Synthesis and Characterization of New Coordination Polymers

Sep 1, 2004 - In 2, Ag(I) centers are interlocked together by L5 ligands through two terminal Npyridine and two Ntriazole donors into a novel noninter...
1 downloads 11 Views 1MB Size
Download PDF
Synthesis and Characterization of New Coordination Polymers Generated from Triazole-Containing Organic Ligands and Inorganic Ag(I) Salts Yu-Bin Dong,* Hai-Ying Wang, Jian-Ping Ma, and Ru-Qi Huang

CRYSTAL GROWTH & DESIGN 2005 VOL. 5, NO. 2 789-800

College of Chemistry, Chemical Engineering and Materials Science, and Shandong Key Lab of Chemical Functional Materials, Shandong Normal University, Jinan 250014, P. R. China

Mark D. Smith Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208 Received June 15, 2004;

Revised Manuscript Received July 17, 2004

ABSTRACT: The coordination chemistry of the triazole-containing rigid crooked tetradentate ligands 3,5-bis(4pyridyl)-4-amino-1,2,4-triazole (L5) and 3,5-bis(3-pyridyl)-4-amino-1,2,4-triazole (L6) with inorganic Ag(I) salts has been investigated. Six new coordination polymers were prepared by solution reactions and fully characterized by infrared spectroscopy, elemental analysis, and single-crystal X-ray diffraction. {[Ag3(L5)2](NO3)3(H2O)4}n (1) (triclinic, P1 h ; a ) 6.9481(5) Å, b ) 9.7267(6) Å, c ) 12.8803(8) Å, R ) 92.7760(10)°, β ) 99.1170(10)°, γ ) 104.4150(10)°, Z ) 1) was obtained by the combination of L5 with AgNO3 in a H2O/CH3OH mixed solvent system, and features a unique two-dimensional sheet, which consists of large tetrameric and small dimeric rings. The approximate dimensions of the rings are ca. 23 × 6 Å and 4 × 8 Å, respectively. {[Ag3(L5)3](PF6)3‚(H2O)‚(CH3OH)}n (2) (monoclinic, P21/n; a ) 10.4641(6) Å, b ) 15.6701(8) Å, c ) 31.1907(17) Å, β ) 94.8840(10)°, Z ) 4) was generated from the reaction of L5 with AgPF6 in a H2O/CH3OH mixed solvent system. In 2, Ag(I) centers are interlocked together by L5 ligands through two terminal Npyridine and two Ntriazole donors into a novel noninterpenetrating three-dimensional framework with elliptical channels (effective cross-section of ca. 12.4 × 8.0 Å) extending along the crystallographic a axis. {[Ag(L5)](ClO4)‚H2O}n (3) (triclinic, P1 h ; a ) 10.3605(16) Å, b ) 10.5224(16) Å, c ) 15.014(2) Å, R ) 89.979(2)°, β ) 76.656(2)°, γ ) 89.980(2)°, Z ) 4) was obtained by a combination of L5 with AgClO4 in a MeOH/H2O mixed solvent system. In the solid state, it forms a novel noninterpenetrating three-dimensional network with rhombic channels (effective cross-section of ca. 9.0 × 8.0 Å) along the crystallographic a axis, in which noncoordinated ClO4- anions and H2O guest molecules are located. {[Ag(L6)](ClO4)‚CH3OH}n (4) (monoclinic, C2/c; a ) 14.1747(10) Å, b ) 16.2713(11) Å, c ) 15.9983(11) Å, β ) 114.9410(10)°, Z ) 8) was obtained by the combination of L6 with AgClO4 in a MeOH/H2O mixed solvent system. In the solid state, 4 features a novel noninterpenetrating three-dimensional framework with honeycomb-like and elliptical channels in two different crystallographic directions. Their dimensions are 8 × 7 and 18 × 4 Å, respectively. Uncoordinated ClO4- counterions and MeOH guest molecules are located in these channels. {[Ag(L6)](PF6)‚CH3OH}n (5) is generated from L6 and AgPF6 in a H2O/MeOH mixed solvent system and crystallizes in the space group C2/c, with a ) 15.2035(10) Å, b ) 16.5919(11) Å, c ) 16.1240(10) Å, β ) 116.8490(10)°, Z ) 8. Compound 5 and 4 are isostructural. {[Ag2(C12H10N6)2](SiF6)‚2H2O}n (6) (monoclinic, P21/c, a ) 11.3839(6) Å, b ) 16.5163(8) Å, c ) 7.4485(4) Å, β ) 95.5450(10)°, Z ) 2) was obtained by the combination of L6 ligand with AgSbF6 in a MeOH/H2O solvent system. In the solid state, compound 6 adopts a noninterpenetrating two-dimensional net. Uncoordinated SiF62- anions and water molecules are located between the layers and further linked by extensive H-bonding systems into a three-dimensional framework. When viewed down the crystallographic [101] direction, honeycomb-like channels were found, in which SiF62- counterions and water guest molecules are located. Introduction The use of soluble inorganic transition metal ions or unsaturated transition metal coordination complexes and organic bidentate or multidentate ligands as precursors to organic/inorganic hybrid materials is a rapidly growing area of interest.1-4 For example, selfassembled coordination polymers with specific network topologies can provide highly ordered networks with different dimensionalities, particularly as two- or threedimensional solids. Generally, some control over the type and topology of the product generated from the selfassembly of inorganic metal species and organic ligands * To whom correspondence [email protected].

should

be

addressed.

E-mail:

can be achieved by careful choice of ligand,5 metal coordination geometry preference, inorganic counterion,6 solvent system,6 and metal salt-to-ligand ratio.7 Among these factors, the choice of the organic spacers is the single greatest influence in determining the type and topology of the product. Properties of organic spacers, such as solubility, coordination activity, length, geometry, and relative orientation of the donor groups, play a very important role in dictating polymer framework topology. As we know, the rigid linear ligands, such as 4,4′bipyridine,1,4-bis(4-pyridyl)ethene, 1,4-bis(4-pyridyl)ethyne, and so on, have been the main theme in the chemistry of coordination polymers. All these bidentate N-donor containing ligands have proven to be among

10.1021/cg049808b CCC: $30.25 © 2005 American Chemical Society Published on Web 09/01/2004

790

Crystal Growth & Design, Vol. 5, No. 2, 2005

Dong et al.

Scheme 1. Five-Membered Heterocyclic Ring-Containing Organic Ligands Used in the Construction of Coordination Polymer Frameworks

the most important types of organic ligands for the design and construction of coordination polymers exhibiting remarkable polymeric structural motifs.8 However, up to now, very little attention has been paid to the organic-inorganic coordination polymers or supramolecular complexes generated from bent organic ligands. We and others have been exploring the coordination chemistry based on oxadiazole-bridged bent organic ligands (Scheme 1).9 As a result of the specific geometry of oxadiazole-containing ligands and the coordination preferences of transition metals, new types of coordination polymers, some with open channels and interesting luminescent properties, have been obtained. This encourages us to continue this project and expend oxadiazole-containing ligands to triazole-containing ligands. Herein, we wish to report six Ag-containing coordination polymers with novel polymeric motifs, namely, {[Ag3(L5)2](NO3)3(H2O)4}n (1), {[Ag3(L5)3](PF6)3‚ (H2O)‚(CH3OH)}n (2),{[Ag(L5)](ClO4)‚H2O}n (3),{[Ag(L6)](ClO4)‚CH3OH}n (4), {[Ag(L6)](PF6)‚CH3OH}n (5), and {[Ag2(L6)2](SiF6)‚2H2O}n (6) generated from 3,5-disubstitued-4-amino-1,2,4-trizole ligands L5 and L6 (Scheme 1) and inorganic Ag(I) salts. Experimental Section Materials and Methods. AgSO3CF3, AgNO3, AgClO4, AgPF6 (Acros) were used as obtained without further purification. L5 (2,5-bis(4-pyridyl)-4-amino-1,2,4-triazole) and L6 (2,5bis(3-pyridyl)-4-amino-1,2,4-triazole) were prepared according to literature methods.10 Infrared (IR) samples were prepared as KBr pellets, and spectra were obtained in the 400-4000 cm-1 range using a Perkin-Elmer 1600 FTIR spectrometer. Elemental analyses were performed on a Perkin-Elmer model 2400 analyzer. Caution! Two of the crystallization procedures involve AgClO4, which is a strong oxidizer. Preparation of {[Ag3(L5)2](NO3)3(H2O)4}n (1). A solution of L5 (4.76 mg, 0.020 mmol) in MeOH (10 mL) was layered onto a solution of AgNO3 (6.80 mg, 0.040 mmol) in H2O (10 mL). The solutions were left for about 3 days at room temperature, and colorless crystals were obtained. Yield, 78% (based on L5). Anal. Calcd. for C24H28Ag3N15O13 (1): C, 27.22; H, 2.65; N, 19.84. Found: C, 27.43; H, 2.60; N, 19.34. IR (KBr,

cm-1): 3500(w), 3350(m), 3320(w), 1615(s), 1375(vs), 1530(w), 1481(w), 1307(vs), 1215(m), 834(s), 735(w). Preparation of {[Ag3(L5)3](PF6)3‚(H2O)‚(CH3OH)}n (2). A solution of L5 (4.76 mg, 0.020 mmol) in MeOH (10 mL) was layered onto a solution of AgPF6 (15.18 mg, 0.060 mmol) in H2O (10 mL). The solutions were left for about 4 days at room temperature, and colorless crystals were obtained. Yield, 73% (based on L5). Anal. Calcd. for C37H36Ag3F18N18O2P3 (2): C, 29.15; H, 2.36; N, 16.54. Found: C, 29.37; H, 2.31; N, 16.26. IR (KBr, cm-1): 3450(m), 1615(s), 1530(w), 1477(m), 1427(m), 1227(w), 1035(w), 840(vs), 735(s). Preparation of {[Ag(L5)](ClO4)‚H2O}n (3). A solution of L5 (4.76 mg, 0.020 mmol) in EtOH (10 mL) was layered onto a solution of AgClO4 (12.75 mg, 0.060 mmol) in H2O (10 mL). The solutions were left for about 2 days at room temperature, and colorless crystals were obtained. Yield, 72% (based on L5). Anal. Calcd. for C12H12AgClN6O5 (3): C, 31.06; H, 2.59; N, 18.12. Found: C, 31.17; H, 2.46; N, 18.06. IR (KBr, cm-1): 3500(s), 3300(s), 3175(s), 1602(s), 1554(s), 1456(m), 1222(m), 1084(vs), 978(m), 938(m), 829(s), 732(m), 700(s), 628(s). Preparation of {[Ag(L6)](ClO4)‚CH3OH }n (4). A solution of L6 (4.76 mg, 0.020 mmol) in MeOH (10 mL) was layered onto a solution of AgClO4 (12.75 mg, 0.060 mmol) in H2O (10 mL). The solutions were left for about 2 days at room temperature, and colorless crystals were obtained. Yield, 64% (based on L6). Anal. Calcd. for C13H14AgClN6O5 (4): C, 32.66; H, 2.93; N, 17.59. Found: C, 32.79; H, 2.90; N, 17.74. IR (KBr, cm-1): 3430(s), 3250(w), 1620(s), 1580(s), 1470(s), 1420(s), 1100(vs), 1090(w), 813(s), 700(s). Preparation of {[Ag(L6)](PF6)‚CH3OH}n (5). A solution of L6 (4.76 mg, 0.020 mmol) in MeOH (10 mL) was layered onto a solution of AgPF6 (15.18 mg, 0.060 mmol) in H2O (10 mL). The solutions were left for about 2 days at room temperature, and colorless crystals were obtained. Yield, 61% (based on L6). Anal. Calcd. for C13H14AgF6N6OP (5): C, 29.82; H, 2.68; N, 13.76. Found: C, 29.87; H, 2.68; N, 13.68. IR (KBr, cm-1): 3470(m), 1610(s), 1585(s), 1474(s), 1423(s), 1200(m), 1030(m), 995(m), 845(vs), 700(s). Preparation of {[Ag2(L6)2](SiF6)‚2H2O}n (6). A solution of L6 (4.76 mg, 0.020 mmol) in MeOH (10 mL) was layered onto a solution of AgSbF6 (20.61 mg, 0.060 mmol) in H2O (10 mL). The solutions were left for about 2 days at room temperature, and colorless crystals were obtained. Yield, 64% (based on L6). Anal. Calcd. for C24H24Ag2F6N12O2Si (6): C, 33.09; H, 2.76; N, 19.30. Found: C, 33.15; H, 2.68; N, 19.25. IR (KBr, cm-1): 3476(m), 3325(m), 1610(s), 1575(s), 1463(s), 1423(s), 1027(s), 968(m), 819(s), 747(vs).

Polymers from Triazole-Containing Ligands

Crystal Growth & Design, Vol. 5, No. 2, 2005 791

Table 1. Crystallographic Data for 1-3 empirical formula fw cryst syst a (Å) b (Å) c (Å) R (°) β (°) γ (°) V (Å3) space group Z value F calc (g/cm3) µ (Mo KR) (mm-1) temp (K) no. of observations (I > 3σ) final R indicesa [I > 2σ(I)]: R; Rw a

C24H28Ag3N15O13, 1 1058.22 triclinic 6.9481(5) 9.7267(6) 12.8803(8) 92.7760(10) 99.1170(10) 104.4150(10) 828.90(9) P1 h 1 2.120 1.845 150 3369 0.0298; 0.0770

C37H36Ag3F18N18O2P3, 2 1523.36 monoclinic 10.4641(6) 15.6701(8) 31.1907(17) 90° 94.8840(10)° 90° 5095.9(5) P21/n 4 1.986 1.358 150 10442 0.0367; 0.0904

C12H12AgClN6O5, 3 463.60 triclinic 10.3605(16) 10.5224(16) 15.014(2) 89.979(2) 76.656(2) 89.980(2) 1592.6(4) P1 h 4 1.524 1.473 293 6733 0.0546; 0.1179

R1 ) ∑ ||Fo| - |Fc||/∑ |Fo|. wR2 ) {∑ [w(Fo2 - Fc2)2]/∑ [w(Fo2)2]}1/2. Table 2. Crystallographic Data for 4-6 empirical formula fw cryst syst a (Å) b (Å) c (Å) R (°) β (°) γ (°) V (Å3) space Group Z value F calc (g/cm3) µ (Mo KR) (mm-1) temp (K) no. of observations (I > 3σ) final R indicesa [I > 2σ(I)]: R; Rw

a

C13H14AgClN6O5, 4 477.62 monoclinic 14.1747(10) 16.2713(11) 15.9983(11) 90 114.9410(10) 90 3345.8(4) C2/c 8 1.896 1.405 150 3430 0.0251; 0.0633

C13H14AgF6N6OP, 5 523.14 monoclinic 15.2035(10) 16.5919(11) 16.1240(10) 90 116.8490 90 3628.9(4) C2/c 8 1.915 1.276 150 3218 0.0250; 0.0622

C24H24Ag2F6N12O2Si, 6 870.38 monoclinic 11.3839(6) 16.5163(8) 7.4485(4) 90 95.5450 90 1393.91(12) P21/c 2 2.074 1.540 150 2858 0.0314; 0.0748

R1 ) ∑ ||Fo| - |Fc||/∑ |Fo|. wR2 ) {∑ [w(Fo2 - Fc2)2]/∑ [w(Fo2)2] }1/2. Table 3. Interatomic Distances (Å) and Bond Angles (°) with esds for 1a Ag(1)-N(1) Ag(1)-O(22)#1 Ag(2)-N(6)#2 Ag(2)-O(11)#4 N(1)-Ag(1)-N(1)#1 N(1)#1-Ag(1)-O(22)#1 N(2)-Ag(2)-N(3)#3 N(2)-Ag(2)-O(11)#4 N(3)#3-Ag(2)-O(11)#4 N(6)#2-Ag(2)-O(13)#4 O(11)#4-Ag(2)-O(13)#4

2.117(3) 2.823(6) 2.251(2) 2.843(3) 180.00(11) 79.98(18) 107.95(8) 83.61(8) 78.58(8) 83.70(8) 43.01(7)

Ag(1)-N(1)#1 Ag(2)-N(2) Ag(2)-N(3)#3 Ag(2)-O(13)#4 N(1)-Ag(1)-O(22)#1 N(2)-Ag(2)-N(6)#2 N(6)#2-Ag(2)-N(3)#3 N(6)#2-Ag(2)-O(11)#4 N(2)-Ag(2)-O(13)#4 N(3)#3-Ag(2)-O(13)#4

2.117(3) 2.240(2) 2.426(2) 2.996(3) 100.02(18) 134.67(9) 113.09(8) 122.23(8) 125.88(8) 75.03(8)

a Symmetry transformations used to generate equivalent atoms: #1 - x + 1, -y + 1, -z. #2 x + 1, y + 1, z. #3 - x + 1, -y, -z + 1. #4 - x + 1, -y + 1, -z + 1. #5 x - 1, y - 1, z.

Single-Crystal Structure Determination. Suitable single crystals of 1-6 were selected and mounted in air onto thin glass fibers. X-ray intensity data were measured at 150 K on a Bruker SMART APEX CCD-based diffractometer (Mo KR radiation, λ ) 0.71073 Å). The raw frame data for 1-6 were integrated into SHELX-format reflection files and corrected for Lorentz and polarization effects using SAINT.11 Corrections for incident and diffracted beam absorption effects were applied using SADABS.11 None of the crystals showed evidence of crystal decay during data collection. Compound 1 and 3 crystallizes in the space group P1 h , compound 2 crystallizes in the space group P21/n, compound 4 and 5 crystallize in the space group C2/c, and compound 6 crystallizes in the space group P21/c, as determined by the pattern of systematic absences in the intensity data. All structures were solved by a combination of direct methods and difference Fourier syntheses and refined against F2 by the full-matrix least squares technique. Crystal data, data collection parameters, and refinement statistics for 1-6 are listed in Tables 1 and 2.

Relevant interatomic bond distances and bond angles for 1-6 are given in Tables 3-8.

Results and Discussion Ligands and Synthesis of Compounds 1-5. L5 and L6 can be considered as new members of this fivemembered heterocyclic ring bridging organic ligands. Compared to L1-L4, L5 and L6 are endowed with more structural information. For example, the 4-amino group on the trizole ring could serve as an additional coordinating donor, hydrogen bond acceptor, or donor. Moreover, it gives us a good chance to modify L5 and L6 to new organic spacers with novel geometries by some derivate reactions related to -NH2. L5 and L6 would be anticipated to exhibit more versatile coordination chemistry than L1-L4 by introducing the 4-amino-1,2, 4-triazole moiety.

792

Crystal Growth & Design, Vol. 5, No. 2, 2005

Dong et al.

Table 4. Interatomic Distances (Å) and Bond Angles (°) with esds for 2a Ag(1)-N(6B)#1 Ag(1)-N(2) Ag(1)-N(7) Ag(2)-N(14) Ag(2)-N(18)#3 Ag(3)-N(15) Ag(3)-N(1)#5 N(6B)#1-Ag(1)-N(2) N(6B)#1-Ag(1)-N(3)#2 N(2)-Ag(1)-N(3)#2 N(6A)#1-Ag(1)-N(7) N(3)#2-Ag(1)-N(7) N(12)#1-Ag(2)-N(8) N(12)#1-Ag(2)-N(18)#3 N(8)-Ag(2)-N(18)#3 N(13)#4-Ag(3)-N(9) N(13)#4-Ag(3)-N(1)#5 N(9)-Ag(3)-N(1)#5

2.248(3) 2.263(2) 2.489(3) 2.326(3) 2.392(3) 2.271(2) 2.473(3) 132.78(10) 112.18(10) 111.86(9) 100.11(11) 102.25(10) 131.79(10) 110.71(10) 85.22(9) 113.10(9) 99.23(11) 105.05(10)

Ag(1)-N(6A)#1 Ag(1)-N(3)#2 Ag(2)-N(12)#1 Ag(2)-N(8) Ag(3)-N(13)#4 Ag(3)-N(9)

2.248(3) 2.311(3) 2.272(3) 2.337(2) 2.246(3) 2.305(3)

N(6A)#1-Ag(1)-N(2) N(6A)#1-Ag(1)-N(3)#2 N(6B)#1-Ag(1)-N(7) N(2)-Ag(1)-N(7) N(12)#1-Ag(2)-N(14) N(14)-Ag(2)-N(8) N(14)-Ag(2)-N(18)#3 N(13)#4-Ag(3)-N(15) N(15)-Ag(3)-N(9) N(15)-Ag(3)-N(1)#5

132.78(10) 112.18(10) 100.11(11) 86.44(10) 113.32(9) 103.76(9) 107.05(9) 134.97(10) 108.08(9) 86.72(10)

a Symmetry transformations used to generate equivalent atoms: #1 x - 1, y, z. #2 -x + 1, -y + 2, -z + 1. #3 -x + 3/2, y + 1/2, -z + 3/2. #4 x + 1, y, z. #5 -x + 1, -y + 1, -z + 1. #6 -x + 3/2, y - 1/2, -z + 3/2.

Table 5. Interatomic Distances (Å) and Bond Angles (°) with esds for 3a Ag(1)-N(7) Ag(1)-N(5) Ag(2)-N(2) Ag(2)-N(4) N(7)-Ag(1)-N(8) N(8)-Ag(1)-N(5) N(8)-Ag(1)-N(6) N(2)-Ag(2)-N(3) N(3)-Ag(2)-N(4) N(3)-Ag(2)-N(1)

2.248(4) 2.368(4) 2.246(4) 2.366(4) 128.65(15) 91.50(15) 112.54(13) 128.68(15) 91.52(15) 12.28(13)

Ag(1)-N(8) Ag(1)-N(6) Ag(2)-N(3) Ag(2)-N(1) N(7)-Ag(1)-N(5) N(7)-Ag(1)-N(6) N(5)-Ag(1)-N(6) N(2)-Ag(2)-N(4) N(2)-Ag(2)-N(1) N(4)-Ag(2)-N(1)

2.306(4) 2.522(4) 2.310(4) 2.520(4) 130.41(16) 97.68(14) 89.88(14) 130.40(16) 97.76(14) 89.96(14)

a Symmetry transformations used to generate equivalent atoms: #1 -x + 1, -y, - z. #2 -x + 1, -y + 1, -z + 1. #3 -x, -y, -z. #4 -x + 1, -y, -z + 1. #5 -x + 2, -y + 1, -z + 1.

Table 6. Interatomic Distances (Å) and Bond Angles (°) with esds for 4a Ag(1)-N(6)#1 Ag(1)-N(3)#3 N(6)#1-Ag(1)-N(2)#2 N(2)#2-Ag(1)-N(3)#3 N(2)#2-Ag(1)-N(1)

2.2296(17) 2.3553(16) 120.87(6) 99.03(6) 89.94(6)

Ag(1)-N(2)#2 Ag(1)-N(1) N(6)#1-Ag(1)-N(3)#3 N(6)#1-Ag(1)-N(1) N(3)#3-Ag(1)-N(1)

2.3215(16) 2.4118(17) 117.79(6) 130.82(6) 90.30(6)

a Symmetry transformations used to generate equivalent atoms: #1 -x + 1/2, y - 1/2, -z + 3/2. #2 -x, -y + 1, -z + 1. #3 x, -y + 1, z - 1/2. #4 x, -y + 1, z + 1/2. #5 -x + 1/2, y + 1/2, -z + 3/2.

Table 7. Interatomic Distances (Å) and Bond Angles (°) with esds for 5a Ag(1)-N(6)#1 Ag(1)-N(3)#3 N(6)#1-Ag(1)-N(2)#2 N(2)#2-Ag(1)-N(3)#3 N(2)#2-Ag(1)-N(1)

2.249(2) 2.355(2) 117.90(7) 99.11(7) 90.26(7)

Ag(1)-N(2)#2 Ag(1)-N(1) N(6)#1-Ag(1)-N(3)#3 N(6)#1-Ag(1)-N(1) N(3)#3-Ag(1)-N(1)

2.347(2) 2.381(2) 115.25(7) 132.71(7) 94.55(7)

a Symmetry transformations used to generate equivalent atoms: #1 -x + 1/2, y + 1/2, -z + 3/2 #2 -x + 1/2, -y + 1/2, -z + 1. #3 x 1/2, -y + 1/2, z - 1/2. #4 -x + 1/2, y - 1/2, -z + 3/2. #5 x + 1/2, -y + 1/2, z + 1/2.

Table 8. Interatomic Distances (Å) and Bond Angles (°) with esds for 6a Ag(1)-N(2)#1 Ag(1)-N(3)#3 N(2)#1-Ag(1)-N(6)#2 N(6)#2-Ag(1)-N(3)#3 N(6)#2-Ag(1)-N(1)

2.327(2) 2.367(2) 121.69(9) 110.97(9) 106.61(9)

Ag(1)-N(6)#2 Ag(1)-N(1) N(2)#1-Ag(1)-N(3)#3 N(2)#1-Ag(1)-N(1) N(3)#3-Ag(1)-N(1)

2.334(3) 2.382(2) 100.81(9) 100.50(9) 116.44(9)

a Symmetry transformations used to generate equivalent atoms: #1 x, -y + 1/2, z - 1/2. #2 -x + 1, -y + 1, -z + 1. #3 -x + 1, y - 1/2, -z + 3/2. #4 x, -y + 1/2, z + 1/2. #5 -x + 1, y + 1/2, -z + 3/2 . #6 -x, -y + 1, -z.

Compounds 1-6 were obtained as polymeric compounds in mixed solvent systems by the combination of L5 and L6 with different inorganic Ag(I) salts. It is worthwhile to point out that, in these specific reactions, the products do not depend on the ligand-to-metal ratio. However, increasing the metal-to-ligand ratio resulted in somewhat higher yield and higher crystal quality. Structural Analysis. Structural Analysis of {[Ag3(L5)2](NO3)3(H2O)4}n (1). Crystallization of L5 with

AgNO3 in methanol/water mixed solvent system at room temperature afforded the infinite two-dimensional sheet structure (1) in 78% yield. The metal-to-ligand ratio is 2:1 in the reaction. Single-crystal analysis revealed (as shown in Figure 1) that there are two different Ag(I) centers in 1. The first Ag(I) center has linear coordination with the two Npyridyl atoms from two L5 ligands (N(1)-Ag(1)-N(1)#1 ) 180.00(11)°, Ag(1)-N(1) ) 2.117(3) Å). The second Ag(I) center, on the other hand,

Polymers from Triazole-Containing Ligands

Crystal Growth & Design, Vol. 5, No. 2, 2005 793

Figure 3. View of crystal packing in 1. Nitrate anions and water molecules (shown as space-filling) between the layers.

Figure 1. Ag(1) (top) and Ag(2) (bottom) coordination environments in 1. Displacement ellipsoids are drawn at the 50% probability level.

Figure 2. Perspective view (top) and side view (bottom) of two-dimensional layer in 1.

lies in a trigonal planar (sum of Ag-N angles ) 355.7°) coordination environment, which consists of two Ntriazole donors (Ag(2)-N(2) ) 2.240(2) and Ag(2)-N(3)#3 ) 2.426(2) Å) from two L5 ligands and one Npyridyl donor (Ag(2)-N(6)#2 ) 2.251(2) Å) from the third L5 ligand, respectively. The Ag-Ntriazole bond length is considerably longer than those of the Ag-Npyridyl bonds by 0.1230.257 Å, but all Ag-N bond distances found in 1 are within the normal range observed in N-containing heterocyclic Ag(I) complexes.12 Each ligand is bound to four Ag(I) centers, including one Ag(1) and three Ag(2) centers. Two Ag(2) atoms are bridged by four Ntriazole atoms into a dinuclear core with a short Ag‚‚‚Ag contact of 4.001(4) Å. The ligand itself is not planar. The corresponding dihedral angles between three rings are {N(1)- - -C(5)}-{N(2)- - -N(3)} ) 59.3°, {N(1)- - -C(5)}{N(6)- - -C(12)} ) 30.5° and {N(2)- - -N(3)}-{N(6)- - C(12)} ) 34.8°. In the solid state, the Ag(1) and Ag(2) centers are linked together into a novel two-dimensional sheet, which is parallel to the [11h 1 h ] plane. As shown in Figure 2, a single net consists of two different individual rings. The large one comprises a tetrameric unit, in which four Ag(I) centers are linked together by L5 ligands through both pyridyl and triazole N-donors into an elliptical 38membered macrocycle. The approximate (crystallographic) dimension of the ring is 23 × 6 Å.13 The small one consists of a 14-membered dimeric unit. The effective cross-section is 4 × 8 Å.13 Surprisingly, no guest solvent molecules have been found in either the large

Figure 4. Alternate views of the Ag(I)-ligand connectivity in 2.

or the small rings. These two-dimensional nets are not planar but undulating, which results from the crooked conformation of the ligand (Figure 2). The crystal packing of 1 is shown in Figure 3. All the twodimensional macrocycle-containing nets stack together along the crystallographic a axis and weak coordinated NO3- counterions and water molecules are located between the interlayer space. Furthermore, amino nitrogen is hydrogen bonded to a water/nitrate disorder assembly (N(5)-H(5A)‚‚‚O(12)#5: dD-H ) 0.88(3), dH‚‚‚A ) 2.08(4), dD‚‚‚A ) 2.957(4) Å, and