Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807041888/hb2524sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807041888/hb2524Isup2.hkl |
CCDC reference: 663539
Ag(CF3SO3) (Aldrich, 0.05 g, 0.19 mmol) was dissolved in CH3CN (20 ml) and layered on top of a CH2Cl2 solution (20 ml) containing 0.04 g (0.19 mmol) of 4-pyridinealdazine (Aldrich). After three days, yellow blocks of (I) were observed at the interface between the two layers; m.p. 522–524 K.
All the H atoms were included in the riding-model approximation, with C—H = 0.95 Å, and with Uiso(H) = 1.2Ueq(C).
The polymeric title compound, [Ag(C12H10N4)]n.n(CF3SO3), or [Ag(4—PA)(CF3SO3)]n (I), was investigated as a part of an on-going study of the structural chemistry of the Ag salts of isomeric n-pyridinealdazine molecules, n = 2, 3 and 4 (Broker & Tiekink, 2007a,b,c). The 4-pyridinealdazine (4-PA) ligand in (I) is bidentate bridging which results in the formation of polymeric chains and a near linear AgN2 geometry for the silver atom (Fig. 1 & Table 1).
The linear chains are connected into supramolecular double chains (Fig. 2) via a combination of C—H···O interactions (Table 2) and a weak Ag···O3i (i = 1 - x, 1 - y, 1 - z) contact of 2.759 (3) Å. The chains stack side by side to form layers in the ac plane and these layers are connected to adjacent layers on either side via Ag···Agii (ii = 1 - x, 1 - y, -z) agentophilic interactions [3.2738 (13) Å] as well as Ag···O2iii (iii = x, y, -1 + z) contacts of 2.854 (3) Å.
Similar polymeric structures to those in (I) are found in the following salts: perchlorate, tetrafluoroborate (as acetonitrile solvates, Kennedy et al., 2005), hexafluoroantimonate (as the acetonitrile water solvate, Kennedy et al., 2005), methanesulfonate (Broker & Tiekink, 2007c), and nitrate, for which two polymorphs have been reported (Shi et al., 2002; Patra & Goldberg, 2003; Kennedy et al., 2005). In all but the nitrate polymorphs, the chains are essentially flat. Only in (I) and the methanesulfonate salt (Broker & Tiekink, 2007c) are Ag···Ag interactions found.
For related polymeric silver salts containing the 4-pyridinealdazine ligand, see: Kennedy et al. (2005); Broker & Tiekink (2007c); Shi et al. (2002); Patra & Goldberg (2003). For related literature, see: Broker & Tiekink (2007a,b).
Data collection: CrystalClear (Rigaku/MSC, 2005); cell refinement: CrystalClear (Rigaku/MSC, 2005); data reduction: CrystalClear (Rigaku/MSC, 2005); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976) and DIAMOND (Brandenburg, 2006); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997).
[Ag(C12H10N4)](CF3SO3) | Z = 2 |
Mr = 467.18 | F(000) = 460 |
Triclinic, P1 | Dx = 1.946 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71070 Å |
a = 8.9608 (18) Å | Cell parameters from 1270 reflections |
b = 8.9816 (18) Å | θ = 3.3–30.2° |
c = 10.804 (2) Å | µ = 1.45 mm−1 |
α = 75.99 (3)° | T = 98 K |
β = 71.09 (3)° | Block, yellow |
γ = 83.30 (3)° | 0.45 × 0.36 × 0.21 mm |
V = 797.4 (3) Å3 |
Rigaku AFC12κ/SATURN724 diffractometer | 2695 independent reflections |
Radiation source: fine-focus sealed tube | 2654 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.036 |
ω scans | θmax = 25.0°, θmin = 3.1° |
Absorption correction: multi-scan (ABSCOR; Higashi, 1995) | h = −9→10 |
Tmin = 0.845, Tmax = 1.000 | k = −10→10 |
7718 measured reflections | l = −11→12 |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.025 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.068 | H-atom parameters constrained |
S = 1.07 | w = 1/[σ2(Fo2) + (0.0382P)2 + 0.6435P] where P = (Fo2 + 2Fc2)/3 |
2695 reflections | (Δ/σ)max = 0.001 |
226 parameters | Δρmax = 0.47 e Å−3 |
0 restraints | Δρmin = −0.55 e Å−3 |
[Ag(C12H10N4)](CF3SO3) | γ = 83.30 (3)° |
Mr = 467.18 | V = 797.4 (3) Å3 |
Triclinic, P1 | Z = 2 |
a = 8.9608 (18) Å | Mo Kα radiation |
b = 8.9816 (18) Å | µ = 1.45 mm−1 |
c = 10.804 (2) Å | T = 98 K |
α = 75.99 (3)° | 0.45 × 0.36 × 0.21 mm |
β = 71.09 (3)° |
Rigaku AFC12κ/SATURN724 diffractometer | 2695 independent reflections |
Absorption correction: multi-scan (ABSCOR; Higashi, 1995) | 2654 reflections with I > 2σ(I) |
Tmin = 0.845, Tmax = 1.000 | Rint = 0.036 |
7718 measured reflections |
R[F2 > 2σ(F2)] = 0.025 | 0 restraints |
wR(F2) = 0.068 | H-atom parameters constrained |
S = 1.07 | Δρmax = 0.47 e Å−3 |
2695 reflections | Δρmin = −0.55 e Å−3 |
226 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
Ag | 0.36832 (2) | 0.36786 (2) | 0.060832 (18) | 0.02608 (10) | |
S1 | 0.26232 (8) | 0.68538 (8) | 0.79915 (7) | 0.02863 (17) | |
F1 | −0.0358 (2) | 0.7776 (2) | 0.8486 (2) | 0.0571 (5) | |
F2 | 0.1221 (3) | 0.9605 (2) | 0.7756 (2) | 0.0600 (6) | |
F3 | 0.0766 (3) | 0.8337 (2) | 0.9775 (2) | 0.0568 (6) | |
O1 | 0.2826 (3) | 0.7020 (3) | 0.6605 (2) | 0.0583 (7) | |
O2 | 0.2017 (3) | 0.5404 (2) | 0.8843 (3) | 0.0469 (6) | |
O3 | 0.3899 (3) | 0.7370 (3) | 0.8300 (2) | 0.0436 (5) | |
N1 | 0.2426 (3) | 0.4890 (2) | 0.2149 (2) | 0.0215 (4) | |
N2 | −0.1451 (3) | 0.8152 (2) | 0.5065 (2) | 0.0247 (5) | |
N3 | −0.1980 (3) | 0.8996 (3) | 0.6078 (2) | 0.0273 (5) | |
N4 | −0.5349 (3) | 1.2325 (2) | 0.9117 (2) | 0.0219 (4) | |
C1 | 0.3015 (3) | 0.5068 (3) | 0.3104 (3) | 0.0234 (5) | |
H1 | 0.4007 | 0.4581 | 0.3132 | 0.028* | |
C2 | 0.2238 (3) | 0.5927 (3) | 0.4042 (3) | 0.0223 (5) | |
H2 | 0.2690 | 0.6028 | 0.4700 | 0.027* | |
C3 | 0.0771 (3) | 0.6650 (3) | 0.4012 (2) | 0.0215 (5) | |
C4 | 0.0148 (3) | 0.6433 (3) | 0.3041 (3) | 0.0236 (5) | |
H4 | −0.0855 | 0.6882 | 0.3005 | 0.028* | |
C5 | 0.1001 (3) | 0.5563 (3) | 0.2138 (3) | 0.0251 (5) | |
H5 | 0.0568 | 0.5430 | 0.1479 | 0.030* | |
C6 | −0.0050 (3) | 0.7582 (3) | 0.4990 (3) | 0.0231 (5) | |
H6 | 0.0462 | 0.7768 | 0.5580 | 0.028* | |
C7 | −0.3364 (3) | 0.9599 (3) | 0.6199 (3) | 0.0277 (6) | |
H7 | −0.3941 | 0.9449 | 0.5644 | 0.033* | |
C8 | −0.4057 (3) | 1.0528 (3) | 0.7210 (3) | 0.0237 (5) | |
C9 | −0.3297 (3) | 1.0618 (3) | 0.8132 (3) | 0.0225 (5) | |
H9 | −0.2320 | 1.0071 | 0.8118 | 0.027* | |
C10 | −0.3976 (3) | 1.1503 (3) | 0.9058 (2) | 0.0216 (5) | |
H10 | −0.3455 | 1.1540 | 0.9689 | 0.026* | |
C11 | −0.6086 (3) | 1.2238 (3) | 0.8233 (3) | 0.0289 (6) | |
H11 | −0.7058 | 1.2803 | 0.8266 | 0.035* | |
C12 | −0.5486 (3) | 1.1358 (3) | 0.7276 (3) | 0.0299 (6) | |
H12 | −0.6042 | 1.1321 | 0.6671 | 0.036* | |
C13 | 0.0992 (3) | 0.8217 (3) | 0.8526 (3) | 0.0298 (6) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Ag | 0.02502 (14) | 0.02762 (14) | 0.02719 (15) | 0.00420 (9) | −0.00387 (9) | −0.01708 (9) |
S1 | 0.0247 (3) | 0.0372 (4) | 0.0324 (4) | 0.0105 (3) | −0.0154 (3) | −0.0196 (3) |
F1 | 0.0286 (10) | 0.0531 (12) | 0.0942 (16) | 0.0092 (8) | −0.0254 (10) | −0.0210 (11) |
F2 | 0.0581 (13) | 0.0333 (10) | 0.0737 (14) | 0.0066 (9) | −0.0168 (11) | 0.0070 (9) |
F3 | 0.0611 (14) | 0.0662 (13) | 0.0445 (11) | 0.0323 (11) | −0.0170 (10) | −0.0297 (10) |
O1 | 0.0528 (15) | 0.094 (2) | 0.0380 (13) | 0.0212 (14) | −0.0215 (11) | −0.0332 (13) |
O2 | 0.0479 (14) | 0.0324 (11) | 0.0642 (15) | 0.0117 (10) | −0.0236 (12) | −0.0152 (10) |
O3 | 0.0281 (11) | 0.0606 (14) | 0.0547 (14) | 0.0096 (10) | −0.0201 (10) | −0.0310 (11) |
N1 | 0.0208 (11) | 0.0224 (10) | 0.0211 (11) | 0.0022 (8) | −0.0043 (8) | −0.0087 (8) |
N2 | 0.0292 (12) | 0.0236 (11) | 0.0215 (11) | 0.0036 (9) | −0.0039 (9) | −0.0126 (9) |
N3 | 0.0296 (13) | 0.0289 (11) | 0.0254 (12) | 0.0069 (9) | −0.0061 (9) | −0.0166 (9) |
N4 | 0.0208 (11) | 0.0218 (10) | 0.0234 (11) | 0.0020 (8) | −0.0044 (9) | −0.0098 (8) |
C1 | 0.0213 (13) | 0.0236 (12) | 0.0236 (13) | 0.0038 (10) | −0.0054 (10) | −0.0062 (10) |
C2 | 0.0233 (13) | 0.0233 (12) | 0.0200 (13) | 0.0002 (10) | −0.0065 (10) | −0.0048 (10) |
C3 | 0.0239 (13) | 0.0198 (12) | 0.0187 (12) | −0.0001 (10) | −0.0021 (10) | −0.0067 (10) |
C4 | 0.0177 (12) | 0.0290 (13) | 0.0244 (13) | 0.0051 (10) | −0.0060 (10) | −0.0098 (10) |
C5 | 0.0252 (13) | 0.0286 (13) | 0.0226 (13) | 0.0023 (10) | −0.0077 (11) | −0.0086 (10) |
C6 | 0.0246 (13) | 0.0232 (12) | 0.0225 (13) | 0.0001 (10) | −0.0054 (10) | −0.0099 (10) |
C7 | 0.0281 (15) | 0.0302 (13) | 0.0287 (14) | 0.0063 (11) | −0.0105 (11) | −0.0147 (11) |
C8 | 0.0235 (13) | 0.0217 (12) | 0.0272 (14) | 0.0039 (10) | −0.0063 (11) | −0.0124 (10) |
C9 | 0.0223 (13) | 0.0227 (12) | 0.0230 (13) | 0.0037 (10) | −0.0069 (10) | −0.0080 (10) |
C10 | 0.0213 (12) | 0.0232 (12) | 0.0213 (12) | 0.0016 (10) | −0.0062 (10) | −0.0084 (10) |
C11 | 0.0207 (13) | 0.0335 (14) | 0.0383 (16) | 0.0088 (11) | −0.0110 (12) | −0.0206 (12) |
C12 | 0.0267 (14) | 0.0375 (15) | 0.0364 (15) | 0.0097 (12) | −0.0166 (12) | −0.0240 (12) |
C13 | 0.0247 (14) | 0.0297 (14) | 0.0369 (16) | 0.0058 (11) | −0.0138 (12) | −0.0077 (11) |
Ag—N1 | 2.144 (2) | C1—H1 | 0.9500 |
Ag—N4i | 2.150 (2) | C2—C3 | 1.403 (4) |
Ag—Agii | 3.2738 (13) | C2—H2 | 0.9500 |
S1—O1 | 1.422 (2) | C3—C4 | 1.397 (4) |
S1—O3 | 1.442 (2) | C3—C6 | 1.463 (3) |
S1—O2 | 1.449 (3) | C4—C5 | 1.376 (4) |
S1—C13 | 1.830 (3) | C4—H4 | 0.9500 |
F1—C13 | 1.333 (3) | C5—H5 | 0.9500 |
F2—C13 | 1.317 (3) | C6—H6 | 0.9500 |
F3—C13 | 1.328 (3) | C7—C8 | 1.469 (4) |
N1—C5 | 1.350 (3) | C7—H7 | 0.9500 |
N1—C1 | 1.351 (3) | C8—C12 | 1.395 (4) |
N2—C6 | 1.284 (4) | C8—C9 | 1.397 (4) |
N2—N3 | 1.407 (3) | C9—C10 | 1.372 (4) |
N3—C7 | 1.273 (4) | C9—H9 | 0.9500 |
N4—C11 | 1.346 (3) | C10—H10 | 0.9500 |
N4—C10 | 1.350 (3) | C11—C12 | 1.385 (4) |
N4—Agiii | 2.150 (2) | C11—H11 | 0.9500 |
C1—C2 | 1.379 (4) | C12—H12 | 0.9500 |
N1—Ag—N4i | 172.36 (8) | N1—C5—H5 | 118.6 |
N1—Ag—Agii | 89.29 (6) | C4—C5—H5 | 118.6 |
N4i—Ag—Agii | 97.80 (6) | N2—C6—C3 | 121.0 (2) |
O1—S1—O3 | 115.54 (16) | N2—C6—H6 | 119.5 |
O1—S1—O2 | 115.44 (17) | C3—C6—H6 | 119.5 |
O3—S1—O2 | 113.75 (15) | N3—C7—C8 | 119.1 (2) |
O1—S1—C13 | 103.95 (14) | N3—C7—H7 | 120.4 |
O3—S1—C13 | 103.31 (13) | C8—C7—H7 | 120.4 |
O2—S1—C13 | 102.47 (14) | C12—C8—C9 | 117.9 (2) |
C5—N1—C1 | 118.0 (2) | C12—C8—C7 | 121.2 (2) |
C5—N1—Ag | 118.75 (17) | C9—C8—C7 | 121.0 (2) |
C1—N1—Ag | 123.24 (17) | C10—C9—C8 | 119.4 (2) |
C6—N2—N3 | 110.3 (2) | C10—C9—H9 | 120.3 |
C7—N3—N2 | 113.4 (2) | C8—C9—H9 | 120.3 |
C11—N4—C10 | 117.7 (2) | N4—C10—C9 | 123.1 (2) |
C11—N4—Agiii | 122.05 (17) | N4—C10—H10 | 118.4 |
C10—N4—Agiii | 120.26 (17) | C9—C10—H10 | 118.4 |
N1—C1—C2 | 122.8 (2) | N4—C11—C12 | 122.7 (2) |
N1—C1—H1 | 118.6 | N4—C11—H11 | 118.6 |
C2—C1—H1 | 118.6 | C12—C11—H11 | 118.6 |
C1—C2—C3 | 119.1 (2) | C11—C12—C8 | 119.3 (2) |
C1—C2—H2 | 120.5 | C11—C12—H12 | 120.4 |
C3—C2—H2 | 120.5 | C8—C12—H12 | 120.4 |
C4—C3—C2 | 118.0 (2) | F2—C13—F3 | 107.5 (2) |
C4—C3—C6 | 122.6 (2) | F2—C13—F1 | 106.6 (2) |
C2—C3—C6 | 119.4 (2) | F3—C13—F1 | 107.1 (3) |
C5—C4—C3 | 119.4 (2) | F2—C13—S1 | 112.5 (2) |
C5—C4—H4 | 120.3 | F3—C13—S1 | 111.70 (18) |
C3—C4—H4 | 120.3 | F1—C13—S1 | 111.1 (2) |
N1—C5—C4 | 122.8 (2) | ||
Agii—Ag—N1—C5 | 111.84 (19) | C12—C8—C9—C10 | 0.2 (4) |
Agii—Ag—N1—C1 | −65.45 (19) | C7—C8—C9—C10 | 179.7 (2) |
C6—N2—N3—C7 | 179.7 (2) | C11—N4—C10—C9 | 1.2 (4) |
C5—N1—C1—C2 | −1.3 (4) | Agiii—N4—C10—C9 | 179.98 (19) |
Ag—N1—C1—C2 | 176.01 (19) | C8—C9—C10—N4 | −1.0 (4) |
N1—C1—C2—C3 | 0.1 (4) | C10—N4—C11—C12 | −0.5 (4) |
C1—C2—C3—C4 | 1.4 (4) | Agiii—N4—C11—C12 | −179.3 (2) |
C1—C2—C3—C6 | −179.1 (2) | N4—C11—C12—C8 | −0.3 (4) |
C2—C3—C4—C5 | −1.7 (4) | C9—C8—C12—C11 | 0.5 (4) |
C6—C3—C4—C5 | 178.9 (2) | C7—C8—C12—C11 | −179.1 (3) |
C1—N1—C5—C4 | 1.0 (4) | O1—S1—C13—F2 | −51.7 (3) |
Ag—N1—C5—C4 | −176.4 (2) | O3—S1—C13—F2 | 69.4 (2) |
C3—C4—C5—N1 | 0.4 (4) | O2—S1—C13—F2 | −172.2 (2) |
N3—N2—C6—C3 | 180.0 (2) | O1—S1—C13—F3 | −172.7 (2) |
C4—C3—C6—N2 | 5.4 (4) | O3—S1—C13—F3 | −51.7 (2) |
C2—C3—C6—N2 | −174.0 (2) | O2—S1—C13—F3 | 66.7 (2) |
N2—N3—C7—C8 | −179.3 (2) | O1—S1—C13—F1 | 67.8 (2) |
N3—C7—C8—C12 | 172.3 (3) | O3—S1—C13—F1 | −171.2 (2) |
N3—C7—C8—C9 | −7.2 (4) | O2—S1—C13—F1 | −52.7 (2) |
Symmetry codes: (i) x+1, y−1, z−1; (ii) −x+1, −y+1, −z; (iii) x−1, y+1, z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
C2—H2···O1 | 0.95 | 2.47 | 3.360 (4) | 155 |
C10—H10···O3iv | 0.95 | 2.49 | 3.274 (3) | 139 |
C11—H11···O2v | 0.95 | 2.54 | 3.235 (4) | 130 |
Symmetry codes: (iv) −x, −y+2, −z+2; (v) x−1, y+1, z. |
Experimental details
Crystal data | |
Chemical formula | [Ag(C12H10N4)](CF3SO3) |
Mr | 467.18 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 98 |
a, b, c (Å) | 8.9608 (18), 8.9816 (18), 10.804 (2) |
α, β, γ (°) | 75.99 (3), 71.09 (3), 83.30 (3) |
V (Å3) | 797.4 (3) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 1.45 |
Crystal size (mm) | 0.45 × 0.36 × 0.21 |
Data collection | |
Diffractometer | Rigaku AFC12κ/SATURN724 |
Absorption correction | Multi-scan (ABSCOR; Higashi, 1995) |
Tmin, Tmax | 0.845, 1.000 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 7718, 2695, 2654 |
Rint | 0.036 |
(sin θ/λ)max (Å−1) | 0.595 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.025, 0.068, 1.07 |
No. of reflections | 2695 |
No. of parameters | 226 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.47, −0.55 |
Computer programs: CrystalClear (Rigaku/MSC, 2005), SIR92 (Altomare et al., 1994), SHELXL97 (Sheldrick, 1997), ORTEPII (Johnson, 1976) and DIAMOND (Brandenburg, 2006).
Ag—N1 | 2.144 (2) | Ag—N4i | 2.150 (2) |
N1—Ag—N4i | 172.36 (8) |
Symmetry code: (i) x+1, y−1, z−1. |
D—H···A | D—H | H···A | D···A | D—H···A |
C2—H2···O1 | 0.95 | 2.47 | 3.360 (4) | 155 |
C10—H10···O3ii | 0.95 | 2.49 | 3.274 (3) | 139 |
C11—H11···O2iii | 0.95 | 2.54 | 3.235 (4) | 130 |
Symmetry codes: (ii) −x, −y+2, −z+2; (iii) x−1, y+1, z. |
The polymeric title compound, [Ag(C12H10N4)]n.n(CF3SO3), or [Ag(4—PA)(CF3SO3)]n (I), was investigated as a part of an on-going study of the structural chemistry of the Ag salts of isomeric n-pyridinealdazine molecules, n = 2, 3 and 4 (Broker & Tiekink, 2007a,b,c). The 4-pyridinealdazine (4-PA) ligand in (I) is bidentate bridging which results in the formation of polymeric chains and a near linear AgN2 geometry for the silver atom (Fig. 1 & Table 1).
The linear chains are connected into supramolecular double chains (Fig. 2) via a combination of C—H···O interactions (Table 2) and a weak Ag···O3i (i = 1 - x, 1 - y, 1 - z) contact of 2.759 (3) Å. The chains stack side by side to form layers in the ac plane and these layers are connected to adjacent layers on either side via Ag···Agii (ii = 1 - x, 1 - y, -z) agentophilic interactions [3.2738 (13) Å] as well as Ag···O2iii (iii = x, y, -1 + z) contacts of 2.854 (3) Å.
Similar polymeric structures to those in (I) are found in the following salts: perchlorate, tetrafluoroborate (as acetonitrile solvates, Kennedy et al., 2005), hexafluoroantimonate (as the acetonitrile water solvate, Kennedy et al., 2005), methanesulfonate (Broker & Tiekink, 2007c), and nitrate, for which two polymorphs have been reported (Shi et al., 2002; Patra & Goldberg, 2003; Kennedy et al., 2005). In all but the nitrate polymorphs, the chains are essentially flat. Only in (I) and the methanesulfonate salt (Broker & Tiekink, 2007c) are Ag···Ag interactions found.