Crystal structure of Hg₂SO₄ – a redetermination

Abstract

The crystal structure of mercury(I) sulfate (or mercurous sulfate), Hg₂SO₄, was re-determined based on modern CCD data. In comparison with the previous determination from Weissenberg film data [Dorm (1969 ▶). Acta Chem. Scand. 23, 1607–1615], all atoms were refined with anisotropic displacement parameters, leading to higher precision in terms of bond lengths and angles [e.g. Hg—Hg = 2.5031 (7) compared to 2.500 (3)Å]. The structure consists of alternating rows along [001] of Hg₂ ²⁺ dumbbells (generated by inversion symmetry) and SO₄ ²⁻ tetra­hedra (symmetry 2). The dumbbells are linked via short O—Hg—Hg—O bonds to the sulfate tetra­hedra into chains extending parallel to [20-1]. More remote O—Hg—Hg—O bonds connect these chains into a three-dimensional framework.

Related literature  

Structural data of the previous refinement of Hg₂SO₄ (Dorm, 1969 ▶) were deposited with the ICSD (2014 ▶), but contain an error in the z coordinate of the sulfur atom. Other phases in the system Hg/S/O were structurally characterized by Aurivillius & Stålhandske (1980 ▶) [HgSO₄], Weil (2001 ▶) [Hg₃(SO₄)O₂] and Logemann & Wickleder (2013 ▶) [Hg(S₂O₇)]. For a review on Hg—Hg bond lengths in mercurous compounds, see: Weil et al. (2005 ▶).

Experimental  

Crystal data  

• Hg₂O₄S

• M _r = 497.24

• Monoclinic,

• a = 6.2771 (8) Å

• b = 4.4290 (6) Å

• c = 8.3596 (10) Å

• β = 91.695 (4)°

• V = 232.31 (5) ų

• Z = 2

• Mo Kα radiation

• μ = 66.35 mm⁻¹

• T = 295 K

• 0.18 × 0.08 × 0.04 mm

Data collection  

• Bruker SMART CCD diffractometer

• Absorption correction: numerical (HABITUS; Herrendorf, 1997 ▶) T _min = 0.012, T _max = 0.119

• 1737 measured reflections

• 701 independent reflections

• 629 reflections with I > 2σ(I)’

• R _int = 0.060

Refinement  

• R[F ² > 2σ(F ²)] = 0.035

• wR(F ²) = 0.087

• S = 1.06

• 701 reflections

• 34 parameters

• Δρ_max = 3.57 e Å⁻³

• Δρ_min = −3.18 e Å⁻³

Data collection: SMART (Bruker, 2005 ▶); cell refinement: SAINT (Bruker, 2005 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ATOMS for Windows (Dowty, 2006 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

CCDC reference: 1004277

Additional supporting information: crystallographic information; 3D view; checkCIF report

Table 1. Selected geometric parameters (Å, °).

Hg—O2i	2.193 (6)
Hg—O2ii	2.518 (6)
Hg—O1iii	2.725 (6)
Hg—O1iv	2.898 (7)
Hg—Hgv	2.5031 (7)
S—O1	1.450 (7)
S—O2	1.509 (6)

O2i—Hg—Hgv

164.47 (14)

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) ; (v) .

supplementary crystallographic information

S1. Experimental

1 g HgO was suspended in 20 ml water. 4 ml sulfuric acid (96%_wt) and 2 drops CS₂ were added to the mixture, transferred into a 50 ml polypropylene beaker that was sealed and heated for 12 h at 393 K. Besides a polycrystalline dirty-white solid with an unknown diffraction pattern, few colourless and transparent single crystals of the title compound were present in the reaction mixture.

S2. Refinement

The coordinates of the previous refinement (Dorm, 1969) were used as starting parameters. The highest and lowest remaining electron density is 0.84 Å and 1.25 Å, respectively, from the Hg atom. It should be noted that in the current version (01/2014) of the Inorganic Structure Data Base (ICSD, 2014), the deposited structure data of the previous refinement by Dorm (1969) contain an error: The z parameter of the sulfur atom must be 1/4, not 3/4.

Figures

Fig. 1.

The crystal structure of Hg2SO4 in a projection along [010]. Displacement ellipsoids are drawn at the 74% probability level; short Hg—O bonds are displayed with closed black lines, longer Hg—O bonds with open lines.

Crystal data

Hg2O4S	F(000) = 416
Mr = 497.24	Dx = 7.109 Mg m−3
Monoclinic, P2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yc	Cell parameters from 1233 reflections
a = 6.2771 (8) Å	θ = 3.3–30.4°
b = 4.4290 (6) Å	µ = 66.35 mm−1
c = 8.3596 (10) Å	T = 295 K
β = 91.695 (4)°	Fragment, colourless
V = 232.31 (5) Å3	0.18 × 0.08 × 0.04 mm
Z = 2

Data collection

Bruker SMART CCD diffractometer	701 independent reflections
Radiation source: fine-focus sealed tube	629 reflections with I > 2σ(I)'
Graphite monochromator	Rint = 0.060
ω–scans	θmax = 30.4°, θmin = 4.6°
Absorption correction: numerical (HABITUS; Herrendorf, 1997)	h = −8→8
Tmin = 0.012, Tmax = 0.119	k = −6→6
1737 measured reflections	l = −11→8

Refinement

Refinement on F2	Primary atom site location: isomorphous structure methods
Least-squares matrix: full	w = 1/[σ2(Fo2) + (0.052P)2 + 1.7115P] where P = (Fo2 + 2Fc2)/3
R[F2 > 2σ(F2)] = 0.035	(Δ/σ)max < 0.001
wR(F2) = 0.087	Δρmax = 3.57 e Å−3
S = 1.06	Δρmin = −3.18 e Å−3
701 reflections	Extinction correction: SHELXL, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
34 parameters	Extinction coefficient: 0.0118 (12)
0 restraints

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
Hg	0.19318 (5)	0.05289 (9)	−0.02034 (4)	0.0275 (2)
S	0.5000	0.5674 (5)	0.2500	0.0134 (5)
O1	0.6943 (11)	0.3901 (16)	0.2586 (8)	0.0224 (12)
O2	0.5038 (9)	0.7720 (13)	0.1058 (6)	0.0172 (10)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Hg	0.0119 (2)	0.0392 (3)	0.0315 (3)	−0.00369 (11)	0.00211 (13)	0.00072 (13)
S	0.0125 (12)	0.0141 (11)	0.0136 (11)	0.000	0.0000 (8)	0.000
O1	0.018 (3)	0.027 (3)	0.022 (3)	0.009 (2)	−0.001 (2)	0.004 (2)
O2	0.015 (2)	0.020 (2)	0.016 (2)	0.001 (2)	0.0010 (18)	0.004 (2)

Geometric parameters (Å, º)

Hg—O2i	2.193 (6)	S—Hgiii	3.7082 (15)
Hg—O2ii	2.518 (6)	S—Hgix	3.8936 (17)
Hg—O1iii	2.725 (6)	S—Hgiv	3.8936 (17)
Hg—O1iv	2.898 (7)	O1—Hgiii	2.725 (6)
Hg—Hgv	2.5031 (7)	O1—Hgiv	2.898 (7)
S—O1iii	1.450 (7)	O1—Hgi	3.261 (7)
S—O1	1.450 (7)	O1—Hgvii	3.716 (7)
S—O2iii	1.509 (6)	O1—Hgx	4.090 (6)
S—O2	1.509 (6)	O2—Hgi	2.193 (6)
S—Hgvi	3.2315 (13)	O2—Hgviii	2.518 (6)
S—Hgi	3.2315 (13)	O2—Hgvi	3.812 (5)
S—Hgvii	3.6309 (15)	O2—Hgvii	4.097 (6)
S—Hgviii	3.6309 (15)
O2i—Hg—Hgv	164.47 (14)	S—O1—Hgx	156.0 (3)
O2i—Hg—O2ii	69.1 (2)	Hgiii—O1—Hgx	36.63 (8)
Hgv—Hg—O2ii	126.30 (13)	Hgiv—O1—Hgx	77.69 (14)
O2i—Hg—O1iii	82.0 (2)	Hgi—O1—Hgx	117.52 (19)
Hgv—Hg—O1iii	102.86 (14)	Hgvii—O1—Hgx	89.04 (14)
O2ii—Hg—O1iii	75.8 (2)	S—O1—Hg	62.8 (3)
O2i—Hg—O1iv	77.5 (2)	Hgiii—O1—Hg	115.4 (2)
Hgv—Hg—O1iv	102.91 (14)	Hgiv—O1—Hg	64.22 (13)
O2ii—Hg—O1iv	75.64 (18)	Hgi—O1—Hg	95.95 (15)
O1iii—Hg—O1iv	149.3 (3)	Hgvii—O1—Hg	138.14 (18)
O1iii—S—O1	114.5 (6)	Hgx—O1—Hg	129.82 (18)
O1iii—S—O2iii	109.4 (3)	S—O2—Hgi	120.5 (3)
O1—S—O2iii	108.6 (4)	S—O2—Hgviii	126.9 (3)
O1iii—S—O2	108.6 (4)	Hgi—O2—Hgviii	110.9 (2)
O1—S—O2	109.4 (3)	S—O2—Hgvi	56.41 (19)
O2iii—S—O2	106.2 (5)	Hgi—O2—Hgvi	131.7 (2)
S—O1—Hgiii	122.3 (4)	Hgviii—O2—Hgvi	80.47 (14)
S—O1—Hgiv	123.6 (4)	S—O2—Hg	72.7 (2)
Hgiii—O1—Hgiv	96.8 (2)	Hgi—O2—Hg	129.6 (2)
S—O1—Hgi	76.0 (3)	Hgviii—O2—Hg	85.11 (15)
Hgiii—O1—Hgi	148.1 (3)	Hgvi—O2—Hg	97.20 (13)
Hgiv—O1—Hgi	91.77 (18)	S—O2—Hgvii	61.6 (2)
S—O1—Hgvii	75.3 (3)	Hgi—O2—Hgvii	77.46 (15)
Hgiii—O1—Hgvii	85.41 (17)	Hgviii—O2—Hgvii	122.59 (19)
Hgiv—O1—Hgvii	153.3 (2)	Hgvi—O2—Hgvii	58.72 (8)
Hgi—O1—Hgvii	73.82 (14)	Hg—O2—Hgvii	134.35 (14)

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