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

Beck, T.; Sheldrick, G.M.

doi:10.1107/S1600536808017741

organic compounds

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Volume 64| Part 7| July 2008| Page o1286

doi:10.1107/S1600536808017741

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

Tobias Beck ^a ^* and George M. Sheldrick ^a

^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 ). 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

Crystal data

C₈H₄I₃NO₄·H₂O
M_r = 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 ) T_min = 0.106, T_max = 0.345 (expected range = 0.061–0.197)
49139 measured reflections
2716 independent reflections
2545 reflections with I > 2σ(I)
R_int = 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
Δρ_max = 0.71 e Å⁻³
Δρ_min = −1.71 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	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⋯O14^iv	0.88 (4)	2.30 (5)	3.067 (6)	147 (5)
N13—H13B⋯O12^iv	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 ); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT; 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 and SHELXTL.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808017741/pk2102sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808017741/pk2102Isup2.hkl

checkCIF report

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.

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

	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.
	Fig. 2. Hydrogen bonding of I3C. Symmetry equivalents are depicted in orange.
	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.
	Fig. 4. Synthetic scheme of I3C.

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

Crystal data top

C₈H₄I₃NO₄·H₂O	F(000) = 2080
M_r = 576.84	D_x = 2.809 Mg m⁻³
Orthorhombic, Pbca	Cu Kα radiation, λ = 1.54178 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 9945 reflections
a = 9.214 (1) Å	θ = 4.7–60.8°
b = 15.735 (2) Å	µ = 54.11 mm⁻¹
c = 18.816 (2) Å	T = 100 K
V = 2728.0 (5) Å³	Block, yellow
Z = 8	0.08 × 0.05 × 0.03 mm

Data collection top

Bruker SMART 6000 diffractometer	2716 independent reflections
Radiation source: rotating anode	2545 reflections with I > 2σ(I)
INCOATEC multilayer optics monochromator	R_int = 0.043
Detector resolution: 5.602 pixels mm^-1	θ_max = 74.3°, θ_min = 4.7°
ω scans	h = −10→10
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	k = −17→19
T_min = 0.106, T_max = 0.345	l = −23→23
49139 measured reflections

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F² > 2σ(F²)] = 0.026	Only H-atom coordinates refined
wR(F²) = 0.061	w = 1/[σ²(F_o²) + (0.0277P)² + 17.3624P] where P = (F_o² + 2F_c²)/3
S = 1.03	(Δ/σ)_max = 0.002
2716 reflections	Δρ_max = 0.72 e Å⁻³
173 parameters	Δρ_min = −1.71 e Å⁻³
14 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.000058 (8)

Crystal data top

C₈H₄I₃NO₄·H₂O	V = 2728.0 (5) Å³
M_r = 576.84	Z = 8
Orthorhombic, Pbca	Cu Kα radiation
a = 9.214 (1) Å	µ = 54.11 mm⁻¹
b = 15.735 (2) Å	T = 100 K
c = 18.816 (2) Å	0.08 × 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)
T_min = 0.106, T_max = 0.345	R_int = 0.043
49139 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.026	14 restraints
wR(F²) = 0.061	Only H-atom coordinates refined
S = 1.03	w = 1/[σ²(F_o²) + (0.0277P)² + 17.3624P] where P = (F_o² + 2F_c²)/3
2716 reflections	Δρ_max = 0.72 e Å⁻³
173 parameters	Δρ_min = −1.71 e Å⁻³

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 U_eq of their parent atom.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
I1	1.18424 (3)	0.630616 (18)	0.012748 (16)	0.02419 (10)
I2	0.71499 (3)	0.674286 (18)	0.234093 (15)	0.02375 (10)
I3	1.04238 (3)	0.979824 (17)	0.124476 (17)	0.02693 (10)
C1	1.0827 (5)	0.7970 (3)	0.0781 (2)	0.0161 (8)
C2	1.0606 (5)	0.7094 (3)	0.0789 (2)	0.0161 (9)
C3	0.9544 (5)	0.6745 (3)	0.1231 (2)	0.0153 (9)
C4	0.8655 (5)	0.7276 (3)	0.1631 (2)	0.0163 (9)
C5	0.8803 (5)	0.8172 (3)	0.1604 (2)	0.0165 (9)
C6	0.9945 (5)	0.8492 (3)	0.1199 (2)	0.0180 (9)
C7	1.1981 (5)	0.8362 (3)	0.0320 (3)	0.0202 (10)
O8	1.1458 (4)	0.8648 (2)	−0.02803 (18)	0.0256 (7)
H8	1.205 (6)	0.883 (4)	−0.055 (3)	0.038*
O9	1.3242 (4)	0.8414 (2)	0.05017 (19)	0.0290 (8)
C10	0.9364 (5)	0.5794 (3)	0.1285 (2)	0.0173 (9)
O11	1.0376 (4)	0.5445 (2)	0.16663 (17)	0.0224 (7)
H11	1.031 (7)	0.494 (3)	0.170 (3)	0.034*
O12	0.8358 (4)	0.54161 (19)	0.10032 (17)	0.0213 (7)
N13	0.7889 (5)	0.8702 (2)	0.1997 (2)	0.0210 (8)
H13A	0.698 (5)	0.855 (4)	0.204 (3)	0.031*
H13B	0.785 (6)	0.922 (3)	0.183 (3)	0.031*
O14	1.0395 (4)	0.3834 (2)	0.17540 (18)	0.0235 (7)
H14A	1.074 (7)	0.366 (4)	0.139 (3)	0.035*
H14B	1.099 (6)	0.376 (4)	0.206 (3)	0.035*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
I1	0.02850 (18)	0.02100 (16)	0.02307 (16)	0.00785 (12)	0.00724 (12)	0.00027 (11)
I2	0.02603 (18)	0.02156 (16)	0.02364 (16)	−0.00544 (11)	0.00910 (12)	−0.00016 (11)
I3	0.02852 (19)	0.01260 (15)	0.03966 (19)	−0.00146 (11)	0.00662 (13)	0.00096 (11)
C1	0.018 (2)	0.0143 (19)	0.0162 (19)	0.0012 (17)	0.0007 (17)	0.0000 (16)
C2	0.019 (2)	0.014 (2)	0.0150 (19)	0.0033 (17)	−0.0002 (17)	−0.0002 (16)
C3	0.020 (2)	0.013 (2)	0.0135 (19)	0.0006 (17)	−0.0052 (17)	0.0019 (15)
C4	0.018 (2)	0.016 (2)	0.0150 (19)	−0.0072 (16)	0.0005 (17)	0.0017 (16)
C5	0.018 (2)	0.015 (2)	0.016 (2)	0.0003 (17)	−0.0023 (17)	−0.0006 (16)
C6	0.023 (2)	0.013 (2)	0.017 (2)	−0.0022 (18)	−0.0013 (18)	0.0009 (16)
C7	0.023 (3)	0.014 (2)	0.023 (2)	−0.0007 (17)	0.0010 (19)	−0.0016 (17)
O8	0.0251 (19)	0.0276 (18)	0.0241 (17)	−0.0019 (14)	0.0036 (15)	0.0093 (14)
O9	0.0216 (19)	0.038 (2)	0.0276 (18)	−0.0045 (15)	0.0035 (15)	0.0013 (15)
C10	0.023 (2)	0.014 (2)	0.015 (2)	−0.0007 (18)	0.0048 (18)	0.0001 (16)
O11	0.0274 (18)	0.0132 (15)	0.0265 (17)	−0.0007 (13)	−0.0074 (14)	0.0043 (13)
O12	0.0279 (18)	0.0121 (14)	0.0239 (16)	−0.0039 (13)	−0.0064 (14)	0.0014 (12)
N13	0.021 (2)	0.0148 (18)	0.027 (2)	0.0019 (15)	0.0035 (17)	−0.0026 (15)
O14	0.0255 (19)	0.0217 (16)	0.0233 (17)	0.0028 (14)	−0.0003 (14)	0.0027 (14)

Geometric parameters (Å, º) top

I1—C2	2.094 (4)	C5—N13	1.396 (6)
I2—C4	2.100 (4)	C7—O9	1.214 (6)
I3—C6	2.103 (4)	C7—O8	1.308 (6)
C1—C2	1.394 (6)	O8—H8	0.80 (5)
C1—C6	1.398 (6)	C10—O12	1.223 (6)
C1—C7	1.504 (6)	C10—O11	1.299 (6)
C2—C3	1.396 (6)	O11—H11	0.79 (5)
C3—C4	1.391 (6)	N13—H13A	0.88 (4)
C3—C10	1.509 (6)	N13—H13B	0.88 (4)
C4—C5	1.418 (6)	O14—H14A	0.81 (4)
C5—C6	1.393 (6)	O14—H14B	0.81 (4)

C2—C1—C6	119.4 (4)	C5—C6—C1	122.3 (4)
C2—C1—C7	121.0 (4)	C5—C6—I3	119.3 (3)
C6—C1—C7	119.6 (4)	C1—C6—I3	118.4 (3)
C1—C2—C3	119.8 (4)	O9—C7—O8	125.0 (4)
C1—C2—I1	120.0 (3)	O9—C7—C1	122.7 (4)
C3—C2—I1	120.2 (3)	O8—C7—C1	112.3 (4)
C4—C3—C2	120.0 (4)	C7—O8—H8	115 (5)
C4—C3—C10	119.6 (4)	O12—C10—O11	125.3 (4)
C2—C3—C10	120.4 (4)	O12—C10—C3	122.5 (4)
C3—C4—C5	121.3 (4)	O11—C10—C3	112.3 (4)
C3—C4—I2	119.6 (3)	C10—O11—H11	114 (5)
C5—C4—I2	119.0 (3)	C5—N13—H13A	117 (4)
C6—C5—N13	122.0 (4)	C5—N13—H13B	113 (4)
C6—C5—C4	116.9 (4)	H13A—N13—H13B	105 (6)
N13—C5—C4	121.0 (4)	H14A—O14—H14B	108 (6)

C6—C1—C2—C3	−2.2 (6)	N13—C5—C6—C1	−177.4 (4)
C7—C1—C2—C3	179.0 (4)	C4—C5—C6—C1	6.0 (6)
C6—C1—C2—I1	176.7 (3)	N13—C5—C6—I3	5.2 (5)
C7—C1—C2—I1	−2.0 (5)	C4—C5—C6—I3	−171.4 (3)
C1—C2—C3—C4	3.5 (6)	C2—C1—C6—C5	−2.8 (6)
I1—C2—C3—C4	−175.4 (3)	C7—C1—C6—C5	176.0 (4)
C1—C2—C3—C10	−175.6 (4)	C2—C1—C6—I3	174.7 (3)
I1—C2—C3—C10	5.5 (5)	C7—C1—C6—I3	−6.5 (5)
C2—C3—C4—C5	−0.1 (6)	C2—C1—C7—O9	−84.0 (6)
C10—C3—C4—C5	179.1 (4)	C6—C1—C7—O9	97.2 (5)
C2—C3—C4—I2	−176.2 (3)	C2—C1—C7—O8	97.3 (5)
C10—C3—C4—I2	3.0 (5)	C6—C1—C7—O8	−81.5 (5)
C3—C4—C5—C6	−4.6 (6)	C4—C3—C10—O12	75.4 (5)
I2—C4—C5—C6	171.5 (3)	C2—C3—C10—O12	−105.5 (5)
C3—C4—C5—N13	178.8 (4)	C4—C3—C10—O11	−103.6 (4)
I2—C4—C5—N13	−5.1 (5)	C2—C3—C10—O11	75.5 (5)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	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···O14^iv	0.88 (4)	2.30 (5)	3.067 (6)	147 (5)
N13—H13B···O12^iv	0.88 (4)	2.68 (5)	3.478 (5)	152 (5)

Symmetry codes: (i) x+1/2, −y+3/2, −z; (ii) −x+5/2, y−1/2, z; (iii) −x+2, y−1/2, −z+1/2; (iv) −x+3/2, y+1/2, z.

Experimental details

Crystal data
Chemical formula	C₈H₄I₃NO₄·H₂O
M_r	576.84
Crystal system, space group	Orthorhombic, Pbca
Temperature (K)	100
a, b, c (Å)	9.214 (1), 15.735 (2), 18.816 (2)
V (Å³)	2728.0 (5)
Z	8
Radiation type	Cu Kα
µ (mm⁻¹)	54.11
Crystal size (mm)	0.08 × 0.05 × 0.03

Data collection
Diffractometer	Bruker SMART 6000 diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 1996)
T_min, T_max	0.106, 0.345
No. of measured, independent and observed [I > 2σ(I)] reflections	49139, 2716, 2545
R_int	0.043
(sin θ/λ)_max (Å⁻¹)	0.624

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.026, 0.061, 1.03
No. of reflections	2716
No. of parameters	173
No. of restraints	14
H-atom treatment	Only H-atom coordinates refined
	w = 1/[σ²(F_o²) + (0.0277P)² + 17.3624P] where P = (F_o² + 2F_c²)/3
Δρ_max, Δρ_min (e Å⁻³)	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···A	D—H	H···A	D···A	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···O14^iv	0.88 (4)	2.30 (5)	3.067 (6)	147 (5)
N13—H13B···O12^iv	0.88 (4)	2.68 (5)	3.478 (5)	152 (5)

Symmetry codes: (i) x+1/2, −y+3/2, −z; (ii) −x+5/2, y−1/2, z; (iii) −x+2, y−1/2, −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

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