8,10-Diiodo-2,6-dioxo-4λ-ioda-3,5-dioxatricyclo-[5.3.1.0]undeca-1(11),7,9-triene-9-carb-oxy-lic acid.

In the title compound, C(9)HI(3)O(6)·2H(2)O, the mol-ecule is located on a twofold axis that gives rise to disorder of the carboxyl group. This disorder is correlated with the disorder of one of the H atoms of the water mol-ecule. The carboxyl group is twisted relative to the attached benzene ring by 75.1 (4)°. The intra-molecular I⋯O distance is 2.112 (6) Å. Mol-ecules are linked via O-H⋯O hydrogen bonding, C-I⋯O halogen bonding, with I⋯O distances in the range 3.156 (5)-3.274 (6) Å, and dipolar C=O⋯C=O inter-actions between the carboxyl and carboxyl-ate groups, with an O⋯C distance of 2.944 (10) Å.

Related literature

For general background to 1,3,5-triiodo­benzene derivatives, see: Morin et al. (1987 ▶); Yu & Watson (1999 ▶). For information on the related compound 1,3,5-triiodo-2,4,6-trimethyl­benzene, see: Bosch & Barnes (2002 ▶); Boudjada et al. (2001 ▶); Reddy et al. (2006 ▶). For the crystal structures of 5-amino-2,4,6-triiodo­isophthalic acid monohydrate and 5-amino-2,4,6-triiodo­isophthalic acid–4,4′-bipyridine N,N′-dioxide–water (1/1/1), see: Beck & Sheldrick (2008 ▶); Zhang et al. (2011 ▶).

Experimental

Crystal data

C9HI3O6·2H2O

M = 621.83

Monoclinic,

a = 14.7667 (8) Å

b = 11.9890 (6) Å

c = 9.7419 (5) Å

β = 127.4236 (5)°

V = 1369.68 (12) Å3

Z = 4

Mo Kα radiation

μ = 6.88 mm−1

T = 130 K

0.32 × 0.14 × 0.12 mm

Data collection

Bruker APEXII CCD area-detector diffractometer

Absorption correction: multi-scan (APEX2; Bruker, 2007 ▶) T min = 0.217, T max = 0.492

4078 measured reflections

1547 independent reflections

1515 reflections with I > 2σ(I)

R int = 0.016

Refinement

R[F 2 > 2σ(F 2)] = 0.042

wR(F 2) = 0.097

S = 1.23

1547 reflections

93 parameters

H-atom parameters constrained

Δρmax = 2.36 e Å−3

Δρmin = −2.23 e Å−3

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg, 1999 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812005351/gk2447sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812005351/gk2447Isup2.hkl

Supplementary material file. DOI: 10.1107/S1600536812005351/gk2447Isup3.cml

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

C9HI3O6·2H2O	F(000) = 1128
Mr = 621.83	Dx = 3.016 Mg m−3
Monoclinic, C2/c	Melting point: 573 K
Hall symbol: -C 2yc	Mo Kα radiation, λ = 0.71069 Å
a = 14.7667 (8) Å	Cell parameters from 3350 reflections
b = 11.9890 (6) Å	θ = 2.4–27.4°
c = 9.7419 (5) Å	µ = 6.88 mm−1
β = 127.4236 (5)°	T = 130 K
V = 1369.68 (12) Å3	Prism, colourless
Z = 4	0.32 × 0.14 × 0.12 mm

Bruker APEXII CCD area-detector diffractometer	1547 independent reflections
Radiation source: fine-focus sealed tube	1515 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.016
φ and ω scans	θmax = 27.4°, θmin = 2.4°
Absorption correction: multi-scan (APEX2; Bruker, 2007)	h = −10→19
Tmin = 0.217, Tmax = 0.492	k = −14→15
4078 measured reflections	l = −12→12

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.042	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.097	H-atom parameters constrained
S = 1.23	w = 1/[σ2(Fo2) + (0.0157P)2 + 40.7765P] where P = (Fo2 + 2Fc2)/3
1547 reflections	(Δ/σ)max < 0.001
93 parameters	Δρmax = 2.36 e Å−3
0 restraints	Δρmin = −2.23 e Å−3

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.

	x	y	z	Uiso*/Ueq	Occ. (<1)
C1	0.5000	0.3381 (8)	0.7500	0.0216 (19)
C2	0.4147 (5)	0.3903 (6)	0.5979 (8)	0.0207 (13)
C3	0.4155 (6)	0.5066 (6)	0.5979 (9)	0.0249 (14)
C4	0.3340 (6)	0.3120 (6)	0.4528 (9)	0.0248 (14)
C5	0.5000	0.5629 (8)	0.7500	0.0222 (19)
C6	0.5000	0.6916 (8)	0.7500	0.027 (2)
I1	0.5000	0.16946 (5)	0.7500	0.02526 (18)
I2	0.29502 (5)	0.59994 (5)	0.37929 (8)	0.0469 (2)
O1	0.2532 (5)	0.3419 (5)	0.3093 (7)	0.0386 (14)
O2	0.3559 (5)	0.2049 (5)	0.4946 (7)	0.0313 (12)
O3	0.5338 (6)	0.7375 (5)	0.6751 (9)	0.0474 (16)
H3	0.5308	0.8054	0.6818	0.071*	0.50
O1W	0.4370 (6)	0.9449 (6)	0.5383 (9)	0.0494 (16)
H1W	0.4763	0.8910	0.5958	0.074*	0.50
H2W	0.4756	0.9896	0.5303	0.074*	0.50
H3W	0.3831	0.9240	0.4416	0.074*

	U11	U22	U33	U12	U13	U23
C1	0.021 (4)	0.019 (4)	0.021 (5)	0.000	0.011 (4)	0.000
C2	0.017 (3)	0.024 (3)	0.012 (3)	0.000 (2)	0.004 (2)	−0.001 (2)
C3	0.021 (3)	0.030 (4)	0.017 (3)	0.005 (3)	0.008 (3)	0.004 (3)
C4	0.021 (3)	0.031 (4)	0.015 (3)	−0.002 (3)	0.007 (3)	−0.003 (3)
C5	0.026 (5)	0.018 (4)	0.029 (5)	0.000	0.020 (4)	0.000
C6	0.039 (6)	0.012 (4)	0.035 (6)	0.000	0.025 (5)	0.000
I1	0.0282 (3)	0.0169 (3)	0.0269 (3)	0.000	0.0148 (3)	0.000
I2	0.0427 (4)	0.0392 (3)	0.0341 (3)	0.0125 (2)	0.0104 (3)	0.0160 (2)
O1	0.031 (3)	0.042 (3)	0.019 (3)	0.000 (3)	0.003 (2)	−0.004 (2)
O2	0.030 (3)	0.029 (3)	0.024 (3)	−0.008 (2)	0.011 (2)	−0.008 (2)
O3	0.074 (5)	0.028 (3)	0.069 (5)	0.000 (3)	0.058 (4)	0.005 (3)
O1W	0.050 (4)	0.044 (4)	0.048 (4)	−0.008 (3)	0.026 (3)	−0.002 (3)

C1—C2i	1.380 (8)	C5—C3i	1.400 (8)
C1—I1	2.022 (9)	C5—C6	1.543 (13)
C2—C3	1.394 (10)	C6—O3	1.237 (7)
C2—C4	1.501 (9)	I1—O2	2.113 (5)
C3—C5	1.400 (8)	O3—H3	0.8200
C3—I2	2.085 (7)	O1W—H1W	0.8201
C4—O1	1.216 (9)	O1W—H2W	0.8200
C4—O2	1.326 (9)	O1W—H3W	0.8201
C4···O3ii	2.944 (10)	I2···O2iv	3.156 (5)
I1···O1Wiii	3.173 (7)	I2···O1iv	3.274 (6)
C2i—C1—C2	126.1 (9)	C3—C5—C3i	122.3 (9)
C2i—C1—I1	117.0 (5)	C3—C5—C6	118.8 (5)
C2—C1—I1	117.0 (5)	O3i—C6—O3	127.1 (10)
C1—C2—C3	116.8 (6)	O3—C6—C5	116.5 (5)
C1—C2—C4	114.3 (6)	C1—I1—O2	78.38 (15)
C3—C2—C4	128.9 (6)	O2i—I1—O2	156.8 (3)
C2—C3—C5	119.0 (7)	C4—O2—I1	116.1 (4)
C2—C3—I2	122.3 (5)	C6—O3—H3	109.5
C5—C3—I2	118.7 (6)	H1W—O1W—H2W	109.6
O1—C4—O2	121.6 (7)	H1W—O1W—H3W	109.5
O1—C4—C2	124.1 (7)	H2W—O1W—H3W	109.6
O2—C4—C2	114.2 (6)
C2i—C1—C2—C3	0.5 (5)	I2—C3—C5—C3i	−179.6 (5)
I1—C1—C2—C3	−179.5 (5)	C2—C3—C5—C6	−179.5 (5)
C2i—C1—C2—C4	179.7 (6)	I2—C3—C5—C6	0.4 (5)
I1—C1—C2—C4	−0.3 (6)	C3—C5—C6—O3i	105.1 (5)
C1—C2—C3—C5	−0.9 (9)	C3—C5—C6—O3	−74.9 (5)
C4—C2—C3—C5	180.0 (6)	C3i—C5—C6—O3	105.1 (5)
C1—C2—C3—I2	179.1 (4)	C2i—C1—I1—O2	179.6 (4)
C4—C2—C3—I2	0.1 (11)	C2—C1—I1—O2	−0.4 (4)
C1—C2—C4—O1	179.7 (7)	O1—C4—O2—I1	180.0 (6)
C3—C2—C4—O1	−1.3 (13)	C2—C4—O2—I1	−1.5 (8)
C1—C2—C4—O2	1.2 (9)	C1—I1—O2—C4	1.1 (5)
C3—C2—C4—O2	−179.7 (7)	O2i—I1—O2—C4	1.1 (5)
C2—C3—C5—C3i	0.5 (5)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3···O1W	0.82	2.08	2.772 (9)	142
O1W—H1W···O3	0.82	1.98	2.772 (9)	163
O1W—H2W···O1Wv	0.82	1.94	2.730 (14)	160
O1W—H3W···O1iv	0.82	2.24	3.053 (9)	172

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3⋯O1W	0.82	2.08	2.772 (9)	142
O1W—H1W⋯O3	0.82	1.98	2.772 (9)	163
O1W—H2W⋯O1Wi	0.82	1.94	2.730 (14)	160
O1W—H3W⋯O1ii	0.82	2.24	3.053 (9)	172

Symmetry codes: (i) ; (ii) .