supplementary materials


HTML versionpdf versioncif file3d viewstructure factorssupplementary materialsCIF check reportsimilar papers Open access

cs2074 scheme

Acta Cryst. (2008). E64, m751-m752    [ doi:10.1107/S1600536808012336 ]

3-Ammoniopyridinium tetrabromidomercurate(II) monohydrate

B. F. Ali, R. H. Al-Far and S. F. Haddad

Abstract top

The asymmetric unit of the title compound, (C5H8N2)[HgBr4]·H2O, consists of one cation, one anion and one water molecule. The anion exhibits a distorted tetrahedral arrangement about the Hg atom. The crystal structure contains alternating sheets of cations (in the ac plane) and stacks of anions. Several strong hydrogen-bonding interactions (pyN-H...Br and C-H...Br; py is pyridine), along with O-H...Br interactions, connect the sheets of cations to the stacks of anions. Cation-cation [pi]-[pi] stacking is also present (C...C distances in the range 3.424-3.865 Å). The shortest Br...Br distance is 3.9527 (9) Å.

Comment top

Noncovalent interactions play an important role in organizing structural units in both natural and artificial systems (Desiraju, 1997). In connection with ongoing studies (Al-Far et al., 2006; Al-Far & Ali 2007a,b; Ali & Al-Far 2007a,b; Ali & Al-Far 2008; Ali et al., 2008) of the structural aspects of bromometal anions' salts, we herein report the crystal structure of the title compound.

In the title compound, Fig. 1, the asymmetric unit contains one cation and one anion along with one water molecules. The anion exhibits a distorted tetrahedral arrangement about Hg atom (Table 1). The Hg—Br1 and Hg—Br4 [2.5875 (6) and 2.5818 (7) Å, respectively] bonds are almost invariant and significantly shorter than Hg—Br2 and Hg—Br3 [2.6309 (7) and 2.6216 (7) Å, respectively]. These lengths fall within the range of Hg—Br distances reported previously for compounds containing [HgBr4]2- anions (Al-Far et al., 2006; Ali & Al-Far 2008). It is noteworthy that the longer Hg—Br2, Br3 bonds are involved in more interactions than the shorter ones (Table 2). In the cation, the bond lengths and angles are in accordance with normal values (Orpen et al., 1989). The cation is, of course, planar, in which N1 and N2 atoms are also coplanar.

The packing can be regarded as sheets of cations in the ac plane that are separated by stacks of anions.

Each two cations are connected via two water centers in a cation···2H2O···cation supramolecular motif, (Fig. 2), through N—H···O and O—H···O hydrogen bonding. These motifs are further connected to the next one via π···π stacking leading to infinite layers of ···pyNH3···OH2···H2O···H3Npy··· pyNH3···OH2···H2O···H3Npy··· connected molecules (Fig. 3). These layers are then connected by π···π stacking to the next layer causing the sheet arrangement (Fig. 3). The sheets are separated by the anion stacks (Fig. 4), where no significant Br···Br interactions (shortest Br···Br is 3.9527 (9) Å) were observed. The anion stacks are interacting extensively with cation sheets by different significant hydrogen bonds of the type pyN—H···Br and C—H···Br (Table 2), along with extra O—H···Br—Hg interactions (Table 2), cause to the formation of a three-dimensional supramolecular architecture. π···π Stacking may be effective in the stabilization of the crystal structure apart from hydrogen bonding, dipole-dipole and van der Waals interactions.

Related literature top

For general background, see: Al-Far & Ali (2007a); Desiraju (1997). For related literature, see: Al-Far, Ali & Al-Sou'od (2006). For bond distances see: Orpen et al. (1989).

For related literature, see: Al-Far & Ali (2007b); Ali & Al-Far (2007a, 2007b, 2008); Ali, Al-Far & Haddad (2008).

Experimental top

A warm solution of HgCl2 (1.0 mmol) dissolved in ethanol (10 ml) and HBr (60%, 3 ml), was added dropwise to a stirred hot solution of 2-aminopyridine (1 mmol) dissolved in ethanol (10 ml). After refluxing for 2 h, the mixture was filtered off, and then allowed to stand undisturbed at room temperature. The salt crystallized over 3 days as pink crystals. Crystals were filtered off and one crystal suitable for diffraction measurements was used to collect data.

Refinement top

H atoms attached to water O atoms were located in a difference map and refined with restraints (O—H distance of 0.89 Å). Other H atoms were positioned geometrically, with N—H = 0.86 Å (for py NH), N—H = 0.89 Å (for ammonium NH) and C—H = 0.93 Å for aromatic H, and constrained to ride on their parent atoms, with Uiso(H) = 1.2Ueq(C,N).

Computing details top

Data collection: SMART (Bruker, 2001); cell refinement: SAINT-Plus (Bruker, 2001); data reduction: SAINT-Plus (Bruker, 2001); program(s) used to solve structure: XS in SHELXTL (Sheldrick, 2008); program(s) used to refine structure: XL in SHELXTL (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008); software used to prepare material for publication: XCIF in SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. A view of the asymmetric unit with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.
[Figure 2] Fig. 2. A cation···2H2O···cation supramolecular motif, via significant N—H···O and O—H···O hydrogen bonding. Hydrogen bonds are shown as dashed lines.
[Figure 3] Fig. 3. Cationic sheets in the ac plane. π···π stacking is represented as double headed arrows. Solid double headed arrows are intra-layer interactions, while dashed double headed arrows are inter-layers interactions.
[Figure 4] Fig. 4. Overall packing of alternating anion stacks and sheets of cations and water molecules. Hydrogen atoms omitted for clarity.
3-Ammoniopyridinium tetrabromidomercurate(II) monohydrate top
Crystal data top
(C5H8N2)[HgBr4]·H2OF000 = 1128
Mr = 634.34Dx = 3.181 Mg m−3
Monoclinic, P21/nMo Kα radiation
λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 5049 reflections
a = 8.1896 (7) Åθ = 2.3–27.6º
b = 14.0245 (12) ŵ = 23.66 mm−1
c = 11.5711 (10) ÅT = 296 (2) K
β = 94.730 (2)ºChunk, pink
V = 1324.5 (2) Å30.20 × 0.10 × 0.03 mm
Z = 4
Data collection top
Bruker–Siemens SMART APEX
diffractometer		3780 independent reflections
Radiation source: fine-focus sealed tube2628 reflections with I > 2σ(I)
Monochromator: graphiteRint = 0.056
Detector resolution: 8.3 pixels mm-1θmax = 30.1º
T = 296(2) Kθmin = 2.3º
ω scansh = −11→11
Absorption correction: multi-scan
(SADABS; Bruker, 2001)		k = −19→19
Tmin = 0.034, Tmax = 0.492l = −16→16
16873 measured reflections
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.035H atoms treated by a mixture of
independent and constrained refinement
wR(F2) = 0.074  w = 1/[σ2(Fo2) + (0.018P)2 + 0.74P]
where P = (Fo2 + 2Fc2)/3
S = 1.03(Δ/σ)max = 0.001
3780 reflectionsΔρmax = 0.85 e Å−3
126 parametersΔρmin = −1.32 e Å−3
3 restraintsExtinction correction: SHELXTL (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.00271 (13)
Crystal data top
(C5H8N2)[HgBr4]·H2OV = 1324.5 (2) Å3
Mr = 634.34Z = 4
Monoclinic, P21/nMo Kα
a = 8.1896 (7) ŵ = 23.66 mm−1
b = 14.0245 (12) ÅT = 296 (2) K
c = 11.5711 (10) Å0.20 × 0.10 × 0.03 mm
β = 94.730 (2)º
Data collection top
Bruker–Siemens SMART APEX
diffractometer		3780 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2001)		2628 reflections with I > 2σ(I)
Tmin = 0.034, Tmax = 0.492Rint = 0.056
16873 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0353 restraints
wR(F2) = 0.074H atoms treated by a mixture of
independent and constrained refinement
S = 1.03Δρmax = 0.85 e Å−3
3780 reflectionsΔρmin = −1.32 e Å−3
126 parameters
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.8331 (6)0.5315 (4)0.4741 (5)0.0770 (15)
H10.883 (9)0.575 (4)0.433 (5)0.116*
H20.802 (10)0.560 (4)0.538 (4)0.116*
Hg10.68459 (3)0.763019 (18)0.84039 (2)0.05085 (10)
Br10.95522 (7)0.85483 (4)0.89061 (5)0.04424 (15)
Br20.53644 (7)0.74688 (4)1.03273 (5)0.04900 (16)
Br30.74834 (8)0.59454 (4)0.75688 (5)0.05157 (17)
Br40.45943 (8)0.83129 (5)0.69416 (6)0.0622 (2)
N10.8418 (6)0.9030 (4)0.1560 (4)0.0506 (13)
H1A0.78840.94470.10890.076*
H1B0.81810.84400.13170.076*
H1C0.94920.91280.15600.076*
C20.7926 (6)0.9151 (4)0.2726 (4)0.0337 (11)
C30.6981 (6)0.8466 (4)0.3172 (5)0.0413 (13)
H30.66370.79340.27370.050*
N40.6563 (6)0.8582 (4)0.4258 (4)0.0501 (12)
H40.59570.81580.45470.060*
C50.7057 (7)0.9339 (4)0.4914 (5)0.0462 (14)
H50.67640.93900.56720.055*
C60.7989 (7)1.0030 (4)0.4463 (5)0.0424 (13)
H60.83181.05620.49030.051*
C70.8433 (7)0.9933 (4)0.3356 (5)0.0419 (13)
H70.90741.03950.30360.050*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.061 (3)0.073 (4)0.096 (4)−0.012 (3)0.003 (3)−0.027 (3)
Hg10.04444 (15)0.05348 (17)0.05300 (16)−0.00161 (11)−0.00571 (10)−0.00193 (11)
Br10.0406 (3)0.0417 (3)0.0508 (3)−0.0052 (2)0.0063 (2)−0.0018 (2)
Br20.0451 (3)0.0563 (4)0.0451 (3)−0.0050 (3)0.0014 (3)−0.0036 (3)
Br30.0573 (4)0.0473 (4)0.0506 (3)−0.0023 (3)0.0077 (3)−0.0071 (3)
Br40.0454 (3)0.0673 (5)0.0713 (4)−0.0031 (3)−0.0099 (3)0.0294 (3)
N10.053 (3)0.061 (3)0.037 (3)0.010 (2)0.003 (2)0.000 (2)
C20.034 (3)0.039 (3)0.027 (2)0.008 (2)−0.001 (2)0.002 (2)
C30.030 (3)0.040 (3)0.053 (3)−0.004 (2)−0.003 (2)−0.012 (3)
N40.041 (3)0.048 (3)0.062 (3)−0.009 (2)0.007 (2)0.003 (2)
C50.045 (3)0.057 (4)0.036 (3)0.001 (3)0.003 (2)−0.004 (3)
C60.045 (3)0.038 (3)0.044 (3)−0.003 (2)−0.001 (3)−0.009 (2)
C70.045 (3)0.034 (3)0.047 (3)0.000 (2)0.006 (3)0.006 (2)
Geometric parameters (Å, °) top
O1—H10.89 (6)C2—C31.362 (7)
O1—H20.89 (6)C3—N41.339 (7)
Hg1—Br42.5818 (7)C3—H30.9300
Hg1—Br12.5875 (6)N4—C51.349 (7)
Hg1—Br32.6216 (7)N4—H40.8600
Hg1—Br22.6309 (7)C5—C61.364 (8)
N1—C21.450 (6)C5—H50.9300
N1—H1A0.8900C6—C71.367 (7)
N1—H1B0.8900C6—H60.9300
N1—H1C0.8900C7—H70.9300
C2—C71.363 (7)
H1—O1—H2108 (5)N4—C3—C2117.8 (5)
Br4—Hg1—Br1120.99 (2)N4—C3—H3121.1
Br4—Hg1—Br3104.23 (2)C2—C3—H3121.1
Br1—Hg1—Br3109.78 (2)C3—N4—C5122.4 (5)
Br4—Hg1—Br2103.42 (2)C3—N4—H4118.8
Br1—Hg1—Br2107.40 (2)C5—N4—H4118.8
Br3—Hg1—Br2110.73 (2)N4—C5—C6119.7 (5)
C2—N1—H1A109.5N4—C5—H5120.2
C2—N1—H1B109.5C6—C5—H5120.2
H1A—N1—H1B109.5C5—C6—C7119.3 (5)
C2—N1—H1C109.5C5—C6—H6120.4
H1A—N1—H1C109.5C7—C6—H6120.4
H1B—N1—H1C109.5C2—C7—C6119.2 (5)
C7—C2—C3121.6 (5)C2—C7—H7120.4
C7—C2—N1119.7 (5)C6—C7—H7120.4
C3—C2—N1118.7 (5)
C7—C2—C3—N4−0.2 (8)N4—C5—C6—C7−1.3 (9)
N1—C2—C3—N4178.8 (5)C3—C2—C7—C60.3 (8)
C2—C3—N4—C5−0.7 (8)N1—C2—C7—C6−178.7 (5)
C3—N4—C5—C61.4 (9)C5—C6—C7—C20.4 (8)
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
O1—H1···Br2i0.89 (6)2.98 (6)3.564 (5)125 (5)
O1—H2···Br30.89 (6)2.65 (3)3.513 (5)162 (7)
N1—H1A···O1ii0.891.802.686 (7)174
N1—H1B···Br4i0.892.793.442 (5)132
N1—H1B···Br2iii0.892.843.535 (5)136
N1—H1C···Br3i0.892.633.436 (5)152
N4—H4···Br1iv0.862.733.419 (5)138
Symmetry codes: (i) x+1/2, −y+3/2, z−1/2; (ii) −x+3/2, y+1/2, −z+1/2; (iii) x, y, z−1; (iv) x−1/2, −y+3/2, z−1/2.
Table 1
Selected geometric parameters (Å, °) top
Hg1—Br42.5818 (7)Hg1—Br32.6216 (7)
Hg1—Br12.5875 (6)Hg1—Br22.6309 (7)
Br4—Hg1—Br1120.99 (2)Br4—Hg1—Br2103.42 (2)
Br4—Hg1—Br3104.23 (2)Br1—Hg1—Br2107.40 (2)
Br1—Hg1—Br3109.78 (2)Br3—Hg1—Br2110.73 (2)
Table 2
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
O1—H1···Br2i0.89 (6)2.98 (6)3.564 (5)125 (5)
O1—H2···Br30.89 (6)2.65 (3)3.513 (5)162 (7)
N1—H1A···O1ii0.891.802.686 (7)174
N1—H1B···Br4i0.892.793.442 (5)132
N1—H1B···Br2iii0.892.843.535 (5)136
N1—H1C···Br3i0.892.633.436 (5)152
N4—H4···Br1iv0.862.733.419 (5)138
Symmetry codes: (i) x+1/2, −y+3/2, z−1/2; (ii) −x+3/2, y+1/2, −z+1/2; (iii) x, y, z−1; (iv) x−1/2, −y+3/2, z−1/2.
Acknowledgements top

Al al-Bayt University and Al-Balqa'a Applied University are thanked for support.

references
References top

Al-Far, R. & Ali, B. F. (2007a). Acta Cryst. C63, m137–m139.

Al-Far, R. & Ali, B. F. (2007b). J. Chem. Crystallogr. 37, 331–341.

Al-Far, R., Ali, B. F. & Al-Sou'od, K. (2006). J. Chem. Crystallogr. 36, 523–529.

Ali, B. F. & Al-Far, R. (2007a). Acta Cryst. C63, m451–m453.

Ali, B. F. & Al-Far, R. (2007b). Acta Cryst. E63, m892–m894.

Ali, B. F. & Al-Far, R. (2008). J. Chem. Crystallogr. (2008). Accepted.

Ali, B. F., Al-Far, R. & Haddad, S. F. (2008). Acta Cryst. E64, m485–m486.

Bruker (2001). SADABS, SAINT and SMART. Bruker AXS Inc., Madison, Wisconsin, USA.

Desiraju, G. R. (1997). Chem. Commun. pp. 1475–1482.

Orpen, A. G., Brammer, L., Allen, F. H., Kennard, O., Watson, D. G. & Taylor, R. (1989). J. Chem. Soc. Dalton Trans. pp. S1–S83.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.