organic compounds
3-Iodoanilinium 2-carboxy-6-nitrobenzoate: a three-dimensional framework built from O—H⋯O and N—H⋯O hydrogen bonds and a two-centre iodo–nitro interaction
aSchool of Chemistry, University of St Andrews, Fife KY16 9ST, Scotland, bDepartment of Chemistry, University of Aberdeen, Meston Walk, Old Aberdeen AB24 3UE, Scotland, and cInstituto de Química, Departamento de Química Inorgânica, Universidade Federal do Rio de Janeiro, 21945-970 Rio de Janeiro, RJ, Brazil
*Correspondence e-mail: cg@st-andrews.ac.uk
In the title compound, C6H7IN+·C8H4NO6−, the anions are linked by a single type of O—H⋯O hydrogen bond into C(7) chains, and these chains are linked via three independent N—H⋯O hydrogen bonds into sheets. The sheets, in turn, are linked by a two-centre iodo–nitro interaction into a single three-dimensional framework.
Comment
We report here the molecular and supramolecular structure of the title compound, (I), and compare it with the isomeric 4-iodoanilinium 2-carboxy-6-nitrobenzoate, (II) (Glidewell et al., 2003). Compound (I) is a salt; the H atoms are all fully ordered, and the C—O distances (Table 1) in both the un-ionized carboxyl group and the anionic carboxylate group are fully consistent with the H-atom locations found from difference maps. Of the three adjacent substituents in the anion, the central carboxylate group is nearly orthogonal to the ring, while the two outer substituents show much smaller rotations about the exocyclic bonds away from planarity, as shown by the key torsion angles (Table 1); these observations can be ascribed to steric congestion.
The supramolecular structure of (I) (Fig. 1) contains hydrogen-bonded sheets, which are linked into a continuous three-dimensional framework structure by a two-centre iodo–nitro interaction. The formation of the hydrogen-bonded sheet is most readily analysed in terms of the low-dimensional substructures from which it is generated.
The anions are linked by a single O—H⋯O hydrogen bond (Table 2) to form chains running parallel to the [010] direction. Carboxyl atom O12 in the anion at (x, y, z) acts as a hydrogen-bond donor to carboxylate atom O21 in the anion at (1 − x, + y, − z), so forming a C(7) chain (Bernstein et al., 1995) of anions generated by the 21 screw axis along (, y, ) (Fig. 2). A second anion chain, antiparallel to the first and related to it by inversion, is generated by the 21 screw axis along (, −y, ), and these chains are linked by N—H⋯O hydrogen bonds into (100) sheets.
Anilinium atom N41 acts as a hydrogen-bond donor, via H41A, to carboxylate atom O22 within the (Fig. 3); in addition, atom N41 in the cation at (x, y, z) acts as a donor, via H41B, to carboxylate atom O21 in the anion at (x, − y, − + z). Propagation of these two N—H⋯O hydrogen bonds then produces a C22(6) chain running parallel to the [001] direction and generated by the c-glide plane at y = (Fig. 3). Since the anions at (x, y, z) and (x, − y, − + z) form parts, respectively, of the anion chains along (, y, ) and (, −y, ), these three hydrogen bonds, one O—H⋯O and two N—H⋯O, suffice to form a (100) sheet. In the third N—H⋯O hydrogen bond, atom N41 in the cation at (x, y, z) acts as a donor, via H41C, to carboxylate atom O22 in the anion at (1 − x, 1 − y, 1 − z), so generating a centrosymmetric R42(8) ring (Fig. 4), which serves further to reinforce the sheet. It is notable that the O atoms of the nitro group play no part in the hydrogen bonding.
Just a single (100) sheet passes through each 3+, –COO− and –COOH units, and with two outer layers containing the iodophenyl and nitrophenyl units. The location of both the iodo and the nitro substituents on the outer faces of this tripartite layer allows the formation of iodo–nitro interactions, which link adjacent sheets.
and it is tripartite in form, with a central polar layer containing the hydrogen bonds linking the –NHAtom I43 in the cation at (x, y, z) lies in the (100) sheet centred at x = ; this atom forms a two-centre iodo–nitro interaction with nitro atom O32 in the anion at (−x, + y, − z) [I⋯Oiv = 3.423 (4) Å, C—I⋯Oiv = 166.1 (2)° and I⋯Oiv—Niv = 141.4 (3)°; symmetry code: (iv) −x, + y, − z], so producing a C22(12) chain (Bernstein et al., 1995; Starbuck et al., 1999) running parallel to the [010] direction (Fig. 5). The anion at (−x, + y, − z) forms part of the (100) sheet centred at x = −, and propagation by inversion of this iodo–nitro interaction thus links each sheet to the two adjacent sheets, hence forming a single three-dimensional framework structure.
The only possible π–π stacking interaction in the structure of (I) is, at best, a weak one and, in any event, it lies within the hydrogen-bonded sheet. The aryl rings of the anion at (x, y, z) and the cation at (x, − y, + z) have a ring-centroid separation of 3.760 (2) Å; in addition, the dihedral angle between the ring planes is 8.4 (2)° and the interplanar spacing is ca 3.65 Å, corresponding to a centroid offset of ca 0.88 Å.
The supramolecular structure of (I) may be compared with that of its isomer (II). In (II), the anions again form C(7) chains generated by a 21 screw axis, but the linking of these chains by the cations into sheets differs in detail from that in (I); in particular, there are no centrosymmetric motifs in (II). Moreover, there are no iodo–nitro interactions in (II) and no significant direction-specific interactions between adjacent hydrogen-bonded sheets.
Experimental
A mixture of 3-iodoaniline and 3-nitrophthalic acid (5 mmol of each) in methanol (20 ml) was heated under reflux for 30 min and then cooled. The solid that formed slowly was collected and recrystallized from acetone (m.p. 460–461 K).
Crystal data
|
Refinement
|
|
For compound (I), the P21/c was uniquely assigned from the All H atoms were located from difference maps and then treated as riding atoms [C—H = 0.93 Å and Uiso(H) = 1.2Ueq(C,N) or 1.5Ueq(O)].
Data collection: SMART (Bruker, 1998); cell SAINT (Bruker, 2000); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97 and PRPKAPPA (Ferguson, 1999).
Supporting information
10.1107/S0108270105006013/sk1819sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S0108270105006013/sk1819Isup2.hkl
A mixture of 3-iodoaniline and 3-nitrophthalic acid (5 mmol of each) in methanol (20 ml) was heated under reflux for 30 min and then cooled. The solid that formed slowly was collected and recrystallized from acetone (m.p. 460–461 K).
For compound (I), the
P21/c was uniquely assigned from the All H atoms were located from difference maps and then treated as riding atoms [C—H = 0.93 Å and Uiso(H) = 1.2Ueq(C,N) or 1.5Ueq(O)].Data collection: SMART (Bruker, 1998); cell
SAINT (Bruker, 2000); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97 and PRPKAPPA (Ferguson, 1999).C6H7IN+·C8H4NO6− | F(000) = 840 |
Mr = 430.15 | Dx = 1.823 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 3603 reflections |
a = 16.0068 (10) Å | θ = 2.8–27.5° |
b = 7.8616 (5) Å | µ = 2.08 mm−1 |
c = 13.5718 (9) Å | T = 291 K |
β = 113.377 (1)° | Plate, colourless |
V = 1567.67 (17) Å3 | 0.50 × 0.10 × 0.08 mm |
Z = 4 |
Bruker SMART 1000 CCD area-detector diffractometer | 3603 independent reflections |
Radiation source: fine-focus sealed X-ray tube | 2253 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.037 |
ϕ–ω scans | θmax = 27.5°, θmin = 2.8° |
Absorption correction: multi-scan (SADABS; Bruker, 2000) | h = −13→20 |
Tmin = 0.424, Tmax = 0.852 | k = −10→10 |
11173 measured reflections | l = −17→17 |
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)] = 0.043 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.113 | H-atom parameters constrained |
S = 0.95 | w = 1/[σ2(Fo2) + (0.0656P)2] where P = (Fo2 + 2Fc2)/3 |
3603 reflections | (Δ/σ)max < 0.001 |
210 parameters | Δρmax = 0.89 e Å−3 |
0 restraints | Δρmin = −0.95 e Å−3 |
C6H7IN+·C8H4NO6− | V = 1567.67 (17) Å3 |
Mr = 430.15 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 16.0068 (10) Å | µ = 2.08 mm−1 |
b = 7.8616 (5) Å | T = 291 K |
c = 13.5718 (9) Å | 0.50 × 0.10 × 0.08 mm |
β = 113.377 (1)° |
Bruker SMART 1000 CCD area-detector diffractometer | 3603 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2000) | 2253 reflections with I > 2σ(I) |
Tmin = 0.424, Tmax = 0.852 | Rint = 0.037 |
11173 measured reflections |
R[F2 > 2σ(F2)] = 0.043 | 0 restraints |
wR(F2) = 0.113 | H-atom parameters constrained |
S = 0.95 | Δρmax = 0.89 e Å−3 |
3603 reflections | Δρmin = −0.95 e Å−3 |
210 parameters |
x | y | z | Uiso*/Ueq | ||
O11 | 0.4599 (2) | 1.1267 (4) | 0.5676 (2) | 0.0730 (10) | |
O12 | 0.47858 (18) | 0.9237 (3) | 0.68785 (18) | 0.0444 (6) | |
O21 | 0.37966 (16) | 0.5996 (3) | 0.70209 (17) | 0.0382 (5) | |
O22 | 0.43485 (16) | 0.5855 (3) | 0.57526 (18) | 0.0383 (5) | |
O31 | 0.2429 (2) | 0.4413 (4) | 0.5109 (3) | 0.0745 (10) | |
O32 | 0.1067 (2) | 0.5267 (5) | 0.4370 (4) | 0.1004 (14) | |
N31 | 0.1878 (2) | 0.5516 (4) | 0.4787 (3) | 0.0470 (8) | |
C1 | 0.3376 (2) | 0.9371 (4) | 0.5372 (3) | 0.0336 (7) | |
C2 | 0.3109 (2) | 0.7683 (4) | 0.5447 (2) | 0.0287 (7) | |
C3 | 0.2203 (2) | 0.7291 (4) | 0.4839 (3) | 0.0347 (8) | |
C4 | 0.1571 (3) | 0.8466 (5) | 0.4206 (3) | 0.0485 (10) | |
C5 | 0.1859 (3) | 1.0100 (5) | 0.4148 (3) | 0.0528 (10) | |
C6 | 0.2757 (3) | 1.0524 (5) | 0.4719 (3) | 0.0483 (10) | |
C11 | 0.4318 (3) | 1.0030 (5) | 0.5986 (3) | 0.0408 (8) | |
C21 | 0.3805 (2) | 0.6391 (4) | 0.6130 (2) | 0.0298 (7) | |
I43 | 0.04980 (2) | 0.70440 (6) | 0.12973 (2) | 0.07919 (18) | |
N41 | 0.41182 (18) | 0.6134 (4) | 0.3645 (2) | 0.0353 (6) | |
C41 | 0.3258 (2) | 0.5310 (4) | 0.2994 (2) | 0.0349 (8) | |
C42 | 0.2487 (2) | 0.6300 (5) | 0.2550 (3) | 0.0394 (8) | |
C43 | 0.1665 (3) | 0.5514 (6) | 0.1956 (3) | 0.0522 (11) | |
C44 | 0.1623 (3) | 0.3772 (7) | 0.1795 (3) | 0.0664 (13) | |
C45 | 0.2406 (4) | 0.2826 (6) | 0.2226 (4) | 0.0673 (14) | |
C46 | 0.3238 (3) | 0.3574 (5) | 0.2847 (3) | 0.0494 (10) | |
H4 | 0.0966 | 0.8157 | 0.3829 | 0.058* | |
H5 | 0.1449 | 1.0910 | 0.3727 | 0.063* | |
H6 | 0.2950 | 1.1622 | 0.4662 | 0.058* | |
H12 | 0.5223 | 0.9822 | 0.7245 | 0.067* | |
H41A | 0.4160 | 0.6247 | 0.4315 | 0.053* | |
H41B | 0.4140 | 0.7156 | 0.3374 | 0.053* | |
H41C | 0.4579 | 0.5502 | 0.3642 | 0.053* | |
H42 | 0.2517 | 0.7472 | 0.2649 | 0.047* | |
H44 | 0.1070 | 0.3248 | 0.1399 | 0.080* | |
H45 | 0.2381 | 0.1660 | 0.2102 | 0.081* | |
H46 | 0.3764 | 0.2922 | 0.3152 | 0.059* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O11 | 0.077 (2) | 0.0629 (19) | 0.0600 (17) | −0.0317 (18) | 0.0076 (17) | 0.0165 (15) |
O12 | 0.0442 (15) | 0.0454 (15) | 0.0342 (12) | −0.0125 (11) | 0.0055 (12) | −0.0010 (11) |
O21 | 0.0377 (13) | 0.0448 (14) | 0.0312 (11) | 0.0087 (11) | 0.0127 (10) | 0.0082 (10) |
O22 | 0.0368 (13) | 0.0457 (14) | 0.0343 (11) | 0.0117 (11) | 0.0161 (11) | 0.0026 (10) |
O31 | 0.061 (2) | 0.0398 (17) | 0.100 (2) | −0.0042 (15) | 0.0079 (19) | 0.0005 (16) |
O32 | 0.043 (2) | 0.078 (2) | 0.159 (4) | −0.0221 (17) | 0.019 (2) | −0.006 (2) |
N31 | 0.0415 (19) | 0.048 (2) | 0.0468 (17) | −0.0071 (16) | 0.0126 (16) | −0.0063 (15) |
C1 | 0.0390 (18) | 0.0316 (19) | 0.0304 (15) | 0.0013 (15) | 0.0139 (15) | −0.0001 (13) |
C2 | 0.0313 (17) | 0.0326 (18) | 0.0227 (14) | 0.0062 (13) | 0.0113 (13) | 0.0000 (12) |
C3 | 0.0320 (17) | 0.040 (2) | 0.0299 (15) | 0.0007 (15) | 0.0096 (14) | −0.0027 (14) |
C4 | 0.0324 (19) | 0.065 (3) | 0.042 (2) | 0.0108 (18) | 0.0081 (17) | 0.0004 (18) |
C5 | 0.051 (2) | 0.051 (2) | 0.051 (2) | 0.024 (2) | 0.015 (2) | 0.0166 (19) |
C6 | 0.060 (3) | 0.032 (2) | 0.053 (2) | 0.0092 (18) | 0.023 (2) | 0.0083 (17) |
C11 | 0.049 (2) | 0.036 (2) | 0.0370 (18) | −0.0059 (17) | 0.0170 (17) | −0.0057 (15) |
C21 | 0.0285 (16) | 0.0279 (17) | 0.0292 (15) | −0.0015 (13) | 0.0075 (14) | −0.0018 (13) |
I43 | 0.03459 (18) | 0.1417 (4) | 0.0517 (2) | 0.01097 (17) | 0.00697 (14) | 0.00028 (18) |
N41 | 0.0317 (14) | 0.0395 (16) | 0.0351 (14) | 0.0021 (13) | 0.0138 (12) | 0.0012 (12) |
C41 | 0.0327 (17) | 0.044 (2) | 0.0285 (15) | −0.0014 (15) | 0.0130 (14) | 0.0008 (14) |
C42 | 0.0360 (18) | 0.053 (2) | 0.0304 (16) | 0.0004 (17) | 0.0142 (15) | 0.0021 (15) |
C43 | 0.037 (2) | 0.083 (3) | 0.0337 (18) | −0.008 (2) | 0.0108 (17) | 0.0003 (19) |
C44 | 0.059 (3) | 0.085 (4) | 0.045 (2) | −0.029 (3) | 0.010 (2) | −0.014 (2) |
C45 | 0.086 (4) | 0.053 (3) | 0.056 (3) | −0.020 (3) | 0.021 (3) | −0.008 (2) |
C46 | 0.062 (3) | 0.040 (2) | 0.044 (2) | 0.0012 (19) | 0.019 (2) | 0.0014 (17) |
C1—C6 | 1.376 (5) | C5—H5 | 0.93 |
C1—C2 | 1.410 (5) | C6—H6 | 0.93 |
C1—C11 | 1.496 (5) | C41—C46 | 1.378 (5) |
C11—O11 | 1.214 (4) | C41—C42 | 1.380 (5) |
C11—O12 | 1.302 (4) | C41—N41 | 1.459 (4) |
O12—H12 | 0.82 | N41—H41A | 0.89 |
C2—C3 | 1.388 (5) | N41—H41B | 0.89 |
C2—C21 | 1.522 (4) | N41—H41C | 0.89 |
C21—O21 | 1.253 (4) | C42—C43 | 1.386 (5) |
C21—O22 | 1.245 (4) | C42—H42 | 0.93 |
C3—C4 | 1.388 (5) | C43—C44 | 1.384 (7) |
C3—N31 | 1.481 (5) | C43—I43 | 2.099 (4) |
N31—O31 | 1.190 (4) | C44—C45 | 1.373 (7) |
N31—O32 | 1.209 (4) | C44—H44 | 0.93 |
C4—C5 | 1.377 (6) | C45—C46 | 1.392 (7) |
C4—H4 | 0.93 | C45—H45 | 0.93 |
C5—C6 | 1.376 (6) | C46—H46 | 0.93 |
C6—C1—C2 | 120.3 (3) | C1—C6—H6 | 119.1 |
C6—C1—C11 | 116.1 (3) | C5—C6—H6 | 119.1 |
C2—C1—C11 | 123.6 (3) | C46—C41—C42 | 122.0 (3) |
O11—C11—O12 | 123.4 (4) | C46—C41—N41 | 119.3 (3) |
O11—C11—C1 | 120.9 (3) | C42—C41—N41 | 118.7 (3) |
O12—C11—C1 | 115.6 (3) | C41—N41—H41A | 109.5 |
C11—O12—H12 | 109.5 | C41—N41—H41B | 109.5 |
C3—C2—C1 | 116.2 (3) | H41A—N41—H41B | 109.5 |
C3—C2—C21 | 123.6 (3) | C41—N41—H41C | 109.5 |
C1—C2—C21 | 120.1 (3) | H41A—N41—H41C | 109.5 |
O22—C21—O21 | 126.2 (3) | H41B—N41—H41C | 109.5 |
O22—C21—C2 | 115.9 (3) | C41—C42—C43 | 118.8 (4) |
O21—C21—C2 | 117.9 (3) | C41—C42—H42 | 120.6 |
C4—C3—C2 | 123.6 (3) | C43—C42—H42 | 120.6 |
C4—C3—N31 | 116.2 (3) | C44—C43—C42 | 120.5 (4) |
C2—C3—N31 | 120.1 (3) | C44—C43—I43 | 121.4 (3) |
O31—N31—O32 | 123.8 (4) | C42—C43—I43 | 118.1 (3) |
O31—N31—C3 | 118.2 (3) | C45—C44—C43 | 119.3 (4) |
O32—N31—C3 | 117.8 (3) | C45—C44—H44 | 120.3 |
C5—C4—C3 | 118.5 (4) | C43—C44—H44 | 120.3 |
C5—C4—H4 | 120.7 | C44—C45—C46 | 121.4 (4) |
C3—C4—H4 | 120.7 | C44—C45—H45 | 119.3 |
C6—C5—C4 | 119.5 (3) | C46—C45—H45 | 119.3 |
C6—C5—H5 | 120.2 | C41—C46—C45 | 117.9 (4) |
C4—C5—H5 | 120.2 | C41—C46—H46 | 121.1 |
C1—C6—C5 | 121.8 (4) | C45—C46—H46 | 121.1 |
C6—C1—C11—O11 | −23.6 (5) | C4—C3—N31—O32 | −13.3 (5) |
C2—C1—C11—O11 | 157.3 (4) | C2—C3—N31—O32 | 170.3 (4) |
C6—C1—C11—O12 | 153.6 (3) | C2—C3—C4—C5 | 2.1 (6) |
C2—C1—C11—O12 | −25.5 (5) | N31—C3—C4—C5 | −174.2 (3) |
C6—C1—C2—C3 | −0.4 (5) | C3—C4—C5—C6 | −0.3 (6) |
C11—C1—C2—C3 | 178.7 (3) | C2—C1—C6—C5 | 2.0 (6) |
C6—C1—C2—C21 | 177.3 (3) | C11—C1—C6—C5 | −177.1 (4) |
C11—C1—C2—C21 | −3.7 (5) | C4—C5—C6—C1 | −1.7 (6) |
C3—C2—C21—O22 | 103.3 (4) | C46—C41—C42—C43 | 1.2 (5) |
C1—C2—C21—O22 | −74.1 (4) | N41—C41—C42—C43 | −178.3 (3) |
C3—C2—C21—O21 | −78.3 (4) | C41—C42—C43—C44 | −1.1 (5) |
C1—C2—C21—O21 | 104.2 (4) | C41—C42—C43—I43 | 179.6 (2) |
C1—C2—C3—C4 | −1.7 (5) | C42—C43—C44—C45 | −0.3 (6) |
C21—C2—C3—C4 | −179.2 (3) | I43—C43—C44—C45 | 178.9 (3) |
C1—C2—C3—N31 | 174.4 (3) | C43—C44—C45—C46 | 1.8 (7) |
C21—C2—C3—N31 | −3.1 (5) | C42—C41—C46—C45 | 0.2 (6) |
C4—C3—N31—O31 | 163.0 (4) | N41—C41—C46—C45 | 179.7 (3) |
C2—C3—N31—O31 | −13.4 (5) | C44—C45—C46—C41 | −1.7 (7) |
D—H···A | D—H | H···A | D···A | D—H···A |
O12—H12···O21i | 0.82 | 1.75 | 2.570 (3) | 176 |
N41—H41A···O22 | 0.89 | 1.88 | 2.745 (4) | 164 |
N41—H41B···O21ii | 0.89 | 2.23 | 3.052 (4) | 153 |
N41—H41C···O22iii | 0.89 | 1.91 | 2.747 (4) | 156 |
Symmetry codes: (i) −x+1, y+1/2, −z+3/2; (ii) x, −y+3/2, z−1/2; (iii) −x+1, −y+1, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C6H7IN+·C8H4NO6− |
Mr | 430.15 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 291 |
a, b, c (Å) | 16.0068 (10), 7.8616 (5), 13.5718 (9) |
β (°) | 113.377 (1) |
V (Å3) | 1567.67 (17) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 2.08 |
Crystal size (mm) | 0.50 × 0.10 × 0.08 |
Data collection | |
Diffractometer | Bruker SMART 1000 CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2000) |
Tmin, Tmax | 0.424, 0.852 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 11173, 3603, 2253 |
Rint | 0.037 |
(sin θ/λ)max (Å−1) | 0.650 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.043, 0.113, 0.95 |
No. of reflections | 3603 |
No. of parameters | 210 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.89, −0.95 |
Computer programs: SMART (Bruker, 1998), SAINT (Bruker, 2000), SAINT, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), PLATON (Spek, 2003), SHELXL97 and PRPKAPPA (Ferguson, 1999).
C11—O11 | 1.214 (4) | C21—O21 | 1.253 (4) |
C11—O12 | 1.302 (4) | C21—O22 | 1.245 (4) |
C2—C1—C11—O11 | 157.3 (4) | C2—C3—N31—O31 | −13.4 (5) |
C1—C2—C21—O21 | 104.2 (4) |
D—H···A | D—H | H···A | D···A | D—H···A |
O12—H12···O21i | 0.82 | 1.75 | 2.570 (3) | 176 |
N41—H41A···O22 | 0.89 | 1.88 | 2.745 (4) | 164 |
N41—H41B···O21ii | 0.89 | 2.23 | 3.052 (4) | 153 |
N41—H41C···O22iii | 0.89 | 1.91 | 2.747 (4) | 156 |
Symmetry codes: (i) −x+1, y+1/2, −z+3/2; (ii) x, −y+3/2, z−1/2; (iii) −x+1, −y+1, −z+1. |
Acknowledgements
X-ray data were collected at the University of Aberdeen; the University is thanked for funding the purchase of the Bruker SMART diffractometer. JNL thanks NCR Self-Service, Dundee, for grants which have provided computing facilities for this work. JLW thanks CNPq and FAPERJ for financial support.
References
Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555–1573. CrossRef CAS Web of Science Google Scholar
Bruker (1998). SMART. Version 5.0. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Bruker (2000). SADABS (Version 2.03) and SAINT (Version 6.02a). Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Ferguson, G. (1999). PRPKAPPA. University of Guelph, Canada. Google Scholar
Glidewell, C., Low, J. N., Skakle, J. M. S. & Wardell, J. L. (2003). Acta Cryst. C59, o509–o511. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany. Google Scholar
Spek, A. L. (2003). J. Appl. Cryst. 36, 7–13. Web of Science CrossRef CAS IUCr Journals Google Scholar
Starbuck, J., Norman, N. C. & Orpen, A. G. (1999). New J. Chem. 23, 969–972. Web of Science CrossRef Google Scholar
© International Union of Crystallography. Prior permission is not required to reproduce short quotations, tables and figures from this article, provided the original authors and source are cited. For more information, click here.
We report here the molecular and supramolecular structure of the title compound, (I), and compare it with the isomeric 4-iodoanilinium 3-nitro(hydrogenphthalate) (II) (Glidewell et al., 2003). Compound (I) is a salt; the H atoms are all fully ordered, and the C—O distances (Table 1) in both the un-ionized carboxyl group and the anionic carboxylate group are fully consistent with the H atom locations found from difference maps. Of the three adjacent substituents in the anion, the central carboxylate group is nearly orthogonal to the ring, while the two outer substituents show much smaller rotations about the exocyclic bonds away from planarity, as shown by the key torsion angles; these observations can be ascribed to steric congestion.
The supramolecular structure of (I) (Fig. 1) contains hydrogen-bonded sheets, which are linked into a continuous three-dimensional framework structure by a two-centre iodo–nitro interaction. The formation of the hydrogen-bonded sheet is most readily analysed in terms of the low-dimensional substructures from which it is generated.
The anions are linked by a single O—H···O hydrogen bond (Table 2) to form chains running parallel to the [010] direction. Carboxyl atom O12 in the anion at (x, y, z) acts as a hydrogen-bond donor to carboxylate atom O21 in the anion at (1 − x, 1/2 + y, 3/2 − z), so forming a C(7) chain (Bernstein et al., 1995) of anions generated by the 21 screw axis along (1/2, y, 3/4) (Fig. 2). A second anion chain, anti-parallel to the first and related to it by inversion, is generated by the 21 screw axis along (1/2, −y, 1/4), and these chains are linked by N—H···O hydrogen bonds into (100) sheets.
Anilinium atom N41 acts as a hydrogen-bond donor, via H41A, to carboxylate atom O22 within the asymmetric unit (Fig. 3); in addition, atom N41 in the cation at (x, y, z) acts as a donor, via H41B, to carboxylate atom O21 in the anion at (x, 3/2 − y, −1/2 + z). Propagation of these two N—H···O hydrogen bonds then produces a C22(6) chain running parallel to the [001] direction and generated by the c-glide plane at y = 0.75 (Fig. 3). Since the anions at (x, y, z) and (x, 3/2 − y, −1/2 + z) form parts, respectively, of the anion chains along (1/2, y, 3/4) and (1/2, −y, 1/4), these three hydrogen bonds, one of O—H···O type and two of N—H···O type, suffice to form a (100) sheet. In the third N—H···O hydrogen bond, atom N41 in the cation at (x, y, z) acts as a donor, via H41C, to carboxylate atom O22 in the anion at (1 − x, 1 − y, 1 − z), so generating a centrosymmetric R24(8) ring (Fig. 4), which serves further to reinforce the sheet. It is notable that the O atoms of the nitro group play no part in the hydrogen bonding.
Just a single (100) sheet passes through each unit cell and it is tripartite in form, with a central polar layer containing the hydrogen bonds linking the –NH3+, –COO− and –COOH units, and with two outer layers containing the iodophenyl and nitrophenyl units. The location of both the iodo and the nitro substituents on the outer faces of this tripartite layer allows the formation of iodo–nitro interactions, which link adjacent sheets
Atom I43 in the cation at (x, y, z) lies in the (100) sheet centred at x = 1/2; this atom forms a two-centre iodo–nitro interaction with nitro atom O32 in the anion at (−x, 1/2 + y, 1/2 − z) [I···Oi = 3.423 (4) Å, C—I···Oi = 166.1 (2)° and I···Oi—Ni = 141.4 (3)°; symmetry code: (i) −x, 1/2 + y, 1/2 − z], so producing a C22(12) chain (Bernstein et al., 1995; Starbuck et al., 1999) running parallel to the [010] direction (Fig. 5). The anion at (−x, 1/2 + y, 1/2 − z) forms part of the (100) sheet centred at x = −1/2, and propagation by inversion of this iodo–nitro interaction thus links each sheet to the two adjacent sheets, hence forming a single three-dimensional framework structure.
The only possible π–π stacking interaction in the structure of (I) is, at best, a weak one and, in any event, it lies within the hydrogen-bonded sheet. The aryl rings of the anion at (x, y, z) and the cation at (x, 3/2 − y, 1/2 + z) have a ring-centroid separation of 3.760 (2) Å; the dihedral angle between the ring planes is 8.4 (2)° and the interplanar spacing is ca 3.65 Å, corresponding to a centroid offset of ca 0.88 Å.
The supramolecular structure of (I) may be compared with that of its isomer (II). In (II), the anions again form C(7) chains generated by a 21 screw axes, but the linking of these chains by the cations into sheets differs in detail from that in (I); in particular there are no centrosymmetric motifs in (II). Moreover, there are no iodo–.nitro interactions in (II) and no significant direction-specific interactions between adjacent hydrogen-bonded sheets.