polymer 2 possesses a 3D porous Cd-BTC framework with (4 · 62)2(42 · 610 · 83) topology by utilizing CHA as a template; polymer 3 exhibits a 3D open Cd-BTC architecture with (62 · 82 · 102)2(62 · 84)(63)4 topology by using TEA as a template; by employing TEA as the template, the polymer 4 shows a 3D porous Cd-BTC network with new (4 · 62)2(42 · 64 · 86 · 103)(6 · 82)2(62 · 84)(62 · 84)2(62 · 8)2 topology; similar to 1, polymer 5 is a 2D Zn-BTC framework with (4 · 82) topology by using TPA as a template; interestingly, polymer 6 possesses a 3D porous Cd-BTC architecture with the same topology as 2 by using TPA as the template; by utilizing TBA as a template, polymer 7 shows a 3D open CdBTC framework with (63)(65 · 10) topology. Structural Chemistry. The molecular structures of polymers 1–7 were studied by X-ray crystallography and further verified by elemental analyses, ICP, and TGA. Crystal Structure of [Cd(HBTC)2] · 2(HDETA) · 4(H2O) (1). X-ray crystallography reveals that 1 crystallizes in the orthorhombic system, space group Fdd2 (No. 43). An asymmetric unit of 1 contains half a cadmium center, one HBTC, one guest HDETA, and two guest H2O. As shown in Figure 1a, the Cd(II) center is coordinated by four different carboxylate groups to construct a tetrahedral secondary building unit (SBU), and HBTC ligand coordinates to two tetrahedral SBUs by two of its carboxylate groups and keeps the third carboxylate group uncoordinated. The tetrahedral SBUs are interconnected through BTC ligands, thereby generating a 2D extended network with quadrangular channel dimensions of ca. 10.1 × 10.1 Å

322 Crystal Growth & Design, Vol. 8, No. 1, 2008

Fang et al.

Figure 1. (a) Representation of BTC unit linked to two tetrahedral SBUs. (b) Single 2D network of 1 viewed along the [010] direction (uncoordinated carboxylate groups of BTC have been omitted for clarity). (c) Crystal structure of 1 in stick representation with guest molecules in space-filling j direction. (Color code: Cd, green; O, red; N, blue; C, pink; H, gray.) (d) Schematic illustrating the sql topology of model viewed along the [101] the 2D 4-connected net of 1. Intersecting nets are shown in two different colors.

(measured between opposite atoms) viewed along the [001] direction (Figure 1b). As shown in Figure 1c, the space between two layers is full of guest H2O and guest HDETA, and the vacancies of each asymmetric unit are filled with two guest H2O and one guest HDETA, which hold the framework together via hydrogen bonds. The TGA curve for 1 shows that the weight loss of 8.79% during the first step between 30 and 85 °C corresponds to the loss of two guest H2O of each asymmetric unit (calculated 8.91%), and the weight loss of 25.61% during the second step between 200 and 315 °C corresponds to the loss of one guest HDETA of each asymmetric unit (calculated 25.75%). However, further heating will lead to the collapse of its framework. A better insight into the nature of 1 can be achieved by the application of topological approach, that is, reducing multidimensional structures to simple node-and-linker nets. As discussed above, the tetrahedral SBU is defined as a 4-connected node. Likewise, HBTC ligating with two SBUs only serves as a bridged ligand. According to the simplification principle, the resulting structure of 1 is a uninodal 4-connected 2D net, and its Schläfli symbol is (44), which is a typical sql structure. As shown in Figure 1d, these 4-connected 2D nets of 1 are parallelly fused together in an ABAB stacking sequence. Crystal Structure of [Cd2(BTC)2(H2O)2] · 2(HCHA) · 2(EtOH) · 2(H2O) (2). The X-ray structural analysis shows that 2 crystallizes in a monoclinic system, space group P21/c (No. 14). An asymmetric unit of 2 contains two cadmium centers, two BTC, two coordinated H2O, two guest HCHA, two guest EtOH, and two guest H2O. As shown in Figure 2a, two Cd(II) centers adopt the same coordination form, and each center and its counterpart via symmetry transformation are coordinated by six different carboxylate groups to construct a dinuclear octahedral SBU, respectively. In addition, two crystallographical independent BTC ligands also adopt the same coordination form and coordinate to three octahedral SBUs by their three carboxylate groups, respectively. These octahedral SBUs are further extended by BTC ligands into a 3D network with quadrangular channel dimensions of ca. 8.1 × 10.9 Å (measured between

opposite atoms) viewed along the [101] direction (Figure 2b). In this structure, the vacancies of each asymmetric unit are filled with two guest H2O, two guest EtOH, and two guest HCHA, which connect to the framework via hydrogen bonds (Figure 2c). The TGA curve for 2 shows that the weight loss of 12.73% during the first step between 30 and 115 °C corresponds to the loss of two guest EtOH and two guest H2O of each asymmetric unit (calculated 12.77%), and the weight loss of 23.48% during the second step between 270 and 320 °C corresponds to the loss of two guest HCHA and two coordination H2O of each asymmetric unit (calculated 23.55%). Decomposition of 2 starts at 350 °C. The XRD patterns of the as-synthesized and the corresponding calcinated product of polymer 2 are similar, although the intensities of the latter become weak and the widths of some peaks show certain differences. This indicates that the porous network of 2 is basically retained after the removal of the guest molecules and terminal H2O molecules. After guest molecules are removed, the effective free volume of 2 is calculated by PLATON analysis38 as 56.2% (0.31 mL/g) of the crystal volume (2087.2 Å3 out of the 3716.1 Å3 unit cell volume). As discussed above, the octahedral SBU is defined as a 6-connected node. Similarly, BTC ligating with three SBUs can act as a 3-connected node. In this structure, the ratio of 3-connected and 6-connected node is 2:1. On the basis of the simplification principle, the resulting structure of polymer 2 is a binodal (3,6)-connected net, and its Schläfli symbol is (4 · 62)2(42 · 610 · 83) (the first symbol for 3-connected BTC and the second one for 6-connected dinuclear octahedral SBU), which is a deformed version of the idealized rutile structure (Figure 2d). Crystal Structure of [Cd5(BTC)4Cl4] · 4(HTEA) · 2(H3O) (3). X-ray crystallography shows that 3 crystallizes in a tetragonal system, space group P4212 (No. 90). The asymmetric unit of 3 contains one and a quarter cadmium centers, one BTC, one coordination chlorine ion, one guest HTEA, and half a guest H3O. As shown in Figure 3a, one Cd(II) center is coordinated by four different carboxylate groups to construct a tetrahedral

Amine-Templated Assembly of MOFs

Crystal Growth & Design, Vol. 8, No. 1, 2008 323

Figure 2. (a) Representation of BTC unit linked to three octahedral SBUs. (b) 3D framework of 2 viewed along the [101] direction. (c) Crystal structure of 2 in stick representation with guest molecules in space-filling model (Color code: Cd, green; O, red; N, blue; C, pink.). (d) Schematic illustrating the rutile topology of the binodal (3,6)-connected net of 2. (Color code: octahedral SBU, green ball; BTC, pink ball.)

SBU, and another Cd(II) center and its counterpart via symmetry transformation are also linked by four carboxylate groups from four distinct BTC ligands into a square “paddle-wheel” SBU, and each of them completes its coordination geometries with an axial chlorine ion opposite to the Cd–Cd vector. Clearly, BTC coordinates to two tetrahedral SBUs and one square SBU by its three carboxylate groups. The tetrahedral SBUs and square SBUs are interconnected through BTC ligands to generate a 3D infinite network with square channel dimensions of ca. 11.5 × 11.5 Å (measured between opposite atoms) viewed along the [001] direction (Figure 3b). As shown in Figure 3c, the vacancies are filled with half a guest H3O and one guest HTEA of each asymmetric unit, which connect to the framework via hydrogen bonds. Its TGA curve reveals that the weight loss of 2.01% during the first step between 30 and 85 °C corresponds to the loss of half a guest H3O of each asymmetric unit (calculated 1.92%), and the weight loss of 20.59% during the second step between 240 and 290 °C corresponds to the loss of one guest HTEA of each asymmetric unit (calculated 20.66%). Decomposition of 3 starts at 350 °C. XRD patterns of the assynthesized and corresponding calcinated product of 3 indicate that the porous network of 3 is still maintained after the calcination, although the intensities show some differences. After guest molecules are removed, its effective free volume is estimated by PLATON analysis as 64.5% (0.50 mL/g) of the crystal volume (3309.9 Å3 out of the 5134.5 Å3 unit cell volume). Clearly, both the tetrahedral and square SBUs can be defined as 4-connected nodes, and BTC ligating with two square SBUs and one tetrahedral SBU serves as a 3-connected node. In 3, the ratio of square SBU, tetrahedral SBU, and 3-connected BTC is 2:1:4. According to the simplification principle, the resulting

structure of polymer 3 is a trinodal (3,4)-connected net, and its Schläfli symbol is (62 · 82 · 102)2(62 · 84)(63)4 (the first symbol for square SBU, the second one for tetrahedral SBU and the third one for 3-connected BTC), which is identical with the reported “USF-3” structure although polymer 3 has a higher symmetry (Figure 3d).21 Crystal Structure of [Cd3(BTC)3(H2O)] · (HTEA) · 2(H3O) (4). The X-ray structural analysis reveals that 4 crystallizes in the monoclinic system, space group P21/c (No. 14). In an asymmetric unit of 4, there are three cadmium centers, three BTC, one coordination H2O, one guest HTEA, and two guest H3O. As shown in Figure 4a, three crystallographical independent Cd(II) centers and their counterparts produced by their symmetry transformation construct three kinds of SBUs: square “paddle-wheel” SBU, tetrahedral SBU, and octahedral SBU, respectively. Otherwise, three crystallographical independent BTC ligands coordinate to one octahedral SBU and two tetrahedral SBUs (named as BTC-a), one square SBU and two octahedral SBUs (named as BTC-b), and one square SBU and two tetrahedral SBUs (named as BTC-c) by their three carboxylate groups, respectively. These octahedral, tetrahedral, and square SBUs are connected to each other through BTC ligands to yield a intricate 3D architecture with two elliptical channels dimensions of ca. 3.2 × 8.4 Å and 8.4 × 9.6 Å (measured between opposite atoms) viewed along the [100] direction (Figure 4b). The vacancies are filled with two guest H3O and one guest HTEA of each asymmetric unit. However, interestingly, only the space of small channels is full of guest HTEA which connect to the framework via hydrogen bonds, while the space of its large channels is kept void (Figure 4c). The TGA curve of 4 exhibits that the weight loss of 3.43% during the first step between 30 and 115 °C corresponds to the loss of two

324 Crystal Growth & Design, Vol. 8, No. 1, 2008

Fang et al.

Figure 3. (a) Representation of BTC unit linked to one tetrahedral SBU and two square SBUs. (b) 3D framework of 3 viewed along the [001] direction. (c) Crystal structure of 3 in stick representation with guest molecules in space-filling model (Color code: Cd, green; O, red; N, blue; C, pink; H, gray). (d) Schematic illustrating the (62 · 82 · 102)2(62 · 84)(63)4 topology of the trinodal (3,4)-connected net of 3. (Color code: tetrahedral SBU, green ball; square SBU, light blue ball; BTC, pink ball.)

guest H3O of each asymmetric unit (calculated 3.41%), and the weight loss of 10.62% during the second step between 255 and 300 °C corresponds to the loss of one guest HTEA and one coordinated H2O of each asymmetric unit (calculated 10.76%). Decomposition of 4 starts at 350 °C. XRD patterns of the assynthesized and corresponding calcinated product of 4 are similar, indicating that the porous framework of 4 is still maintained after the calcination. After those guest H3O and HTEA molecules are removed, the effective free volume of 4 is evaluated by PLATON analysis as 64.1% (0.57 mL/g) of the crystal volume (4244.0 Å3 out of the 6619.0 Å3 unit cell volume). As discussed above, the octahedral, tetrahedral, and square SBUs are defined as 6- and 4-connected nodes, respectively, and all crystallographical independent BTC ligands can act as 3-connected nodes. In this structure, the ratio of octahedral SBU, square SBU, tetrahedral SBU, BTC-a, BTC-b, and BTC-c is 1:1:2:2:2:2. According to the simplification principle, the resulting structure of polymer 4 is a hexanodal (3,4,6)-connected network, and its Schläfli symbol is (4 · 62)2(42 · 64 · 86 · 103)(6 · 82)2(62 · 84)(62 · 84)2(62 · 8)2 (the first symbol for BTC-b, the second one for octahedral SBU, the third one for BTC-a, the fourth one for square SBUs, the fifth one for tetrahedral SBUs, and the last one for BTC-c) (Figure 4d). To the best of our knowledge, it is a new topology structure. Crystal Structure of [Zn(BTC)(H2O)] · (HTPA) · (H2O) (5). Single-crystal X-ray analysis of 5 reveals that it crystallizes in the monoclinic system, space group P21/c (No. 14). The asymmetric unit of 5 comprises one zinc center, one BTC, one coordinated H2O, one guest HTPA, and one guest H2O. As shown in Figure 5a, the Zn(II) center is coordinated by four oxygen atoms from three different carboxylate groups and one

terminal H2O to construct a triangular SBU, and BTC ligand coordinates to three triangular SBUs by its three carboxylate groups. These triangular SBUs are further extended by BTC ligands, thereby producing a 2D framework with elliptical channel dimensions of ca. 9.9 × 10.6 Å (measured between opposite atoms) viewed along the [101] direction (Figure 5b). In this structure the space between two layers is full of guest H2O and guest HTPA, and the vacancies of each asymmetric unit are filled with one guest H2O and one guest HTPA, which connect to the framework via hydrogen bonds (Figure 5c). The TGA curve for 5 shows that the weight loss of 4.02% during the first step between 30 and 112 °C corresponds to the loss of one guest H2O of each asymmetric unit (calculated 3.98%), and the weight loss of 35.73% during the second step between 255 and 310 °C corresponds to the loss of one guest HTPA and one coordinated H2O of each asymmetric unit (calculated 35.84%). However, similar to 1, further heating leads to collapse of the framework of 5. Similarly, the triangular SBU are defined as a 3-connected node, and the BTC ligand ligating with three triangular SBUs can serve as a 3-connected node. In 5, the ratio of triangular SBU and 3-connected BTC is 1:1. According to the simplification principle, the resulting structure of polymer 5 is a binodal 3-connected net, and its Schläfli symbol is (4 · 82) (the symbol for both triangular SBU and 3-connected BTC, Figure 5d). Clearly, these 3-connected 2D nets of 5 are also parallelly fused together in an ABAB stacking sequence. Crystal Structure of [Cd(BTC)] · (HTPA) · (H2O) (6). The structural analysis of 6 reveals that it crystallizes in the monoclinic system, space group P21/c (No. 14). An asymmetric unit of 6 includes one cadmium center, one BTC, one guest

Amine-Templated Assembly of MOFs

Crystal Growth & Design, Vol. 8, No. 1, 2008 325

Figure 4. (a) Representation of three kinds of BTC units linked to one octahedral SBU and two tetrahedral SBUs, one square SBU and two octahedral SBUs, as well as one square SBU and two tetrahedral SBUs, respectively. (b) 3D framework of 4 viewed along the [100] direction. (c) Crystal structure of 4 in stick representation with guest molecules in space-filling model (Color code: Cd, green; O, red; N, blue; C, pink; H, gray). (d) Schematic illustrating the (4 · 62)2(42 · 64 · 86 · 103)(6 · 82)2(62 · 84)3(62 · 8)2 topology of the hexanodal (3,4,6)-connected net of 4. (Color code: tetrahedral SBU, green ball; square SBU, light blue ball; octahedral SBU, sky blue ball; BTC, pink ball.)

Figure 5. (a) Representation of BTC unit linked to three trigonal SBUs. (b) Single 2D network of 5 viewed along the [101] direction. (c) Crystal j direction (Color code: Zn, sky blue; O, structure of 5 in stick representation with guest molecules in ball and stick model viewed along the [101] red; N, blue; C, pink or light blue). (d) Schematic illustrating the (4 · 82) topology of the 2D binodal (3,4)-connected net of 5. Alternatively intersecting nets are shown in two different colors.

HTPA, and one guest H2O. As shown in Figure 6a, the Cd(II) center and other Cd(II) center generated by its symmetry

transformation are coordinated to six different carboxylate groups to construct a octahedral SBU. Clearly, the BTC ligand

326 Crystal Growth & Design, Vol. 8, No. 1, 2008

Fang et al.

Figure 6. (a) Representation of BTC unit linked to three octahedral SBUs. (b) 3D framework of 6 viewed along the [100] direction. (c) Crystal structure of 6 in stick representation with guest molecules in space-filling model (Color code: Cd, green; O, red; N, blue; C, pink). (d) Schematic illustrating the rutile topology of the binodal (3,6)-connected net of 6. (Color code: octahedral SBU, green ball; BTC, pink ball.)

coordinates to three octahedral SBUs by their three carboxylate groups. Extension of the coordination geometry around these octahedral SBUs and BTC ligands will therefore give a 3D infinite framework with quadrangular channel dimensions of ca. 9.2 × 9.8 Å (measured between opposite atoms) viewed along the [100] direction (Figure 6b). The vacancies of each asymmetric unit are filled with one guest H2O and one guest HTPA, which connect to the framework via hydrogen bonds (Figure 6c). TGA of 6 shows that the weight loss of 3.79% during the first step between 30 and 110 °C corresponds to the loss of one guest H2O of each asymmetric unit (calculated 3.74%), and the weight loss of 29.86% during the second step between 290 and 360 °C corresponds to the loss of one guest HTPA of each asymmetric unit (calculated 29.94%). Decomposition of 6 starts at 430 °C. Although the intensities become weak and the widths of some peaks appear different, XRD pattern of the calcinated product of 6 are very similar to 6, which explains that the porous architecture of 6 is still retained after removal of its guest molecules. After removing those guest molecules, the effective free volume of 6 is calculated by PLATON analysis as 59.2% (0.36 mL/g) of the crystal volume (1151.9 Å3 out of the 1944.3 Å3 unit cell volume). As discussed above, the octahedral SBU can be defined as a 6-connected node, and the BTC ligand ligating with three octahedral SBUs can serve as a 3-connected node. In this structure, the ratio of octahedral SBU and 3-connected BTC is 1:2. According to the simplification principle, the resulting structure of polymer 6 is a binodal (3,6)-connected net, and its Schläfli symbol is (4 · 62)2(42 · 610 · 83) (the first symbol for 3-connected BTC and the second one for octahedral SBU) (Figure 6d). Similar to polymer 2, it is also a deformed version of the idealized rutile structure. Crystal Structure of [Cd2(BTC)(HBTC)] · (HTBA) · (H2O) (7). X-ray crystallography shows that 7 crystallizes in the monoclinic system, space group P21/c (No. 14). In an asymmetric unit of 7, there are two cadmium centers, one BTC,

one HBTC, one guest HTBA, and one guest H2O. As shown in Figure 7a, two Cd(II) centers are coordinated to five different carboxylate groups to construct a dinuclear trigonal bipyramid SBU. In addition, BTC molecule coordinates to three trigonal bipyramid SBUs by its three carboxylate groups, and HBTC molecule coordinates to two trigonal bipyramid SBUs by its two carboxylate groups and keeps the third carboxylate group uncoordinated. The trigonal bipyramid SBUs are interconnected by BTC and HBTC to give a 3D extended architecture with quadrangular channel dimensions of ca. 10.0 × 12.5 Å (measured between opposite atoms) viewed along the [100] direction (Figure 7b). The vacancies of each asymmetric unit are full of one guest H2O and one guest HTBA, which connect to the framework via hydrogen bonds (Figure 7c). The TGA curve of 7 shows that the weight loss of 2.10% during the first step between 30 and 150 °C corresponds to the loss of one guest H2O of each asymmetric unit (calculated 2.13%), and the weight loss of 21.98% during the second step between 200 and 280 °C corresponds to the loss of one guest HTBA of each asymmetric unit (calculated 22.07%). Decomposition of 7 starts at 350 °C. Despite of certain differences in the intensities and the widths of some peaks, the XRD patterns for the assynthesized and corresponding calcinated product of 7 are similar, indicating that the porous structure of 7 is still retained after the calcination. After guest molecules are removed, the effective free volume of 7 is estimated by PLATON analysis as 62.2% (0.45 mL/g) of the crystal volume (2518.6 Å3 out of the 4046.1 Å3 unit cell volume). As shown in Figure 7d, because two HBTC ligands bridge the same two trigonal bipyramid SBUs, the trigonal bipyramid SBU is only defined as a 4-connected node, while the BTC ligand binding to three trigonal bipyramid SBUs can act as a 3-connected node. As for HBTC ligand, it acts as a bridged ligand, so there is no need to consider it in topology analysis. In this structure, the ratio of 4-connected node and 3-connected

Amine-Templated Assembly of MOFs

Crystal Growth & Design, Vol. 8, No. 1, 2008 327

Figure 7. (a) Representation of two kinds of BTC units linked to two or three trigonal bipyramidal SBUs, respectively. (b) 3D framework of 7 viewed along the [100] direction (uncoordinated carboxylate groups of BTC have been omitted for clarity). (c) Crystal structure of 7 in stick representation with guest molecules in space-filling model (Color code: Cd, green; O, red; N, blue; C, pink). (d) Schematic illustrating the InS topology of the binodal (3,4)-connected net of 7. (Color code: trigonal bipyramidal SBU, green ball; 3-connected BTC, pink ball; bridged BTC, green line.)

Figure 8. View of different organic amine cations residing in the interlayer or channel space to play roles such as templating, space-filling, and charge-balancing. From (a) to (g), the corresponding compounds are 1–7. (Color code: Cd, green; Zn, sky blue; O, red; N, blue; C, pink; H, gray.)

node is 1:1. According to the simplification principle, the resulting structure of polymer 7 is a binodal (3, 4)-connected net, and its Schläfli symbol is (63)(65 · 10) (the first symbol for 3-connected BTC and the second one for 4-connected SBU), which is a new structure. Template Effect of Organic Amines. The structural analysis of the polymer 1–7 reveals that those organic amine cations reside in the interlayer or channel space, playing significant roles in the formation of various structures (Figure 8). For 2D network, the layers of 1 and 5 are held together via hydrogen bonds between the oxygen atoms of carboxylate groups of BTC and the nitrogen atoms of organic amine cations. Because the HTPA molecule is more contorted than the HDETA molecule, the structure of 5 templated by HTPA is an undulated layer,

while the framework of 1 templated by HDETA is a planar sheet. However, as for 3D open MOFs, the different organic amine cations are trapped in the vacancies of 2, 3, 4, 6, or 7, which also connect to the framework via hydrogen bonds between the oxygen atoms of BTC and the nitrogen atoms of the organic amine cations, thereby generating their 3D extended networks. In the structures of 2, 4, and 7, the organic amines are located in the center of the channels, and their dimensions (HCHA: 5.4 Å, TEA: 4.9 Å and TBA: 9.7 Å) are similar to those of channels (2: 7.5 Å, 4: 5.4 Å, 7: 10.1 Å, and van der Waals radii of the atoms have been taken into account), whereas the organic amine molecules in 6 are located between those channels and fill the corresponding space. More interestingly, the HTEA molecules in 3 are located only in cagelike structures,

328 Crystal Growth & Design, Vol. 8, No. 1, 2008

Fang et al.

Table 2. Optimized Interaction Energies of Host–Guest (Einter) including VDW and H-Bond Per Unit Cell of 1–7 based on the Experimental Structural Data polymer

organic amine

VDW/kcal mol-1

H-bond/kcal mol-1

Einter/kcal mol-1

1 2 3 4 5 6 7

DETA CHA TEA TEA TPA TPA TBA

-239.18 -102.28 -91.69 -61.68 -100.57 -97.24 -132.82

-152.54 -20.27 -20.27 -12.17 -8.97 -11.13 -19.97

-391.72 -122.55 -111.96 -73.85 -109.54 -108.37 -152.79

while compound 3 keeps very open framework (11.5 Å) without guest amines in those channels. To better understand the templating ability of these organic amines, we calculate the nonbonding interaction energies (Einter), including H-bond and van der Waals, between the host frameworks and the guest organic amines based on the experimental structural data.36 The results are listed in Table 2. The H-bond interaction energies between the host frameworks and the organic templates are -152.54, -20.27, -20.27, -12.17, -8.97, -11.13, and -19.97 kcal mol-1 per unit cell of polymers 1–7, respectively. It is believed that the manner of H-bond interactions is important in stabilizing these structures, even though the size and shape of the organic amines are different from each other. Additionally, the values of Einter between the host frameworks and the organic amines are different from each other (from -73.85 to -391.72 kcal mol-1 per unit cell), which implies that these organic amines have different structure-directing abilities in the formation of MOF structures. Further research on the interaction energies of host–guest systems is currently underway, and we believe that the results of the calculated interaction energies of host–guest systems can be used to direct the synthesis of novel structures. Ion-Exchange Properties. For anionic frameworks, the ionexchanges of 1–7 were carried out in solution by substituting the guest organic cations with inorganic cation (K+).39 Typically, a 200 mg single crystal sample was treated with 5 mL of DMF containing 1 M KSCN for 20 h at room temperature. The sample was filtered, washed thoroughly with ethanol and acetone, and then dried in air. The exchanged products maintained their crystalline transparency, and the powder XRD patterns were similar to that of the as-synthesized polymers. In the experiment of 1, a concomitant change of the carbon, hydrogen, nitrogen, cadmium, and potassium content in the exchanged solids of 1 was observed as C23.2H26.2N3.9O12CdK0.7 (found: C 40.33, H 3.80, N 7.85, Cd 16.29, K 3.92%; cacld: C 40.30, H 3.82, N 7.90, Cd 16.26, K 3.96%), corresponding to the exchange of about 35% of cation with K+. Similar to 1, the change of 2 was observed as C26.4H29.6N1.4O14Cd2K0.6 (found: C 37.82, H 3.59, N 2.38, Cd 26.82, K 2.77%; calcd: C 37.80, H 3.56, N 2.34, Cd 26.80, K 2.80%), corresponding to the exchange of about 30%; the change of 3 was observed as C60H76N4O24Cd5Cl4K2 (found: C 35.66, H 3.75, N 2.73, Cd 27.80, K 3.88%; calcld: C 35.69, H 3.79, N 2.77, Cd 27.83, K 3.87%), corresponding to the exchange of about 33%; the change of 4 was observed as C33H30NO20Cd3K (found: C 34.83, H 2.61, N 1.22, Cd 29.69, K 3.40%; calcld: C 34.86, H 2.66, N 1.23, Cd 29.66, K 3.44%), corresponding to the exchange of about 33%; the change of 5 was observed as C14.58H18.64N0.62O7ZnK0.38 (found: C 44.38, H 4.72, N 2.14, Zn 16.59, K 3.71%; calcld: C 44.35, H 4.76, N 2.20, Zn 16.56, K 3.76%), corresponding to the exchange of about 38%; the change of 6 was observed as C15.57H19.06N0.73O6CdK0.27 (found: C 42.91, H 4.45, N 2.39, Cd 25.78, K 2.38%; calcld: C 42.95, H 4.41, N 2.35, Cd 25.82, K 2.42%), corresponding to the exchange of about 27%; the change

of 7 was observed as C26.64H27.16N0.72O12Cd2K0.28 (found: C 40.71, H 3.44, N 1.26, Cd 28.58, K 1.35%; calcld: C 40.75, H 3.49, N 1.28, Cd 28.63, K 1.39%), corresponding to the exchange of about 28%. Conclusion We have reported the synthesis and crystal structures of seven MOFs by using different organic amines as templates: [Cd(HBTC)2] · 2(HDETA) · 4(H2O) (1), [Cd2(BTC)2(H2O)2] · 2(HCHA) · 2(EtOH) · 2(H2O) (2), [Cd5(BTC)4Cl4] · 4(HTEA) · 2(H3O) (3), [Cd3(BTC)3 (H2O)] · (HTEA) · 2(H3O) (4), [Zn(BTC)(H2O)] · (HTPA) · (H2O) (5), [Cd(BTC)] · (HTPA) · (H2O) (6), and [Cd2(BTC)(HBTC)] · (HTBA) · (H2O) (7). With the application of a topological approach, we found that polymer 1 exhibits a 2D Cd-HBTC network with (44) topology; polymer 2 possesses a 3D porous Cd-BTC framework with (4 · 62)2(42 · 610 · 83) topology; polymer 3 exhibits a 3D open CdBTC architecture with (62 · 82 · 102)2(62 · 84)(63)4 topology; polymer 4 is a 3D porous Cd-BTC network with new (4 · 62)2(42 · 64 · 86 · 103)(6 · 82)2(62 · 84)(62 · 84)2(62 · 8)2 topology; similar to 1, polymer 5 is a 2D Zn-BTC framework with (4 · 82) topology; interestingly, polymer 6 possesses a 3D porous CdBTC architecture with the same topology as 2; polymer 7 shows a 3D open Cd-BTC framework with (63)(65 · 10) topology. In addition, after removing guest molecules, the porous structures of 2, 3, 4, 6, and 7 are still retained, indicating that these compounds may have potential applications in porosity. Ionexchange studies show that the organic guests in 1–7 can be exchanged in solution by inorganic cation (K+), and their frameworks are maintained after the exchange. It is noticeable that the organic amines (such as DETA, CHA, TEA, TPA, and TBA) used in the preparations play significant roles in the formation of above-mentioned structures: (a) as an agent to deprotonate O-donor ligands; (b) as a template to direct the framework of the product; and (c) as a charge-balancing agent. We believe that the discovery of the templating effect of organic amine cations, together with the study of the calculated nonbonding interaction energies in these host–guest systems, would direct the synthesis of novel architectures and facilitate the exploration of new MOFs with charming molecular topologies and multifunctional properties. Acknowledgment. This research was supported by the State Basic Research Project (2006CB806100), Outstanding Young Scientist Foundation of NSFC (20625102), and NSFC (Grant Nos. 20571030, 20531030, and 20371020). Supporting Information Available: Crystallographic data in CIF format, ORTEP drawings, IR spectra, powder X-ray patterns, TGA, and hydrogen bonds for 1–7. This material is available free of charge via the Internet at http//pubs.acs.org.

References (1) (a) Eddaoudi, M.; Moler, D. B.; Li, H.; Chen, B.; Reineke, T. M.; O’Keefee, M.; Yaghi, O. M. Acc. Chem. Res. 2001, 34, 319. (b)

Amine-Templated Assembly of MOFs

(2)

(3) (4) (5)

(6)

(7) (8) (9)

(10)

(11) (12)

(13)

(14) (15)

(16)

Moulton, B.; Zaworotko, M. J. Chem. ReV. 2001, 101, 1629. (c) Batten, S. R.; Robson, R. Angew. Chem., Int. Ed. 1998, 37, 1460. (d) Férey, G.; Mellot-Draznieks, C.; Serre, C.; Millange, F.; Dutour, J.; Surblé, S.; Margiolaki, I. Science 2005, 309, 2040. (e) Zhao, X.; Xiao, B.; Fletcher, A. J.; Thomas, K. M.; Bradshaw, D.; Rosseinsky, M. J. Science 2004, 306, 1012. (f) Kitagawa, S.; Kitaura, R.; Noro, S. Angew. Chem., Int. Ed. 2004, 43, 2334. (g) Erxleben, A. Coord. Chem. ReV. 2003, 246, 203. (h) Janiak, C. Dalton Trans. 2003, 2781. (i) Fang, Q. R.; Zhu, G. S.; Xue, M.; Sun, J. Y.; Wei, Y.; Qiu, S. L.; Xu, R. R. Angew. Chem., Int. Ed. 2005, 44, 3845. (a) Chen, B. L.; Liang, C. D.; Yang, J.; Contreras, D. S.; Clancy, Y. L.; Lobkovsky, E. B.; Yaghi, O. M.; Dai, S. Angew. Chem., Int. Ed. 2006, 45, 1390. (b) Sudik, A. C.; Millward, A. R.; Ockwig, N. W.; Côté, A. P.; Kim, J.; Yaghi, O. M. J. Am. Chem. Soc. 2005, 127, 7110. (c) Pan, L.; Liu, H. M.; Lei, X. G.; Huang, X. Y.; Olson, D. H.; Turro, N. J.; Li, J. Angew. Chem., Int. Ed. 2003, 42, 542. Seo, J. S.; Whang, D.; Lee, H.; Jun, S. I.; Oh, J.; Jeon, Y. J.; Kim, K. Nature 2000, 404, 982. James, S. L. Chem. Soc. ReV. 2003, 32, 276. (a) Lin, W. B. J. Solid State Chem. 2005, 178, 2486. (b) Xiong, R.; You, X.; Abrahams, B. F.; Xue, Z.; Che, C. Angew. Chem., Int. Ed. 2001, 40, 4422. (c) Shi, X.; Zhu, G. S.; Qiu, S. L.; Huang, K. L.; Yu, J. H.; Xu, R. R. Angew. Chem., Int. Ed. 2004, 43, 6482. (d) Tian, G.; Zhu, G. S.; Yang, X. Y.; Fang, Q. R.; Xue, M.; Sun, J. Y.; Wei, Y.; Qiu, S. L. Chem. Commun. 2005, 1396. (a) Pang, J.; Marcotte, E. J. P.; Seward, C.; Brown, R. S.; Wang, S. N. Angew. Chem., Int. Ed. 2001, 40, 4042. (b) Tao, J.; Tong, M. L.; Shi, J. X.; Chen, X. M.; Ng, S. W. Chem. Commun. 2000, 2043. (c) Fang, Q. R.; Zhu, G. S.; Shi, X.; Wu, G.; Tian, G.; Wang, R. W.; Qiu, S. L. J. Solid State Chem. 2004, 177, 1060. Lin, W.; Evans, O. R.; Xiong, R. G.; Wang, Z. J. Am. Chem. Soc. 1998, 120, 13272. (a) Mitzi, D. B.; Wang, S.; Field, C. A.; Chess, C. A.; Guloy, A. M. Science 1995, 267, 1473. (b) Wang, S.; Mitzi, D. B.; Field, C. A.; Guloy, A. M. J. Am. Chem. Soc. 1995, 117, 5297. (a) Chen, W.; Yuan, H. M.; Wang, J. Y.; Liu, Z. Y.; Xu, J. J.; Yang, M.; Chen, J. S. J. Am. Chem. Soc. 2003, 125, 9266. (b) Fang, Q. R.; Zhu, G. S.; Xue, M.; Zhang, Q. L.; Sun, J. Y.; Guo, X. D.; Qiu, S. L.; Xu, S. T.; Wang, P.; Wang, D. J.; Wei, Y. Chem. J. Eur. 2006, 12, 3754. (a) Barthelet, K.; Marrot, J.; Riou, D.; Férey, G. Angew. Chem., Int. Ed. 2002, 41, 281. (b) Inoue, K.; Imai, H.; Ghalsasi, P. S.; Kikuchi, K.; Ohba, M.; Okawa, H.; Yakhmi, J. V. Angew. Chem., Int. Ed. 2001, 40, 4242. (c) Cave, D.; Gascon, J. M.; Bond, A. D.; Teat, S. J.; Wood, P. T. Chem. Commun. 2002, 1050. (a) Kahn, O.; Martinez, C. J. Science 1998, 279, 44. (b) Gütlich, P.; Hauser, A.; Spiering, H. Angew. Chem., Int. Ed. 1994, 33, 2024. (a) Goodgame, D. M. I.; Menzer, S.; Ross, A. T.; Williams, D. J. Chem. Commun. 1994, 2605. (b) Abrahams, B. F.; Batten, S. R.; Grannas, M. J.; Hamit, H.; Hoskins, B. F.; Robson, R. Angew. Chem., Int. Ed. 1999, 38, 1475. (a) Hong, M. C.; Zhao, Y. J.; Su, W. P.; Cao, R.; Fujita, M.; Zhou, Z. Y.; Chan, A. S. C. Angew. Chem., Int. Ed. 2000, 39, 2468. (b) Hong, M. C.; Zhao, Y. J.; Su, W. P.; Cao, R.; Fujita, M.; Zhou, Z. Y.; Chan, A. S. C. J. Am. Chem. Soc. 2000, 122, 4819. (c) Janiak, C.; Uehlin, L.; Wu, H. P.; Klufers, P.; Piotrowski, H.; Scharmann, T. G. J. Chem. Soc., Dalton Trans. 1999, 3121. Withersby, M. A.; Blake, A. J.; Champness, N. R.; Cooke, P. A.; Hubberstey, P.; Li, W. S.; Schröder, M. Inorg. Chem. 1999, 38, 2259. (a) Hennigar, T. L.; MacQuarrie, D. C.; Losier, P.; Rogers, R. D.; Zaworotko, M. L. Angew. Chem., Int. Ed. 1997, 36, 972. (b) Gudbjartson, H.; Biradha, K.; Poirier, K. M.; Zaworotko, M. J. J. Am. Chem. Soc. 1999, 121, 2599. Pan, L.; Huang, X. Y.; Li, J.; Wu, Y. G.; Zheng, N. W. Angew. Chem., Int. Ed. 2000, 39, 527.

Crystal Growth & Design, Vol. 8, No. 1, 2008 329 (17) (a) Tong, M. L.; Chen, X. M.; Ye, B. H.; Ng, S. W. Inorg. Chem. 1998, 37, 5168. (b) Wu, H. P.; Janiak, C.; Rheinwald, G.; Lang, H. J. Chem. Soc., Dalton Trans. 1999, 183. (18) Wang, R. H.; Hong, M. C.; Zhao, Y. J.; Weng, J. B.; Cao, R. Inorg. Chem. Commun. 2002, 5, 487. (19) Tong, M. L.; Zheng, S. L.; Chen, X. M. Chem. Eur. J. 2000, 6, 3729. (20) Yaghi, O. M.; Davis, C. E.; Li, G. M.; Li, H. L. J. Am. Chem. Soc. 1997, 119, 2861. (21) Wang, Z. Q.; Kravtsov, V.Ch.; Zaworotko, M. J Angew. Chem., Int. Ed. 2005, 44, 2877. (22) (a) Fang, Q. R.; Zhu, G. S.; Xue, M.; Sun, J. Y.; Sun, F. X.; Qiu, S. L. Inorg. Chem. 2006, 45, 3582. (b) Fang, Q. R.; Zhu, G. S.; Xue, M.; Sun, J. Y.; Qiu, S. L. Dalton Trans. 2006, 2399. (c) Fang, Q. R.; Zhu, G. S.; Xue, M.; Sun, J. Y.; Shi, X.; Tian, G.; Wu, G.; Liu, X. J.; Qiu, S. L. Dalton Trans. 2003, 2781. (d) Wu, G.; Shi, X.; Fang, Q. R.; Tian, G.; Wang, L. F.; Zhu, G. S.; Addison, A. W.; Wei, Y.; Qiu, S. L. Inorg. Chem. Commun. 2003, 6, 402. (23) Yaghi, O. M.; Li, H. L. J. Am. Chem. Soc. 1996, 118, 295. (24) (a) Yaghi, O. M.; Li, G.; Li, H. Chem. Mater. 1997, 9, 1074. (b) Tian, Y.; Cai, C.; Ji, Y.; You, X.; Peng, S.; Lee, G. Angew. Chem., Int. Ed. 2002, 41, 1384. (25) Zhang, X. M.; Chen, X. M. Eur. J. Inorg. Chem. 2003, 413. (26) Sun, J. Y.; Weng, L. H.; Zhou, Y. M.; Chen, J. X.; Chen, Z. X.; Liu, Z. C.; Zhao, D. Y. Angew. Chem., Int. Ed. 2002, 41, 4471. (27) Hoskins, B. F.; Roberson, R. J. Am. Chem. Soc. 1990, 112, 1546. (28) Carlucci, L.; Ciani, G.; Proserpio, D. M.; Sironi, A. Angew. Chem., Int. Ed. 1995, 34, 1895. (29) Batten, S. R.; Houskins, B. F.; Robson, R. J. Chem. Soc. Chem. Commun. 1991, 445. (30) (a) Gable, R. W.; Houskins, B. F.; Robson, R. J. Chem. Soc. Chem. Commun. 1990, 762. (b) Chen, B.; Eddaoudi, M.; Reineke, T. M.; Kampf, J. W.; O’Keeffe, M.; Yaghi, O. M. J. Am. Chem. Soc. 2000, 122, 11559. (31) Keller, S. W. Angew. Chem, Int. Ed. 1997, 36, 247. (32) (a) Wells, A. F. Three-Dimensional Nets and Polyhedra; Wiley: New York, 1977. (b) Wells, A. F. Further Studies of Three-Dimensional Nets; American Crystallographic Association (distributed by Polycrystal Book Service): New York (Pittsburgh, PA), 1979. (c) O’Keeffe, M.; Hyde, B. G. Crystal Structures I. Patterns and Symmetry; Mineralogical Society of America: Washington, DC, 1996. (d) Blake, A. J.; Champness, N. R.; Hubberstey, P.; Li, W. S.; Withersby, M. A.; Schröder, M. Coord. Chem. ReV. 1999, 183, 117. (e) Friedrichs, O. D.; O’Keeffe, M.; Yaghi, O. M. Acta Crystallogr. 2003, A59, 22. (f) Qin, C.; Wang, X. L.; Wang, E. B.; Su, Z. M. Inorg. Chem. 2005, 44, 7122. (33) (a) Han, S.; Smith, J. V. Acta Crystallogr. 1999, A55, 322. (b) Robson, R. J. Chem. Soc., Dalton Trans. 2000, 3735. (c) O’Keeffe, M.; Eddaoudi, M.; Li, H.; Reineke, T.; Yaghi, O. M. J. Solid State Chem. 2000, 152, 3. (d) Batten, S. R. CrystEngComm 2001, 3, 67. (e) Biradha, K. CrystEngComm 2003, 5, 374. (f) Barnett, S. A.; Champness, N. R. Coord. Chem. ReV. 2003, 246, 145. (g) Carlucci, L.; Ciani, G.; Proserpio, D. M. Coord. Chem. ReV. 2003, 246, 247. (h) Blatov, V. A.; Carlucci, L.; Ciani, G.; Proserpio, D. M. CrystEngComm 2004, 6, 377. (34) Ockwig, N. W.; Delgado-Friederichs, O.; O’Keeffe, M.; Yaghi, O. M. Acc. Chem. Res. 2005, 38, 176. (35) Cerius2 ;Molecular Simulation/Biosystems Corporation, San Diego, CA, 1995. (36) Li, J.; Yu, J.; Yan, W.; Xu, Y.; Xu, W.; Qiu, S.; Xu, R. Chem. Mater. 1999, 11, 2600. (37) Sheldrick, G. M. SHELX-97, Program for Structure Refinement; University of Göttingen, Göttingen (Germany), 1997. (38) van der Sluis, P.; Spek, A. L. Acta Crystallogr. 1990, A46, 194. (39) Dalrymple, S. A.; Shimizu, G. K. H. Chem. Eur. J. 2002, 8, 3010.

CG070604F