Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807048969/lh2524sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807048969/lh2524Isup2.hkl |
CCDC reference: 667142
Key indicators
- Single-crystal X-ray study
- T = 295 K
- Mean (l-O) = 0.003 Å
- Disorder in main residue
- R factor = 0.021
- wR factor = 0.052
- Data-to-parameter ratio = 10.7
checkCIF/PLATON results
No syntax errors found
Alert level B PLAT242_ALERT_2_B Check Low Ueq as Compared to Neighbors for Cl1 PLAT301_ALERT_3_B Main Residue Disorder ......................... 29.00 Perc.
Alert level C PLAT062_ALERT_4_C Rescale T(min) & T(max) by ..................... 0.95 PLAT764_ALERT_4_C Overcomplete CIF Bond List Detected (Rep/Expd) . 1.27 Ratio
Alert level G FORMU01_ALERT_1_G There is a discrepancy between the atom counts in the _chemical_formula_sum and _chemical_formula_moiety. This is usually due to the moiety formula being in the wrong format. Atom count from _chemical_formula_sum: C4 H4 Ag1 Cl1 N2 O4 Atom count from _chemical_formula_moiety:C4 H4 Ag1 Cl1 N2 O1
0 ALERT level A = In general: serious problem 2 ALERT level B = Potentially serious problem 2 ALERT level C = Check and explain 1 ALERT level G = General alerts; check 1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 1 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
Silver perchlorate (0.207 g, 1 mmol), pyrazine (0.08 g, 1 mmol) and water (10 ml) were sealed in a Teflon-lined stainless-steel autoclave (20 ml capacity). The autoclave was heated 433 K for 3 days. It was then cooled at 5 K h-1. Colorless crystals were obtained in about 60% yield based on Ag.
The pyrazine molecule is disordered with respect to the carbon atoms, which were refined as four atoms, each of half-site occupancy. The four carbon-bound H atoms were placed at calculated positions (C–H 0.93 Å) and were included in the refinement in the riding model approximation, with U(H) set to 1.2 times Ueq(C).
Silver salts react with the bidentate pyrazine N-heterocycles to furnish adducts that display a diverse range of architectures. The nitrate adduct consists of a polycationic [Ag(C4H4N2)]∞ chain that is surrounded by the nitrate anions, albeit at somewhat long distances (Vranka & Amma, 1966). In silver nitrite adduct, the anion is much closer to the metal atom, the anion chelating to it (Blake et al., 1999) in the resulting pyrazine-bridged chain. With the hexafluorophosphate counterion, the adduct exists as a chain as the counterion is not Lewis-basic enough to have any coordinating ability. One adduct shows the chain motif in whcih the silver atom shows linear coordination; another is a cocrystal that has both [Ag(C4H4N2)]∞ and [Ag2(C4H4N2)5]∞ chains (Carlucci et al., 1995a). Another adduct has the silver in a four-coordinate N4Ag environment (Carlucci et al., 1995b). The silver tetrafluoroborate adduct exists in two forms. One form has polycationic chains and non-interacting tetrafluoroborate anions; in other polymorphs, the silver atom shows three- and four-coordinate heterocycle-linked silver (Carlucci et al., 1995c).
For details of the silver nitrite–pyrazine, see Blake et al. (1999); for the silver hexafluorophosphate–pyrazine, see Carlucci et al. (1995a,b); for the silver tetrafluoroborate–pyrazine, see Carlucci et al. (1995c); and for the silver nitrate–pyrazine adducts, see Vranka & Amma (1966).
Data collection: APEX2 (Bruker, 2005); cell refinement: APEX2 (Bruker, 2005); data reduction: SAINT (Bruker 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: X-SEED (Barbour, 2001) and OLEX (Dolomanov et al., 2003); software used to prepare material for publication: publCIF (Westrip, 2007).
[Ag(C4H4N2)]ClO4 | F(000) = 552 |
Mr = 287.41 | Dx = 2.468 Mg m−3 |
Orthorhombic, Cmcm | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2c 2 | Cell parameters from 1486 reflections |
a = 7.4838 (2) Å | θ = 2.8–27.8° |
b = 7.1954 (2) Å | µ = 2.93 mm−1 |
c = 14.3623 (4) Å | T = 295 K |
V = 773.39 (4) Å3 | Block, colorless |
Z = 4 | 0.29 × 0.23 × 0.18 mm |
Bruker APEXII area-detector diffractometer | 493 independent reflections |
Radiation source: fine-focus sealed tube | 443 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.023 |
φ and ω scans | θmax = 27.5°, θmin = 2.8° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −8→9 |
Tmin = 0.489, Tmax = 0.621 | k = −9→7 |
2749 measured reflections | l = −18→16 |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.021 | H-atom parameters constrained |
wR(F2) = 0.052 | w = 1/[σ2(Fo2) + (0.0321P)2] where P = (Fo2 + 2Fc2)/3 |
S = 1.08 | (Δ/σ)max = 0.001 |
493 reflections | Δρmax = 0.46 e Å−3 |
46 parameters | Δρmin = −0.36 e Å−3 |
0 restraints | Extinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0057 (6) |
[Ag(C4H4N2)]ClO4 | V = 773.39 (4) Å3 |
Mr = 287.41 | Z = 4 |
Orthorhombic, Cmcm | Mo Kα radiation |
a = 7.4838 (2) Å | µ = 2.93 mm−1 |
b = 7.1954 (2) Å | T = 295 K |
c = 14.3623 (4) Å | 0.29 × 0.23 × 0.18 mm |
Bruker APEXII area-detector diffractometer | 493 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 443 reflections with I > 2σ(I) |
Tmin = 0.489, Tmax = 0.621 | Rint = 0.023 |
2749 measured reflections |
R[F2 > 2σ(F2)] = 0.021 | 0 restraints |
wR(F2) = 0.052 | H-atom parameters constrained |
S = 1.08 | Δρmax = 0.46 e Å−3 |
493 reflections | Δρmin = −0.36 e Å−3 |
46 parameters |
x | y | z | Uiso*/Ueq | Occ. (<1) | |
Ag1 | 0.5000 | 0.05768 (4) | 0.2500 | 0.0418 (2) | |
Cl1 | 0.0000 | 0.0621 (1) | 0.2500 | 0.0397 (3) | |
O1 | 0.1546 (3) | 0.1779 (3) | 0.2500 | 0.0588 (7) | |
O2 | 0.0000 | −0.0517 (4) | 0.3301 (3) | 0.093 (1) | |
N1 | 0.5000 | 0.0229 (4) | 0.40375 (18) | 0.0366 (6) | |
C1 | 0.6234 (7) | −0.0790 (6) | 0.4472 (3) | 0.046 (1) | 0.50 |
H1 | 0.7133 | −0.1351 | 0.4125 | 0.055* | 0.50 |
C2 | 0.6208 (7) | −0.1030 (7) | 0.5424 (3) | 0.046 (1) | 0.50 |
H2 | 0.7071 | −0.1783 | 0.5697 | 0.055* | 0.50 |
U11 | U22 | U33 | U12 | U13 | U23 | |
Ag1 | 0.0551 (3) | 0.0518 (3) | 0.0186 (2) | 0.000 | 0.000 | 0.000 |
Cl1 | 0.0362 (6) | 0.0377 (6) | 0.0452 (7) | 0.000 | 0.000 | 0.000 |
O1 | 0.036 (2) | 0.056 (2) | 0.084 (2) | −0.007 (1) | 0.000 | 0.000 |
O2 | 0.085 (2) | 0.096 (3) | 0.097 (3) | 0.000 | 0.000 | 0.054 (2) |
N1 | 0.043 (1) | 0.044 (1) | 0.023 (1) | 0.000 | 0.000 | 0.003 (1) |
C1 | 0.046 (3) | 0.064 (3) | 0.028 (2) | 0.016 (2) | 0.005 (2) | −0.002 (2) |
C2 | 0.047 (3) | 0.061 (3) | 0.029 (2) | 0.020 (2) | 0.000 (2) | 0.005 (2) |
Ag1—N1 | 2.222 (3) | N1—C2iv | 1.322 (5) |
Ag1—N1i | 2.222 (3) | N1—C2v | 1.322 (5) |
Ag1—O1 | 2.726 (2) | N1—C1ii | 1.334 (5) |
Ag1—O1ii | 2.726 (2) | N1—C1 | 1.334 (5) |
Cl1—O2i | 1.412 (3) | C1—C2 | 1.377 (7) |
Cl1—O2 | 1.412 (3) | C2—N1v | 1.322 (5) |
Cl1—O1 | 1.426 (2) | C1—H1 | 0.9300 |
Cl1—O1iii | 1.426 (2) | C2—H2 | 0.9300 |
N1i—Ag1—N1 | 167.1 (1) | C2v—N1—C1ii | 59.5 (3) |
N1—Ag1—O1 | 92.05 (2) | C2iv—N1—C1 | 59.5 (3) |
N1—Ag1—O1ii | 92.05 (2) | C2v—N1—C1 | 116.0 (3) |
N1i—Ag1—O1 | 92.05 (2) | C1ii—N1—C1 | 87.6 (4) |
N1i—Ag1—O1ii | 92.05 (2) | C2iv—N1—Ag1 | 122.2 (2) |
O1—Ag1—O1ii | 143.0 (1) | C2v—N1—Ag1 | 122.2 (2) |
O1—Cl1—O1iii | 108.5 (2) | C1ii—N1—Ag1 | 121.8 (2) |
O1—Cl1—O2 | 109.8 (1) | C1—N1—Ag1 | 121.8 (2) |
O1—Cl1—O2i | 109.8 (1) | N1—C1—C2 | 121.6 (4) |
O1iii—Cl1—O2 | 109.8 (1) | N1v—C2—C1 | 122.4 (4) |
O1iii—Cl1—O2i | 109.8 (1) | N1—C1—H1 | 119.2 |
O2—Cl1—O2i | 109.1 (3) | C2—C1—H1 | 119.2 |
Cl1—O1—Ag1 | 125.8 (1) | N1v—C2—H2 | 118.8 |
C2iv—N1—C2v | 86.3 (5) | C1—C2—H2 | 118.8 |
C2iv—N1—C1ii | 116.0 (3) | ||
O2i—Cl1—O1—Ag1 | −60.0 (2) | N1i—Ag1—N1—C1ii | −54.5 (3) |
O2—Cl1—O1—Ag1 | 60.0 (2) | O1ii—Ag1—N1—C1ii | −162.9 (3) |
O1iii—Cl1—O1—Ag1 | 180.0 | O1—Ag1—N1—C1ii | 53.9 (3) |
N1i—Ag1—O1—Cl1 | 83.87 (6) | N1i—Ag1—N1—C1 | 54.5 (3) |
N1—Ag1—O1—Cl1 | −83.87 (6) | O1ii—Ag1—N1—C1 | −53.9 (3) |
O1ii—Ag1—O1—Cl1 | 180.0 | O1—Ag1—N1—C1 | 162.9 (3) |
N1i—Ag1—N1—C2iv | 126.1 (3) | C2iv—N1—C1—C2 | 70.1 (4) |
O1ii—Ag1—N1—C2iv | 17.7 (3) | C2v—N1—C1—C2 | 1.9 (7) |
O1—Ag1—N1—C2iv | −125.5 (3) | C1ii—N1—C1—C2 | −52.2 (6) |
N1i—Ag1—N1—C2v | −126.1 (3) | Ag1—N1—C1—C2 | −178.7 (3) |
O1ii—Ag1—N1—C2v | 125.5 (3) | N1—C1—C2—N1v | −2.0 (8) |
O1—Ag1—N1—C2v | −17.7 (3) |
Symmetry codes: (i) x, y, −z+1/2; (ii) −x+1, y, z; (iii) −x, y, z; (iv) x, −y, −z+1; (v) −x+1, −y, −z+1. |
Experimental details
Crystal data | |
Chemical formula | [Ag(C4H4N2)]ClO4 |
Mr | 287.41 |
Crystal system, space group | Orthorhombic, Cmcm |
Temperature (K) | 295 |
a, b, c (Å) | 7.4838 (2), 7.1954 (2), 14.3623 (4) |
V (Å3) | 773.39 (4) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 2.93 |
Crystal size (mm) | 0.29 × 0.23 × 0.18 |
Data collection | |
Diffractometer | Bruker APEXII area-detector |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.489, 0.621 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2749, 493, 443 |
Rint | 0.023 |
(sin θ/λ)max (Å−1) | 0.650 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.021, 0.052, 1.08 |
No. of reflections | 493 |
No. of parameters | 46 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.46, −0.36 |
Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker 2005), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), X-SEED (Barbour, 2001) and OLEX (Dolomanov et al., 2003), publCIF (Westrip, 2007).
Silver salts react with the bidentate pyrazine N-heterocycles to furnish adducts that display a diverse range of architectures. The nitrate adduct consists of a polycationic [Ag(C4H4N2)]∞ chain that is surrounded by the nitrate anions, albeit at somewhat long distances (Vranka & Amma, 1966). In silver nitrite adduct, the anion is much closer to the metal atom, the anion chelating to it (Blake et al., 1999) in the resulting pyrazine-bridged chain. With the hexafluorophosphate counterion, the adduct exists as a chain as the counterion is not Lewis-basic enough to have any coordinating ability. One adduct shows the chain motif in whcih the silver atom shows linear coordination; another is a cocrystal that has both [Ag(C4H4N2)]∞ and [Ag2(C4H4N2)5]∞ chains (Carlucci et al., 1995a). Another adduct has the silver in a four-coordinate N4Ag environment (Carlucci et al., 1995b). The silver tetrafluoroborate adduct exists in two forms. One form has polycationic chains and non-interacting tetrafluoroborate anions; in other polymorphs, the silver atom shows three- and four-coordinate heterocycle-linked silver (Carlucci et al., 1995c).