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ISSN: 2056-9890

Guanidinium tetra­bromidomercurate(II)

aFaculty of Integrated Arts and Sciences, Tokushima University, Minamijosanjima-cho, Tokushima 770-8502, Japan, bFB05 Kristallographie, Universität Bremen, Klagenfurther Strasse, 28359 Bremen, Germany, cFaculty of Culture and Education, Saga University, Saga 840-8502, Japan, dGraduate School of Education, Hiroshima University, Higashi-Hiroshima 739-8524, Japan, and eDepartment of Chemistry, Mangalore University, Mangalagangotri 574 199, Mangalore, India
*Correspondence e-mail: gowdabt@yahoo.com

(Received 17 February 2009; accepted 19 February 2009; online 25 February 2009)

The Hg atoms in the crystal structure of the title compound, (CH6N3)2[HgBr4], are tetra­hedrally coordinated by four Br atoms and the resulting [HgBr4]2− tetra­hedral ions are linked to the [C(NH2)3]+ ions by bromine–hydrogen bonds, forming a three-dimensional network. In the structure, the anions are located on special positions. The two different Hg⋯Br distances of 2.664 (1) and 2.559 (1) Å observed in the tetra­bromidomercurate unit are due to the connection of Br atoms to different number of H atoms.

Related literature

For the ability of the guanidinium ion to make hydrogen bonds and its unique planar shape, see: Terao et al. (2000[Terao, H., Hashimoto, M., Hashimoto, A. & Furukawa, Y. (2000). Z. Naturforsch. Teil A, 55, 230-236.]). For related literature, see: Ishihara et al. (2002[Ishihara, H., Hatano, N., Horiuchi, K. & Terao, H. (2002). Z. Naturforsch. Teil A, 57, 343-347.]); Furukawa et al. (2005[Furukawa, Y., Terao, H., Ishihara, H., Gesing, T. M. & Buhl, J.-C. (2005). Hyperfine Interactions, 159, 143-148.])

[Scheme 1]

Experimental

Crystal data
  • (CH6N3)2[HgBr4]

  • Mr = 640.41

  • Monoclinic, C 2/c

  • a = 10.035 (2) Å

  • b = 11.164 (2) Å

  • c = 13.358 (3) Å

  • β = 111.67 (3)°

  • V = 1390.7 (6) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 22.53 mm−1

  • T = 298 K

  • 0.09 × 0.09 × 0.09 mm

Data collection
  • Stoe IPDS-I diffractometer

  • Absorption correction: none

  • 9651 measured reflections

  • 1361 independent reflections

  • 982 reflections with I > 2σ(I)

  • Rint = 0.093

Refinement
  • R[F2 > 2σ(F2)] = 0.030

  • wR(F2) = 0.069

  • S = 0.90

  • 1361 reflections

  • 79 parameters

  • 6 restraints

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.71 e Å−3

  • Δρmin = −1.03 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1A⋯Br2i 0.87 (9) 3.03 (4) 3.845 (8) 158 (9)
N1—H1B⋯Br1ii 0.87 (9) 2.77 (6) 3.512 (7) 144 (8)
N2—H2A⋯Br1iii 0.87 (9) 2.72 (4) 3.541 (7) 159 (8)
N2—H2B⋯Br2i 0.87 (9) 2.74 (4) 3.535 (7) 153 (8)
N3—H3A⋯Br1iv 0.87 (9) 3.05 (10) 3.505 (8) 115 (8)
N3—H3B⋯Br1iii 0.87 (9) 2.98 (8) 3.667 (9) 137 (9)
Symmetry codes: (i) [-x+1, y, -z+{\script{1\over 2}}]; (ii) -x+1, -y+2, -z+1; (iii) [-x+{\script{1\over 2}}, -y+{\script{3\over 2}}, -z+1]; (iv) [x, -y+2, z+{\script{1\over 2}}].

Data collection: EXPOSE (Stoe & Cie, 1999[Stoe & Cie (1999). EXPOSE and CELL. Stoe & Cie GmbH, Darmstadt, Germany.]); cell refinement: CELL (Stoe & Cie, 1999[Stoe & Cie (1999). EXPOSE and CELL. Stoe & Cie GmbH, Darmstadt, Germany.]); data reduction: XPREP (Bruker, 2003[Bruker (2003). XPREP. Bruker AXS GmbH, Karlsruhe, Germany.]); program(s) used to solve structure: SHELXS86 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL93 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: DIAMOND (Crystal Impact, 2008[Crystal Impact (2008). DIAMOND. Crystal Impact GmbH, Bonn, Germany.]); software used to prepare material for publication: SHELXL93 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]).

Supporting information


Comment top

The guanidium ion, [C(NH2)3]+ is interesting due to its ability of making hydrogen bonds and its unique planar shape (Terao et al., 2000). Further, the guanidium ions tend to undergo reorientation motions about their (pseudo) C3 axes in the crystals. Due to the soft nature of the Hg atom amenable to polarization, the Hg-halogen bonds are sensitive to the intermolecular interactions such as hydrogen bonding (Ishihara et al., 2002). This was evident in the halogen NQR of the Hg compounds in which the resonance lines are widely spread in frequency (Furukawa et al., 2005). Thus we are interested in studying the structure and bonding in this class of compounds. As a part of our study, we report herein the crystal structure of Guanidinium tetrabromidomercurate(II). In the structure, mercury atoms are tetrahedrally coordinated by four bromine atoms and the resulting HgBr4 tetrahedra are interconnected to the [C(NH2)3]+ ions by bromine-hydrogen bonds (Fig. 1) forming a three-dimensional network. In the tetrabromidomercurate unit, two different Hg—Br distances were observed: Hg—Br1 = 2.664 (1) Å and Hg—Br2 = 2.559 (1) Å. The shorter distance of the latter is due to its connection with two hydrogen atoms, whereas the Br1 is connected to four different hydrogen atoms, which elongate the Hg—Br bond (Fig.2). The C(NH2)3 moity (Fig. 3) itself is planar where the N—H bonds are somewhat elongated (1.01 (2) Å) to form the network bonds to the bromine atoms of the HgBr4 tetrahedra.

Related literature top

For the guanidium ion, see: Terao et al. (2000). For related literature, see: Ishihara et al. (2002); Furukawa et al. (2005)

Experimental top

Guanidinium tetrabromidomercurate(II) was prepared by slow concentration of methanolic solution containing mercuric bromide (0.01 mole) and guanidium bromide (0.02 mole) in 1:2 molar ratio. The purity of the compound was checked by elemental analysis and characterized by its NMR and NQR spectra (Furukawa et al., 2005). The single crystals used in X-ray diffraction studies were grown in methanolic solution by a slow evaporation at room temperature.

Refinement top

The N-H distances were restrained to 0.87 (1)Å and the coordinates of the H atoms were refined with isotropic displacement parameters set to 1.2 times of the Ueq of the parent atom.

Computing details top

Data collection: EXPOSE (Stoe & Cie, 1999); cell refinement: CELL (Stoe & Cie, 1999); data reduction: XPREP (Bruker, 2003); program(s) used to solve structure: SHELXS86 (Sheldrick, 2008); program(s) used to refine structure: SHELXL93 (Sheldrick, 2008); molecular graphics: DIAMOND (Crystal Impact, 2008); software used to prepare material for publication: SHELXL93 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. Molecular structure of (I), showing the atom labeling scheme. The displacement ellipsoids are drawn at the 50% probability level. The H atoms are represented as small spheres of arbitrary radii.
[Figure 2] Fig. 2. : Connection scheme of the HgBr42- tetrahedra with the [C(NH2)3]+ ions.
[Figure 3] Fig. 3. : The planar [C(NH2)3]+ ion.
Guanidinium tetrabromidomercurate(II) top
Crystal data top
(CH6N3)2[HgBr4]F(000) = 1144
Mr = 640.41Dx = 3.059 Mg m3
Monoclinic, C2/cMelting point: not measured K
Hall symbol: -C 2ycMo Kα radiation, λ = 0.71073 Å
a = 10.035 (2) ÅCell parameters from 2000 reflections
b = 11.164 (2) Åθ = 2.9–26.1°
c = 13.358 (3) ŵ = 22.53 mm1
β = 111.67 (3)°T = 298 K
V = 1390.7 (6) Å3Cylindric, colourless transparent
Z = 40.09 × 0.09 × 0.09 mm
Data collection top
Stoe IPDS-I
diffractometer
982 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.093
Graphite monochromatorθmax = 26.1°, θmin = 2.9°
imaging plate dynamic profile intergration scansh = 1212
9651 measured reflectionsk = 1313
1361 independent reflectionsl = 1616
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)] = 0.030H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.069 w = 1/[σ2(Fo2) + (0.0376P)2]
where P = (Fo2 + 2Fc2)/3
S = 0.90(Δ/σ)max = 0.001
1361 reflectionsΔρmax = 0.71 e Å3
79 parametersΔρmin = 1.03 e Å3
6 restraintsExtinction correction: SHELXL93 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.00077 (10)
Crystal data top
(CH6N3)2[HgBr4]V = 1390.7 (6) Å3
Mr = 640.41Z = 4
Monoclinic, C2/cMo Kα radiation
a = 10.035 (2) ŵ = 22.53 mm1
b = 11.164 (2) ÅT = 298 K
c = 13.358 (3) Å0.09 × 0.09 × 0.09 mm
β = 111.67 (3)°
Data collection top
Stoe IPDS-I
diffractometer
982 reflections with I > 2σ(I)
9651 measured reflectionsRint = 0.093
1361 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0306 restraints
wR(F2) = 0.069H atoms treated by a mixture of independent and constrained refinement
S = 0.90Δρmax = 0.71 e Å3
1361 reflectionsΔρmin = 1.03 e Å3
79 parameters
Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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
xyzUiso*/Ueq
Hg10.50000.71191 (4)0.25000.0577 (2)
Br10.30789 (8)0.86270 (7)0.27353 (7)0.0555 (2)
Br20.38905 (10)0.60032 (7)0.07086 (6)0.0635 (3)
C10.4454 (8)0.8215 (6)0.6018 (6)0.0492 (18)
N10.5515 (10)0.8736 (7)0.5829 (6)0.070 (2)
H1A0.592 (10)0.818 (7)0.558 (8)0.084*
H1B0.549 (10)0.950 (2)0.594 (8)0.084*
N20.4254 (7)0.7072 (6)0.5904 (6)0.0625 (17)
H2A0.363 (7)0.673 (8)0.612 (7)0.075*
H2B0.485 (8)0.665 (7)0.571 (7)0.075*
N30.3560 (9)0.8857 (7)0.6335 (7)0.075 (2)
H3A0.369 (11)0.960 (3)0.622 (8)0.090*
H3B0.278 (7)0.856 (9)0.636 (9)0.090*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Hg10.0706 (3)0.0544 (3)0.0586 (3)0.0000.0359 (2)0.000
Br10.0569 (4)0.0485 (4)0.0714 (5)0.0003 (3)0.0359 (4)0.0070 (4)
Br20.0950 (6)0.0453 (5)0.0638 (5)0.0062 (4)0.0454 (5)0.0100 (4)
C10.051 (4)0.043 (4)0.043 (4)0.005 (3)0.005 (3)0.006 (3)
N10.090 (5)0.054 (4)0.064 (5)0.021 (4)0.026 (4)0.001 (4)
N20.058 (4)0.052 (4)0.081 (5)0.005 (3)0.030 (4)0.011 (4)
N30.081 (5)0.063 (5)0.073 (5)0.011 (5)0.018 (5)0.009 (4)
Geometric parameters (Å, º) top
Hg1—Br22.5593 (10)N1—H1A0.87 (9)
Hg1—Br2i2.5593 (10)N1—H1B0.87 (9)
Hg1—Br12.6639 (9)N2—H2A0.87 (9)
Hg1—Br1i2.6639 (9)N2—H2B0.87 (9)
C1—N21.293 (10)N3—H3A0.87 (9)
C1—N11.316 (11)N3—H3B0.87 (9)
C1—N31.334 (11)
Br2—Hg1—Br2i121.74 (4)C1—N1—H1A107 (7)
Br2—Hg1—Br1109.51 (4)C1—N1—H1B109 (7)
Br2i—Hg1—Br1106.33 (3)H1A—N1—H1B144 (10)
Br2—Hg1—Br1i106.33 (3)C1—N2—H2A120 (6)
Br2i—Hg1—Br1i109.51 (4)C1—N2—H2B118 (7)
Br1—Hg1—Br1i101.62 (4)H2A—N2—H2B121 (9)
N2—C1—N1121.0 (8)C1—N3—H3A107 (8)
N2—C1—N3118.3 (8)C1—N3—H3B122 (8)
N1—C1—N3120.7 (7)H3A—N3—H3B125 (10)
Symmetry code: (i) x+1, y, z+1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···Br2i0.87 (9)3.03 (4)3.845 (8)158 (9)
N1—H1B···Br1ii0.87 (9)2.77 (6)3.512 (7)144 (8)
N2—H2A···Br1iii0.87 (9)2.72 (4)3.541 (7)159 (8)
N2—H2B···Br2i0.87 (9)2.74 (4)3.535 (7)153 (8)
N3—H3A···Br1iv0.87 (9)3.05 (10)3.505 (8)115 (8)
N3—H3B···Br1iii0.87 (9)2.98 (8)3.667 (9)137 (9)
Symmetry codes: (i) x+1, y, z+1/2; (ii) x+1, y+2, z+1; (iii) x+1/2, y+3/2, z+1; (iv) x, y+2, z+1/2.

Experimental details

Crystal data
Chemical formula(CH6N3)2[HgBr4]
Mr640.41
Crystal system, space groupMonoclinic, C2/c
Temperature (K)298
a, b, c (Å)10.035 (2), 11.164 (2), 13.358 (3)
β (°) 111.67 (3)
V3)1390.7 (6)
Z4
Radiation typeMo Kα
µ (mm1)22.53
Crystal size (mm)0.09 × 0.09 × 0.09
Data collection
DiffractometerStoe IPDS-I
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
9651, 1361, 982
Rint0.093
(sin θ/λ)max1)0.618
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.030, 0.069, 0.90
No. of reflections1361
No. of parameters79
No. of restraints6
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.71, 1.03

Computer programs: EXPOSE (Stoe & Cie, 1999), CELL (Stoe & Cie, 1999), XPREP (Bruker, 2003), SHELXS86 (Sheldrick, 2008), SHELXL93 (Sheldrick, 2008), DIAMOND (Crystal Impact, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···Br2i0.87 (9)3.03 (4)3.845 (8)158 (9)
N1—H1B···Br1ii0.87 (9)2.77 (6)3.512 (7)144 (8)
N2—H2A···Br1iii0.87 (9)2.72 (4)3.541 (7)159 (8)
N2—H2B···Br2i0.87 (9)2.74 (4)3.535 (7)153 (8)
N3—H3A···Br1iv0.87 (9)3.05 (10)3.505 (8)115 (8)
N3—H3B···Br1iii0.87 (9)2.98 (8)3.667 (9)137 (9)
Symmetry codes: (i) x+1, y, z+1/2; (ii) x+1, y+2, z+1; (iii) x+1/2, y+3/2, z+1; (iv) x, y+2, z+1/2.
 

References

First citationBruker (2003). XPREP. Bruker AXS GmbH, Karlsruhe, Germany.  Google Scholar
First citationCrystal Impact (2008). DIAMOND. Crystal Impact GmbH, Bonn, Germany.  Google Scholar
First citationFurukawa, Y., Terao, H., Ishihara, H., Gesing, T. M. & Buhl, J.-C. (2005). Hyperfine Interactions, 159, 143–148.  Web of Science CSD CrossRef Google Scholar
First citationIshihara, H., Hatano, N., Horiuchi, K. & Terao, H. (2002). Z. Naturforsch. Teil A, 57, 343–347.  CAS Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationStoe & Cie (1999). EXPOSE and CELL. Stoe & Cie GmbH, Darmstadt, Germany.  Google Scholar
First citationTerao, H., Hashimoto, M., Hashimoto, A. & Furukawa, Y. (2000). Z. Naturforsch. Teil A, 55, 230–236.  CAS Google Scholar

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ISSN: 2056-9890
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