A synchrotron study of mercury(I) acetate

Mercury(I) actetate, [Hg(C₂H₃O₂)]_n, crystallizes as centrosymmetric dimers, CH₃COO-Hg-Hg-OOCCH₃, with an Hg-Hg distance of 2.5202 (15) Å and an Hg-O distance of 2.152 (12) Å. The dimers are assembled into infinite ribbons by long, weaker Hg-O bonds [Hg-O = 2.6802 (12) Å]. There are no strong inter­molecular forces between the ribbons.

Key indicators

• Single-crystal synchrotron study
• T = 150 K
• Mean [sigma](C-C) = 0.017 Å
• R factor = 0.043
• wR factor = 0.109
• Data-to-parameter ratio = 12.2

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT029_ALERT_3_B _diffrn_measured_fraction_theta_full Low .......       0.95

Alert level C
PLAT241_ALERT_2_C Check High      Ueq as Compared to Neighbors for         O2

Author Response: Inspection of the ORTEP plot suggests there is no serious problem with the atomic displacement parameter for O2.

PLAT342_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ...         17

Author Response: Diffraction is dominated by scattering from mercury (80 electrons). The precision with which light atoms are located will be moderate.

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

   0 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
   2 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: APEXII (Bruker, 2004); cell refinement: APEXII; data reduction: APEXII; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: WinGX (Version 1.164; Farrugia, 1999); software used to prepare material for publication: SHELXL97.

Mercury(I) acetate

Crystal data

[Hg(C2H3O2)]	F(000) = 444
Mr = 259.63	Dx = 4.763 Mg m^−3
Monoclinic, C2/m	Synchrotron radiation, λ = 0.84640 Å
Hall symbol: -C 2y	Cell parameters from 1173 reflections
a = 5.133 (3) Å	θ = 4.0–32.4°
b = 5.866 (3) Å	µ = 79.55 mm^−1
c = 12.202 (6) Å	T = 150 K
β = 99.779 (7)°	Plate, colourless
V = 362.1 (3) Å^3	0.02 × 0.02 × 0.01 mm
Z = 4

Data collection

Bruker D8 diffractometer	404 independent reflections
Radiation source: Daresbury SRS, Station 16.2SMX	395 reflections with I > 2σ(I)
Silicon 111 monochromator	Rint = 0.046
ω rotation with narrow frame scans	θmax = 32.4°, θmin = 4.0°
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	h = −6→6
Tmin = 0.204, Tmax = 0.672	k = −7→7
1173 measured reflections	l = −15→15

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)] = 0.043	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.109	H-atom parameters constrained
S = 1.10	w = 1/[σ^2(Fo^2) + (0.0852P)^2] where P = (Fo^2 + 2Fc^2)/3
404 reflections	(Δ/σ)max < 0.001
33 parameters	Δρmax = 2.89 e Å^−3
24 restraints	Δρmin = −5.57 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	Occ. (<1)
Hg1	−0.38573 (10)	0.0000	0.09993 (4)	0.0116 (4)
O1	−0.177 (2)	0.0000	0.2686 (10)	0.019 (3)
C1	0.063 (2)	0.0000	0.2661 (9)	0.004 (2)
O2	0.1553 (19)	0.0000	0.1768 (9)	0.027 (3)
C2	0.246 (3)	0.0000	0.3761 (10)	0.008 (2)
H2A	0.1809	−0.1070	0.4268	0.012*	0.50
H2B	0.2544	0.1536	0.4081	0.012*	0.50
H2C	0.4236	−0.0466	0.3652	0.012*	0.50

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Hg1	0.0098 (5)	0.0144 (5)	0.0094 (5)	0.000	−0.0018 (3)	0.000
O1	0.015 (5)	0.035 (5)	0.008 (5)	0.000	0.005 (4)	0.000
C1	0.003 (2)	0.003 (2)	0.004 (2)	0.000	0.0001 (10)	0.000
O2	0.012 (5)	0.056 (7)	0.016 (5)	0.000	0.006 (4)	0.000
C2	0.008 (5)	0.010 (4)	0.005 (5)	0.000	−0.002 (4)	0.000

Geometric parameters (Å, º)

Hg1—O1	2.152 (12)	C1—C2	1.503 (16)
Hg1—Hg1^i	2.5202 (15)	C2—H2A	0.9800
O1—C1	1.239 (15)	C2—H2B	0.9800
C1—O2	1.259 (15)	C2—H2C	0.9800
O1—Hg1—Hg1^i	178.0 (3)	C1—C2—H2B	109.5
C1—O1—Hg1	108.2 (9)	H2A—C2—H2B	109.5
O1—C1—O2	122.9 (11)	C1—C2—H2C	109.5
O1—C1—C2	117.0 (11)	H2A—C2—H2C	109.5
O2—C1—C2	120.2 (9)	H2B—C2—H2C	109.5
C1—C2—H2A	109.5

Symmetry code: (i) −x−1, −y, −z.