catena-Poly­[[silver(I)-μ-2,5-bis(4-pyridyl)-1,3,4-oxa­diazo­le] nitrate], a one-dimensional coordination polymer exhibiting a double-chain supramolecular structure through hydrogen bonds

In the crystal structure of the title complex, [Ag(C₁₂H₈N₄O)(NO₃)]_n, each silver(I) center is coordinated by two N atoms of the pyridine rings of the bridging ligand 2,5-bis(4-pyridyl)-1,3,4-oxa­diazo­le and one oxy­gen donor of the nitrate anion, giving a trigonal coordination geometry. The ligands bridge the silver(I) centers to form a one-dimensional linear structure, which is further linked into a double-chain motif through intermolecular C—H...O hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.006 Å
• R factor = 0.040
• wR factor = 0.117
• Data-to-parameter ratio = 11.6

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level C:



PLAT_737  Alert C D...A   Calc    3.271(7), Rep    3.270(3) ....       2.33 su-Ratio
                     C9   -O12     1.555   2.776


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 1 Alert Level C = Please check

---

S1. Comment

Great efforts have been devoted to metal-directed coordination supramolecules due to their interesting topological structures and potential applications as functional materials (Batten & Robson, 1998; Eddaoudi et al., 2001). Using a `building block' methodology, combination of linear 4,4'-bipyridine-based ligands and metal ions has generated a wide variety of solid-state architectures (Hagrman et al., 1999). Recently, an interesting angular dipyridyl ligand, 2,5-bis(4-pyridyl)-1,3,4-oxadiazole, which could potentially provide both discrete and divergent topologies upon metal complexation under appropriate conditions (Du, Bu et al., 2002; Du, Chen et al., 2002; Du, Liu et al., 2002) has been developed. Here, we report on the crystal structure of a silver(I) complex of this ligand, which reveals that it is a neutral one-dimensional coordination polymer, (I).

As depicted in Fig. 1, the Ag^I center coordinates to two N atoms of the pyridine rings from the bridging ligand, and one O atom of the nitrate anion. The coordination environment of each Ag^I ion can best be described as trigonal, with the Ag^I ion deviating from the mean coordination plane by ca 0.18 Å. The mean atomic displacement from the least-squares plane of the ligand is equal to 0.0733 Å. The two pyridine rings in the same ligand molecule are inclined by 4.9 and 4.7°, with respect to the central oxadiazole plane, and by 8.5° with respect to one another.

As shown in Fig. 2, within this 1:1 ligand–metal polymeric chain, the neighboring Ag···Ag separation is 14.191 Å, and the nearest Ag···Ag distance between the coordination chains is only 3.592 Å. This is slightly longer than the van der Waals contact distance for Ag···Ag (3.40 Å), illustrating the lack of direct metal—metal interaction (Hartshorn & Steel, 1998). Of further interest is the fact that each nitrate anion in the chain acts as an acceptor of two intermolecular C—H···O hydrogen bonds (with the pyridine rings of the adjacent coordination chain), forming a unique double-chain supramolecular motif (Fig. 2). The C···O and H···O separations, and the bond angles are listed in Table 2, which are in the normal range for weak hydrogen bonding interactions.

S2. Experimental

A CH₃CN solution of AgNO₃ (42.5 mg, 0.25 mmol) was carefully layered onto a CHCl₃ solution of the ligand 2,5-bis(4-pyridyl)-1,3,4-oxadiazole (56.0 mg, 0.25 mmol). Colorless block-shaped single crystals of (I) suitable for X-ray diffraction were obtained after ca two weeks at room temperature. Yield: 75%. Analysis calculated for the title complex: C 36.57, H 2.05, N 17.77%; found: C 36.48, H 2.06, N 17.82%. FT—IR data (KBr pellet, cm⁻¹): 3178 (w), 3096 (m), 3049 (m), 2934 (w), 2430 (m), 2332 (m), 1993 (w), 1971 (w), 1876 (w), 1747 (m), 1612 (s), 1564 (s), 1540 (s), 1485 (s), 1427 (s), 1402 (s), 1356 (s), 1336 (s), 1302 (s), 1215 (s), 1121 (m), 1097 (m), 1061 (m), 1039 (m), 1012 (s), 970 (m), 892 (w), 846 (s), 823 (m), 747 (m), 727 (s), 713 (s), 699 (m).

S3. Refinement

H atoms were placed in the geometrically calculated positions and included in the final refinement in the riding-model approximation, with displacement parameters derived from the atoms to which they were bonded.

Data collection: SMART (BRUKER, 1998); cell refinement: SMART (BRUKER, 1998); data reduction: SAINT (BRUKER, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP (Bruker, 1998)

Computing details

Figures

	Fig. 1. View of the coordination geometry around the Ag^I center in complex (I).
	Fig. 2. View of the double-chain structure in (I), though Ag—N coordination interactions and C—H···O hydrogen bonds.

catena-Poly[silver(I)-2,5-bis(4-pyridyl)-1,3,4-oxadiazole nitrate]

Crystal data

[Ag(C12H8N4O)(NO3]	Z = 2
Mr = 394.10	F(000) = 388
Triclinic, P1	Dx = 1.986 Mg m^−3
a = 8.3649 (11) Å	Mo Kα radiation, λ = 0.71073 Å
b = 8.9480 (13) Å	Cell parameters from 2737 reflections
c = 9.8344 (14) Å	θ = 2.5–25.0°
α = 74.713 (2)°	µ = 1.56 mm^−1
β = 77.828 (3)°	T = 298 K
γ = 69.389 (3)°	Block, colorless
V = 658.90 (16) Å^3	0.15 × 0.15 × 0.15 mm

Data collection

Bruker SMART 1000 diffractometer	2016 reflections with I > 2σ(I)
ω scans	Rint = 0.021
Absorption correction: multi-scan [SAINT (Bruker 1998) and SADABS (Sheldrick, 1997)]	θmax = 25.0°
Tmin = 0.491, Tmax = 0.792	h = −6→9
2737 measured reflections	k = −7→10
2303 independent reflections	l = −11→11

Refinement

Refinement on F^2	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.040	w = 1/[σ^2(Fo^2) + (0.087P)^2] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.117	(Δ/σ)max = 0.001
S = 1.06	Δρmax = 0.81 e Å^−3
2303 reflections	Δρmin = −0.73 e Å^−3
199 parameters

Special details

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

Refinement. Full-MATRIX

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

	x	y	z	Uiso*/Ueq
Ag1	1.08174 (4)	0.79990 (4)	0.95985 (3)	0.0569 (2)
O1	0.4770 (3)	0.7225 (3)	0.5734 (3)	0.0376 (6)
N1	0.8793 (4)	0.7625 (4)	0.8714 (3)	0.0457 (8)
N2	0.3830 (5)	0.6032 (4)	0.7866 (4)	0.0448 (8)
N3	0.2890 (4)	0.5953 (4)	0.6876 (3)	0.0432 (7)
N4	0.1864 (4)	0.7403 (4)	0.1672 (4)	0.0424 (7)
C1	0.8614 (5)	0.8098 (5)	0.7311 (4)	0.0444 (9)
H1A	0.9386	0.8582	0.6696	0.053*
C2	0.7353 (5)	0.7897 (5)	0.6761 (4)	0.0391 (8)
H2A	0.7255	0.8261	0.5796	0.047*
C3	0.6219 (5)	0.7143 (4)	0.7666 (4)	0.0362 (8)
C4	0.6394 (6)	0.6652 (5)	0.9100 (4)	0.0459 (9)
H4A	0.5654	0.6144	0.9736	0.055*
C5	0.7689 (6)	0.6931 (6)	0.9563 (4)	0.0501 (10)
H5A	0.7790	0.6612	1.0529	0.060*
C6	0.4906 (5)	0.6787 (5)	0.7149 (4)	0.0380 (8)
C7	0.3489 (5)	0.6659 (4)	0.5659 (4)	0.0360 (8)
C8	0.2947 (5)	0.6915 (4)	0.4278 (4)	0.0363 (8)
C9	0.3639 (5)	0.7798 (5)	0.3066 (4)	0.0413 (9)
H9A	0.4484	0.8230	0.3107	0.050*
C10	0.3054 (5)	0.8023 (5)	0.1806 (4)	0.0431 (9)
H10A	0.3506	0.8637	0.0999	0.052*
C11	0.1230 (5)	0.6531 (5)	0.2829 (4)	0.0454 (9)
H11A	0.0420	0.6077	0.2747	0.054*
C12	0.1720 (5)	0.6262 (5)	0.4156 (4)	0.0445 (9)
H12A	0.1235	0.5656	0.4949	0.053*
N11	1.2250 (4)	1.0537 (4)	0.7428 (4)	0.0489 (8)
O11	1.2338 (6)	1.0113 (5)	0.8723 (4)	0.0788 (11)
O12	1.2765 (6)	1.1659 (6)	0.6709 (4)	0.0891 (13)
O13	1.1575 (5)	0.9844 (4)	0.6877 (5)	0.0754 (10)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ag1	0.0655 (3)	0.0801 (3)	0.0394 (3)	−0.0343 (2)	−0.02544 (17)	−0.00568 (17)
O1	0.0391 (13)	0.0523 (15)	0.0262 (13)	−0.0175 (11)	−0.0123 (10)	−0.0054 (11)
N1	0.0491 (18)	0.066 (2)	0.0307 (17)	−0.0221 (16)	−0.0161 (14)	−0.0095 (15)
N2	0.0519 (19)	0.0573 (19)	0.0329 (17)	−0.0252 (16)	−0.0132 (15)	−0.0049 (15)
N3	0.0508 (18)	0.0544 (18)	0.0316 (17)	−0.0246 (15)	−0.0129 (14)	−0.0038 (14)
N4	0.0433 (17)	0.0515 (18)	0.0353 (17)	−0.0106 (14)	−0.0175 (14)	−0.0096 (14)
C1	0.047 (2)	0.056 (2)	0.033 (2)	−0.0199 (18)	−0.0117 (17)	−0.0050 (17)
C2	0.048 (2)	0.048 (2)	0.0247 (17)	−0.0172 (17)	−0.0138 (15)	−0.0033 (15)
C3	0.0374 (18)	0.0419 (18)	0.0328 (18)	−0.0114 (15)	−0.0125 (15)	−0.0086 (15)
C4	0.053 (2)	0.064 (2)	0.0276 (19)	−0.027 (2)	−0.0102 (16)	−0.0034 (17)
C5	0.058 (2)	0.072 (3)	0.0289 (19)	−0.028 (2)	−0.0164 (18)	−0.0065 (18)
C6	0.0405 (19)	0.046 (2)	0.0269 (18)	−0.0102 (16)	−0.0100 (15)	−0.0064 (15)
C7	0.0352 (18)	0.0414 (19)	0.0327 (19)	−0.0086 (15)	−0.0123 (15)	−0.0083 (15)
C8	0.0360 (18)	0.0419 (19)	0.0317 (19)	−0.0085 (15)	−0.0119 (15)	−0.0080 (15)
C9	0.045 (2)	0.049 (2)	0.036 (2)	−0.0202 (17)	−0.0152 (17)	−0.0047 (16)
C10	0.047 (2)	0.051 (2)	0.034 (2)	−0.0175 (17)	−0.0141 (17)	−0.0032 (16)
C11	0.042 (2)	0.060 (2)	0.041 (2)	−0.0194 (18)	−0.0155 (17)	−0.0102 (18)
C12	0.049 (2)	0.059 (2)	0.0328 (19)	−0.0260 (18)	−0.0116 (16)	−0.0046 (16)
N11	0.0431 (18)	0.063 (2)	0.041 (2)	−0.0186 (16)	−0.0064 (15)	−0.0074 (16)
O11	0.096 (3)	0.096 (3)	0.0357 (18)	−0.025 (2)	−0.0187 (18)	0.0009 (17)
O12	0.090 (3)	0.128 (3)	0.066 (2)	−0.076 (3)	−0.021 (2)	0.018 (2)
O13	0.076 (2)	0.073 (2)	0.092 (3)	−0.0243 (19)	−0.021 (2)	−0.032 (2)

Geometric parameters (Å, º)

Ag1—N1	2.216 (3)	C3—C4	1.385 (5)
Ag1—N4^i	2.250 (3)	C3—C6	1.460 (5)
Ag1—O11	2.512 (5)	C4—C5	1.380 (6)
O1—C7	1.358 (5)	C4—H4A	0.9300
O1—C6	1.361 (4)	C5—H5A	0.9300
N1—C5	1.319 (5)	C7—C8	1.458 (5)
N1—C1	1.356 (5)	C8—C9	1.384 (5)
N2—C6	1.294 (5)	C8—C12	1.386 (5)
N2—N3	1.404 (5)	C9—C10	1.368 (6)
N3—C7	1.286 (5)	C9—H9A	0.9300
N4—C11	1.324 (5)	C10—H10A	0.9300
N4—C10	1.341 (5)	C11—C12	1.385 (6)
N4—Ag1^ii	2.250 (3)	C11—H11A	0.9300
C1—C2	1.365 (6)	C12—H12A	0.9300
C1—H1A	0.9300	N11—O12	1.223 (5)
C2—C3	1.388 (5)	N11—O11	1.239 (5)
C2—H2A	0.9300	N11—O13	1.245 (5)
N1—Ag1—N4^i	139.84 (13)	C4—C5—H5A	118.1
N1—Ag1—O11	130.27 (12)	N2—C6—O1	112.5 (3)
N4^i—Ag1—O11	87.79 (12)	N2—C6—C3	128.3 (3)
C7—O1—C6	102.3 (3)	O1—C6—C3	119.1 (3)
C5—N1—C1	117.3 (4)	N3—C7—O1	113.2 (3)
C5—N1—Ag1	120.0 (3)	N3—C7—C8	128.0 (3)
C1—N1—Ag1	122.7 (3)	O1—C7—C8	118.9 (3)
C6—N2—N3	106.2 (3)	C9—C8—C12	118.5 (3)
C7—N3—N2	105.9 (3)	C9—C8—C7	121.4 (3)
C11—N4—C10	117.7 (4)	C12—C8—C7	120.1 (3)
C11—N4—Ag1^ii	121.0 (3)	C10—C9—C8	118.7 (4)
C10—N4—Ag1^ii	121.1 (3)	C10—C9—H9A	120.7
N1—C1—C2	123.0 (4)	C8—C9—H9A	120.7
N1—C1—H1A	118.5	N4—C10—C9	123.4 (4)
C2—C1—H1A	118.5	N4—C10—H10A	118.3
C1—C2—C3	118.9 (3)	C9—C10—H10A	118.3
C1—C2—H2A	120.5	N4—C11—C12	123.0 (4)
C3—C2—H2A	120.5	N4—C11—H11A	118.5
C4—C3—C2	118.4 (3)	C12—C11—H11A	118.5
C4—C3—C6	119.2 (3)	C11—C12—C8	118.6 (4)
C2—C3—C6	122.3 (3)	C11—C12—H12A	120.7
C5—C4—C3	118.6 (4)	C8—C12—H12A	120.7
C5—C4—H4A	120.7	O12—N11—O11	120.4 (4)
C3—C4—H4A	120.7	O12—N11—O13	120.3 (4)
N1—C5—C4	123.7 (4)	O11—N11—O13	119.2 (4)
N1—C5—H5A	118.1	N11—O11—Ag1	104.7 (3)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2A···O12^iii	0.93	2.45	3.350 (4)	163
C9—H9A···O12^iii	0.93	2.38	3.270 (3)	160

Symmetry code: (iii) −x+2, −y+2, −z+1.