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In [HgCl2(Pyp)]n (Pyp = pyrazine, C4H4N2), chloride-bridged HgCl4/2 strands are connected into layers by pyrazine molecules. The Hg atom is on a site of symmetry 2/m, the unique Cl atom is on a mirror plane, the unique N atom is on a twofold rotation axis, and the unique C and H atoms are in general positions.
Supporting information
CCDC reference: 242030
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (C-C) = 0.009 Å
- R factor = 0.023
- wR factor = 0.051
- Data-to-parameter ratio = 13.6
checkCIF/PLATON results
No syntax errors found
Alert level A
PLAT029_ALERT_3_A _diffrn_measured_fraction_theta_full Low ....... 0.94
Alert level C
CHEMW01_ALERT_1_C The difference between the given and expected weight for
compound is greater 1 mass unit. Check that all hydrogen
atoms have been taken into account.
REFLT03_ALERT_3_C Reflection count < 95% complete
From the CIF: _diffrn_reflns_theta_max 25.93
From the CIF: _diffrn_reflns_theta_full 0.00
From the CIF: _reflns_number_total 354
TEST2: Reflns within _diffrn_reflns_theta_max
Count of symmetry unique reflns 378
Completeness (_total/calc) 93.65%
PLAT022_ALERT_3_C Ratio Unique / Expected Reflections too Low .... 0.94
PLAT068_ALERT_1_C Reported F000 Differs from Calcd (or Missing)... ?
PLAT150_ALERT_1_C Volume as Calculated Differs from that Given ... 355.60 Ang-3
PLAT342_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ... 9
PLAT720_ALERT_4_C Number of Unusual/Non-Standard Label(s) ........ 1
PLAT742_ALERT_1_C Angle Calc 90.00(6), Rep 90.00 ...... Missing su
N -HG -CL 1.555 1.555 1.555
PLAT764_ALERT_4_C Overcomplete CIF Bond List Detected (Rep/Expd) . 1.11 Ratio
Alert level G
ABSTM02_ALERT_3_G The ratio of expected to reported Tmax/Tmin(RR') is < 0.90
Tmin and Tmax reported: 0.150 0.399
Tmin' and Tmax expected: 0.005 0.012
RR' = 0.814
Please check that your absorption correction is appropriate.
1 ALERT level A = In general: serious problem
0 ALERT level B = Potentially serious problem
9 ALERT level C = Check and explain
1 ALERT level G = General alerts; check
4 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
5 ALERT type 3 Indicator that the structure quality may be low
2 ALERT type 4 Improvement, methodology, query or suggestion
Data collection: X-AREA (Stoe & Cie, 2001); cell refinement: X-STEP32 (Stoe & Cie, 2000); data reduction: X-RED (Stoe & Cie, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: SHELXL97.
Poly[di-µ-chloro-µ-pyrazine-
κ2N:
N'-mercury(II)]
top
Crystal data top
[HgCl2(C4H4N2)] | F(000) = 308 |
Mr = 349.57 | Dx = 3.265 Mg m−3 |
Monoclinic, C2/m | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2y | Cell parameters from 1625 reflections |
a = 11.8970 (17) Å | θ = 3.4–25.9° |
b = 7.783 (3) Å | µ = 22.30 mm−1 |
c = 3.840 (7) Å | T = 293 K |
β = 90.99 (6)° | Prism, colorless |
V = 355.6 (7) Å3 | 0.2 × 0.2 × 0.2 mm |
Z = 2 | |
Data collection top
Stoe IPDS-I diffractometer | 354 independent reflections |
Radiation source: fine-focus sealed tube | 354 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.079 |
φ scans | θmax = 25.9°, θmin = 3.4° |
Absorption correction: numerical (X-SHAPE; Stoe & Cie, 1998) | h = −14→14 |
Tmin = 0.150, Tmax = 0.399 | k = −9→9 |
1625 measured reflections | l = −4→4 |
Refinement top
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)] = 0.023 | H-atom parameters constrained |
wR(F2) = 0.051 | w = 1/[σ2(Fo2) + (0.0286P)2] where P = (Fo2 + 2Fc2)/3 |
S = 1.09 | (Δ/σ)max < 0.001 |
354 reflections | Δρmax = 1.12 e Å−3 |
26 parameters | Δρmin = −1.28 e Å−3 |
0 restraints | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0103 (13) |
Special details top
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 (Å2) top | x | y | z | Uiso*/Ueq | |
Hg | 0.0000 | −0.5000 | 0.5000 | 0.0346 (2) | |
Cl | 0.15561 (15) | −0.5000 | 1.0698 (6) | 0.0391 (4) | |
N | 0.0000 | −0.1776 (9) | 0.5000 | 0.0339 (14) | |
C | 0.0900 (4) | −0.0902 (8) | 0.4042 (19) | 0.0393 (12) | |
H0 | 0.1540 | −0.1491 | 0.3362 | 0.047* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Hg | 0.0386 (3) | 0.0315 (3) | 0.0342 (3) | 0.000 | 0.01371 (15) | 0.000 |
Cl | 0.0304 (9) | 0.0464 (10) | 0.0408 (11) | 0.000 | 0.0088 (7) | 0.000 |
N | 0.029 (3) | 0.038 (3) | 0.034 (4) | 0.000 | 0.008 (2) | 0.000 |
C | 0.030 (3) | 0.038 (3) | 0.050 (4) | 0.005 (2) | 0.010 (2) | −0.002 (3) |
Geometric parameters (Å, º) top
Hg—Cli | 2.503 (3) | Cl—Hgiv | 2.503 (3) |
Hg—Clii | 2.503 (3) | N—C | 1.326 (7) |
Hg—Niii | 2.510 (7) | N—Cv | 1.326 (7) |
Hg—N | 2.510 (7) | C—Cvi | 1.404 (12) |
Hg—Cliii | 2.842 (4) | C—H0 | 0.930 |
Hg—Cl | 2.842 (4) | | |
| | | |
Cli—Hg—Clii | 180 | Clii—Hg—Cl | 88.35 (12) |
Cli—Hg—Niii | 90 | Niii—Hg—Cl | 90 |
Clii—Hg—Niii | 90 | N—Hg—Cl | 90 |
Cli—Hg—N | 90 | Cliii—Hg—Cl | 180 |
Clii—Hg—N | 90 | Hgiv—Cl—Hg | 91.65 (12) |
Niii—Hg—N | 180 | C—N—Cv | 118.3 (7) |
Cli—Hg—Cliii | 88.35 (12) | C—N—Hg | 120.9 (4) |
Clii—Hg—Cliii | 91.65 (12) | Cv—N—Hg | 120.9 (4) |
Niii—Hg—Cliii | 90 | N—C—Cvi | 120.9 (4) |
N—Hg—Cliii | 90 | N—C—H0 | 119.6 |
Cli—Hg—Cl | 91.65 (12) | Cvi—C—H0 | 119.6 |
Symmetry codes: (i) x, y, z−1; (ii) −x, −y−1, −z+2; (iii) −x, −y−1, −z+1; (iv) x, y, z+1; (v) −x, y, −z+1; (vi) x, −y, z. |
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