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ISSN: 2056-9890

5-Amino-2,4,6-tri­iodo­isophthalic acid monohydrate

aDepartment of Structural Chemistry, Georg-August Universität, Tammannstrasse 4, 37077 Göttingen, Germany
*Correspondence e-mail: tbeck@shelx.uni-ac.gwdg.de

(Received 22 May 2008; accepted 11 June 2008; online 19 June 2008)

The title compound, C8H4I3NO4·H2O, shows an extensive hydrogen-bond network; in the crystal structure, mol­ecules are linked by O—H⋯O, N—H⋯O and O—H⋯N hydrogen bonds involving all possible donors and also the water mol­ecule.

Related literature

For the synthetic procedure, see Larsen et al. (1956[Larsen, A. A., Moore, C., Sprague, J., Cloke, B., Moss, J. & Hoppe, J. O. (1956). J. Am. Chem. Soc. 78, 3210-3216.]). For related crystal structure determinations: 1,3,5-triiodo­benzene, see: Margraf & Bats (2006[Margraf, D. & Bats, J. W. (2006). Acta Cryst. E62, o502-o504.]); sodium diatrizoate, see: Tonnessen et al. (1996[Tonnessen, L. E., Pedersen, B. F. & Klaveness, J. (1996). Acta Chem. Scand. 50, 603-608.]). For the 1,3,5-triiodo­benzene core as the basis of contrast agents, see: Yu & Watson (1999[Yu, S. B. & Watson, A. D. (1999). Chem. Rev. 99, 2353-2378.]).

[Scheme 1]

Experimental

Crystal data
  • C8H4I3NO4·H2O

  • Mr = 576.84

  • Orthorhombic, P b c a

  • a = 9.214 (1) Å

  • b = 15.735 (2) Å

  • c = 18.816 (2) Å

  • V = 2728.0 (5) Å3

  • Z = 8

  • Cu Kα radiation

  • μ = 54.11 mm−1

  • T = 100 (2) K

  • 0.08 × 0.05 × 0.03 mm

Data collection
  • Bruker SMART 6000 diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.]) Tmin = 0.106, Tmax = 0.345 (expected range = 0.061–0.197)

  • 49139 measured reflections

  • 2716 independent reflections

  • 2545 reflections with I > 2σ(I)

  • Rint = 0.043

Refinement
  • R[F2 > 2σ(F2)] = 0.026

  • wR(F2) = 0.061

  • S = 1.03

  • 2716 reflections

  • 173 parameters

  • 14 restraints

  • Only H-atom coordinates refined

  • Δρmax = 0.71 e Å−3

  • Δρmin = −1.71 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
O11—H11⋯O14 0.79 (5) 1.75 (5) 2.540 (5) 173 (7)
O8—H8⋯O12i 0.80 (5) 1.90 (5) 2.662 (5) 161 (7)
O14—H14A⋯O9ii 0.81 (4) 1.95 (4) 2.751 (5) 170 (6)
O14—H14B⋯N13iii 0.81 (4) 2.05 (4) 2.841 (5) 166 (6)
N13—H13A⋯O14iv 0.88 (4) 2.30 (5) 3.067 (6) 147 (5)
N13—H13B⋯O12iv 0.88 (4) 2.68 (5) 3.478 (5) 152 (5)
Symmetry codes: (i) [x+{\script{1\over 2}}, -y+{\script{3\over 2}}, -z]; (ii) [-x+{\script{5\over 2}}, y-{\script{1\over 2}}, z]; (iii) [-x+2, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]; (iv) [-x+{\script{3\over 2}}, y+{\script{1\over 2}}, z].

Data collection: APEX2 (Bruker, 2007[Bruker (2007). APEX and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2007[Bruker (2007). APEX and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXL97 and SHELXTL.

Supporting information


Comment top

Iodine-based compounds have always been in the focus of contrast agents for X-ray imaging. The 1,3,5-triiodobenzene core has been the basis of many contrast agents (Yu & Watson 1999). The ionic monomer diatrizoate was one of the first compounds used (Tonnessen et al. 1996).

The title compound, 5-Amino-2,4,6-triiodoisophthalic acid (hereafter I3C), crystallizes as a monohydrate, due to water impurities in the crystallization solution. It forms hydrogen bonds with all potential donors as well as the lattice water being involved (Fig. 2, Table 1). However, the interaction between N13 and O12 is slightly weaker. In the crystal, the molecules are positioned perpendicular to each other, showing no π-π interactions of the phenyl rings (Fig. 3).

The three functional groups for hydrogen bonding, along with the three iodine atoms, render I3C a suitable agent for experimental phasing of macromolecules (Beck et al., unpublished results). The iodine atoms give rise to a large anomalous signal, even at in-house sources. Additionally, they form an equilateral triangle (I—I 6.0 Å) which is easy to recognize in the heavy atom substructure when this compound is used as a heavy atom derivative for macromolecular phasing.

Related literature top

For the synthetic procedure, see Larsen et al. (1956). For related crystal structure determinations: 1,3,5-triiodobenzene, see: Margraf & Bats (2006); sodium diatrizoate, see: Tonnessen et al. (1996). For the 1,3,5-triiodobenzene core as the basis of contrast agents, see: Yu & Watson (1999).

Experimental top

The title compound was prepared according to the reported procedure (Larsen et al. 1956). It was recrystallized from a methanol-acetonitrile solution by slowly evaporating the solvents to obtain crystals suitable for X-ray single-crystal diffraction.

Refinement top

Hydrogen atoms were located via the difference Fourier map and their geometrical positions were refined with restraints. The U values were set to 1.5 Ueq of their parent atom. Bond lengths for hydrogen atoms were restrained to be equal (SADI in SHELXL-97). Phenyl ring and carboxylate groups were restrained to planarity.

Computing details top

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008) and SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. A view of I3C. Displacement ellipsoids are drawn at the 50% probability level. The hydrogen bond within the asymmetric unit is shown as a dashed line.
[Figure 2] Fig. 2. Hydrogen bonding of I3C. Symmetry equivalents are depicted in orange.
[Figure 3] Fig. 3. Packing of I3C, viewed along b. Hydrogen atoms are omitted for clarity. In alternating layers molecules are positioned perpendicular to each other. Hydrogen bonds are shown as dashed lines.
[Figure 4] Fig. 4. Synthetic scheme of I3C.
5-Amino-2,4,6-triiodoisophthalic acid monohydrate top
Crystal data top
C8H4I3NO4·H2OF(000) = 2080
Mr = 576.84Dx = 2.809 Mg m3
Orthorhombic, PbcaCu Kα radiation, λ = 1.54178 Å
Hall symbol: -P 2ac 2abCell parameters from 9945 reflections
a = 9.214 (1) Åθ = 4.7–60.8°
b = 15.735 (2) ŵ = 54.11 mm1
c = 18.816 (2) ÅT = 100 K
V = 2728.0 (5) Å3Block, yellow
Z = 80.08 × 0.05 × 0.03 mm
Data collection top
Bruker SMART 6000
diffractometer
2716 independent reflections
Radiation source: rotating anode2545 reflections with I > 2σ(I)
INCOATEC multilayer optics monochromatorRint = 0.043
Detector resolution: 5.602 pixels mm-1θmax = 74.3°, θmin = 4.7°
ω scansh = 1010
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
k = 1719
Tmin = 0.106, Tmax = 0.345l = 2323
49139 measured reflections
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.026Only H-atom coordinates refined
wR(F2) = 0.061 w = 1/[σ2(Fo2) + (0.0277P)2 + 17.3624P]
where P = (Fo2 + 2Fc2)/3
S = 1.03(Δ/σ)max = 0.002
2716 reflectionsΔρmax = 0.72 e Å3
173 parametersΔρmin = 1.71 e Å3
14 restraintsExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.000058 (8)
Crystal data top
C8H4I3NO4·H2OV = 2728.0 (5) Å3
Mr = 576.84Z = 8
Orthorhombic, PbcaCu Kα radiation
a = 9.214 (1) ŵ = 54.11 mm1
b = 15.735 (2) ÅT = 100 K
c = 18.816 (2) Å0.08 × 0.05 × 0.03 mm
Data collection top
Bruker SMART 6000
diffractometer
2716 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
2545 reflections with I > 2σ(I)
Tmin = 0.106, Tmax = 0.345Rint = 0.043
49139 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.02614 restraints
wR(F2) = 0.061Only H-atom coordinates refined
S = 1.03 w = 1/[σ2(Fo2) + (0.0277P)2 + 17.3624P]
where P = (Fo2 + 2Fc2)/3
2716 reflectionsΔρmax = 0.72 e Å3
173 parametersΔρmin = 1.71 e Å3
Special details top

Experimental. Intensities were measured with a Bruker SMART 6000 area-detector

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 > 2 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. Hydrogen atoms were located via the difference Fourier map and their geometrical positions were refined with restraints. The U values were set to 1.5 Ueq of their parent atom.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
I11.18424 (3)0.630616 (18)0.012748 (16)0.02419 (10)
I20.71499 (3)0.674286 (18)0.234093 (15)0.02375 (10)
I31.04238 (3)0.979824 (17)0.124476 (17)0.02693 (10)
C11.0827 (5)0.7970 (3)0.0781 (2)0.0161 (8)
C21.0606 (5)0.7094 (3)0.0789 (2)0.0161 (9)
C30.9544 (5)0.6745 (3)0.1231 (2)0.0153 (9)
C40.8655 (5)0.7276 (3)0.1631 (2)0.0163 (9)
C50.8803 (5)0.8172 (3)0.1604 (2)0.0165 (9)
C60.9945 (5)0.8492 (3)0.1199 (2)0.0180 (9)
C71.1981 (5)0.8362 (3)0.0320 (3)0.0202 (10)
O81.1458 (4)0.8648 (2)0.02803 (18)0.0256 (7)
H81.205 (6)0.883 (4)0.055 (3)0.038*
O91.3242 (4)0.8414 (2)0.05017 (19)0.0290 (8)
C100.9364 (5)0.5794 (3)0.1285 (2)0.0173 (9)
O111.0376 (4)0.5445 (2)0.16663 (17)0.0224 (7)
H111.031 (7)0.494 (3)0.170 (3)0.034*
O120.8358 (4)0.54161 (19)0.10032 (17)0.0213 (7)
N130.7889 (5)0.8702 (2)0.1997 (2)0.0210 (8)
H13A0.698 (5)0.855 (4)0.204 (3)0.031*
H13B0.785 (6)0.922 (3)0.183 (3)0.031*
O141.0395 (4)0.3834 (2)0.17540 (18)0.0235 (7)
H14A1.074 (7)0.366 (4)0.139 (3)0.035*
H14B1.099 (6)0.376 (4)0.206 (3)0.035*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
I10.02850 (18)0.02100 (16)0.02307 (16)0.00785 (12)0.00724 (12)0.00027 (11)
I20.02603 (18)0.02156 (16)0.02364 (16)0.00544 (11)0.00910 (12)0.00016 (11)
I30.02852 (19)0.01260 (15)0.03966 (19)0.00146 (11)0.00662 (13)0.00096 (11)
C10.018 (2)0.0143 (19)0.0162 (19)0.0012 (17)0.0007 (17)0.0000 (16)
C20.019 (2)0.014 (2)0.0150 (19)0.0033 (17)0.0002 (17)0.0002 (16)
C30.020 (2)0.013 (2)0.0135 (19)0.0006 (17)0.0052 (17)0.0019 (15)
C40.018 (2)0.016 (2)0.0150 (19)0.0072 (16)0.0005 (17)0.0017 (16)
C50.018 (2)0.015 (2)0.016 (2)0.0003 (17)0.0023 (17)0.0006 (16)
C60.023 (2)0.013 (2)0.017 (2)0.0022 (18)0.0013 (18)0.0009 (16)
C70.023 (3)0.014 (2)0.023 (2)0.0007 (17)0.0010 (19)0.0016 (17)
O80.0251 (19)0.0276 (18)0.0241 (17)0.0019 (14)0.0036 (15)0.0093 (14)
O90.0216 (19)0.038 (2)0.0276 (18)0.0045 (15)0.0035 (15)0.0013 (15)
C100.023 (2)0.014 (2)0.015 (2)0.0007 (18)0.0048 (18)0.0001 (16)
O110.0274 (18)0.0132 (15)0.0265 (17)0.0007 (13)0.0074 (14)0.0043 (13)
O120.0279 (18)0.0121 (14)0.0239 (16)0.0039 (13)0.0064 (14)0.0014 (12)
N130.021 (2)0.0148 (18)0.027 (2)0.0019 (15)0.0035 (17)0.0026 (15)
O140.0255 (19)0.0217 (16)0.0233 (17)0.0028 (14)0.0003 (14)0.0027 (14)
Geometric parameters (Å, º) top
I1—C22.094 (4)C5—N131.396 (6)
I2—C42.100 (4)C7—O91.214 (6)
I3—C62.103 (4)C7—O81.308 (6)
C1—C21.394 (6)O8—H80.80 (5)
C1—C61.398 (6)C10—O121.223 (6)
C1—C71.504 (6)C10—O111.299 (6)
C2—C31.396 (6)O11—H110.79 (5)
C3—C41.391 (6)N13—H13A0.88 (4)
C3—C101.509 (6)N13—H13B0.88 (4)
C4—C51.418 (6)O14—H14A0.81 (4)
C5—C61.393 (6)O14—H14B0.81 (4)
C2—C1—C6119.4 (4)C5—C6—C1122.3 (4)
C2—C1—C7121.0 (4)C5—C6—I3119.3 (3)
C6—C1—C7119.6 (4)C1—C6—I3118.4 (3)
C1—C2—C3119.8 (4)O9—C7—O8125.0 (4)
C1—C2—I1120.0 (3)O9—C7—C1122.7 (4)
C3—C2—I1120.2 (3)O8—C7—C1112.3 (4)
C4—C3—C2120.0 (4)C7—O8—H8115 (5)
C4—C3—C10119.6 (4)O12—C10—O11125.3 (4)
C2—C3—C10120.4 (4)O12—C10—C3122.5 (4)
C3—C4—C5121.3 (4)O11—C10—C3112.3 (4)
C3—C4—I2119.6 (3)C10—O11—H11114 (5)
C5—C4—I2119.0 (3)C5—N13—H13A117 (4)
C6—C5—N13122.0 (4)C5—N13—H13B113 (4)
C6—C5—C4116.9 (4)H13A—N13—H13B105 (6)
N13—C5—C4121.0 (4)H14A—O14—H14B108 (6)
C6—C1—C2—C32.2 (6)N13—C5—C6—C1177.4 (4)
C7—C1—C2—C3179.0 (4)C4—C5—C6—C16.0 (6)
C6—C1—C2—I1176.7 (3)N13—C5—C6—I35.2 (5)
C7—C1—C2—I12.0 (5)C4—C5—C6—I3171.4 (3)
C1—C2—C3—C43.5 (6)C2—C1—C6—C52.8 (6)
I1—C2—C3—C4175.4 (3)C7—C1—C6—C5176.0 (4)
C1—C2—C3—C10175.6 (4)C2—C1—C6—I3174.7 (3)
I1—C2—C3—C105.5 (5)C7—C1—C6—I36.5 (5)
C2—C3—C4—C50.1 (6)C2—C1—C7—O984.0 (6)
C10—C3—C4—C5179.1 (4)C6—C1—C7—O997.2 (5)
C2—C3—C4—I2176.2 (3)C2—C1—C7—O897.3 (5)
C10—C3—C4—I23.0 (5)C6—C1—C7—O881.5 (5)
C3—C4—C5—C64.6 (6)C4—C3—C10—O1275.4 (5)
I2—C4—C5—C6171.5 (3)C2—C3—C10—O12105.5 (5)
C3—C4—C5—N13178.8 (4)C4—C3—C10—O11103.6 (4)
I2—C4—C5—N135.1 (5)C2—C3—C10—O1175.5 (5)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O11—H11···O140.79 (5)1.75 (5)2.540 (5)173 (7)
O8—H8···O12i0.80 (5)1.90 (5)2.662 (5)161 (7)
O14—H14A···O9ii0.81 (4)1.95 (4)2.751 (5)170 (6)
O14—H14B···N13iii0.81 (4)2.05 (4)2.841 (5)166 (6)
N13—H13A···O14iv0.88 (4)2.30 (5)3.067 (6)147 (5)
N13—H13B···O12iv0.88 (4)2.68 (5)3.478 (5)152 (5)
Symmetry codes: (i) x+1/2, y+3/2, z; (ii) x+5/2, y1/2, z; (iii) x+2, y1/2, z+1/2; (iv) x+3/2, y+1/2, z.

Experimental details

Crystal data
Chemical formulaC8H4I3NO4·H2O
Mr576.84
Crystal system, space groupOrthorhombic, Pbca
Temperature (K)100
a, b, c (Å)9.214 (1), 15.735 (2), 18.816 (2)
V3)2728.0 (5)
Z8
Radiation typeCu Kα
µ (mm1)54.11
Crystal size (mm)0.08 × 0.05 × 0.03
Data collection
DiffractometerBruker SMART 6000
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.106, 0.345
No. of measured, independent and
observed [I > 2σ(I)] reflections
49139, 2716, 2545
Rint0.043
(sin θ/λ)max1)0.624
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.026, 0.061, 1.03
No. of reflections2716
No. of parameters173
No. of restraints14
H-atom treatmentOnly H-atom coordinates refined
w = 1/[σ2(Fo2) + (0.0277P)2 + 17.3624P]
where P = (Fo2 + 2Fc2)/3
Δρmax, Δρmin (e Å3)0.72, 1.71

Computer programs: APEX2 (Bruker, 2007), SAINT (Bruker, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008) and SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O11—H11···O140.79 (5)1.75 (5)2.540 (5)173 (7)
O8—H8···O12i0.80 (5)1.90 (5)2.662 (5)161 (7)
O14—H14A···O9ii0.81 (4)1.95 (4)2.751 (5)170 (6)
O14—H14B···N13iii0.81 (4)2.05 (4)2.841 (5)166 (6)
N13—H13A···O14iv0.88 (4)2.30 (5)3.067 (6)147 (5)
N13—H13B···O12iv0.88 (4)2.68 (5)3.478 (5)152 (5)
Symmetry codes: (i) x+1/2, y+3/2, z; (ii) x+5/2, y1/2, z; (iii) x+2, y1/2, z+1/2; (iv) x+3/2, y+1/2, z.
 

Acknowledgements

Financial support of the ICDD (Ludo Frevel Scholarship Award 2008 for TB) and DFG (IRTG 1422) is gratefully acknowledged. The authors thank Regine Herbst-Irmer and Stephan Rühl for advice regarding the refinement.

References

First citationBruker (2007). APEX and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationLarsen, A. A., Moore, C., Sprague, J., Cloke, B., Moss, J. & Hoppe, J. O. (1956). J. Am. Chem. Soc. 78, 3210–3216.  CrossRef CAS Web of Science Google Scholar
First citationMargraf, D. & Bats, J. W. (2006). Acta Cryst. E62, o502–o504.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationSheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationTonnessen, L. E., Pedersen, B. F. & Klaveness, J. (1996). Acta Chem. Scand. 50, 603–608.  CrossRef Web of Science Google Scholar
First citationYu, S. B. & Watson, A. D. (1999). Chem. Rev. 99, 2353–2378.  Web of Science CSD CrossRef PubMed CAS Google Scholar

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