Bis(guanidinium) tetra-iodidomercurate(II).

The Hg atom in the crystal structure of the title compound, (CH(6)N(3))(2)[HgI(4)], is tetra-hedrally coordinated by four I atoms. The [HgI(4)](2-) ions are inter-connected to the [C(NH(2))(3)](+) ions by N-H⋯I hydrogen bonds, forming a three-dimensional network. The four different observed Hg-I distances [2.760 (2), 2.7762 (15), 2.8098 (14) and 2.833 (2) Å] are consistent with four different (127)I NQR frequencies observed, showing the existence of four unique I atoms in the tetra-iodidomercurate unit.

Related literature

For synthetic methods, see: Furukawa et al. (2005 ▶); For the ability of the guanidinium ion to make hydrogen bonds and its unique planar shape, see: Terao et al. (2000 ▶). Hg–halogen bonds are sensitive to inter­molecular inter­actions such as hydrogen bonding (Ishihara et al., 2002 ▶), as evidenced by the halogen NQR of Hg compounds in which the resonance frequencies are widely spread (Furukawa et al., 2005 ▶). For background to this study, see: Terao et al. (2009 ▶).

Experimental

Crystal data

(CH6N3)2[HgI4]

M = 828.37

Triclinic,

a = 8.981 (2) Å

b = 8.996 (2) Å

c = 12.302 (3) Å

α = 105.80 (3)°

β = 95.79 (4)°

γ = 118.46 (2)°

V = 808.9 (5) Å3

Z = 2

Mo Kα radiation

μ = 17.13 mm−1

T = 298 K

0.42 × 0.38 × 0.32 mm

Data collection

Stoe IPDS-I diffractometer

Absorption correction: numerical (X-SHAPE; Stoe & Cie, 1999 ▶) T min = 0.017, T max = 0.057

14500 measured reflections

3613 independent reflections

1846 reflections with I > 2σ(I)

R int = 0.118

Refinement

R[F 2 > 2σ(F 2)] = 0.059

wR(F 2) = 0.135

S = 0.81

3613 reflections

156 parameters

32 restraints

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 3.08 e Å−3

Δρmin = −2.71 e Å−3

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 ▶) and PLATON (Spek, 2009 ▶); software used to prepare material for publication: SHELXL93.

Crystal structure: contains datablocks I, global. DOI: 10.1107/S160053680901280X/bx2201sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S160053680901280X/bx2201Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

(CH6N3)2[HgI4]	Z = 2
Mr = 828.37	F(000) = 716
Triclinic, P1	Dx = 3.401 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 8.981 (2) Å	Cell parameters from 2000 reflections
b = 8.996 (2) Å	θ = 2.7–28.0°
c = 12.302 (3) Å	µ = 17.13 mm−1
α = 105.80 (3)°	T = 298 K
β = 95.79 (4)°	Cylindric, yellow
γ = 118.46 (2)°	0.42 × 0.38 × 0.32 mm
V = 808.9 (5) Å3

Stoe IPDS-I diffractometer	3613 independent reflections
Radiation source: fine-focus sealed tube	1846 reflections with I > 2σ(I)
graphite	Rint = 0.118
imaging plate dynamic profile intergration scans	θmax = 28.0°, θmin = 2.7°
Absorption correction: numerical (X-SHAPE; Stoe & Cie, 1999)	h = −11→11
Tmin = 0.017, Tmax = 0.057	k = −11→11
14500 measured reflections	l = −16→16

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)] = 0.059	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.135	w = 1/[σ2(Fo2) + (0.0353P)2] where P = (Fo2 + 2Fc2)/3
S = 0.81	(Δ/σ)max < 0.001
3613 reflections	Δρmax = 3.08 e Å−3
156 parameters	Δρmin = −2.71 e Å−3
32 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: 0.00075 (10)

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.

	x	y	z	Uiso*/Ueq
Hg1	0.34641 (9)	0.61562 (10)	0.73508 (6)	0.0667 (3)
I1	0.0809 (2)	0.5696 (2)	0.84518 (10)	0.0650 (3)
I2	0.53156 (14)	0.4740 (2)	0.82071 (9)	0.0607 (3)
I3	0.58185 (14)	0.9944 (2)	0.80058 (10)	0.0627 (3)
I4	0.22651 (14)	0.4550 (2)	0.49342 (9)	0.0673 (3)
C1	0.0864 (17)	0.0540 (15)	0.8824 (8)	0.051 (3)
N11	0.2387 (17)	0.0661 (18)	0.9149 (13)	0.072 (4)
H11A	0.246 (12)	−0.030 (7)	0.902 (4)	0.12 (3)*
H11B	0.333 (7)	0.174 (5)	0.9499 (19)	0.12 (3)*
N12	0.0824 (14)	0.2000 (14)	0.9034 (11)	0.066 (4)
H12A	0.179 (2)	0.3056 (13)	0.9387 (16)	0.12 (3)*
H12B	−0.0169 (19)	0.193 (2)	0.8825 (17)	0.12 (3)*
N13	−0.0542 (16)	−0.1065 (19)	0.8300 (14)	0.080 (4)
H13A	−0.152 (4)	−0.111 (8)	0.810 (3)	0.12 (3)*
H13B	−0.054 (9)	−0.207 (5)	0.815 (3)	0.12 (3)*
C2	0.2590 (18)	−0.012 (2)	0.5152 (16)	0.067 (4)
N21	0.4067 (18)	0.136 (2)	0.5198 (14)	0.086 (5)
H21A	0.453 (8)	0.138 (11)	0.461 (4)	0.12 (3)*
H21B	0.457 (8)	0.232 (6)	0.584 (3)	0.12 (3)*
N22	0.1800 (17)	−0.158 (2)	0.4211 (13)	0.092 (5)
H22A	0.085 (3)	−0.246 (11)	0.427 (11)	0.12 (3)*
H22B	0.212 (14)	−0.173 (18)	0.357 (5)	0.12 (3)*
N23	0.193 (2)	−0.009 (3)	0.6078 (14)	0.110 (7)
H23A	0.098 (3)	−0.100 (11)	0.610 (12)	0.12 (3)*
H23B	0.252 (13)	0.093 (8)	0.668 (7)	0.12 (3)*

	U11	U22	U33	U12	U13	U23
Hg1	0.0686 (4)	0.0651 (5)	0.0641 (4)	0.0319 (4)	0.0196 (3)	0.0262 (4)
I1	0.0802 (7)	0.0566 (7)	0.0743 (7)	0.0413 (6)	0.0367 (6)	0.0307 (6)
I2	0.0632 (6)	0.0535 (7)	0.0608 (6)	0.0271 (6)	0.0115 (5)	0.0233 (5)
I3	0.0605 (6)	0.0547 (7)	0.0725 (7)	0.0284 (6)	0.0193 (5)	0.0259 (6)
I4	0.0606 (6)	0.0668 (8)	0.0540 (6)	0.0182 (6)	0.0137 (5)	0.0237 (6)
C1	0.060 (9)	0.039 (10)	0.050 (8)	0.023 (8)	0.014 (7)	0.017 (8)
N11	0.063 (9)	0.069 (11)	0.111 (12)	0.045 (8)	0.032 (9)	0.047 (10)
N12	0.063 (8)	0.039 (9)	0.077 (9)	0.022 (7)	−0.004 (7)	0.009 (8)
N13	0.068 (9)	0.053 (11)	0.113 (13)	0.033 (9)	0.004 (9)	0.027 (10)
C2	0.053 (9)	0.047 (12)	0.076 (12)	0.014 (9)	0.003 (9)	0.016 (10)
N21	0.079 (10)	0.048 (11)	0.088 (11)	0.005 (9)	0.033 (9)	0.013 (9)
N22	0.076 (10)	0.054 (12)	0.060 (9)	−0.012 (9)	0.006 (8)	−0.006 (8)
N23	0.074 (11)	0.096 (15)	0.077 (11)	−0.007 (10)	0.032 (10)	0.010 (11)

Hg1—I4	2.760 (2)	N11—H11A	0.88 (8)
Hg1—I1	2.7762 (15)	N11—H11B	0.87 (5)
Hg1—I2	2.8098 (14)	N12—H12A	0.87 (2)
Hg1—I3	2.833 (2)	N12—H12B	0.87 (2)
I1—H13Bi	2.87 (7)	N13—H13A	0.87 (5)
I1—H11Ai	3.00 (4)	N13—H13B	0.88 (6)
I2—H21B	2.91 (3)	C2—N22	1.30 (2)
I2—H23B	2.99 (5)	C2—N21	1.34 (2)
I3—H13Aii	2.97 (5)	C2—N23	1.34 (2)
I3—H22Biii	3.05 (7)	N21—H21B	0.87 (4)
I3—H21Aiii	3.03 (4)	N21—H21A	0.87 (7)
I3—H12Bii	3.057 (19)	N22—H22B	0.87 (9)
C1—N13	1.29 (2)	N22—H22A	0.87 (9)
C1—N12	1.29 (2)	N23—H23A	0.87 (9)
C1—N11	1.32 (2)	N23—H23B	0.87 (8)
I4—Hg1—I1	113.75 (5)	H13A—N13—H13B	120 (6)
I4—Hg1—I2	109.54 (5)	H13A—N13—C1	117.4 (42)
I1—Hg1—I2	108.81 (4)	H13B—N13—C1	122.5 (42)
I4—Hg1—I3	109.38 (6)	N22—C2—N21	120.3 (17)
I1—Hg1—I3	107.26 (5)	N22—C2—N23	119.8 (15)
I2—Hg1—I3	107.93 (5)	N21—C2—N23	119.9 (17)
N13—C1—N12	121.1 (14)	H21B—N21—H21A	120 (7)
N13—C1—N11	119.7 (14)	H21B—N21—C2	118.6 (57)
N12—C1—N11	119.2 (14)	H21A—N21—C2	121.3 (58)
H11A—N11—H11B	120 (7)	H22B—N22—H22A	120 (11)
H11A—N11—C1	120 (11)	H22B—N22—C2	126.5 (91)
H11B—N11—C1	118.4 (62)	H22A—N22—C2	113.5 (90)
H12A—N12—H12B	120 (2)	H23A—N23—H23B	120 (11)
H12A—N12—C1	119.9 (19)	H23A—N23—C2	125.3 (100)
H12B—N12—C1	120.0 (18)	H23B—N23—C2	114.6 (100)
N13—C1—N11—H11A	0.0 (6)	N22—C2—N21—H21B	180.0 (5)
N12—C1—N11—H11A	−180.0 (5)	N23—C2—N21—H21B	−0.1 (6)
N13—C1—N11—H11B	180.0 (6)	N22—C2—N21—H21A	0.0 (5)
N12—C1—N11—H11B	0.0 (5)	N23—C2—N21—H21A	179.9 (6)
N13—C1—N12—H12A	−180.0 (6)	N21—C2—N22—H22B	0.1 (6)
N11—C1—N12—H12A	0.0 (4)	N23—C2—N22—H22B	−179.9 (6)
N13—C1—N12—H12B	0.1 (9)	N21—C2—N22—H22A	180.0 (5)
N11—C1—N12—H12B	−180.0 (8)	N23—C2—N22—H22A	0.1 (6)
N12—C1—N13—H13A	−0.1 (10)	N22—C2—N23—H23A	−0.2 (11)
N11—C1—N13—H13A	179.9 (7)	N21—C2—N23—H23A	179.9 (8)
N12—C1—N13—H13B	−179.9 (7)	N22—C2—N23—H23B	−179.9 (7)
N11—C1—N13—H13B	0.1 (10)	N21—C2—N23—H23B	0.1 (9)

D—H···A	D—H	H···A	D···A	D—H···A
N11—H11A···I1iv	0.87 (4)	3.00 (4)	3.78 (2)	151 (2)
N12—H12A···I2	0.87 (4)	3.46 (2)	3.83 (2)	123 (2)
N13—H13A···I3v	0.87 (4)	2.96 (4)	3.80 (2)	161 (2)
N13—H13B···I1iv	0.87 (4)	2.88 (4)	3.69 (2)	156 (2)
N21—H21A···I3iii	0.87 (4)	3.03 (4)	3.82 (2)	151 (2)
N21—H21B···I2	0.87 (4)	2.91 (4)	3.74 (2)	162 (6)
N22—H22A···I4vi	0.87 (9)	2.98 (4)	3.82 (2)	162 (2)
N22—H22B···I3iii	0.87 (10)	3.05 (4)	3.81 (2)	147 (2)
N23—H23A···I4vi	0.87 (9)	2.91 (4)	3.71 (2)	153 (2)
N23—H23B···I2	0.87 (4)	2.99 (4)	3.82 (2)	161 (6)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N11—H11A⋯I1i	0.87 (4)	3.00 (4)	3.78 (2)	151 (2)
N12—H12A⋯I2	0.87 (4)	3.46 (2)	3.83 (2)	123 (2)
N13—H13A⋯I3ii	0.87 (4)	2.96 (4)	3.80 (2)	161 (2)
N13—H13B⋯I1i	0.87 (4)	2.88 (4)	3.69 (2)	156 (2)
N21—H21A⋯I3iii	0.87 (4)	3.03 (4)	3.82 (2)	151 (2)
N21—H21B⋯I2	0.87 (4)	2.91 (4)	3.74 (2)	162 (6)
N22—H22A⋯I4iv	0.87 (9)	2.98 (4)	3.82 (2)	162 (2)
N22—H22B⋯I3iii	0.87 (10)	3.05 (4)	3.81 (2)	147 (2)
N23—H23A⋯I4iv	0.87 (9)	2.91 (4)	3.71 (2)	153 (2)
N23—H23B⋯I2	0.87 (4)	2.99 (4)	3.82 (2)	161 (6)

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