Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270199013736/na1432sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270199013736/na1432Isup2.hkl |
CCDC reference: 140945
The title compound was prepared as described elsewhere (Popović, Matković-Čalogović, Soldin et al., 1999). Crystals suitable for X-ray analysis were formed from a dilute ethanol solution of mercury(II) chloride and the thione ligand in a 1:2 molar ratio at room temperature after standing for several days (yield: 89%). The title compound was characterized by IR spectroscopy and elemental analysis (calculated for C6H8Cl2HgN4S2: C 15.28, H 1.71, Hg 42.54, N 11.88, S 13.57%; found: C 15.89, H 2.44, Hg 42.65, N 11.92, S 13.59%; m.p. 478 K). IR (cm−1): 3298 (s), 3250 (s), 3190 (s), 3131 (s, sh), 2981 (m), 2859 (m), 2625 (m), 1583 (versus), 1477 (versus), 1430 (sh), 1404 (s), 1282 (m), 1227 (m), 1122 (m), 1104 (w), 1077 (s), 955 (m), 918 (m), 746 (s), 739 (s), 683 (s), 666 (versus), 491 (m). The IR spectrum in the region of 4000–450 cm−1 was recorded on a Perkin-Elmer FT—IR spectrophotometer Model 1600 using a KBr disk.
The number of Friedel pairs measured (579) corresponds only to a 0.313 fraction of the measured symmetry-unique reflections, nevertheless there is no reason for rejecting the absolute structure indicated by the Flack (1983) parameter.
Data collection: STADI4 (Stoe & Cie, 1995b); cell refinement: STADI4; data reduction: X-RED (Stoe & Cie, 1995a); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997a); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997b); molecular graphics: PLATON98 (Spek, 1998); software used to prepare material for publication: SHELXL97.
[HgCl2(C3H4N2S)2] | Dx = 2.579 Mg m−3 |
Mr = 471.77 | Mo Kα radiation, λ = 0.71073 Å |
Orthorhombic, Pca21 | Cell parameters from 56 reflections |
a = 7.5296 (11) Å | θ = 9.0–15.4° |
b = 13.7209 (19) Å | µ = 13.43 mm−1 |
c = 11.7587 (16) Å | T = 293 K |
V = 1214.8 (3) Å3 | Prism, colourless |
Z = 4 | 0.44 × 0.12 × 0.03 mm |
F(000) = 872 |
Philips PW1100 diffractometer updated by Stoe | 1545 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.029 |
Graphite monochromator | θmax = 29.9°, θmin = 3.0° |
ω scans | h = −2→10 |
Absorption correction: numerical (X-RED; Stoe & Cie, 1995a) | k = 0→19 |
Tmin = 0.158, Tmax = 0.668 | l = −4→16 |
3067 measured reflections | 5 standard reflections every 90 min |
2426 independent reflections | intensity decay: 3.3% |
Refinement on F2 | Hydrogen site location: inferred from neighbouring sites |
Least-squares matrix: full | H-atom parameters constrained |
R[F2 > 2σ(F2)] = 0.030 | Calculated w = 1/[σ2(Fo2) + (0.0278P)2] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.064 | (Δ/σ)max < 0.001 |
S = 0.90 | Δρmax = 0.79 e Å−3 |
2426 reflections | Δρmin = −0.90 e Å−3 |
137 parameters | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
1 restraint | Extinction coefficient: 0.00034 (9) |
Primary atom site location: structure-invariant direct methods | Absolute structure: Flack (1983) |
Secondary atom site location: difference Fourier map | Absolute structure parameter: −0.022 (10) |
[HgCl2(C3H4N2S)2] | V = 1214.8 (3) Å3 |
Mr = 471.77 | Z = 4 |
Orthorhombic, Pca21 | Mo Kα radiation |
a = 7.5296 (11) Å | µ = 13.43 mm−1 |
b = 13.7209 (19) Å | T = 293 K |
c = 11.7587 (16) Å | 0.44 × 0.12 × 0.03 mm |
Philips PW1100 diffractometer updated by Stoe | 1545 reflections with I > 2σ(I) |
Absorption correction: numerical (X-RED; Stoe & Cie, 1995a) | Rint = 0.029 |
Tmin = 0.158, Tmax = 0.668 | 5 standard reflections every 90 min |
3067 measured reflections | intensity decay: 3.3% |
2426 independent reflections |
R[F2 > 2σ(F2)] = 0.030 | H-atom parameters constrained |
wR(F2) = 0.064 | Δρmax = 0.79 e Å−3 |
S = 0.90 | Δρmin = −0.90 e Å−3 |
2426 reflections | Absolute structure: Flack (1983) |
137 parameters | Absolute structure parameter: −0.022 (10) |
1 restraint |
Refinement. The structure was solved from diffractometer data by direct methods and subsequent difference syntheses and refined by the full-matrix least squares procedure on F2 with anisotropic temperature factors for all non-hydrogen atoms. The H atoms belonging to C atoms of the imidazole ring were generated geometrically using a riding model with the isotropic displacement parameter set at 1.2Ueq of the carrier C atom. Those on the N atoms were located in the difference Fourier map, but were not well defined and were therefore generated and refined applying the riding model. |
x | y | z | Uiso*/Ueq | ||
Hg | 0.26266 (4) | 0.277323 (18) | −0.31937 (7) | 0.03887 (10) | |
Cl1 | 0.3805 (3) | 0.28374 (15) | −0.10969 (19) | 0.0384 (5) | |
Cl2 | 0.5592 (3) | 0.21051 (15) | −0.41497 (19) | 0.0369 (5) | |
S1 | 0.2352 (3) | 0.44395 (15) | −0.39103 (19) | 0.0365 (5) | |
C11 | 0.2971 (10) | 0.5213 (5) | −0.2842 (7) | 0.031 (2) | |
N11 | 0.3781 (10) | 0.5020 (5) | −0.1843 (6) | 0.0335 (16) | |
H11 | 0.4059 | 0.4448 | −0.1602 | 0.040* | |
C12 | 0.4092 (13) | 0.5859 (7) | −0.1279 (8) | 0.043 (2) | |
H12 | 0.4638 | 0.5916 | −0.0572 | 0.051* | |
C13 | 0.3478 (12) | 0.6592 (6) | −0.1911 (8) | 0.042 (2) | |
H13 | 0.3519 | 0.7252 | −0.1733 | 0.051* | |
N12 | 0.2777 (8) | 0.6182 (5) | −0.2872 (6) | 0.0380 (19) | |
H12N | 0.2284 | 0.6501 | −0.3417 | 0.046* | |
S2 | 0.0653 (3) | 0.13537 (16) | −0.3401 (2) | 0.0430 (6) | |
C21 | 0.1217 (10) | 0.0596 (5) | −0.2297 (8) | 0.0311 (19) | |
N21 | 0.1117 (9) | −0.0374 (5) | −0.2318 (7) | 0.0355 (18) | |
H21 | 0.0810 | −0.0709 | −0.2904 | 0.043* | |
C22 | 0.1565 (14) | −0.0770 (7) | −0.1287 (10) | 0.050 (3) | |
H22 | 0.1600 | −0.1428 | −0.1099 | 0.060* | |
C23 | 0.1943 (12) | −0.0017 (7) | −0.0606 (11) | 0.052 (3) | |
H23 | 0.2296 | −0.0053 | 0.0150 | 0.062* | |
N22 | 0.1715 (11) | 0.0820 (6) | −0.1231 (6) | 0.0430 (19) | |
H22N | 0.1869 | 0.1402 | −0.0977 | 0.052* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Hg | 0.05281 (17) | 0.02776 (11) | 0.03603 (15) | −0.00145 (15) | −0.0001 (3) | −0.0009 (3) |
Cl1 | 0.0574 (12) | 0.0268 (8) | 0.0309 (10) | −0.0012 (10) | −0.0050 (11) | 0.0000 (10) |
Cl2 | 0.0451 (10) | 0.0316 (11) | 0.0339 (12) | 0.0029 (9) | 0.0006 (10) | −0.0017 (10) |
S1 | 0.0508 (12) | 0.0309 (9) | 0.0279 (10) | 0.0018 (10) | −0.0043 (12) | 0.0027 (9) |
C11 | 0.035 (4) | 0.024 (3) | 0.035 (5) | 0.002 (3) | 0.007 (3) | 0.003 (3) |
N11 | 0.045 (4) | 0.025 (3) | 0.030 (4) | −0.003 (3) | −0.002 (4) | 0.003 (4) |
C12 | 0.064 (6) | 0.042 (5) | 0.022 (5) | −0.014 (5) | 0.006 (5) | −0.007 (4) |
C13 | 0.050 (5) | 0.028 (4) | 0.049 (6) | −0.007 (4) | 0.010 (5) | 0.002 (5) |
N12 | 0.045 (4) | 0.029 (3) | 0.040 (5) | 0.000 (3) | −0.004 (4) | 0.005 (3) |
S2 | 0.0544 (11) | 0.0351 (9) | 0.0395 (17) | −0.0067 (9) | −0.0099 (12) | −0.0038 (11) |
C21 | 0.033 (4) | 0.022 (4) | 0.038 (5) | −0.002 (3) | −0.005 (4) | −0.007 (4) |
N21 | 0.046 (4) | 0.027 (3) | 0.033 (4) | −0.007 (3) | 0.002 (4) | −0.019 (3) |
C22 | 0.064 (6) | 0.030 (5) | 0.056 (7) | 0.001 (5) | 0.003 (6) | 0.004 (5) |
C23 | 0.067 (7) | 0.042 (4) | 0.047 (6) | −0.006 (4) | −0.003 (8) | 0.027 (7) |
N22 | 0.075 (5) | 0.030 (4) | 0.024 (4) | −0.014 (4) | −0.004 (4) | −0.004 (3) |
Hg—S1 | 2.445 (2) | C12—C13 | 1.333 (12) |
Hg—S2 | 2.462 (2) | C13—N12 | 1.369 (11) |
Hg—Cl1 | 2.622 (2) | S2—C21 | 1.717 (9) |
Hg—Cl2 | 2.663 (2) | C21—N21 | 1.333 (9) |
S1—C11 | 1.709 (8) | C21—N22 | 1.344 (11) |
C11—N12 | 1.339 (9) | N21—C22 | 1.370 (13) |
C11—N11 | 1.350 (10) | C22—C23 | 1.337 (14) |
N11—C12 | 1.348 (11) | C23—N22 | 1.373 (11) |
S1—Hg—S2 | 130.87 (8) | C13—C12—N11 | 108.0 (8) |
S1—Hg—Cl1 | 108.74 (7) | C12—C13—N12 | 106.5 (8) |
S2—Hg—Cl1 | 108.91 (8) | C11—N12—C13 | 110.1 (7) |
S1—Hg—Cl2 | 104.32 (7) | C21—S2—Hg | 104.8 (3) |
S2—Hg—Cl2 | 101.07 (7) | N21—C21—N22 | 105.2 (8) |
Cl1—Hg—Cl2 | 97.17 (7) | N21—C21—S2 | 125.2 (7) |
C11—S1—Hg | 107.7 (3) | N22—C21—S2 | 129.5 (6) |
N12—C11—N11 | 105.5 (7) | C21—N21—C22 | 111.4 (8) |
N12—C11—S1 | 124.6 (7) | C23—C22—N21 | 106.0 (9) |
N11—C11—S1 | 129.9 (6) | C22—C23—N22 | 107.4 (10) |
C12—N11—C11 | 109.9 (7) | C21—N22—C23 | 110.0 (8) |
S2—Hg—S1—C11 | 137.3 (3) | S1—Hg—S2—C21 | −158.7 (3) |
Cl1—Hg—S1—C11 | −0.9 (3) | Cl1—Hg—S2—C21 | −20.5 (3) |
Cl2—Hg—S1—C11 | −103.8 (3) | Cl2—Hg—S2—C21 | 81.2 (3) |
Hg—S1—C11—N12 | −171.1 (6) | Hg—S2—C21—N21 | −149.2 (7) |
Hg—S1—C11—N11 | 11.6 (8) | Hg—S2—C21—N22 | 36.0 (9) |
N12—C11—N11—C12 | −0.5 (9) | N22—C21—N21—C22 | −0.8 (10) |
S1—C11—N11—C12 | 177.2 (7) | S2—C21—N21—C22 | −176.6 (7) |
C11—N11—C12—C13 | 0.1 (10) | C21—N21—C22—C23 | 0.4 (11) |
N11—C12—C13—N12 | 0.3 (10) | N21—C22—C23—N22 | 0.2 (11) |
N11—C11—N12—C13 | 0.7 (9) | N21—C21—N22—C23 | 0.8 (10) |
S1—C11—N12—C13 | −177.2 (6) | S2—C21—N22—C23 | 176.5 (7) |
C12—C13—N12—C11 | −0.7 (10) | C22—C23—N22—C21 | −0.6 (11) |
D—H···A | D—H | H···A | D···A | D—H···A |
N11—H11···Cl1 | 0.86 | 2.30 | 3.121 (7) | 160 |
N22—H22N···Cl1 | 0.86 | 2.46 | 3.188 (7) | 144 |
N12—H12N···Cl2i | 0.86 | 2.45 | 3.238 (7) | 152 |
N21—H21···Cl2ii | 0.86 | 2.42 | 3.232 (8) | 158 |
Symmetry codes: (i) x−1/2, −y+1, z; (ii) x−1/2, −y, z. |
Experimental details
Crystal data | |
Chemical formula | [HgCl2(C3H4N2S)2] |
Mr | 471.77 |
Crystal system, space group | Orthorhombic, Pca21 |
Temperature (K) | 293 |
a, b, c (Å) | 7.5296 (11), 13.7209 (19), 11.7587 (16) |
V (Å3) | 1214.8 (3) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 13.43 |
Crystal size (mm) | 0.44 × 0.12 × 0.03 |
Data collection | |
Diffractometer | Philips PW1100 diffractometer updated by Stoe |
Absorption correction | Numerical (X-RED; Stoe & Cie, 1995a) |
Tmin, Tmax | 0.158, 0.668 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 3067, 2426, 1545 |
Rint | 0.029 |
(sin θ/λ)max (Å−1) | 0.701 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.030, 0.064, 0.90 |
No. of reflections | 2426 |
No. of parameters | 137 |
No. of restraints | 1 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.79, −0.90 |
Absolute structure | Flack (1983) |
Absolute structure parameter | −0.022 (10) |
Computer programs: STADI4 (Stoe & Cie, 1995b), STADI4, X-RED (Stoe & Cie, 1995a), SHELXS97 (Sheldrick, 1997a), SHELXL97 (Sheldrick, 1997b), PLATON98 (Spek, 1998), SHELXL97.
Hg—S1 | 2.445 (2) | Hg—Cl2 | 2.663 (2) |
Hg—S2 | 2.462 (2) | S1—C11 | 1.709 (8) |
Hg—Cl1 | 2.622 (2) | S2—C21 | 1.717 (9) |
S1—Hg—S2 | 130.87 (8) | S2—Hg—Cl2 | 101.07 (7) |
S1—Hg—Cl1 | 108.74 (7) | Cl1—Hg—Cl2 | 97.17 (7) |
S2—Hg—Cl1 | 108.91 (8) | C11—S1—Hg | 107.7 (3) |
S1—Hg—Cl2 | 104.32 (7) | C21—S2—Hg | 104.8 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
N11—H11···Cl1 | 0.86 | 2.30 | 3.121 (7) | 160 |
N22—H22N···Cl1 | 0.86 | 2.46 | 3.188 (7) | 144 |
N12—H12N···Cl2i | 0.86 | 2.45 | 3.238 (7) | 152 |
N21—H21···Cl2ii | 0.86 | 2.42 | 3.232 (8) | 158 |
Symmetry codes: (i) x−1/2, −y+1, z; (ii) x−1/2, −y, z. |
The current interest in the coordination chemistry of mercury(II) complexes containing an exocyclic thione (thioketo) group on a heterocyclic molecule which may contain nitrogen, oxygen or sulfur or a combination of these is related to mercury–cysteine thionate interactions in the toxicological behaviour of mercury (Cheesman et al., 1988), in detoxification of the mercury by metallothioneins (Nielsen et al., 1985), in a DNA-binding protein (Dance, 1986), and in mercury reductase and related proteins (Blower & Dillworth, 1987). Deprotonated heterocyclic thiones, i.e. heterocyclic thionates, are ambidentate ligands with exocyclic S or thioamido N donating atoms. The coordination mode depends on the nature of the metal centre, hence N-donor atoms are found in Zn complexes, while in mercury(II) complexes, the S atom is undoubtedly the expected ligating site for Hg2+ (Raper, 1996; Popović, Matković-Čalogović, Hasić & Vikić-Topić, 1999; Popović, Matković-Čalogović, Soldin et al., 1999). The structural identification of mercury(II) complexes with thione ligands has, in the past, relied largely on spectroscopic methods such as IR and 13C NMR (Shunmugam & Sathyanarayana, 1983). The crystal structure of the free ligand is not known, but its hemihydrate (Raper et al., 1984), as well as its alkyl and aryl derivatives (Form et al., 1976; Raper et al., 1983; Ansell, 1972) or even its saturated analogoue imidazolidine-2-thione (Wheatley, 1953), have been examined. Mercury(II) complexes with 1,3-imidazole-2-thione derivatives and corresponding halides show different HgX2 and L ratios that can be deduced as: HgX2.L and HgX2.L2 [X = halide or pseudo-halide ions; L = imtH2 (1,3-imidazole-2-thione) or meimtH (1-methyl-1,3-imidazole-2-thione)] or HgL2 (L = imtH− or meimt−), depending dominantly on the stoichiometry of the reactants, pH and the coordination ability of the ligand. The structural diversity is present too, i.e. the complexes may be discrete (Popović, Matković-Čalogović, Soldin et al., 1999), dimeric (Raper et al., 1998; Popović, Matković-Čalogović, Soldin et al., 1999) or polymeric (Popović, Matković-Čalogović, Soldin et al., 1999), reflecting the character of Hg—L and Hg—X interactions. In the context of our previous work on mercury(II) complexes with heterocyclic thiones (Popović, Matković-Čalogović, Hasić & Vikić-Topić, 1999; Popović, Matković-Čalogović, Soldin et al., 1999), the crystal and molecular structure of [HgCl2(imtH2)2], (I), is reported here.
The molecule (Fig. 1) is built up of a monomeric HgCl2 unit [Hg—Cl1 2.622 (2) Å and Hg—Cl2 2.663 (2) Å], with two thione ligands coordinated to the Hg atom via the S atom [Hg—S1 2.445 (2) Å and Hg—S2 2.462 (2) Å] in a distorted tetrahedral environment. The smallest and largest bond angles around the Hg atom are S2—Hg—Cl2 101.07 (7)° and S1—Hg—S2 130.87 (8)°. The Hg—Cl distances are longer than the sum of the covalent radii for Cl and tetrahedrally coordinated Hg atoms (0.99 and 1.48 Å, respectively; Pauling, 1960; Grdenić, 1965). The contribution of the Cl atoms in intramolecular and intermolecular hydrogen-bond formation makes the Hg—Cl bond lengths elongated to some extent. A similar value is found in the structure of dichlorobis(6-merkaptopurine)mercury(II) [2.622 (3) Å; Lavertue et al., 1976]. The reason for such elongation is probably also the existence of N—H···Cl hydrogen bonds. The Hg—S distances are shorter than the sum of the covalent radii of S and tetrahedral Hg (2.52 Å; Pauling, 1960; Grdenić, 1965), indicating that the thione ligand forms a strong covalent bond to Hg. The structural comparison with other analogous mercury(II) complexes is quite difficult due to possible secondary interactions between Hg and halogen atoms. Despite this, there are a few monomeric tetrahedral mercury(II)–chloride complexes that contain sulfur bound to mercury. The S atom in those complexes exists in chemically different environments. The Hg—S values vary between 2.417 (3) Å in the structure of dichlorobis(thiosemicarbazide)mercury(II) (Chieh, 1977) and 2.536 (6) Å in bis(N,N'-dimethylthioformamide)mercury(II) (Stålhandske et al., 1997). Similar S—Hg distances to those in (I) are found in mercury(II) chloride complexes of the N,N'-diethyl and N-ethyl imidazolidine-2-thione derivatives (Hg—S 2.42–2.50 Å; Cannas et al., 1981), while in the [(µ2-dibromo)bis(trans{(bromo)(1-methyl-imidazoline-2(3H)-thione)}- mercury(II))] complex (Raper et al., 1998), the Hg—S values are slightly shorter [range 2.405 (4)–2.419 (4) Å]. The S—C bond distances, retaining appreciable double-bond character [S1—C11 1.709 (8) Å and S2—C21 1.717 (9) Å], suggest, along with endocyclic bond-distance values, the zwitterionic nature of the ligand (Allen et al., 1987). The dihedral angle between the two imidazole ring planes amounts to 12.5 (3)°. Such spatial orientation of the imidazole rings is a consequence of the crystal packing of the complex molecules. There are two intramolecular N—H···Cl hydrogen bonds of 3.121 (7) and 3.188 (7) Å (Table 2). Discrete title complex molecules, held together by intermolecular N—H···Cl hydrogen bonds form infinite puckered sheets perpendicular to the z axis (Fig. 2 and Table 2). The shortest intermolecular mercury-to-halogen distance of 3.581 (2) Å exists between the Hg and Cl1 atoms, and is longer than the sum of the van der Waals radii for Hg and Cl (3.20–3.36 Å; Matković-Čalogović, 1994; Nyburg & Faerman, 1985).