Poly[μ₂-nitrato-(μ₄-pyrazine-2-carboxyl­ato)disilver(I)]

The title compound, [Ag₂(C₅H₃N₂O₂)(NO₃)]_n, is a three-dimensional coordination polymer containing two-dimensional slabs held together by bridging nitrate groups. AgNO₄ and AgNO₅ silver coordination polyhedra arise. Weak argentophilic inter­actions [Ag...Ag = 3.0686 (7) Å] occur in the crystal structure.

Key indicators

• Single-crystal X-ray study
• T = 150 K
• Mean [sigma](C-C) = 0.008 Å
• R factor = 0.030
• wR factor = 0.063
• Data-to-parameter ratio = 10.5

checkCIF/PLATON results

No syntax errors found





Alert level C
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       0.91
PLAT764_ALERT_4_C Overcomplete CIF Bond List Detected (Rep/Expd) .       1.32 Ratio

Alert level G
ABSTM02_ALERT_3_G  When printed, the submitted absorption T values will be
            replaced by the scaled T values. Since the ratio of scaled T's
            is identical to the ratio of reported T values, the scaling
            does not imply a change to the absorption corrections used in
            the study.
            Ratio of Tmax expected/reported      0.907
            Tmax scaled      0.907 Tmin scaled      0.782

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   2 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check


checkCIF publication errors

Alert level A
PUBL022_ALERT_1_A There is a mismatched ~ on line 198
              riding with U~iso(H) = 1.2U~eq~(C).
              If you require a ~ then it should be escaped
              with a \, i.e. \~
              Otherwise there must be a matching closing ~, e.g. C~2~H~4~

   1 ALERT level A = Data missing that is essential or data in wrong format
   0 ALERT level G = General alerts. Data that may be required is missing

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S1. Comment

Single crystal X-ray analysis of the title compound, (I), revealed a three-dimensional structure composed of silver dimer units [Ag1···Ag2 = 3.0686 (7), linked into two-dimensional slabs by the pca (2-pyrazinecarboxylate, C₅H₃N₂O₂^-) groups. (Dong et al., 2000) The asymmetric unit is shown in Figure 1 and geometrical data are listed in Table 1. All available coordination sites of the pca ligands (Qin et al., 2004) are used in bonding to silver. The pca ligands bind to Ag1 atoms in a chelating fashion through N1 and O1 as shown in Figure 2. The Ag1 atoms are bridged to each other through an µ-2 interaction from the chelating oxygen atoms on the pca ligands (Figure 2) forming one-dimensional zigzag chains along the b axis (Figure 3). Each Ag1 atom is also bonded to the non-chelating oxygen atom O2. The terminal nitrogen atom (N2) and non-chelating oxygen atom (O2) (Figure 3) on the pca ligands are bonded to Ag2 atoms, connecting the zigzag chains in the c direction, propagating them into two-dimensional slabs in the [001] plane (Figure 4). Extending form either side of the slabs are nitrate groups, which are bonded to both Ag1 and Ag2. Ag1 is coordinated to one nitrate group through O5 and Ag2 is coordinated to three nitrate groups through O5, O3, and O4. These nitrate groups serve to tether the slabs into the extended three-dimensional structure shown in Figure 5.

Related literature

For related literature, see: Dong et al. (2000); Qin et al. (2004).

S2. Experimental

2-Pyrazinecarboxylic acid (8.05 mmol, 1000 mg) and Co(NO₃)(H₂O)₆ (8.05 mmol, 2340 mg) were weighed and placed into a 100 ml round bottom flask. which was then heated to a temperature of 373 K and kept constant for 12 h and then allowed to cool to room temperature. The product, cobalt (III) pyrazinecarboxylate, (II), was suction filtrated and allowed to dry. After drying, (II) and AgNO₃ were combined in a 23 ml Teflon-lined autoclave with 5 ml of distilled water. The autoclave was sealed and heated to 403 K at a rate of 1.0 K/min. and held at a constant temperature for 24 h. After this period, the autoclave was cooled to 305 K at a rate of 0.1 K/min. Colorless plates of (I) were hand picked from the reaction.

S3. Refinement

The hydrogen atoms were geometrically placed (C—H = 0.93 Å) and refined as riding with U_iso(H) = 1.2U_eq(C).

Computing details

Data collection: SMART (Bruker, 1998); cell refinement: SAINT-Plus (Bruker, 2001); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Sheldrick, 2000); software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. Asymmetric unit of (I) with additional atoms in a 3.5 Å coordination sphere around the Ag atoms. Atoms of the asymmetric unit highlighted with solid bonds. Displacement ellipsoids for the non-hydrogen atoms are drawn at the 50% probability level.
	Fig. 2. Chelating binding mode of pca ligands to Ag1 atoms, Ag2 atoms omitted for clarity.
	Fig. 3. Detail of the zigzag chain along the b axis, Ag2 atoms omitted for clarity.
	Fig. 4. Views (a) parallel and (b) perpendicular to the infinite slabs which propagate in the bc plane.
	Fig. 5. Full three-dimensional structure viewed along the [001] direction.

Poly[µ₂-nitrato-(µ₄-pyrazine-2-carboxylato)disilver(I)]

Crystal data

[Ag2(C5H3N2O2)(NO3)]	F(000) = 752
Mr = 400.84	Dx = 3.302 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1599 reflections
a = 8.8263 (6) Å	θ = 2.3–22.7°
b = 5.9804 (4) Å	µ = 4.86 mm^−1
c = 15.3032 (11) Å	T = 150 K
β = 93.480 (2)°	Plate, colorless
V = 806.29 (10) Å^3	0.08 × 0.04 × 0.02 mm
Z = 4

Data collection

Bruker SMART APEX CCD diffractometer	1425 independent reflections
Radiation source: fine-focus sealed tube	1216 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.063
ω scans	θmax = 25.0°, θmin = 2.3°
Absorption correction: multi-scan (SADABS; Bruker, 2001)	h = −10→10
Tmin = 0.862, Tmax = 1.000	k = −7→7
8281 measured reflections	l = −18→18

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)] = 0.030	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.063	H-atom parameters constrained
S = 1.03	w = 1/[σ^2(Fo^2) + (0.0283P)^2] where P = (Fo^2 + 2Fc^2)/3
1425 reflections	(Δ/σ)max = 0.001
136 parameters	Δρmax = 0.83 e Å^−3
0 restraints	Δρmin = −0.64 e Å^−3

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. 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 > σ(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	0.36377 (5)	0.31527 (7)	0.81236 (3)	0.01864 (15)
Ag2	0.25055 (5)	−0.04248 (8)	0.68028 (3)	0.01901 (15)
C1	0.6342 (6)	0.3866 (9)	0.5699 (4)	0.0133 (13)
C2	0.6641 (6)	0.2422 (10)	0.5023 (4)	0.0154 (13)
H2	0.6167	0.0995	0.5003	0.018*
C3	0.8236 (6)	0.4983 (10)	0.4470 (4)	0.0180 (14)
H3	0.8890	0.5454	0.4035	0.022*
C4	0.7993 (7)	0.6392 (10)	0.5159 (4)	0.0184 (14)
H4	0.8528	0.7770	0.5203	0.022*
C5	0.5214 (6)	0.3149 (10)	0.6354 (4)	0.0153 (13)
N1	0.7015 (6)	0.5872 (8)	0.5776 (3)	0.0175 (11)
N2	0.7577 (5)	0.2963 (8)	0.4394 (3)	0.0173 (11)
N3	−0.0623 (6)	0.1116 (8)	0.7017 (3)	0.0188 (12)
O1	0.4992 (5)	0.4448 (7)	0.6981 (3)	0.0191 (10)
O2	0.4573 (4)	0.1311 (7)	0.6200 (2)	0.0169 (9)
O3	0.0463 (5)	0.1172 (7)	0.7592 (3)	0.0236 (10)
O4	−0.0353 (5)	0.0837 (8)	0.6231 (3)	0.0287 (11)
O5	−0.1959 (4)	0.1354 (7)	0.7241 (3)	0.0224 (10)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ag1	0.0219 (3)	0.0141 (3)	0.0204 (3)	0.0010 (2)	0.0058 (2)	0.00323 (19)
Ag2	0.0166 (3)	0.0229 (3)	0.0182 (3)	−0.0022 (2)	0.00601 (19)	−0.0016 (2)
C1	0.012 (3)	0.013 (3)	0.014 (3)	0.002 (2)	−0.002 (2)	0.002 (2)
C2	0.017 (3)	0.017 (3)	0.012 (3)	−0.001 (3)	−0.002 (2)	0.001 (2)
C3	0.011 (3)	0.026 (4)	0.016 (3)	0.002 (3)	0.000 (3)	0.009 (3)
C4	0.018 (3)	0.011 (3)	0.027 (4)	−0.004 (3)	0.000 (3)	0.002 (3)
C5	0.014 (3)	0.017 (3)	0.014 (3)	0.005 (3)	0.002 (2)	0.005 (3)
N1	0.018 (3)	0.018 (3)	0.016 (3)	0.000 (2)	0.000 (2)	−0.001 (2)
N2	0.015 (3)	0.024 (3)	0.014 (3)	−0.002 (2)	0.004 (2)	0.001 (2)
N3	0.022 (3)	0.007 (3)	0.027 (3)	−0.004 (2)	0.005 (3)	−0.003 (2)
O1	0.023 (2)	0.015 (2)	0.021 (2)	−0.0017 (18)	0.0110 (19)	−0.0045 (18)
O2	0.021 (2)	0.016 (2)	0.015 (2)	−0.0063 (18)	0.0053 (18)	−0.0018 (17)
O3	0.019 (2)	0.022 (2)	0.029 (3)	0.0013 (19)	−0.003 (2)	−0.007 (2)
O4	0.031 (3)	0.033 (3)	0.023 (3)	−0.003 (2)	0.011 (2)	−0.004 (2)
O5	0.011 (2)	0.024 (3)	0.032 (3)	−0.0001 (19)	0.006 (2)	−0.008 (2)

Geometric parameters (Å, º)

Ag1—N1^i	2.268 (5)	C2—H2	0.9500
Ag1—O1	2.311 (4)	C3—N2	1.343 (8)
Ag1—O5^ii	2.464 (4)	C3—C4	1.377 (9)
Ag1—O1^i	2.534 (4)	C3—H3	0.9500
Ag1—O2^iii	2.633 (4)	C4—N1	1.354 (8)
Ag1—Ag2	3.0686 (7)	C4—H4	0.9500
Ag2—O2	2.337 (4)	C5—O2	1.252 (7)
Ag2—N2^iv	2.377 (5)	C5—O1	1.260 (7)
Ag2—O3	2.426 (4)	N1—Ag1^iii	2.268 (5)
Ag2—O5^v	2.483 (4)	N2—Ag2^iv	2.377 (5)
Ag2—O4	2.726 (5)	N3—O4	1.250 (6)
Ag2—O1^i	2.801 (4)	N3—O5	1.256 (6)
C1—N1	1.341 (7)	N3—O3	1.262 (6)
C1—C2	1.384 (8)	O1—Ag1^iii	2.534 (4)
C1—C5	1.516 (8)	O5—Ag1^v	2.464 (4)
C2—N2	1.346 (7)	O5—Ag2^ii	2.483 (4)
N1^i—Ag1—O1	158.37 (16)	O1^i—Ag2—Ag1	50.89 (8)
N1^i—Ag1—O5^ii	117.34 (16)	N1—C1—C2	121.4 (5)
O1—Ag1—O5^ii	84.23 (14)	N1—C1—C5	120.0 (5)
N1^i—Ag1—O1^i	70.42 (16)	C2—C1—C5	118.7 (5)
O1—Ag1—O1^i	88.53 (9)	N2—C2—C1	122.5 (5)
O5^ii—Ag1—O1^i	161.38 (14)	N2—C2—H2	118.7
N1^i—Ag1—O2^iii	108.24 (15)	C1—C2—H2	118.7
O1—Ag1—O2^iii	74.41 (13)	N2—C3—C4	122.0 (6)
O5^ii—Ag1—O2^iii	82.52 (13)	N2—C3—H3	119.0
O1^i—Ag1—O2^iii	112.02 (13)	C4—C3—H3	119.0
N1^i—Ag1—Ag2	88.99 (13)	N1—C4—C3	121.9 (6)
O1—Ag1—Ag2	84.16 (10)	N1—C4—H4	119.0
O5^ii—Ag1—Ag2	103.01 (10)	C3—C4—H4	119.0
O1^i—Ag1—Ag2	59.08 (10)	O2—C5—O1	126.5 (5)
O2^iii—Ag1—Ag2	157.29 (9)	O2—C5—C1	115.6 (5)
O2—Ag2—N2^iv	88.14 (15)	O1—C5—C1	117.9 (5)
O2—Ag2—O3	130.03 (15)	C1—N1—C4	116.2 (5)
N2^iv—Ag2—O3	130.27 (16)	C1—N1—Ag1^iii	118.2 (4)
O2—Ag2—O5^v	139.56 (14)	C4—N1—Ag1^iii	125.5 (4)
N2^iv—Ag2—O5^v	87.74 (15)	C3—N2—C2	115.8 (5)
O3—Ag2—O5^v	80.52 (14)	C3—N2—Ag2^iv	129.3 (4)
O2—Ag2—O4	118.69 (14)	C2—N2—Ag2^iv	114.0 (4)
N2^iv—Ag2—O4	86.86 (15)	O4—N3—O5	121.0 (5)
O3—Ag2—O4	49.43 (14)	O4—N3—O3	119.5 (5)
O5^v—Ag2—O4	101.22 (13)	O5—N3—O3	119.5 (5)
O2—Ag2—O1^i	70.81 (13)	C5—O1—Ag1	118.8 (4)
N2^iv—Ag2—O1^i	118.73 (14)	C5—O1—Ag1^iii	113.2 (4)
O3—Ag2—O1^i	105.05 (13)	Ag1—O1—Ag1^iii	127.74 (17)
O5^v—Ag2—O1^i	76.19 (13)	C5—O2—Ag2	132.1 (4)
O4—Ag2—O1^i	153.84 (12)	N3—O3—Ag2	101.4 (3)
O2—Ag2—Ag1	73.70 (9)	N3—O4—Ag2	87.4 (3)
N2^iv—Ag2—Ag1	161.16 (12)	N3—O5—Ag1^v	114.3 (3)
O3—Ag2—Ag1	67.65 (10)	N3—O5—Ag2^ii	117.9 (3)
O5^v—Ag2—Ag1	102.71 (10)	Ag1^v—O5—Ag2^ii	126.91 (17)
O4—Ag2—Ag1	106.05 (10)
N1^i—Ag1—Ag2—O2	−145.90 (16)	C1—C2—N2—C3	1.4 (8)
O1—Ag1—Ag2—O2	13.55 (15)	C1—C2—N2—Ag2^iv	−169.3 (4)
O5^ii—Ag1—Ag2—O2	96.24 (14)	O2—C5—O1—Ag1	12.5 (8)
O1^i—Ag1—Ag2—O2	−78.24 (15)	C1—C5—O1—Ag1	−168.8 (4)
O2^iii—Ag1—Ag2—O2	−5.7 (3)	O2—C5—O1—Ag1^iii	−173.1 (5)
N1^i—Ag1—Ag2—N2^iv	−130.0 (4)	C1—C5—O1—Ag1^iii	5.6 (6)
O1—Ag1—Ag2—N2^iv	29.5 (4)	N1^i—Ag1—O1—C5	53.1 (7)
O5^ii—Ag1—Ag2—N2^iv	112.2 (4)	O5^ii—Ag1—O1—C5	−122.9 (4)
O1^i—Ag1—Ag2—N2^iv	−62.3 (4)	O1^i—Ag1—O1—C5	39.9 (3)
O2^iii—Ag1—Ag2—N2^iv	10.3 (4)	O2^iii—Ag1—O1—C5	153.3 (4)
N1^i—Ag1—Ag2—O3	66.45 (17)	Ag2—Ag1—O1—C5	−19.1 (4)
O1—Ag1—Ag2—O3	−134.10 (15)	N1^i—Ag1—O1—Ag1^iii	−120.4 (4)
O5^ii—Ag1—Ag2—O3	−51.42 (15)	O5^ii—Ag1—O1—Ag1^iii	63.6 (2)
O1^i—Ag1—Ag2—O3	134.11 (15)	O1^i—Ag1—O1—Ag1^iii	−133.6 (3)
O2^iii—Ag1—Ag2—O3	−153.3 (3)	O2^iii—Ag1—O1—Ag1^iii	−20.20 (19)
N1^i—Ag1—Ag2—O5^v	−7.57 (15)	Ag2—Ag1—O1—Ag1^iii	167.4 (2)
O1—Ag1—Ag2—O5^v	151.88 (14)	O1—C5—O2—Ag2	9.9 (9)
O5^ii—Ag1—Ag2—O5^v	−125.44 (17)	C1—C5—O2—Ag2	−168.8 (3)
O1^i—Ag1—Ag2—O5^v	60.09 (14)	N2^iv—Ag2—O2—C5	166.0 (5)
O2^iii—Ag1—Ag2—O5^v	132.7 (2)	O3—Ag2—O2—C5	21.2 (6)
N1^i—Ag1—Ag2—O4	98.23 (16)	O5^v—Ag2—O2—C5	−109.6 (5)
O1—Ag1—Ag2—O4	−102.32 (14)	O4—Ag2—O2—C5	80.6 (5)
O5^ii—Ag1—Ag2—O4	−19.63 (14)	O1^i—Ag2—O2—C5	−72.6 (5)
O1^i—Ag1—Ag2—O4	165.89 (14)	Ag1—Ag2—O2—C5	−19.0 (5)
O2^iii—Ag1—Ag2—O4	−121.5 (2)	O4—N3—O3—Ag2	−16.1 (5)
N1^i—Ag1—Ag2—O1^i	−67.66 (16)	O5—N3—O3—Ag2	164.3 (4)
O1—Ag1—Ag2—O1^i	91.79 (11)	O2—Ag2—O3—N3	104.4 (3)
O5^ii—Ag1—Ag2—O1^i	174.48 (14)	N2^iv—Ag2—O3—N3	−26.6 (4)
O2^iii—Ag1—Ag2—O1^i	72.6 (2)	O5^v—Ag2—O3—N3	−105.4 (3)
N1—C1—C2—N2	−2.1 (9)	O4—Ag2—O3—N3	8.4 (3)
C5—C1—C2—N2	177.2 (5)	O1^i—Ag2—O3—N3	−178.2 (3)
N2—C3—C4—N1	−3.5 (9)	Ag1—Ag2—O3—N3	146.6 (3)
N1—C1—C5—O2	175.8 (5)	O5—N3—O4—Ag2	−166.4 (5)
C2—C1—C5—O2	−3.5 (8)	O3—N3—O4—Ag2	14.0 (5)
N1—C1—C5—O1	−3.1 (8)	O2—Ag2—O4—N3	−128.1 (3)
C2—C1—C5—O1	177.7 (5)	N2^iv—Ag2—O4—N3	145.8 (3)
C2—C1—N1—C4	0.0 (8)	O3—Ag2—O4—N3	−8.3 (3)
C5—C1—N1—C4	−179.2 (5)	O5^v—Ag2—O4—N3	58.7 (3)
C2—C1—N1—Ag1^iii	177.5 (4)	O1^i—Ag2—O4—N3	−22.8 (5)
C5—C1—N1—Ag1^iii	−1.8 (7)	Ag1—Ag2—O4—N3	−48.2 (3)
C3—C4—N1—C1	2.7 (8)	O4—N3—O5—Ag1^v	60.4 (6)
C3—C4—N1—Ag1^iii	−174.6 (4)	O3—N3—O5—Ag1^v	−120.0 (4)
C4—C3—N2—C2	1.3 (8)	O4—N3—O5—Ag2^ii	−129.7 (4)
C4—C3—N2—Ag2^iv	170.3 (4)	O3—N3—O5—Ag2^ii	49.9 (6)

Symmetry codes: (i) −x+1, y−1/2, −z+3/2; (ii) −x, y+1/2, −z+3/2; (iii) −x+1, y+1/2, −z+3/2; (iv) −x+1, −y, −z+1; (v) −x, y−1/2, −z+3/2.