Coordination Behavior of 5,6-Substituted 1,10-Phenanthroline

Apr 7, 2010 - Three 5,6-substituted 1,10-phenanthroline derivatives exhibit two types of ... Bis-Pyridyl Organic Linkers for Single-Component Light-Em...
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DOI: 10.1021/cg901431r

Coordination Behavior of 5,6-Substituted 1,10-Phenanthroline Derivatives and Structural Diversities by Coligands in the Construction of Lead(II) Complexes

2010, Vol. 10 2174–2184

Xiu-Li Wang,* Yong-Qiang Chen, Qiang Gao, Hong-Yan Lin, Guo-Cheng Liu, Jin-Xia Zhang, and Ai-Xiang Tian Faculty of Chemistry and Chemical Engineering, Bohai University, Jinzhou 121000, People’s Republic of China Received November 16, 2009; Revised Manuscript Received February 11, 2010

ABSTRACT: Eight new Pb(II) metal-organic coordination polymers, {[Pb(3-PDIP)2(1,4-bdc)] 3 4H2O}n (1), [Pb(3-PDIP)2(bpea)]n (2), [Pb(HOIP)(pyc)2]2 (3), [Pb(HOIP)(1,3-bdc)]n (4), {[Pb(4-PDIP)(glu)] 3 H2O}n (5), {[Pb(4-PDIP)(1,4-bdc)] 3 2H2O}n (6), [Pb(4-PDIP)(1,3-bdc)]n (7), and [Pb(4-PDIP)(4,40 -bpdc)]n (8) (3-PDIP = 2-(3-pyridine) imidazo[4,5-f ]1,10-phenanthroline, HOIP=2-(4-hydroxylbenzene) imidazo[4,5-f ]1,10-phenanthroline, 4-PDIP=2-(4-pyridine) imidazo[4,5-f ]1,10-phenanthroline, 1,4-H2bdc=benzene-1,4-dicarboxylic acid, H2bpea=biphenylethene-4,40 -dicarboxylic acid, Hpyc=pyridyl-2-carboxylic acid, 1,3H2bdc = benzene-1,3-dicarboxylic acid, H2glu = glutaric acid, 4,40 -H2bpdc = biphenyl-4,40 -dicarboxylic acid), have been hydrothermally synthesized and structurally characterized. Complexes 1, 2, 4, and 6 possess one-dimensional (1D) chain structures. 3 is a mononuclear structure, and two separated molecules are connected by noncovalent interactions to generate an interesting double layer. 5 and 7 feature two-dimensional networks with (4,4) topology. Finally, complexes 1-7 are extended into threedimensional (3D) supramolecular frameworks. 8 shows a 2-fold interpenetrating 3D framework with a rare self-penetrated topology. Three 5,6-substituted 1,10-phenanthroline derivatives exhibit two types of coordination modes and play important roles in the formation of supramolecular frameworks. The diverse structures of eight complexes may result from the different coordination behaviors of 1,10-phenanthroline derivatives, the coordination geometry of Pb(II) ion, and the coligands. Moreover, the fluorescence properties of complexes 5-8 have been investigated.

Introduction Crystal engineering of metal complexes, especially coordination polymers, has been greatly developed in the past decades, not only for their intriguing topological variety and the theoretical prediction of the assembling processes, but also for their fascinating potential applications in functional materials.1-3 The structures of coordination polymers can be effectively influenced by multiple factors such as the coordination trend of metal ions, ligands, solvent system, templates, counterions, noncovalent interactions, and so on.4 Among those mentioned above, the most important ones are the geometrical and electronic properties of the metal ions and ligands. Metal complexes of 1,10-phenanthroline (1,10-phen) and its derivatives often show attractive chemical and physical properties in the area of coordination chemistry, material chemistry, analytical chemistry, metalloenzymes, probes of nucleic acids, and redox processes because of their strong chelating abilities and good π-conjugated character.5,6 Up to now, many metal complexes based on 5,6-substituted 1,10-phen derivatives have been prepared and characterized.7-14 However, studies on the coordination behavior of such ligands toward lead(II) coordination polymers are comparatively rare. To our knowledge, only three papers have been reported recently by Yang and co-workers.11 To date, although many kinds of 5,6-substituted 1,10-phen derivatives have been used, the majority of them only act as terminal ligands in its complexes similar to 1,10-phen. In this *Corresponding author. E-mail: [email protected]. Fax: þ86-4163400158. Tel: þ86-416-3400158. pubs.acs.org/crystal

Published on Web 04/07/2010

article, we chose three 5,6-substituted 1,10-phen derivatives 2-(3pyridine) imidazo [4,5-f ]1,10-phenanthroline (3-PDIP), 2-(4hydroxylbenzene) imidazo[4,5-f ]1,10-phenanthroline (HOIP), and 2-(4-pyridine) imidazo[4,5-f ]1,10-phenanthroline (4-PDIP) (Scheme 1) in view of their following characteristics: (1) Compared with 1,10-phen, the three ligands contain an extended π-system and potential hydrogen bonding groups, which have more probability to form high-dimensional supramolecular architectures. (2) Unlike the related 5,6-substituted 1,10-phen derivatives 2-phenyl imidazo[4,5-f ]1,10-phenanthroline (PIP),15 the three ligands provide potential coordination sites (the hydroxyl group in HOIP ligand, the pyridyl group in 3-PDIP, and 4-PDIP ligands). The feature of these ligands could increase the flexibility and enrich their coordination modes compared with the 1,10-phen. Thus, three N-dornor ligands HOIP, 3-PDIP, and 4-PDIP are different from previously reported 1,10-phen derivatives, which maybe act as bridging linkers in the construction of coordination polymers. On the other hand, as a heavy p-block metal ion, lead(II), with its large radius and flexible coordination environment, exhibits variable coordination number and geometry with ligands.11a,16 And the intrinsic features of lead(II) inspire chemists’ extensive interests in its coordination chemistry, photophysics, and photochemistry.17 Moreover, the impact of the toxic heavy metal lead on the natural environment is reflected in the wealth of recent literature concerning the health hazards posed by lead to humans.18 In view of the steady increase in the amount of lead released into the environment by human activity, the removal of this toxic metal from the human body using chelating agents is a good method.16 r 2010 American Chemical Society

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Crystal Growth & Design, Vol. 10, No. 5, 2010 Scheme 1. Molecular Structure of Ligands

Herein, we report eight new Pb(II) complexes with different structures, namely, {[Pb(3-PDIP)2(1,4-bdc)] 3 4H2O}n (1), [Pb(3-PDIP)2(bpea)]n (2), [Pb(HOIP)(pyc)2]2 (3), [Pb(HOIP)(1,3-bdc)]n (4), {[Pb(4-PDIP)(glu)] 3 H2O}n (5), {[Pb(4-PDIP)(1,4-bdc)] 3 2H2O}n (6), [Pb(4-PDIP)(1,3-bdc)]n (7), and [Pb(4-PDIP)(4,40 -bpdc)]n (8), where 1,4-H2bdc = benzene1,4-dicarboxylic acid, H2bpea = biphenylethene-4,40 -dicarboxylic acid, Hpyc = pyridyl-2-carboxylic acid, 1,3-H2bdc = benzene-1,3-dicarboxylic acid, H2glu=glutaric acid, 4,40 -H2bpdc=biphenyl-4,40 -dicarboxylic acid (Scheme 1), which were obtained by three 5,6-substituted 1,10-phen neutral ligands in the presence of different organic acids. On the basis of synthesis and structural characterization, the influence of organic carboxylate linkers and neutral N-dornor ligands on the control of the final complex structures and the role of weak intermolecular interactions in the creation of molecular architectures are discussed. Moreover, the fluorescence properties of the complexes 5-8 have been investigated in the solid state. Experimental Section Materials and Measurements. All chemicals were used as supplied from commercial sources without further purification. The N-donor ligands HOIP, 3-PDIP, and 4-PDIP were synthesized by the methods of the literature19 and characterized by FT-IR spectra and 1H NMR. FT-IR spectra (KBr pellets) were taken on a Magna FT-IR 560 spectrometer. Elemental analyses were performed on a Perkin-Elmer 2400CHN analyzer. Fluorescence spectra were performed on a Hitachi F-4500 fluorescence/phosphorescence spectrophotometer at room temperature. Synthesis of {[Pb(3-PDIP)2(1,4-bdc)] 3 4H2O}n (1). A mixture of PbSO4 (0.03 g, 0.1 mmol), 3-PDIP (0.03 g, 0.1 mmol), 1,4-H2bdc (0.017 g, 0.1 mmol), H2O (8 mL), and NaOH (2.2 mL, 0.1 mol/L) was stirred for 30 min in air, and then transferred and sealed in a 25 mL Teflon reactor, which was heated at 170 °C for 5 days leading to the formation of yellow block crystals of 1. Yield 10% based on Pb(II). Anal. Calc. for C44H26N10O8Pb (1029.95): C, 51.26; H, 2.52; N, 13.59%. Found: C, 51.37; H, 2.38; N, 13.41%. IR (KBr, cm-1): 3349w, 2364m, 1556s, 1444m, 1369s, 1181w, 1128w, 1074m, 1032w, 951w, 812s, 753s, 732s, 710m, 630w. Synthesis of [Pb(3-PDIP)2(bpea)]n (2). The preparation of 2 was similar to that of 1 except that H2bpea (0.027 g, 0.1 mmol) was used instead of 1,4-H2bdc and Pb(NO3)2 (0.033, 0.1 mmol) was used instead of PbSO4. Yellow block crystals of 2 were obtained. Yield 8% based on Pb(II). Anal. Calc. for C52H32N10O4Pb (1068.08): C, 58.43; H, 3.00; N, 13.11%. Found: C, 58.59; H, 2.89; N, 12.93%. IR (KBr, cm-1): 3035w, 2355m, 1578s, 1534s, 1367s, 1178w, 1070m, 973w, 849w, 806m, 784m, 736m, 682m, 622w.

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Synthesis of [Pb(HOIP)(pyc)2]2 (3). A mixture of Pb(NO3)2 (0.033 g, 0.1 mmol), HOIP (0.031 g, 0.1 mmol), Hpyc (0.025 g, 0.2 mmol), H2O (7 mL), and NaOH (2.1 mL, 0.1 mol/L) was stirred for 30 min in air, and then transferred and sealed in a 25 mL Teflon reactor, which was heated at 150 °C for 5 days leading to the formation of yellow block crystals of 3. Yield 13% based on Pb(II). Anal. Calc. for C31H20N6O5Pb (763.73): C, 48.71; H, 2.62; N, 11.00%. Found: C, 48.57; H, 2.75; N, 11.18%. IR (KBr, cm-1): 3159w, 3067w, 2360w, 1610s, 1588s, 1556s, 1480m, 1448m, 1372s, 1281s, 1237m, 1167m, 1065m, 843m, 806m, 757m, 692s, 628 m. Synthesis of [Pb(HOIP)(1,3-bdc)]n (4). A mixture of Pb(Ac)2 3 3H2O (0.037 g, 0.1 mmol), HOIP (0.016 g, 0.05 mmol), 1,3H2bdc (0.017 g, 0.1 mmol), CH3OH (1 mL), H2O (7 mL), and triethylamine (1.2 mL, 0.1 mol/L) was stirred for 30 min in air, and then transferred and sealed in a 25 mL Teflon reactor, which was heated at 170 °C for 3 days leading to the formation of yellow block crystals of 4. Yield 11% based on Pb(II). Anal. Calc. for C27H15N4O5Pb (682.63): C, 47.47; H, 2.20; N, 8.20%. Found: C, 47.29; H, 2.06; N, 8.39%. IR (KBr, cm-1): 3191w, 2360w, 1599s, 1518s, 1475m, 1432m, 1372s, 1237m, 1184m, 1065m, 1038w, 843m, 752m, 709s, 638w. Synthesis of {[Pb(4-PDIP)(glu)] 3 H2O}n (5). The preparation of 5 was similar to that of 1 except that glutaric acid (0.013 g, 0.1 mmol) was used instead of 1,4-H2bdc, 4-PDIP was used instead of 3-PDIP, and Pb(NO3)2 (0.033, 0.1 mmol) was used instead of PbSO4. Yellow block crystals of 5 were obtained. Yield 25% based on Pb(II). Anal. Calc. for C23H17N5O5Pb (650.62): C, 42.42; H, 2.61; N, 10.76%. Found: C, 42.26; H, 2.74; N, 10.59%. IR (KBr, cm-1): 3412w, 2959m, 2360w, 1545s, 1389s, 1259w, 1140w, 1059m, 1027w, 827m, 730m, 703m, 665m, 644m. Synthesis of {[Pb(4-PDIP)(1,4-bdc)] 3 2H2O}n (6). The preparation of 6 was similar to that of 1 except that 4-PDIP (0.015, 0.05 mmol) was used instead of 3-PDIP. Yellow block crystals of 6 were obtained. Yield 20% based on Pb(II). Anal. Calc. for C26H15N5O6Pb (700.63): C, 44.53; H, 2.14; N, 9.99%. Found: C, 44.37; H, 2.27; N, 9.83%. IR (KBr, cm-1): 3038w, 2353s, 1561s, 1363s, 1069w, 834m, 742m, 667m. Synthesis of [Pb(4-PDIP)(1,3-bdc)]n (7). The preparation of 7 was similar to that of 6 except that 1,3-H2bdc (0.017 g, 0.1 mmol) was used instead of 1,4-H2bdc and Pb(NO3) (0.033, 0.1 mmol) was used instead of PbSO4. Yellow block crystals of 7 were obtained. Yield 18% based on Pb(II). Anal. Calc. for C26H15N5O4Pb (668.63): C, 58.43; H, 3.00; N, 13.11%. Found: C, 58.59; H, 2.89; N, 12.93%. IR (KBr, cm-1): 3056w, 2360w, 1605s, 1540s, 1432m, 1362s, 1059m, 806m, 746s, 709s, 671m, 628m. Synthesis of [Pb(4-PDIP)(4,40 -bpdc)]n (8). A mixture of PbC2O4 (0.03 g, 0.1 mmol), 4-PDIP (0.03 g, 0.1 mmol), 4,40 -H2bpdc (0.024 g, 0.1 mmol), H2O (8 mL), and NaOH (2.5 mL, 0.1 mol/L) was stirred for 30 min in air, and then transferred and sealed in a 25 mL Teflon reactor, which was heated at 150 °C for 5 days leading to the formation of yellow block crystals of 8. Yield 28% based on Pb(II). Anal. Calc. for C32H19N5O4Pb (744.72): C, 51.56; H, 2.55; N, 9.40%. Found: C, 51.67; H, 2.41; N, 9.37%. IR (KBr, cm-1): 3040w, 2365w, 1605m, 1578s, 1523m, 1378s, 1059m, 1000m, 833s, 773s, 730s, 698s, 676s. Crystal Structure Determination. All diffraction data were collected using a Bruker Apex CCD diffractometer (Mo-KR radiation, graphite monochromator, λ=0.71073 A˚). The structures were solved by direct methods with SHELXS-97 and Fourier techniques and refined by the full-matrix least-squares method on F2 with SHELXL-97.20,21 All non-hydrogen atoms were refined anisotropically, the H atoms from nitrogen atom of imidazole ring in HOIP, 3-PDIP, or 4-PDIP were located in different Fourier synthesis maps, and other hydrogen atoms of the ligands were generated theoretically onto the specific atoms and refined isotropically with fixed thermal factors. The H-atoms of water molecules have not been localized. All the crystal data and structure refinement details for the eight complexes are given in Table 1. The data of relevant bond distances and angles are listed in Table S1, Supporting Information and hydrogen-bonding geometries are summarized in Table S2, Supporting Information. CCDC: 748044-748051 for complexes 1-8, respectively.

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Table 1. Crystal Data and Structure Refinement Parameters for Complexes 1-8 formula fw space group a [A˚] b [A˚] c [A˚] R [°] β [°] γ [°] V (A˚ 3) D/g cm-3 Z F(000) μ/mm-1 R /wR [I > 2σ(I)] a GOF on F2

1

2

3

4

C44H26N10O8Pb 1029.95 P21/c 11.5808(12) 17.4629(18) 19.585(2) 90 91.4180(10) 90 3959.5(7) 1.728 4 2024 4.332 0.0478/0.1013 1.001

C52H32N10O4Pb 1068.08 Pnna 8.5980(7) 31.731(3) 15.4683(13) 90 90 90 4220.1(6) 1.681 4 2112 4.061 0.0457/0.1326 1.005

C31H20N6O5Pb 763.73 P21/c 15.7551(13) 17.4602(15) 20.7841(13) 90 115.010(5) 90 5181.3(7) 1.958 8 2960 6.570 0.0341/0.0565 0.942

C27H15N4O5Pb 682.63 C2/c 14.517(18) 16.34(2) 20.00(2) 90 110.61(8) 90 4441(9) 2.042 8 2616 7.649 0.0252/0.0512 1.035

5

6

C26H15N5O6Pb formula C23H17N5O5Pb fw 650.62 700.63 P21/c space group P1 a [A˚] 9.3674(12) 10.2350(12) b [A˚] 9.4589(12) 13.7970(16) c [A˚] 12.6197(16) 19.4061(17) R [°] 95.391(2) 90 β [°] 102.858(2) 117.958(5) γ [°] 100.959(2) 90 1059.4(2) 2420.6(5) V (A˚3) 2.040 1.923 D/g cm-3 Z 2 4 F(000) 624 1344 8.011 7.023 μ/mm-1 0.0455/0.1350 0.0448/0.1060 R /wR [I > 2σ(I)] a 2 1.011 1.049 GOF on F P P P P a R = (||F0| - |FC||)/ |F0|. wR2 = [ w(|F0|2 - |FC|2)2/( w|F0|2)2]1/2.

Results and Discussion Synthesis. Initially, the same Pb(II) salt lead nitrate was used in the assembly process of complexes 1-8 in the presence of 5,6-substituted 1,10-phen derivatives and organic carboxylate anions, only complexes 2, 3, 5, and 7 with good-quality for X-ray analysis have been obtained, while the good-quality complexes 1, 4, 6, and 8 for X-ray analysis have been thus unsuccessful. Thus, as is the case in the results reported here, the metal salt with different anions may control the formation of the product in ways that are difficult to predict beforehand. Moreover, the yields of compounds 1-4 are very low. Structural Description of 1 and 2. Single-crystal X-ray diffraction analysis reveals that complex 1 consists of one Pb(II) ion, two 3-PDIP ligands, one 1,4-bdc anion, and four disordered uncoordinated water molecules, as shown in Figure 1a. Each Pb(II) ion is a hepta-coordinated environment by four nitrogen atoms from two 3-PDIP chelating ligands with the Pb-N bond distances in the range of 2.530(6)-2.731(7) A˚, and three oxygen atoms belonging to two carboxylate groups from two separated 1,4-bdc anions with the Pb-O bond lengths ranging from 2.543(6) to 2.685 (6) A˚. In 1, two carboxylate groups of 1,4-bdc anion adopting different coordination modes (chelating/monodentate) link a pair of neighboring Pb(II) ions to form a [Pb2N8(1,4-bdc)] unit with a Pb-Pb distance of 11.934 A˚. All 1,4-bdc anions adopt an effective tridentate bridging coordination mode by μ-O atoms connecting [Pb2N8(1,4-bdc)] units to a onedimensional (1D) infinite zigzag chain (Figure S1a, Supporting Information). It should be pointed out that the coordination mode of 1,4-bdc anion was very different from

7

8

C26H15N5O4Pb 668.63 C2/c 15.2410(10) 15.0400(10) 19.7935(13) 90 108.8300(10) 90 4294.3(5) 2.068 8 2560 7.906 0.0218/0.0506 1.019

C32H19N5O4Pb 744.72 P3121 15.0313(15) 15.0313(15) 20.896(2) 90 90 120 4088.7(7) 1.815 6 2160 6.238 0.0431/0.0650 0.946

the related complex [Pb(ptc)(1,4-bdc)] 3 0.75H2O (ptc = 2-phenyl-1H-1,3,7,8,-teraaza-cyclopenta[l]-phenanthrence) reported by Ma et al.,11c in which two carboxylate groups of 1,4-bdc anion only adopt the same coordination mode. Interestingly, two 3-PDIP ligands of each Pb(II) ion could be described as a “V” shape with a dihedral angle of 85.63°, which are attached to both sides of the zigzag chain. In addition, interchain N-H 3 3 3 O and C-H 3 3 3 O hydrogen bonds (Table S2, Supporting Information) are present and assemble the neighboring 1D chain into a three-dimensional (3D) supramolecular structure (Figure 1b). In addition, π-π stacking interactions between 3-PDIP ligands within the supramolecular structure of 1 are found with face-to-face separations in the range of 3.558(5)-3.695(5) A˚ (Figure S1b, Supporting Information), which also play a significant role in the stabilization of the supramolecular structure. To evaluate the effect of the flexibility (the spacer length of carboxyl groups and the structural rigidity of the spacer) of dicarboxylate ligands on the framework formation of complex, we selected H2bpea to react with lead(II) salt. The complex 2 consisting of a 1D zigzag chain with a smaller pitch than 1 was obtained. Complex 2 crystallizes in the orthorhombic space group Pnna, and the coordination environment around Pb(II) is shown in Figure 2a. Each Pb(II) ion sits in a distorted pentagonal pyramidal geometry defined by four nitrogen atoms (Pb1-N1, 2.664(7) A˚; Pb1-N2, 2.621(8) A˚; Pb1-N1#1, 2.664(7) A˚; Pb1-N2#1, 2.621(8) A˚) of two 3-PDIP chelating ligands, and two oxygen atoms (Pb1-O1, 2.651(7) A˚; Pb1-O1#1, 2.651(7) A˚) belonging to two carboxylate groups from two separated bpea

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Figure 1. (a) View of the coordination environment of Pb(II) in complex 1; thermal ellipsoids are drawn at the 30% probability level. Lattice water molecules and hydrogen atoms have been omitted for clarity. (b) The 3D supramolecular architecture by hydrogen bonding interactions (green broken lines represent hydrogen bonding interactions).

anions. Thus, the coordination number of Pb(II) ion in 2 is different from that in complex 1. The bpea anions in 2 only exhibit one coordination mode, bridging bis-monodentate, which is comparable to those in the previously reported bpea-M complexes.10d,22 The neighboring Pb(II) ions are connected by bpea anions to construct a 1D chain with Pb-Pb of 18.686 A˚ (Figure S2a, Supporting Information). Like 1, 3-PDIP ligands are also attached to both sides of the 1D chain in 2. As shown in Figure 2b, the 3-PDIP ligands from adjacent chains are well assembled to each other by π-π stacking interactions with face-to-face separations in the range of 3.610(6)-3.710(6) A˚ (Figure S2b, Supporting Information), extending the 1D chain into a 3D supramolecular network. Moreover, the hydrogen-bonding interactions originating from the imidazole ring H4A atom of 3-PDIP ligand and the uncoordinated carboxyl O2 atom of bpea anion between the adjacent chains (N4-H4A 3 3 3 O2, 2.678(9) A˚) stabilized the 3D supramolecular structure (FigureS2c, Supporting Information). Structural Description of 3 and 4. When another 5,6substituted 1,10-phen derivative HOIP was used in the presence of Hpyc or 1,3-H2bdc, complexes 3 and 4 were obtained. Complex 3 exhibits a discrete asymmetric structure constructed from HOIP ligands and pyc anions. Interestingly, there are two crystallographically unique mononuclear molecules in 3. As depicted in Figure 3a, each Pb(II) ion is six coordinated and exhibits a pentagonal pyramidal environment supplied by two nitrogen atoms from the HOIP

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Figure 2. (a) View of the coordination environment of Pb(II) in complex 2; thermal ellipsoids are drawn at the 30% probability level. Hydrogen atoms have been omitted for clarity. (b) The 3D supramolecular architecture by π-π stacking interactions (broken lines represent π-π stacking interactions).

ligand (Pb1-N1, 2.731(4) A˚; Pb1-N2, 2.777(4) A˚; Pb2-N9, 2.749(4) A˚; Pb2-N10, 2.810(4) A˚), two nitrogen atoms from two separated pyc anions (Pb1-N5, 2.641(4) A˚; Pb1-N6, 2.430(4) A˚; Pb2-N11, 2.617(4) A˚; Pb2-N12, 2.407(4) A˚), and two oxygen atoms of two separated pyc anions (Pb1-O1, 2.500(4) A˚; Pb1-O3, 2.420(4) A˚; Pb2-O5, 2.448(4) A˚; Pb2-O7, 2.475(4) A˚). In complex 3, the HOIP ligands act as hydrogen bond donors to the uncoordinated oxygen atoms of pyc anions and exhibit two kinds of hydrogen-bonding interactions. As illustrated in Figure 3b, a R44(42) hydrogen bonding ring structure involving O-H 3 3 3 O (O9-H9A 3 3 3 O2, 2.670(8) A˚; O10-H10A 3 3 3 O8, 2.608(6) A˚) and N-H 3 3 3 O (N4-H4A 3 3 3 O4, 2.811(6) A˚; N7-H7A 3 3 3 O6, 2.860(6) A˚) interactions is formed in 3. The resulting discrete mononuclear structure is further cross-linked via the hydrogen bonding interactions to generate an interesting two-dimensional (2D) supramolecular layer (Figure 3b). We can consider each HOIP ligand to be 3-connected node; thus a 2D supramolecular layer constructed from 3-connected hydrogen bonds has been obtained in 3. The most interesting structure feature of complex 3 is that π-π stacking interactions exist between crystallographically unique molecules (the face-to-face separation is 3.779(4) A˚. Figure S3, Supporting Information). Therefore, two unique 2D hydrogen bonding layers are further extended into an interesting supramolecular double layer structure (Figure 3c). Although double-layer coordination polymers have been reported,23 s2 metal complexes with a double layer formed by π-π stacking and hydrogen bonding interactions have not been documented. To our knowledge, only a related lead complex with the double

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Figure 3. (a) View of the coordination environment of Pb(II) in complex 3; thermal ellipsoids are drawn at the 30% probability level. Hydrogen atoms have been omitted for clarity. (b) The 2D supramolecular network with a R44(42) ring structure via hydrogen bonding interactions. (c) The 2D double layer structure by hydrogen bonding and π-π stacking interactions (blue broken lines represent π-π stacking interactions; green broken lines represent hydrogen bonding interactions).

layer structure constructed of π-π interactions has been reported by now.11a The results indicate that the weak noncovalent interactions are important in the formation of the final supramolecular structure of 3. Complex 4, obtained by using 1,3-H2bdc, is a 1D ladder chain strucure based on dimetal Pb2 units. Figure 4a illustrates the coordination environment of the Pb(II) ions. Each Pb(II) ion was coordinated by two nitrogen atoms of HOIP ligand (Pb1-N1, 2.642(4) A˚; Pb1-N2, 2.497(4) A˚), three carboxylic oxygen atoms of two different 1,3-bdc anions (Pb1-O1, 2.463(5) A˚; Pb1-O3#1, 2.408(4) A˚; Pb1-O4#1, 2.579(4) A˚), and one hydroxyl oxygen atom from HOIP ligand (Pb1-O5#2, 2.922(5) A˚), which exhibits a distorted pentagonal pyramidal environment similar to 3. The Pb-O distances are similar to the average Pb-O bond length of 2.77 A˚.16,24

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Figure 4. (a) View of the coordination environment of Pb(II) in complex 4; thermal ellipsoids are drawn at the 30% probability level. Hydrogen atoms have been omitted for clarity. (b) The 2D supramolecular layer with a R22(18) ring formed by hydrogen bonding interactions (green broken lines represent hydrogen bonding interactions). (c) The 3D supramolecular architecture by weak interactions (blue broken lines represent π-π stacking interactions).

In complex 4, two carboxylate groups of each 1,3-bdc adopt different coordination modes (monodentate and bidentate) connecting two adjacent Pb(II) ions with a Pb-Pb distance of 8.145 A˚ to form a dimetal Pb2 units. Furthermore, each HOIP ligand adopts a μ2-κO:κN,N0 mode connecting the dimetal Pb2 units, resulting in a 1D ladder chain (Figure S4a, Supporting Information). It is worth noting that the coordination behavior of HOIP ligand is very different from the related complex [Pb2(ndc)2(HOIP)] (ndc=1,4-naphthalenedicarboxylate).11a Unlike 3, complex 4 possesses only one kind of hydrogen bonding interaction. As shown in Figure 4b, a R22(18) hydrogen bonding ring involving N-H 3 3 3 O (N4-H4A 3 3 3 O4, 2.896(6) A˚) is obtained and the 1D chain is extended into a 2D supramolecular layer by hydrogen bonding interactions. Differing from complexes 1 and 2, the N-donor HOIP ligands are arranged acting as the backbone of a 1D chain structure in 4, and stacked through π-π interactions (the face-to-face distances 3.715(5)-3.774(5) A˚, Figure S4b, Supporting Information); thus, the 2D supramolecular layers are further extended into a 3D supramolecular framework (Figure 4c). Structural Description of 5-8. When the 5,6-substituted 1,10-phen derivative 4-PDIP was used in the presence of

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Figure 5. (a) View of the coordination environment of Pb(II) in complex 5; thermal ellipsoids are drawn at the 30% probability level. Lattice water molecules and hydrogen atoms have been omitted for clarity. (b) The 2D network with (4,4)-connected topology. (c) The 3D supramolecular architecture by weak interactions (blue broken lines represent π-π stacking interactions; green broken lines represent hydrogen bonding interactions).

H2glu, 1,4-H2bdc, 1,3-H2bdc, or 4,40 -H2bpdc, complexes 5-8 were obtained. Single crystal X-ray analysis reveals that the asymmetric unit of 5 contains one Pb(II) ion, one 4-PDIP ligand, one glu anion, and one disordered uncoordinated water molecule. Each Pb(II) ion is six coordinated and exhibits a pentagonal pyramidal environment supplied by three oxygen atoms from the carboxylate groups of two unique glu anions with normal Pb-O distances from 2.384(8) to 2.672(8) A˚, and three nitrogen atoms of one 4-PDIP ligand (Pb1-N1, 2.783(8) A˚; Pb1-N2, 2.730(9) A˚; Pb1-N5#2, 2.789(9) A˚), as illustrated in Figure 5a. The Pb-Npyridyl bond length is slightly longer than the Pb-Nphen bond length. In 5, all glu anions adopt the same bridging coordination mode and link the neighboring Pb(II) ions to form a 1D

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chain structure with a Pb-Pb distance of 9.367 A˚. The 4-PDIP ligand with a μ2-κN:κN,N0 bridging mode further connects such chains to generate a network that is topologically equivalent to a (4,4) network (Figure 5b). In fact, the 4-PDIP ligand plays an important role in the formation of the final structure of 5. Compared with the aforementioned complexes, 5 shows weak N-H 3 3 3 O hydrogen bonding interactions (N4-H4A 3 3 3 O4, 3.0103 A˚). Interestingly, two ring motifs are formed in an -ABAB- sequence through the hydrogen bonding interactions involving N-H 3 3 3 O interactions, namely, the R22(20) ring (A) and R22(30) ring (B) (Figure S5a, Supporting Information). In addition, the π-π stacking interactions are observed between 4-PDIP ligands (the face-to-face distances 3.7778 and 3.8780 A˚, respectively. Figure S5b, Supporting Information). Thus, the 2D layers are interacted by weak interactions, leading to a 3D supramolecular structure (Figure 5c). When the rigid 1,4-bdc was used instead of glu, complex 6 was obtained in the presence of the 4-PDIP ligand. As shown in Figure 6a, each Pb(II) ion is coordinated by two nitrogen atoms from one 4-PDIP ligand (Pb1-N1, 2.666(7) A˚; Pb1-N2, 2.685(8) A˚), and four oxygen atoms from two different 1,4-bdc anions (Pb1-O1, 2.393(7) A˚; Pb1-O2, 2.671(7) A˚; Pb1-O3, 2.592(6) A˚; Pb1-O4, 2.384(6) A˚), showing a distorted pentagonal pyramidal environment. In addition, there are two disordered uncoordinated water molecules in 6. Unlike 1, each carboxylate moiety in 6 chelates one Pb(II) ion in a bidentate mode. All 1,4-bdc anions assume one kind of coordination mode, namely, bridging bis(bidentate). The adjacent Pb(II) ions are bridged by 1,4-bdc ligands to form a 1D zigzag chain with the Pb-Pb distance of 11.454 A˚ (Figure S6a, Supporting Information). Similar to complexes 1 and 2, the N-donor ligands are also attached to both sides of 1D chain. It is noteworthy that there are different types of π-π interactions compared with those of complexes 1-5 (Figure S6b, Supporting Information). The 1D chains are interacted by one type of π-π stacking among 4-PDIP ligands (the face-to-face distance 3.609(9) A˚) to form an interesting 2D supramolecular network (Figure 6b). Furthermore, the neighboring 2D networks are connected by another type of strong π-π stacking interaction with a face-to-face distance of 3.482(7) A˚ between 4-PDIP and 1,4-bdc to form a 3D supramolecular structure (Figure 6c). The direct hydrogen bonding interactions between 4-PDIP and 1,4-bdc have not been observed in 6; however, the water molecule goes between the neighboring 4-PDIP ligands and joins them by N-H 3 3 3 O and O-H 3 3 3 N hydrogen bonds. To evaluate the effect of position of carboxylate groups of the dicarboxylate ligand on the framework formation of complex, we selected 1,3-H2bdc to react with lead salt in the presence of the same N-donor ligand and obtained complex 7. Complex 7 has a corrugated network structure. In 7, each Pb(II) ion sits in an irregular hepta-coordinated environment by three nitrogen atoms of two 4-PDIP ligands with the Pb-N bond distances in the range of 2.682(3)-2.872(4) A˚, and four oxygen atoms from three separated 1,3-bdc anions with the Pb-O bond lengths ranging from 2.437(3) to 2.672(3) A˚ (Figure 7a). Compared with complex 4, 1,3-bdc anion adopts a different coordination mode in 7: chelating monobidentate and bridging monobidentate. Two Pb(II) ions related by a 2-fold axis are bridged by a pair of 1,3bdc μ-carboxylate ends into a dinuclear Pb2 unit, and the intradimer Pb-Pb distance is 8.054 A˚. The V-shaped 1,3-bdc

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Figure 6. (a) View of the coordination environment of Pb(II) in complex 6; thermal ellipsoids are drawn at the 30% probability level. Lattice water molecules and hydrogen atoms have been omitted for clarity. (b) The 2D layer structure formed by π-π stacking interactions between 4-PDIP ligands (blue broken lines represent π-π stacking interactions). (c) The 3D supramolecular architecture by weak interactions.

anion further acts as a chelate-bidentate ligand and links the adjacent Pb(II) ions to 1D double chain based on a doublestrand helix that has a 10.152 A˚ pitch (Figure S7a, Supporting Information). Like complex 5, the 4-PDIP ligands further connect the adjacent 1D ribbon chains into a 2D (4,4) corrugated network in 7 (Figure 7b). The weak noncovalent interactions also play an important role in the formation and stabilization of the final structure of 7. The neighboring 2D corrugated layers interact by π-π stacking interactions between the 4-PDIP ligands (face-to-face distances in the range of 3.680(2)-3.880(3) A˚, Figure S7b, Supporting Information), leading to a 3D supramolecular structure (Figure 7c). However, hydrogen bonding interactions do not exist within the supramolecular structure in 7.

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Figure 7. (a) View of the coordination environment of Pb(II) in complex 7; thermal ellipsoids are drawn at the 30% probability level. Hydrogen atoms have been omitted for clarity. (b) The corrugated 2D layer structure with (4,4) topology. (c) The 3D supramolecular framework by weak interactions.

When the rigid-rod tether 4,40 -H2bpdc was employed, intending to observe the effect of long rigid ligand on the assembly of complexes, complex 8 with an expected high dimension was obtained. Up to now, only two 3D complexes have been reported by us and Wu et al. based on the 5,6substituted 1,10-phen derivative of R-IP type (Scheme 1) under the existence or nonexistence of organic dicarboxylate anions.25 The asymmetric unit of 8 includes one Pb(II) ion, one 4,40 -bpdc anion, and one 4-PDIP ligand. Each Pb(II) ion is eight-coordinated by three nitrogen atoms of a 4-PDIP ligand with distances of Pb-N of 2.730(9)-2.865(8) A˚, and five oxygen atoms from three 4,40 -bpdc anions with Pb-O bond distances in the range of 2.486(7)-2.685(7) A˚. Thus, the polyhedron of the Pb(II) coordination sphere for complex 8 is best described as a distorted square antiprism according to the related report in the literature (Figure 8a).11a,26

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Figure 8. (a) View of the coordination environment of Pb(II) in complex 8; thermal ellipsoids are drawn at the 30% probability level. Hydrogen atoms have been omitted for clarity. (b) The sixconnected binuclear lead clusters. (c) The 6-connected 3D network with self-penetrating (blue, yellow, and purple line). (d) The 2-fold interpenetrated structure along the a-axis.

In 8, all 4,40 -bpdc anions adopting a chelating bis-bidentate/ bridging monomonodentate coordination mode through monodentate moieties link a pair of Pb(II) ions to form [Pb2O8] units with Pb-Pb separations of 4.017 A˚. Each [Pb2O8] unit is fused to four neighboring units by the 4,40 -bpdc anion

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arms with a different orientation to form a 3D Pb(II)-4,40 bpdc network structure along the [010] direction (Figure S8a, Supporting Information). Interestingly, when viewed along the c-axis, the 3D network contains a 3-fold helix axis (Figure S8b, Supporting Information). Like complexes 5 and 7, the 4-PDIP ligand also adopts a μ2-κN:κN,N0 bridging mode, which extends the Pb(II)-4,40 -bpdc network into a complicated 3D framework. A better insight into the structure of 8 can be obtained by the standard procedure of reducing multidimensional structures to simple node-and-linker reference nets known as the topological approach.27 As shown in Figure 8b, the [Pb2O8N6] unit can be viewed as a six-connected linker, keeping two 4-PDIP ligands as doubled linkers and 4,40 -bpdc anions as spacers, respectively. So the 3D metal organic frameworks (MOFs) of 8 can be considered to be 6-connected net, and it can be regarded as a (44,510,7) topology analyzed by the OLEX program (Figure 8c).28 In order to minimize the big void cavities and stabilize the framework, the potential void cavities are filled by another identical network, resulting in a 2-fold interpenetrating array (Figure 8d). The most interesting structure feature of complex 8 is different from the 41263 topology in the NaCl-type structure, which represents a rare 6-connected self-penetrating 3D structure. It is noteworthy that the structure of 8 is entirely different from that of the related selfpenetrating complex {Pb(II)(C6H4O2N)2}n (C6H4O2N = isonicotinic acid),29 which possesses cross-linked puckered sheets of (4, 4) nets and the final structure has not become a 2-fold interpenetrating array. Furthermore, the π-π stacking interactions between 4-PDIP ligands within the 3D networks of 8 are found with face-to-face distances in the range of 3.647(2)-3.805(3) A˚ (Figure S8c, Supporting Information). Effect of the Center Ion and N-donor Ligands on the Structures of the Complexes. It is well-known that a lead(II) center, bearing a stereochemically active electron lone-pair and large ionic radius, can adopt variable coordination numbers ranging from 2 to 10 and versatile coordination modes such as hemidirected and holodirected geometries, which may become the decisive factors to successfully construct lead(II) complexes with different structures and dimensions.16,30 In complexes 1, 2, 7, and 8, the coordination sphere of the central Pb(II) ion is holodirected, whereas in complexes 3-6, the coordination sphere of Pb(II) ion can be regarded as hemidirected and shows the presence of a stereochemically active lone pair of electrons (Figure 9). Three kinds of coordination numbers are observed in them: hexa-coordinated for 2-6, hepta-coordinated for 1 and 7, and octa-coordinated for 8. On the basis of reports in the literature, when the coordination geometry of Pb(II) transforms from hemidirected to holodirected or the number of the coordination sites for the Pb(II) centers increases for the related Pb(II) complexes, higher dimensional framework structures usually occur.17,30b As a result, the structural and dimensional differences of 1-8 imply that the coordination geometry and the number of the coordination sites of the center Pb(II) ion have an important influence on the formation of their structures. As important phen derivatives, the 5,6-substituted 1,10-phen ligands of R-IP type (3-PDIP, 4-PDIP, and HOIP) contain both an extended π-system, additional coordination sites, and an imidazole ring, capable of acting as hydrogen bond acceptors/ donors or of forming coordination interactions to some metal ions. So, R-IP type ligands have an important function in the formation of the supramolecular framework and have more chance to assemble higher dimensional complexes. In complexes

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Figure 9. The coordination geometry of Pb(II) ions of complexes 1-8.

4, 5, 7, and 8, HOIP or 4-PDIP as a bridging ligand with a μ2-κO:κN,N0 or μ2-κN:κN,N0 mode can extend the metalcarboxylate units into higher dimensional frameworks. Obviously, the additional coordination group (the hydroxyl group in HOIP ligand and the pyridyl group in 4-PDIP) is the most critical factor in determining the final structures. Unfortunately, the coordination behavior of 3-PDIP ligand is similar to 1,10phen in complexes 1 and 2, which only exhibits a chelating coordination mode. Although the Cd(II) complex [Cd3(1,3bdc)3(3-PDIP)2] 3 8H2O with an unprecedented (5,6)-connected topology where the 3-PDIP acted as a bridging ligand has been reported by us,25a all our attempts to separate complexes 1 and 2 into different structures by changing the synthesis conditions have been thus far unsuccessful. Comparing 3-PDIP and 4-PDIP, the only difference is the position of the pyridyl N-donor. The 3-PDIP ligand has a comparatively large steric hindrance, which may decrease the ability of coordination to metal Pb(II) ion. On the other hand, complexes 1-5 show the hydrogen bonding interactions originating from H atom of the imidazole ring and the uncoordinated or coordinated O atom of carboxylate anion. It is different from 3-PDIP and 4-PDIP; the hydroxyl group in the HOIP ligand is also a good hydrogen bonding donor. In 3, two kinds of hydrogen bonding interactions are formed. The π-π stacking interactions are found in all complexes and play the most important roles in the assembly of supramolecular structures for complexes 6 and 7. It is noteworthy that the π-π stacking interactions of 6 are entirely different from the other complexes. There are two types of π-π interactions. Moreover, the different 5,6-substituted 1,10-phen derivatives can influence the coordination modes of the carboxylate anions and the Pb-Pb distance bridged by the carboxylate anions. For example, complexes 1 and 6 show an identical zigzag chain structure, whereas the 1,4-bdc anion has a different bridging mode with a Pb-Pb distance of 11.934 and 11.454 A˚, respectively. Effect of Organic Carboxylate Anions on the Structures of the Complexes. According to previous reports, the role of organic carboxylate anions can be illustrated in terms of their differences in shape, size, and flexibility.1f,11,15 For the N-donor ligand with a large conjugated π-system, the selecting of multicarboxylates anions is an effective way because they can connect metal ions or metal clusters into coordination polymers exhibiting intriguing structural and dimensional diversities. In this paper, the structural difference of 5-8 indicates that organic carboxylate anions are also important factors in the formation of such coordination architectures in the presence of the same 5,6-substituted 1,10phen derivative 4-PDIP (Figure 10). For 5, the fatty acid

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Figure 10. The coordination diversified structures in complexes 5-8.

H2glu was utilized, in order to investigate the influence of the flexibility on the complex structure. As a result, a planar 2D network with (4,4) topology was obtained. In contrast, the 1,4-H2bdc and 1,3-H2bdc possess different steric hindrance and the two carboxylate groups have 180° and 120° angles, respectively. The short 1,4-bdc is a very rigid ligand and the two carboxyl groups adopt a bridging bis(bidentate) coordination mode, which results in a 1D zigzag chain in 6. Different from 1,4-H2bdc, the carboxyl groups of 1,3-H2bdc bridge adjacent Pb2 units to form a 1D ribbon chain in 7, and the adjacent 1D ribbon chains are connected by the 4-PDIP ligands into a 2D (4,4) corrugated network. When the rigid-rod tether 4,40 -H2bpdc was employed, an interesting 3D framework with a rare self-penetrating was obtained. Different from 1,4-H2bdc, the 4,40 -H2bpdc possesses an additional benzene ring, which increases the length between two carboxyl groups. This feature may allow the 4,40 -H2bpdc to have more of a chance to assemble higher dimensional complexes in the presence of the bigger N-donor ligand. Obviously, as far as complexes 5-8 are concerned, the organic carboxylate anions are the most critical factors in determining the final structures of complexes. Fluorescence Property. Luminescence is of great importance in photochemistry and photophysics.31 Complexes of heavy metals with s2 electron configuration, which may reduce the radiative lifetime of triplets by increasing spin-orbit coupling and promote emission from the triplet state under ambient conditions, have attracted much recent attention.17,32 The Pb(II) complexes are a potential class of functional materials with interesting photic properties. The fluorescence spectra of complexes 5-8 were examined in the solid state at room temperature (Figure 11). The free ligands display emission at 385 nm (λex = 335 nm) for 1,4-H2bdc, at 350 nm (λex = 310 nm) for 1,3H2bdc,26a at 361 nm (λex=260 nm) for H2glu, at 431 nm (λex= 310 nm) for 4,40 -H2bpdc, and 473 and 535 nm (λex=340 nm) for 4-PDIP. These emission bands of free ligands can probably be assigned to the π f π* transitions. For complexes, it is clear that there are emission bands at 505 and 533 nm (λex=335 nm) for 5, 426 nm (λex=350 nm) for 6, 526 nm (λex=329 nm) for 7, and 422 nm (λex=343 nm) for 8, respectively. Compared to the emission peak of 4-PDIP ligand, only one emission peak for complexes 6 and 8 was observed. Meanwhile, an obvious blue shift has been observed in complexes 6 and 8. Therefore, the fluorescence behavior of complexes 6 and 8 are best ascribed to the ligand-tometal charge-transfer (LMCT) according to the literature.26a,30a Complexes 5 and 7 exhibit main emission bands at 533 and 526 nm, respectively, and these emissions may probably be assigned to the intraligand (n f π* or π f π*) transfer since a similar emission was observed at ca. 535 nm for the free

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Figure 11. Emission spectra of complexes 5-8 and the ligand 4-PDIP.

ligand 4-PDIP.33a Complex 8 was found to show the highest energy emission relative to complexes 5-7 and 4-PDIP ligand, which may be attributed to a different rigidity of the crystal packing in the solid state.33b Conclusions Eight new coordination polymers have been successfully isolated under hydrothermal conditions by reactions of different 5,6-substituted 1,10-phen derivatives and Pb(II) salts together with organic carboxylate anion auxiliary ligands. The HOIP and 4-PDIP ligands both exhibit bridging ligand coordination behavior with a μ2-κO:κN,N0 or μ2-κN:κN,N0 mode in complexes 4, 5, 7, and 8, respectively. The structural differences of complexes 1-8 may result from the different coordination behaviors of 1,10-phenanthroline derivatives, the coordination geometry of Pb(II) ion, and the different organic carboxylate anion auxiliary ligands. Moreover, three 5,6-substituted 1,10-phen ligands (3-PDIP, 4-PDIP, and HOIP) with the large conjugate system play crucial roles in the formation of a supramolecular framework by π-π stacking or hydrogen bonding interactions. Acknowledgment. We are thankful for financial support from the National Natural Science Foundation of China (Project No. 20871022) and Talent-supporting Program Foundation of Liaoning Province (No. 2009R03). Supporting Information Available: Eight X-ray crystallographic files (CIF); selected bond distances and angles and figures for complexes 1-8. This material is available free of charge via the Internet at http://pubs.acs.org.

References (1) (a) Seddon, K. R.; Zaworotko, M., Eds. Crystal Engineering: Dordrecht, 1996. (b) Batten, S. R.; Robson, R. Angew. Chem., Int. Ed. 1998, 37, 1460. (c) Leininger, S.; Olenyuk, B.; Stang, P. J. Chem. Rev. 2000, 100, 853. (d) Swiegers, G. F.; Malefetse, T. J. Chem. Rev. 2000, 100, 3483. (e) Moulton, B.; Zaworotko, M. J. Chem. Rev. 2001, 101, 1629. (f) Ye, B. H.; Tong, M. L.; Chen, X. M. Coord. Chem. Rev. 2005, 249, 545. (g) Li, Z. X.; Xu, Y.; Zuo, Y.; Li, L.; Pan, Q. H.; Hu, T. L.; Bu, X. H. Cryst. Growth Des. 2009, 9, 3904. (2) (a) Batten, S. R.; Robson, R. Angew. Chem., Int. Ed. 1998, 37, 1460. (b) Kitagawa, S.; Kitaura, R.; Noro, S. I. Angew. Chem., Int. Ed. 2004, 43, 2334. (c) Robin, A. Y.; Fromm, K. M. Coord. Chem. Rev. 2006, 250, 2127. (d) Dalgarno, S. J.; Thallapally, P. K.; Barbour, L. J.; Atwood, J. L. Chem. Soc. Rev. 2007, 36, 236. (3) (a) Yaghi, O. M.; O’Keeffe, M.; Ockwig, N. W.; Chae, H. K.; Eddaoudi, M.; Kim, J. Nature 2003, 423, 705. (b) Janiak, C. Dalton Trans. 2003, 2781. (c) Eddaoudi, M.; Moler, D. B.; Li, H.; Chen, B.; Reineke, T. M.; O'Keeffe, M.; Yaghi, O. M. Acc. Chem. Res. 2001, 34, 319. (d) Feng, R.; Jiang, F. L.; Chen, L.; Yan, C. F.; Wu, M. Y.; Hong, M. C. Chem. Commun. 2009, 5296.

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(4) (a) Jin, C. M.; Wu, L. Y.; Lu, H.; Xu, Y. Cryst. Growth Des. 2008, 8, 215. (b) Ma, Y.; Cheng, A. L.; Zhang, J. Y.; Yue, Q.; Gao, E. Q. Cryst. Growth Des. 2009, 9, 867. (c) Chang, Z.; Zhang, A. S.; Hu, T. L.; Bu, X. H. Cryst. Growth Des. 2009, 9, 4840. (5) Wang, L.; You, W.; Huang, W.; Wang, C.; You, X. Z. Inorg. Chem. 2009, 48, 4295. (6) (a) Schilt, A. Applications of 1,10-Phenanthroline and Related Compounds; Pergamon: London, 1969. (b) Tomasik, P.; Ratajewicz, Z. Pyridine Metal Complexes; John Wiley & Sons: New York, 1985. (c) Sammes, P. G.; Yahioglu, G. Chem. Soc. Rev. 1994, 23, 327. (d) Chelucci, G.; Thummel, R. P. Chem. Rev. 2002, 102, 3129. (7) (a) Yamada, M.; Tanaka, Y.; Yashimoto, Y.; Kuroda, S.; Shimao, I. Bull. Chem. Soc. Jpn. 1992, 65, 1006. (b) Calderazzo, F.; Marchetti, F.; Pampaloni, G.; Passarelli, V. J. Chem. Soc., Dalton Trans. 1999, 4389. (c) Paw, W.; Eisenberg, R. Inorg. Chem. 1997, 36, 2287. (d) Ruiz, R.; Caneschi, A.; Gatteschi, D.; Gaspar, A. B.; Real, J. A.; Fernandez, I.; Munoz, M. C. Inorg. Chem. Commun. 1999, 2, 521. (8) (a) Zhang, X. M.; Wu, H. S.; Chen, X. M. Eur. J. Inorg. Chem. 2003, 2959. (b) Han, Z. B.; Cheng, X. N.; Chen, X. M. Cryst. Growth Des. 2005, 5, 695. (9) (a) Che, G. B.; Su, Z. S.; Li, W. L.; Chu, B.; Li, M. T.; Hu, Z. Z.; Zhang, Z. Q. Appl. Phys. Lett. 2006, 89, 103511. (b) Che, G. B.; Liu, C.-B. Acta Crystallogr. Sect. E 2006, E62, m1728. (c) Che, G. B.; Liu, C.-B.; Xu, Z.-L. Acta Crystallogr. Sect. E 2006, E62, m1948. (d) Che, G. B.; Liu, B. Acta Crystallogr., Sect. E 2006, E62, m2036. (10) (a) Wang, X. L.; Bi, Y. F.; Lin, H. Y.; Liu, G. C. Cryst. Growth Des. 2007, 6, 1086. (b) Wang, X. L.; Bi, Y. F.; Liu, G. C.; Lin, H. Y.; Hu, T. L.; Bu, X. H. CrystEngComm 2008, 10, 349. (c) Liu, G. C.; Chen, Y. Q.; Wang, X. L.; Chen, B. K.; Lin, H. Y. J. Solid State Chem. 2009, 182, 566. (d) Wang, X. L.; Chen, Y. Q.; Liu, G. C.; Lin, H. Y.; Zheng, W. Y.; Zhang, J. X. J. Organomet. Chem. 2009, 694, 2263. (11) (a) Yang, J.; Li, G. D.; Cao, J. J.; Yue, Q.; Li, G. H.; Chen, J. S. Chem.;Eur. J. 2007, 13, 3248. (b) Yang, J.; Ma, J. F.; Liu, Y. Y.; Ma, J. C.; Batten, S. R. Inorg. Chem. 2007, 46, 6542. (c) Yang, J.; Ma, J. F.; Liu, Y. Y.; Ma, J. C.; Batten, S. R. Cryst. Growth Des. 2009, 9, 1894. (12) (a) Gupta, T.; Dhar, S.; Nethaji, M.; Chakravarty, A. R. J. Chem. Soc., Dalton Trans. 2004, 1896. (b) Zhao, Q.; Liu, S. J.; Shi, M.; Li, F. Y.; Jing, H.; Yi, T.; Huang, C. H. Organometallics 2007, 26, 5922. (13) (a) Liu, H.; Du, M.; Ge, X. J.; Bu, X. H.; Yang, M. Acta Crystallogr., Sect. E 2001, 57, m100. (b) Xu, Z. D.; Liu, H.; Wang, M.; Xiao, S. D. J. Inorg. Biochem. 2002, 92, 149. (c) Sastri, C. V.; Eswaramoorthy, D.; Giribabu, L.; Maiya, B. G. J. Inorg. Biochem. 2003, 94, 138. (d) Ambroise, A.; Maiya, B. G. Inorg. Chem. 2000, 39, 4264. (14) (a) Stephenson, M. D.; Hardie, M. J. Cryst. Growth Des. 2006, 6, 423. (b) Wei, Y. Q.; Yu, Y. F.; Wu, K. C. Cryst. Growth Des. 2007, 7, 2262. (c) Stephenson, M. D.; Prior, T. J.; Hardie, M. J. Cryst. Growth Des. 2008, 8, 643. (15) (a) Wang, X. L.; Chen, Y. Q.; Liu, G. C.; Lin, H. Y.; Zhang, J. X. J. Solid State Chem. 2009, 182, 2392. (b) Zhao, J. P.; Hu, B. W.; Yang, Q.; Hu, T. L.; Bu, X. H. Inorg. Chem. 2009, 48, 7111. (16) Hu, M. L.; Lu, Y. P.; Zhang, H. M.; Tu, B.; Jin, Z. M. Inorg. Chem. Commun. 2006, 9, 962. (17) Zhao, Y. H.; Xu, H. B.; Fu, Y. M.; Shao, K. Z.; Yang, S. Y.; Su, Z. M.; Hao, X. R.; Zhu, D. X.; Wang, E. B. Cryst. Growth Des. 2008, 8, 3566. (18) (a) Radecka-Paryzek, W.; Gdaniec, M. Polyhedron 1997, 16, 3681. (b) Chiaradia, M.; Chenhall, B. F.; Depers, A. M.; Gulson, B. L.; Jones, B. G. Sci. Total Environ. 1997, 205, 107. (c) Sauve, S.; MeBride, M. B.; Hendershot, W. H. Environ. Pollut. 1997, 98, 149. (19) Zhang, Q. L.; Liu, J. H.; Ren, X. Z.; Xu, H.; Huang, Y.; Liu, J. Z.; Ji, L. N. J. Inorg. Biochem. 2003, 95, 194. (20) Sheldrick, G. M. SHELXS-97, Program for the Solution of Crystal Structure; University of G€ottingen: G€ottingen, Germany, 1997. (21) Sheldrick, G. M. SHELXL-97, Program for the Refinement of Crystal Structure; University of G€ottingen: G€ottingen, Germany, 1997. (22) Wang, X. L.; Chen, Y. Q.; Liu, G. C.; Lin, H. Y.; Zhang, J. X. Solid. State. Sci. 2009, 11, 1567. (23) Zhang, J.; Li, Z. J.; Kang, Y.; Cheng, J. K.; Yao, Y. G. Inorg. Chem. 2004, 43, 8085. (24) Hancock, R. D.; Reibenspies, J. H.; Maumela, H. Inorg. Chem. 2004, 43, 2981. (25) (a) Wang, X. L.; Liu, G. C.; Zhang, J. X.; Cheng, Y. Q.; Lin, H. Y.; Zheng, W. Y. Dalton Trans. 2009, 7347. (b) Wei, Y. Q.; Yu, Y. F.; Wu, K. C. Cryst. Growth Des. 2007, 7, 2262. (26) (a) Zhang, L.; Zhao, J. L.; Lin, Q. P.; Qin, Y. Y.; Zhang., J.; Yin, P. X.; Cheng, J. K.; Yao, Y. G. Inorg. Chem. 2009, 48, 6517. (b) Harrowfield, J. M.; Maghaminia, S.; Soudi, A. A. Inorg. Chem. 2004,

2184

Crystal Growth & Design, Vol. 10, No. 5, 2010

43, 1810. (c) Wang, Y.; Quillian, B.; Wei, P.; Yang, X. J.; Robinson, G. H. Chem. Commun. 2004, 2222. (d) Shi, Y. J.; Li, L. H.; Li, Y. Z.; Chen, X. T.; Xue, Z. L.; You, X. Z. Polyhedron 2003, 22, 917. (27) Wells, A. F. Three-Dimensional Nets and Polyhedra; Wiley: New York, 1977. (28) Dolomanov, O. V.; Blake, A. J.; Champness, N. R.; Schr€ oer, M. J. Appl. Crystallogr. 2003, 36, 1283. (29) Guo, H. X.; Li, X. Z.; Weng, W. Inorg. Chem. Commun. 2009, 12, 948.

Wang et al. (30) (a) Yang, E. C.; Li, J.; Ding, B.; Liang, Q. Q.; Wang, X. G.; Zhao, X. J. CrystEngComm 2008, 10, 158. (b) Shi, J.; Ye, J. W.; Song, T. Y.; Zhang, D. J.; Ma, K. R.; Ha, J.; Xu, J. N.; Zhang, P. Inorg. Chem. Commun. 2007, 10, 1534. (31) Chen, C. H.; Shi, J. M. Coord. Chem. Rev. 1998, 171, 161. (32) Dutta, S. K.; Perkovic, M. W. Inorg. Chem. 2002, 41, 6938. (33) (a) Tong, X. L.; Wang, D. Z.; Hu, T. L.; Song, W. C.; Tao, Y.; Bu, X. H. Cryst. Growth Des. 2009, 9, 2280. (b) Zheng, S. L.; Yang, J. H.; Yu, X. L.; Chen, X. M.; Wong, W. T. Inorg. Chem. 2004, 43, 830.