catena-Poly[bis­[silver(I)-μ₂-4,4′-bi­pyridine-κ²N:N′] naphthalene-2,6-dicarboxyl­ate tetra­hydrate]: self-assembly of a supra­molecular framework via coordination bonds and supra­molecular inter­actions

The ultrasonic reaction of AgNO₃, 4,4′-bipyridine (bipy) and naphthalene-2,6-dicarboxylic acid (H₂NDC) gives rise to the title compound, {[Ag₂(C₁₀H₈N₂)₂](C₁₂H₆O₄)·4H₂O}_n. The NDC dianion is located on an inversion centre. The Ag^I centre is coordinated in a linear manner by two N atoms from two bipy ligands. The crystal structure consists of one-dimensional Ag^I–bipy cationic chains and two-dimensional NDC–H₂O anionic sheets, constructed by coordination bonds and supra­molecular inter­actions, respectively.

S1. Comment

Interest in crystal engineering and supramolecular chemistry is rapidly increasing due to the diverse and aesthetic structural topologies of the resulting compounds and their potential use in optical, electrical, catalytic and adsorptive applications as functional solid materials (Blake, Brooks et al., 1999; Blake, Champness et al., 1999; Blake et al., 1997; Evans & Lin, 2002; Kitagawa et al., 2004; Yaghi et al., 2003; Applegarth et al., 2005). In the past few years, the development of supramolecular self-assembly has allowed the possibility of the rational design and preparation of supramolecular architectures through noncovalent interactions, in which it is crucial to meet both geometric and energetic considerations (Pedireddi et al., 1996). Doubtless, the hydrogen bond is the most familiar secondary force in supramolecular assembly, since it is a moderately directional intermolecular interaction that may control molecular packing (Kolotuchin et al., 1995; Zartilas et al., 2007), and many papers have focused on studies of the hydrogen bond (Li et al., 2006; Sun et al., 2003; Lough et al., 2000; Massoud & Langer, 2009). Compared with the hydrogen bond, C—H···π and π–π interactions have been somewhat less well covered (Blake et al., 2000; Goodgame et al., 2002). 4,4'-Bipyridine (bipy) and its analogues are neutral linear ligands widely used as excellent spacers in the construction of novel supramolecular compounds incorporating diverse supramolecular interactions (Wang & Englert, 2007; Withersby et al., 1997). Recently, we have undertaken a series of investigations into the assembly of Ag^I cations with different angular and linear bipodal N-donor ligands, such as aminopyrimidine and aminopyrazine (Luo, Huang, Chen et al., 2008; Luo, Huang, Zhang et al., 2008; Luo et al., 2009; Sun, Luo, Huang et al., 2009; Sun, Luo, Xu et al., 2009; Sun, Luo, Zhang et al., 2009), with the principal aim of obtaining supramolecular compounds or multifunctional coordination polymers. In an attempt to exploit Ag–bipy/dicarboxylates under ammoniacal conditions, we successfully synthesized the title supramolecular coordination polymer, (I).

The asymmetric unit of (I) contains one Ag^I cation, one-half of a naphthalene-2,6-dicarboxylate (NDC) dianion located on an inversion centre, one bipy ligand and two water molecules. The Ag^I cation adopts a nearly linear geometry [N—Ag—N = 176.00 (7)°], and each Ag^I cation is coordinated by N atoms from two different bipy ligands (Fig. 1). The Ag—N bond lengths (Table 1) are comparable with those in related compounds (Turner et al., 2005; Oxtoby et al., 2002; Fan et al., 2007). There are also weak Ag···O_water interactions with Ag···O distances in the range 2.797 (2)–3.173 (3)Å, which are a little longer but still fall in the secondary bonding range (the sum of Van der Waals radii of Ag and O is 3.24Å; Pan et al., 2003). The bipy ligands have a nontwisted nearly coplanar conformation, with a dihedral angle between the two pyridyl rings of 3.45 (16)°, and act as N,N'-bidentate ligands linking Ag^I cations into one-dimensional cationic chains. Between the neighboring cationic chains, the shortest Ag···Ag separations are 3.5594 (5) and 3.8982 (5)Å, which are longer than twice the van der Waals radius of Ag^I (3.44Å) indicating no direct metal–metal interaction (Bondi, 1964). Weak aromatic π–π stacking interactions [Cg1···Cg2^vii = 3.6808 (18) Å and Cg1···Cg2^viii = 3.7586 (19) Å;Cg1 and Cg2 are the centroids of N1/C1–C5 ring and N2/C6–10 rings, respectively; symmetry codes: (vii) -x + 1, -y + 1, -z + 2;(viii) -x, -y + 1, -z + 2] also exist between the pyridyl rings of neighbouring bipy ligands (Fig. 2).

In addition, the ancillary ligand H₂NDC deprotonates to balance the charge and does not participate in coordinating to the Ag^I centres. Each O1W atom acts as a donor to two O atoms (Table 2) from two different carboxylate groups, forming centrosymmetric R₄⁴(12) (Bernstein et al., 1995) water-bridged carboxylate rings. The NDC anions thus form a supramolecular one-dimensional anionic chain. Neighbouring anionic chains are interlinked to form a two-dimensional anionic sheet (Fig. 3) through C—H···O and O—H···O hydrogen bonds (Table 2).

The crystal structure features one-dimensional Ag^I–bipy cationic chains and two-dimensional NDC–H₂O anionic sheets, constructed by coordination bonds and supramolecular interactions, respectively. To our best knowledge, most of the reported Ag^I-containing complexes exhibiting one-dimensional chains only have one type of charge-neutral chain, however, the chains are usually not independent and are interconnected by coordination bonds (Shi et al., 2000). In (I), C—H···O intermolecular hydrogen bonds and C—H···π interactions are observed [C2–H2···Cg3^ix = 154°, H2···Cg3^ix = 2.81 Å and C2···Cg3^ix = 3.671 (3) Å; C9–H9···Cg4^ix = 143°, H9···Cg4^ix = 2.73 Å, C9···Cg4^ix = 3.521 (2) Å; Cg3 and Cg4 are the centroids of C11-C14/C14^iv/C15^iv ring and C14/C15/C11^iv/C12^iv/C13^iv/C14^iv ring, respectively, symmetry codes: (iv) -x + 1, -y, -z + 2; (ix) x, y + 1, z; Fig. 4], which link the one-dimensional cationic chains and two-dimensional anionic sheets into a three-dimensional supramolecular framework.

S2. Experimental

All reagents and solvents were used as obtained commercially without further purification. A mixture of AgNO₃ (170 mg, 1 mmol), 4,4'-bipyridine (156 mg, 1 mmol) and H₂NDC (216 mg, 1mmol) were added to a methanol–water solvent mixture (12 ml, 1:2 v/v) under ultrasonic conditions, which helped to dissolve the white precipitation. An aqueous NH₃ solution (25%) was added dropwise to the mixture to give a clear solution. The formation of the products is not affected by changing the reaction mole ratio of organic ligands to metal ions. The resulting solution was left to evaporate slowly in darkness at room temperature for several weeks to give colourless block crystals of (I). The crystals were isolated using deionized water and dried in air (yield ca 56% based on Ag). Analysis calculated for C₁₆H₁₅AgN₂O₄: C 64.21, H 5.05, N 9.36%; found: C 64.18, H. 5.09, N 9.29%.

S3. Refinement

The aromatic H atoms were generated geometrically (C—H 0.93Å) and were allowed to ride on their parent atoms in the riding model approximations with U_iso(H) = 1.2U_eq(C). The positions of the water H atoms were refined with the O—H distances restrained to 0.85 (1) Å with U_iso(H) = 1.2Ueq(O).

Computing details

Data collection: CrysAlis CCD (Oxford Diffraction, 2008); cell refinement: CrysAlis RED (Oxford Diffraction, 2008); data reduction: CrysAlis RED (Oxford Diffraction, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2008); software used to prepare material for publication: SHELXL97 and publCIF (Westrip, 2009).

Figures

	Fig. 1. The structure of (I), showing the atom-numbering scheme and the coordination environment around the Ag^I centre. Displacement ellipsoids are drawn at the 50% probability level. H atoms have been omitted for clarity. [Symmetry codes: (i) x, y, z - 1; (ii) -x + 1, -y, -z + 2; (iii) x, y, z + 1.] [ii = v in Table 2.]
	Fig. 2. A ball-and-stick perspective view of the weak π–π stacking (dashed lines) between the pyridyl rings of neighbouring bipy ligands.
	Fig. 3. A ball-and-stick perspective view of the two-dimensional anionic sheet incorporating hydrogen bonds (dashed lines).
	Fig. 4. A ball-and-stick perspective view of the C—H···π interactions (dashed lines) between the bipy and NDC ligands.

catena-Poly[bis[silver(I)-µ₂-4,4'-bipyridine-κ²N,N'] naphthalene-2,6-dicarboxylate tetrahydrate]

Crystal data

[Ag2(C10H8N2)2](C12H6O4)·4H2O	Z = 2
Mr = 814.34	F(000) = 408
Triclinic, P1	Dx = 1.829 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.1444 (3) Å	Cell parameters from 6972 reflections
b = 9.6123 (5) Å	θ = 6.1–54.9°
c = 11.4228 (5) Å	µ = 1.39 mm^−1
α = 90.460 (1)°	T = 298 K
β = 94.924 (1)°	BLOCK, colourless
γ = 108.783 (2)°	0.20 × 0.15 × 0.15 mm
V = 739.40 (6) Å^3

Data collection

Oxford Diffraction Gemini S Ultra diffractometer	2894 independent reflections
Radiation source: sealed tube	2689 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.027
Detector resolution: 16.1903 pixels mm^-1	θmax = 26.0°, θmin = 3.0°
ω scans	h = −8→7
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2008)	k = −11→11
Tmin = 0.769, Tmax = 0.819	l = −14→14
6452 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.029	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.078	H-atom parameters constrained
S = 1.01	w = 1/[σ^2(Fo^2) + (0.0392P)^2 + 0.502P] where P = (Fo^2 + 2Fc^2)/3
2894 reflections	(Δ/σ)max = 0.001
220 parameters	Δρmax = 0.68 e Å^−3
4 restraints	Δρmin = −0.80 e Å^−3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > 2sigma(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Ag1	0.24444 (4)	0.47190 (2)	0.457956 (14)	0.05739 (11)
C1	0.3024 (6)	0.6058 (3)	0.7112 (2)	0.0592 (8)
H1	0.3504	0.6941	0.6737	0.071*
C2	0.3038 (5)	0.6096 (3)	0.8321 (2)	0.0555 (8)
H2	0.3509	0.6996	0.8737	0.067*
C3	0.2357 (3)	0.4810 (2)	0.89223 (18)	0.0270 (4)
C4	0.1683 (4)	0.3524 (3)	0.8230 (2)	0.0414 (5)
H4	0.1207	0.2624	0.8582	0.050*
C5	0.1710 (4)	0.3565 (3)	0.7029 (2)	0.0449 (6)
H5	0.1257	0.2682	0.6591	0.054*
C6	0.1663 (6)	0.3515 (3)	1.2005 (2)	0.0661 (10)
H6	0.1136	0.2627	1.2365	0.079*
C7	0.1611 (6)	0.3501 (3)	1.0801 (2)	0.0615 (9)
H7	0.1056	0.2615	1.0371	0.074*
C8	0.2375 (3)	0.4789 (2)	1.02194 (18)	0.0273 (4)
C9	0.3136 (4)	0.6053 (2)	1.0930 (2)	0.0380 (5)
H9	0.3646	0.6959	1.0593	0.046*
C10	0.3145 (4)	0.5980 (3)	1.2134 (2)	0.0404 (5)
H10	0.3683	0.6850	1.2586	0.048*
C11	0.4370 (3)	0.0142 (2)	0.77988 (19)	0.0310 (4)
H11	0.3838	0.0191	0.7034	0.037*
C12	0.6372 (3)	0.0176 (2)	0.80075 (18)	0.0284 (4)
C13	0.7142 (3)	0.0099 (2)	0.91361 (19)	0.0285 (4)
H13	0.8446	0.0101	0.9268	0.034*
C14	0.6006 (3)	0.0016 (2)	1.01106 (18)	0.0262 (4)
C15	0.6788 (3)	−0.0035 (2)	1.12871 (19)	0.0298 (4)
H15	0.8103	0.0003	1.1441	0.036*
C16	0.7664 (3)	0.0326 (2)	0.69980 (19)	0.0324 (4)
N1	0.2357 (3)	0.4817 (2)	0.64613 (16)	0.0393 (4)
N2	0.2428 (3)	0.4735 (2)	1.26862 (17)	0.0368 (4)
O1	0.9224 (2)	0.0001 (2)	0.71925 (15)	0.0427 (4)
O2	0.7122 (3)	0.0790 (2)	0.60529 (15)	0.0536 (5)
O1W	0.9988 (4)	−0.1777 (2)	0.5534 (2)	0.0674 (7)
H1WA	0.988 (6)	−0.112 (3)	0.599 (3)	0.081*
H1WB	1.092 (4)	−0.148 (4)	0.510 (3)	0.081*
O2W	0.4625 (3)	0.2384 (2)	0.5210 (2)	0.0601 (5)
H2WA	0.535 (5)	0.186 (3)	0.538 (3)	0.072*
H2WB	0.349 (3)	0.181 (3)	0.498 (3)	0.072*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ag1	0.0891 (2)	0.07053 (18)	0.01265 (12)	0.02514 (13)	0.00797 (10)	0.00346 (9)
C1	0.118 (3)	0.0361 (13)	0.0198 (12)	0.0176 (14)	0.0135 (14)	0.0051 (9)
C2	0.114 (2)	0.0290 (12)	0.0192 (12)	0.0154 (13)	0.0125 (13)	0.0017 (9)
C3	0.0334 (9)	0.0325 (10)	0.0157 (9)	0.0113 (8)	0.0037 (7)	0.0012 (7)
C4	0.0610 (14)	0.0338 (11)	0.0204 (11)	0.0016 (10)	0.0084 (10)	−0.0008 (8)
C5	0.0605 (14)	0.0421 (13)	0.0214 (11)	0.0011 (11)	0.0070 (10)	−0.0039 (9)
C6	0.124 (3)	0.0351 (13)	0.0201 (12)	0.0000 (15)	0.0036 (14)	0.0054 (10)
C7	0.120 (3)	0.0282 (12)	0.0207 (12)	0.0026 (13)	0.0049 (14)	0.0009 (9)
C8	0.0341 (9)	0.0303 (10)	0.0173 (10)	0.0102 (8)	0.0031 (8)	0.0012 (7)
C9	0.0610 (14)	0.0280 (10)	0.0182 (10)	0.0050 (9)	0.0046 (9)	0.0014 (8)
C10	0.0631 (14)	0.0328 (11)	0.0196 (11)	0.0081 (10)	0.0024 (10)	−0.0020 (8)
C11	0.0331 (10)	0.0337 (10)	0.0243 (10)	0.0086 (8)	0.0011 (8)	0.0028 (8)
C12	0.0318 (9)	0.0260 (9)	0.0264 (10)	0.0069 (7)	0.0068 (8)	−0.0001 (7)
C13	0.0267 (9)	0.0284 (9)	0.0306 (11)	0.0089 (7)	0.0045 (8)	0.0015 (8)
C14	0.0273 (9)	0.0243 (9)	0.0270 (10)	0.0078 (7)	0.0039 (7)	0.0022 (7)
C15	0.0271 (9)	0.0333 (10)	0.0286 (11)	0.0094 (8)	0.0023 (8)	0.0030 (8)
C16	0.0352 (10)	0.0346 (11)	0.0260 (11)	0.0081 (8)	0.0072 (8)	−0.0025 (8)
N1	0.0555 (11)	0.0470 (11)	0.0136 (8)	0.0138 (9)	0.0051 (8)	0.0009 (7)
N2	0.0546 (11)	0.0395 (10)	0.0138 (8)	0.0115 (8)	0.0039 (8)	0.0028 (7)
O1	0.0419 (8)	0.0585 (10)	0.0345 (9)	0.0234 (7)	0.0120 (7)	0.0034 (7)
O2	0.0508 (10)	0.0904 (15)	0.0276 (9)	0.0312 (10)	0.0125 (8)	0.0143 (9)
O1W	0.0937 (16)	0.0484 (11)	0.0459 (12)	−0.0039 (10)	0.0366 (11)	−0.0078 (9)
O2W	0.0669 (13)	0.0456 (11)	0.0615 (14)	0.0113 (9)	−0.0006 (11)	0.0001 (9)

Geometric parameters (Å, º)

Ag1—N1	2.1579 (19)	C10—N2	1.329 (3)
Ag1—N2^i	2.1620 (19)	C10—H10	0.9300
C1—N1	1.327 (3)	C11—C15^ii	1.371 (3)
C1—C2	1.381 (4)	C11—C12	1.419 (3)
C1—H1	0.9300	C11—H11	0.9300
C2—C3	1.386 (3)	C12—C13	1.370 (3)
C2—H2	0.9300	C12—C16	1.517 (3)
C3—C4	1.386 (3)	C13—C14	1.421 (3)
C3—C8	1.481 (3)	C13—H13	0.9300
C4—C5	1.374 (3)	C14—C15	1.418 (3)
C4—H4	0.9300	C14—C14^ii	1.428 (4)
C5—N1	1.337 (3)	C15—C11^ii	1.371 (3)
C5—H5	0.9300	C15—H15	0.9300
C6—N2	1.334 (3)	C16—O2	1.250 (3)
C6—C7	1.373 (4)	C16—O1	1.254 (3)
C6—H6	0.9300	N2—Ag1^iii	2.1620 (19)
C7—C8	1.383 (3)	O1W—H1WA	0.840 (10)
C7—H7	0.9300	O1W—H1WB	0.841 (10)
C8—C9	1.384 (3)	O2W—H2WA	0.848 (10)
C9—C10	1.377 (3)	O2W—H2WB	0.840 (10)
C9—H9	0.9300
N1—Ag1—N2^i	176.00 (7)	N2—C10—H10	118.2
N1—C1—C2	122.9 (2)	C9—C10—H10	118.2
N1—C1—H1	118.6	C15^ii—C11—C12	120.68 (19)
C2—C1—H1	118.6	C15^ii—C11—H11	119.7
C1—C2—C3	120.8 (2)	C12—C11—H11	119.7
C1—C2—H2	119.6	C13—C12—C11	119.28 (19)
C3—C2—H2	119.6	C13—C12—C16	120.10 (18)
C2—C3—C4	115.6 (2)	C11—C12—C16	120.61 (19)
C2—C3—C8	122.9 (2)	C12—C13—C14	121.86 (18)
C4—C3—C8	121.53 (19)	C12—C13—H13	119.1
C5—C4—C3	120.7 (2)	C14—C13—H13	119.1
C5—C4—H4	119.7	C15—C14—C13	122.73 (18)
C3—C4—H4	119.7	C15—C14—C14^ii	118.9 (2)
N1—C5—C4	123.0 (2)	C13—C14—C14^ii	118.3 (2)
N1—C5—H5	118.5	C11^ii—C15—C14	120.89 (18)
C4—C5—H5	118.5	C11^ii—C15—H15	119.6
N2—C6—C7	123.5 (2)	C14—C15—H15	119.6
N2—C6—H6	118.3	O2—C16—O1	125.2 (2)
C7—C6—H6	118.3	O2—C16—C12	117.97 (19)
C6—C7—C8	120.7 (2)	O1—C16—C12	116.83 (19)
C6—C7—H7	119.6	C1—N1—C5	117.1 (2)
C8—C7—H7	119.6	C1—N1—Ag1	123.59 (17)
C7—C8—C9	115.5 (2)	C5—N1—Ag1	119.22 (16)
C7—C8—C3	122.1 (2)	C10—N2—C6	116.2 (2)
C9—C8—C3	122.5 (2)	C10—N2—Ag1^iii	121.31 (15)
C10—C9—C8	120.5 (2)	C6—N2—Ag1^iii	122.46 (16)
C10—C9—H9	119.7	H1WA—O1W—H1WB	114 (4)
C8—C9—H9	119.7	H2WA—O2W—H2WB	107 (4)
N2—C10—C9	123.6 (2)
N1—C1—C2—C3	0.6 (6)	C16—C12—C13—C14	177.53 (18)
C1—C2—C3—C4	0.0 (4)	C12—C13—C14—C15	−178.73 (19)
C1—C2—C3—C8	178.8 (3)	C12—C13—C14—C14^ii	1.3 (3)
C2—C3—C4—C5	0.0 (4)	C13—C14—C15—C11^ii	−178.83 (19)
C8—C3—C4—C5	−178.8 (2)	C14^ii—C14—C15—C11^ii	1.2 (3)
C3—C4—C5—N1	−0.5 (4)	C13—C12—C16—O2	−160.7 (2)
N2—C6—C7—C8	0.1 (6)	C11—C12—C16—O2	18.1 (3)
C6—C7—C8—C9	−1.1 (5)	C13—C12—C16—O1	17.7 (3)
C6—C7—C8—C3	179.5 (3)	C11—C12—C16—O1	−163.5 (2)
C2—C3—C8—C7	177.2 (3)	C2—C1—N1—C5	−1.2 (5)
C4—C3—C8—C7	−4.1 (4)	C2—C1—N1—Ag1	−177.1 (3)
C2—C3—C8—C9	−2.1 (4)	C4—C5—N1—C1	1.1 (4)
C4—C3—C8—C9	176.6 (2)	C4—C5—N1—Ag1	177.2 (2)
C7—C8—C9—C10	1.4 (4)	N2^i—Ag1—N1—C1	−52.8 (11)
C3—C8—C9—C10	−179.2 (2)	N2^i—Ag1—N1—C5	131.3 (10)
C8—C9—C10—N2	−0.8 (4)	C9—C10—N2—C6	−0.3 (4)
C15^ii—C11—C12—C13	0.1 (3)	C9—C10—N2—Ag1^iii	−178.8 (2)
C15^ii—C11—C12—C16	−178.73 (19)	C7—C6—N2—C10	0.7 (5)
C11—C12—C13—C14	−1.3 (3)	C7—C6—N2—Ag1^iii	179.1 (3)

Symmetry codes: (i) x, y, z−1; (ii) −x+1, −y, −z+2; (iii) x, y, z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H1WA···O1	0.84 (1)	1.92 (1)	2.744 (3)	167 (4)
O1W—H1WB···O2^iv	0.84 (1)	1.97 (1)	2.803 (3)	174 (4)
O2W—H2WA···O2	0.85 (1)	1.98 (1)	2.819 (3)	170 (4)
O2W—H2WB···O1W^v	0.84 (1)	2.49 (2)	3.193 (3)	142 (3)
C5—H5···O1W^v	0.93	2.56	3.312 (3)	139
C6—H6···O1^ii	0.93	2.51	3.381 (3)	155
C15—H15···O1^vi	0.93	2.36	3.197 (3)	150

Symmetry codes: (ii) −x+1, −y, −z+2; (iv) −x+2, −y, −z+1; (v) −x+1, −y, −z+1; (vi) −x+2, −y, −z+2.