Guanidinium tetra­bromidomercurate(II)

Terao, H.; Gesing, T.M.; Ishihara, H.; Furukawa, Y.; Gowda, B.T.

doi:10.1107/S1600536809005972

metal-organic compounds

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Volume 65| Part 3| March 2009| Page m323

doi:10.1107/S1600536809005972

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Guanidinium tetrabromidomercurate(II)

Hiromitsu Terao,^a Thorsten M. Gesing,^b Hideta Ishihara,^c Yoshihiro Furukawa ^d and B. Thimme Gowda ^e ^*

^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 ). For related literature, see: Ishihara et al. (2002 ); Furukawa et al. (2005 )

Experimental

Crystal data

(CH₆N₃)₂[HgBr₄]
M_r = 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)
R_int = 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
Δρ_max = 0.71 e Å⁻³
Δρ_min = −1.03 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	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⋯Br1^iv	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 ); 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).

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809005972/bt2874sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809005972/bt2874Isup2.hkl

checkCIF report

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.

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

	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.
	Fig. 2. : Connection scheme of the HgBr₄2^- tetrahedra with the [C(NH₂)₃]⁺ ions.
	Fig. 3. : The planar [C(NH₂)₃]⁺ ion.

Guanidinium tetrabromidomercurate(II) top

Crystal data top

(CH₆N₃)₂[HgBr₄]	F(000) = 1144
M_r = 640.41	D_x = 3.059 Mg m⁻³
Monoclinic, C2/c	Melting point: not measured K
Hall symbol: -C 2yc	Mo Kα radiation, λ = 0.71073 Å
a = 10.035 (2) Å	Cell parameters from 2000 reflections
b = 11.164 (2) Å	θ = 2.9–26.1°
c = 13.358 (3) Å	µ = 22.53 mm⁻¹
β = 111.67 (3)°	T = 298 K
V = 1390.7 (6) Å³	Cylindric, colourless transparent
Z = 4	0.09 × 0.09 × 0.09 mm

Data collection top

Stoe IPDS-I diffractometer	982 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.093
Graphite monochromator	θ_max = 26.1°, θ_min = 2.9°
imaging plate dynamic profile intergration scans	h = −12→12
9651 measured reflections	k = −13→13
1361 independent reflections	l = −16→16

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.030	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.069	w = 1/[σ²(F_o²) + (0.0376P)²] where P = (F_o² + 2F_c²)/3
S = 0.90	(Δ/σ)_max = 0.001
1361 reflections	Δρ_max = 0.71 e Å⁻³
79 parameters	Δρ_min = −1.03 e Å⁻³
6 restraints	Extinction correction: SHELXL93 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.00077 (10)

Crystal data top

(CH₆N₃)₂[HgBr₄]	V = 1390.7 (6) Å³
M_r = 640.41	Z = 4
Monoclinic, C2/c	Mo Kα radiation
a = 10.035 (2) Å	µ = 22.53 mm⁻¹
b = 11.164 (2) Å	T = 298 K
c = 13.358 (3) Å	0.09 × 0.09 × 0.09 mm
β = 111.67 (3)°

Data collection top

Stoe IPDS-I diffractometer	982 reflections with I > 2σ(I)
9651 measured reflections	R_int = 0.093
1361 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.030	6 restraints
wR(F²) = 0.069	H atoms treated by a mixture of independent and constrained refinement
S = 0.90	Δρ_max = 0.71 e Å⁻³
1361 reflections	Δρ_min = −1.03 e Å⁻³
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

	x	y	z	U_iso*/U_eq
Hg1	0.5000	0.71191 (4)	0.2500	0.0577 (2)
Br1	0.30789 (8)	0.86270 (7)	0.27353 (7)	0.0555 (2)
Br2	0.38905 (10)	0.60032 (7)	0.07086 (6)	0.0635 (3)
C1	0.4454 (8)	0.8215 (6)	0.6018 (6)	0.0492 (18)
N1	0.5515 (10)	0.8736 (7)	0.5829 (6)	0.070 (2)
H1A	0.592 (10)	0.818 (7)	0.558 (8)	0.084*
H1B	0.549 (10)	0.950 (2)	0.594 (8)	0.084*
N2	0.4254 (7)	0.7072 (6)	0.5904 (6)	0.0625 (17)
H2A	0.363 (7)	0.673 (8)	0.612 (7)	0.075*
H2B	0.485 (8)	0.665 (7)	0.571 (7)	0.075*
N3	0.3560 (9)	0.8857 (7)	0.6335 (7)	0.075 (2)
H3A	0.369 (11)	0.960 (3)	0.622 (8)	0.090*
H3B	0.278 (7)	0.856 (9)	0.636 (9)	0.090*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Hg1	0.0706 (3)	0.0544 (3)	0.0586 (3)	0.000	0.0359 (2)	0.000
Br1	0.0569 (4)	0.0485 (4)	0.0714 (5)	−0.0003 (3)	0.0359 (4)	−0.0070 (4)
Br2	0.0950 (6)	0.0453 (5)	0.0638 (5)	−0.0062 (4)	0.0454 (5)	−0.0100 (4)
C1	0.051 (4)	0.043 (4)	0.043 (4)	0.005 (3)	0.005 (3)	−0.006 (3)
N1	0.090 (5)	0.054 (4)	0.064 (5)	−0.021 (4)	0.026 (4)	−0.001 (4)
N2	0.058 (4)	0.052 (4)	0.081 (5)	−0.005 (3)	0.030 (4)	−0.011 (4)
N3	0.081 (5)	0.063 (5)	0.073 (5)	0.011 (5)	0.018 (5)	−0.009 (4)

Geometric parameters (Å, º) top

Hg1—Br2	2.5593 (10)	N1—H1A	0.87 (9)
Hg1—Br2ⁱ	2.5593 (10)	N1—H1B	0.87 (9)
Hg1—Br1	2.6639 (9)	N2—H2A	0.87 (9)
Hg1—Br1ⁱ	2.6639 (9)	N2—H2B	0.87 (9)
C1—N2	1.293 (10)	N3—H3A	0.87 (9)
C1—N1	1.316 (11)	N3—H3B	0.87 (9)
C1—N3	1.334 (11)

Br2—Hg1—Br2ⁱ	121.74 (4)	C1—N1—H1A	107 (7)
Br2—Hg1—Br1	109.51 (4)	C1—N1—H1B	109 (7)
Br2ⁱ—Hg1—Br1	106.33 (3)	H1A—N1—H1B	144 (10)
Br2—Hg1—Br1ⁱ	106.33 (3)	C1—N2—H2A	120 (6)
Br2ⁱ—Hg1—Br1ⁱ	109.51 (4)	C1—N2—H2B	118 (7)
Br1—Hg1—Br1ⁱ	101.62 (4)	H2A—N2—H2B	121 (9)
N2—C1—N1	121.0 (8)	C1—N3—H3A	107 (8)
N2—C1—N3	118.3 (8)	C1—N3—H3B	122 (8)
N1—C1—N3	120.7 (7)	H3A—N3—H3B	125 (10)

Symmetry code: (i) −x+1, y, −z+1/2.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	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···Br1^iv	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+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]
M_r	640.41
Crystal system, space group	Monoclinic, C2/c
Temperature (K)	298
a, b, c (Å)	10.035 (2), 11.164 (2), 13.358 (3)
β (°)	111.67 (3)
V (Å³)	1390.7 (6)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	22.53
Crystal size (mm)	0.09 × 0.09 × 0.09

Data collection
Diffractometer	Stoe IPDS-I diffractometer
Absorption correction	–
No. of measured, independent and observed [I > 2σ(I)] reflections	9651, 1361, 982
R_int	0.093
(sin θ/λ)_max (Å⁻¹)	0.618

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.030, 0.069, 0.90
No. of reflections	1361
No. of parameters	79
No. of restraints	6
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	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···A	D—H	H···A	D···A	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···Br1^iv	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+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

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

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CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 65| Part 3| March 2009| Page m323

doi:10.1107/S1600536809005972

Open

access