organic compounds
Ammonium hydrogen bis[4-(2-phenyl-2H-tetrazol-5-yl)benzoate]
aSt. Catherine University, Dept. of Chemistry and Biochemistry, 2004 Randolph Avenue, St. Paul, MN 55105, USA
*Correspondence e-mail: dejanzen@stkate.edu
The title salt, NH4+·H+·2C14H9N4O2−, is composed of an ammonium cation with a strong intermolecular negatively charge-assisted hydrogen-bonded acid/conjugate base-pair monoanion. The carboxylic acid H atom is located on an inversion center, while the N atom of the ammonium cation is located on a twofold rotation axis. In the crystal, the N—H bonds of each ammonium cation act as donors with carboxylate O-atom acceptors to form chains along the a-axis direction. The chains are linked by offset π–π interactions [intercentroid distances = 3.588 (2) and 3.686 (2) Å], forming layers parallel to the ab plane.
Keywords: crystal structure; tetrazole; photoclick chemistry; O⋯O symmetric hydrogen bond; ammonium.
CCDC reference: 1508475
Structure description
Tetrazoles are an interesting class of compounds that are utilized in a bioorthogonal reaction called photoclick chemistry (Ramil & Lin, 2014). When tetrazoles are irradiated with UV light, a nitrile imine is formed which can subsequently complete a cycloaddition with present in situ (Zheng et al., 2009). After cycloaddition, a fluorescent pyrazoline is produced that can be used as a tag to monitor product formation. This technology has been successfully used to impart fluorescent properties onto alkene-containing proteins (Song et al., 2008; Lim & Lin, 2011). Upon synthesizing 4-(2-phenyl-2H-tetrazol-5-yl)benzoic acid for this purpose, X-ray diffraction quality ammonium salt crystals of the title compound were produced and we report herein on its crystal structure.
The molecular structure of the title compound is illustrated in Fig. 1. The ammonium cation (N5) is located on a twofold rotation axis, and the carboxylic acid H atom (H1A), located on an inversion center, interacts with two inversion-related 4-(2-phenyl-2H-tetrazol-5-yl)benzoate ions (Fig. 1 and Table 1). The conjugate acid/base O1⋯O1(−x + 1, −y − 2, −z + 1) distance of 2.561 (3) Å is short, consistent with a strong negatively charge-assisted hydrogen bond (Gilli et al., 2009). The narrow range of bond lengths [1.312 (3)–1.359 (3) Å] in the tetrazole moiety suggests significant conjugation in this ring. The 4-(2-phenyl-2H-tetrazol-5-yl)benzoate moiety is relatively planar. The phenyl (atoms C1–C6) and benzoate rings (atoms C8–C13) are inclined to the plane of the tetrazole ring (atoms N1–N4/C7) by 2.54 (15) and 6.10 (14)°, respectively, and by 3.84 (13)° to each another. The acetate group (C11/C14/O1/O2) is inclined to the benzene ring (C8–C13) to which it is attached by 10.44 (14)°.
In the crystal, intermolecular hydrogen bonding is present between the ammonium donor and four O-atom acceptors from two conjugate acid/base pairs. The hydrogen-bonding motif [R22(8)] occurs as a chain of rings (joined at N5) along the a-axis direction plane (Table 1 and Fig. 2). This pattern of hydrogen bonding is unique to the small group of existing reported ammonium hydrogen bis(carboxylate) structures, which all exhibit hydrogen bonding of ammonium cations with carboxylate O atoms from four unique conjugate acid/base pairs (Chowdhury & Kariuki, 2006; Golic & Lazarini, 1975; Ichikawa, 1972; Nahringbauer, 1969; Perumalla & Sun, 2013). Adjacent chains are linked via offset π–π interactions, forming layers parallel to the ab plane; see Fig. 3 [Cg1⋯Cg3i = 3.588 (2) Å, interplanar distance = 3.480 (1) Å, slippage = 1.121 Å; Cg1⋯Cg2ii = 3.686 (2) Å, interplanar distance = 3.352 (1) Å, slippage = 1.384 Å; Cg1, Cg2, and Cg3 are the centroids of the N1–N4/C7, C1–C6 and C8–C13 rings, respectively; symmetry codes: (i) x, y + 1, z; (ii) x, y − 1, z].
Synthesis and crystallization
The title compound was synthesized using procedures adopted from multiple literature reports (Song et al., 2008; Ito et al., 1976). To a solution of 4-formylbenzoic acid (0.75 g, 5.0 mmol) in ethanol (50 ml) was added benzenesulfonohydrazide (0.86 g, 25 mmol) and the solution was stirred for 35 min. Water (200 ml) was then added and the beaker containing the reaction was placed in an ice bath to produce a precipitate, which was subsequently filtered off and dissolved in pyridine (30 ml). This was labeled solution A. In another flask aniline (0.47 g, 5.0 mmol) was dissolved in a solution consisting of water (4 ml), ethanol (4 ml), and concentrated HCl (1.3 ml). This solution was placed in an ice bath while a cooled solution of NaNO2 (0.35 g, 5.0 mmol) in 2 ml water was added dropwise. This was labeled solution B. Solution A was then placed in an ice salt bath while solution B was added dropwise over 10 min under magnetic stirring. This solution was allowed to sit for 20 min, after which time it was extracted with ethyl acetate (3 × 30 ml). Then 3 M HCl (250 ml) was added to the combined organic extracts and the mixture was stirred for 15 min. The organic layer was then collected, concentrated, and recrystallized from hot ethyl acetate to produce 0.235 g of light-pink crystals of 4-(2-phenyl-2H-tetrazol-5-yl)benzoic acid (17.7% yield). 1H NMR (400 MHz, DMSO-d6): δ 13.31 (br s, 1H), 8.27 (d, J = 8.7 Hz, 2H), 8.14 (d, J = 7.8, 2H), 8.12 (d, J = 8.3 Hz, 2H), 7.68 (dd, J = 7.8, 8.7 Hz, 2H), 7.61 (t, J = 7.3 Hz, 1H); 13C NMR (100 MHz, DMSO-d6): δ 166.6, 163.6, 136.0, 132.6 130.3, 130.2, 130.1, 126.7, 119.1.
Crystals of the title compound were prepared by dissolving 4-(2-phenyl-2H-tetrazol-5-yl)benzoic acid (30 mg) in 6 ml of a 2:1 solution of methanol–H2O. This gave a cloudy solution which became clear on the addition of 6 drops of 6 M NH4OH. The solution was allowed to sit in an open vial at room temperature, and yielded colourless prismatic crystals of the title compound after ca 10 d.
Refinement
Crystal data, data collection and structure .
details are summarized in Table 2
|
Structural data
CCDC reference: 1508475
https://doi.org/10.1107/S2414314616015704/su4081sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314616015704/su4081Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S2414314616015704/su4081Isup3.cml
Data collection: CrystalClear-SM Expert (Rigaku, 2011); cell
CrystalClear-SM Expert (Rigaku, 2011); data reduction: CrystalClear-SM Expert (Rigaku, 2011); program(s) used to solve structure: SIR2004 (Burla et al., 2005); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Mercury (Macrae et al., 2008); software used to prepare material for publication: CrystalStructure (Rigaku, 2014).NH4+·H+·2C14H9N4O2− | F(000) = 1144.00 |
Mr = 549.55 | Dx = 1.448 Mg m−3 |
Monoclinic, I2/a | Mo Kα radiation, λ = 0.71075 Å |
a = 12.350 (3) Å | Cell parameters from 4069 reflections |
b = 4.8107 (13) Å | θ = 3.3–25.1° |
c = 42.812 (11) Å | µ = 0.10 mm−1 |
β = 97.569 (9)° | T = 173 K |
V = 2521.4 (12) Å3 | Prism, colourless |
Z = 4 | 0.43 × 0.43 × 0.08 mm |
Rigaku XtaLAB mini diffractometer | 2206 independent reflections |
Radiation source: sealed X-ray tube | 1788 reflections with F2 > 2.0σ(F2) |
Detector resolution: 6.849 pixels mm-1 | Rint = 0.031 |
ω scans | θmax = 25.0°, θmin = 3.3° |
Absorption correction: multi-scan (REQAB; Rigaku, 1998) | h = −14→12 |
Tmin = 0.679, Tmax = 0.992 | k = −5→5 |
4744 measured reflections | l = −50→50 |
Refinement on F2 | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.060 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.128 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.19 | w = 1/[σ2(Fo2) + (0.0357P)2 + 4.8932P] where P = (Fo2 + 2Fc2)/3 |
2206 reflections | (Δ/σ)max < 0.001 |
195 parameters | Δρmax = 0.23 e Å−3 |
0 restraints | Δρmin = −0.21 e Å−3 |
Primary atom site location: structure-invariant direct methods |
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 was performed using all reflections. The weighted R-factor (wR) and goodness of fit (S) are based on F2. R-factor (gt) are based on F. The threshold expression of F2 > 2.0 sigma(F2) is used only for calculating R-factor (gt). |
x | y | z | Uiso*/Ueq | ||
O1 | 0.52029 (14) | −0.8059 (4) | 0.48115 (4) | 0.0259 (4) | |
O2 | 0.34227 (14) | −0.6986 (4) | 0.47209 (5) | 0.0359 (5) | |
N1 | 0.45919 (17) | 0.2934 (5) | 0.35894 (5) | 0.0260 (5) | |
N2 | 0.51882 (16) | 0.4507 (5) | 0.34221 (5) | 0.0248 (5) | |
N3 | 0.62631 (17) | 0.4060 (5) | 0.34874 (6) | 0.0326 (6) | |
N4 | 0.63802 (18) | 0.2133 (5) | 0.37061 (6) | 0.0321 (6) | |
N5 | 0.7500 | 0.1560 (9) | 0.5000 | 0.0551 (14) | |
C1 | 0.4723 (2) | 0.6455 (5) | 0.31930 (6) | 0.0242 (6) | |
C2 | 0.3595 (2) | 0.6681 (6) | 0.31350 (7) | 0.0318 (7) | |
H2 | 0.3137 | 0.5576 | 0.3247 | 0.038* | |
C3 | 0.3158 (2) | 0.8570 (6) | 0.29087 (7) | 0.0366 (7) | |
H3 | 0.2387 | 0.8747 | 0.2863 | 0.044* | |
C4 | 0.3818 (2) | 1.0198 (6) | 0.27481 (7) | 0.0358 (7) | |
H4 | 0.3503 | 1.1480 | 0.2593 | 0.043* | |
C5 | 0.4942 (2) | 0.9957 (6) | 0.28133 (7) | 0.0354 (7) | |
H5 | 0.5399 | 1.1084 | 0.2704 | 0.043* | |
C6 | 0.5402 (2) | 0.8083 (6) | 0.30370 (6) | 0.0304 (7) | |
H6 | 0.6173 | 0.7917 | 0.3083 | 0.037* | |
C7 | 0.5358 (2) | 0.1465 (6) | 0.37659 (6) | 0.0238 (6) | |
C8 | 0.5118 (2) | −0.0604 (6) | 0.39962 (6) | 0.0245 (6) | |
C9 | 0.4036 (2) | −0.1329 (6) | 0.40206 (6) | 0.0265 (6) | |
H9 | 0.3455 | −0.0479 | 0.3887 | 0.032* | |
C10 | 0.3813 (2) | −0.3281 (6) | 0.42394 (6) | 0.0254 (6) | |
H10 | 0.3076 | −0.3769 | 0.4254 | 0.030* | |
C11 | 0.4652 (2) | −0.4553 (6) | 0.44397 (6) | 0.0236 (6) | |
C12 | 0.5730 (2) | −0.3826 (6) | 0.44126 (6) | 0.0277 (6) | |
H12 | 0.6310 | −0.4687 | 0.4546 | 0.033* | |
C13 | 0.5963 (2) | −0.1879 (6) | 0.41957 (6) | 0.0279 (6) | |
H13 | 0.6701 | −0.1398 | 0.4181 | 0.034* | |
C14 | 0.4385 (2) | −0.6670 (6) | 0.46713 (6) | 0.0249 (6) | |
H1A | 0.5000 | −1.0000 | 0.5000 | 0.11 (2)* | |
H5A | 0.770 (8) | 0.061 (16) | 0.4864 (18) | 0.19 (4)* | |
H5B | 0.806 (8) | 0.25 (2) | 0.507 (3) | 0.31 (7)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0212 (9) | 0.0254 (10) | 0.0312 (10) | 0.0015 (8) | 0.0033 (8) | 0.0051 (8) |
O2 | 0.0192 (10) | 0.0465 (13) | 0.0433 (12) | 0.0006 (9) | 0.0088 (8) | 0.0150 (10) |
N1 | 0.0245 (12) | 0.0269 (12) | 0.0278 (12) | −0.0017 (10) | 0.0084 (10) | 0.0009 (10) |
N2 | 0.0194 (11) | 0.0284 (13) | 0.0277 (12) | −0.0011 (10) | 0.0067 (9) | 0.0024 (10) |
N3 | 0.0188 (11) | 0.0408 (15) | 0.0387 (14) | 0.0015 (11) | 0.0062 (10) | 0.0105 (12) |
N4 | 0.0219 (12) | 0.0390 (15) | 0.0361 (14) | 0.0018 (10) | 0.0060 (10) | 0.0125 (12) |
N5 | 0.0184 (19) | 0.022 (2) | 0.126 (5) | 0.000 | 0.014 (2) | 0.000 |
C1 | 0.0252 (13) | 0.0231 (14) | 0.0244 (13) | 0.0010 (11) | 0.0036 (11) | −0.0015 (12) |
C2 | 0.0247 (14) | 0.0338 (16) | 0.0383 (16) | 0.0012 (13) | 0.0090 (12) | 0.0009 (14) |
C3 | 0.0250 (15) | 0.0414 (18) | 0.0426 (18) | 0.0058 (13) | 0.0015 (13) | −0.0008 (15) |
C4 | 0.0412 (17) | 0.0316 (17) | 0.0334 (16) | 0.0078 (14) | 0.0002 (13) | 0.0039 (14) |
C5 | 0.0366 (16) | 0.0335 (17) | 0.0378 (16) | −0.0003 (14) | 0.0107 (13) | 0.0049 (14) |
C6 | 0.0255 (14) | 0.0355 (16) | 0.0309 (15) | 0.0001 (13) | 0.0058 (12) | 0.0035 (14) |
C7 | 0.0207 (13) | 0.0265 (15) | 0.0243 (13) | 0.0016 (11) | 0.0033 (11) | −0.0022 (12) |
C8 | 0.0230 (13) | 0.0262 (15) | 0.0250 (14) | 0.0007 (12) | 0.0058 (11) | −0.0034 (12) |
C9 | 0.0204 (13) | 0.0301 (16) | 0.0288 (14) | 0.0017 (11) | 0.0029 (11) | 0.0022 (13) |
C10 | 0.0176 (13) | 0.0298 (15) | 0.0291 (14) | −0.0001 (11) | 0.0047 (11) | 0.0010 (13) |
C11 | 0.0217 (13) | 0.0242 (14) | 0.0260 (14) | 0.0001 (11) | 0.0067 (11) | −0.0043 (12) |
C12 | 0.0189 (13) | 0.0304 (15) | 0.0332 (15) | 0.0020 (11) | 0.0013 (11) | 0.0030 (13) |
C13 | 0.0194 (13) | 0.0317 (15) | 0.0333 (15) | −0.0025 (12) | 0.0052 (11) | 0.0009 (13) |
C14 | 0.0232 (14) | 0.0243 (14) | 0.0275 (14) | 0.0016 (11) | 0.0047 (11) | −0.0019 (12) |
O1—C14 | 1.291 (3) | C4—H4 | 0.9500 |
O2—C14 | 1.244 (3) | C5—C6 | 1.382 (4) |
N1—N2 | 1.329 (3) | C5—H5 | 0.9500 |
N1—C7 | 1.333 (3) | C6—H6 | 0.9500 |
N2—N3 | 1.337 (3) | C7—C8 | 1.458 (4) |
N2—C1 | 1.422 (3) | C8—C9 | 1.399 (3) |
N3—N4 | 1.312 (3) | C8—C13 | 1.400 (4) |
N4—C7 | 1.359 (3) | C9—C10 | 1.379 (4) |
N5—H5A | 0.80 (8) | C9—H9 | 0.9500 |
N5—H5B | 0.84 (11) | C10—C11 | 1.396 (4) |
C1—C6 | 1.382 (4) | C10—H10 | 0.9500 |
C1—C2 | 1.387 (4) | C11—C12 | 1.396 (3) |
C2—C3 | 1.385 (4) | C11—C14 | 1.489 (4) |
C2—H2 | 0.9500 | C12—C13 | 1.376 (4) |
C3—C4 | 1.378 (4) | C12—H12 | 0.9500 |
C3—H3 | 0.9500 | C13—H13 | 0.9500 |
C4—C5 | 1.384 (4) | ||
N2—N1—C7 | 101.8 (2) | N1—C7—N4 | 112.0 (2) |
N1—N2—N3 | 113.7 (2) | N1—C7—C8 | 123.5 (2) |
N1—N2—C1 | 123.0 (2) | N4—C7—C8 | 124.4 (2) |
N3—N2—C1 | 123.3 (2) | C9—C8—C13 | 119.2 (2) |
N4—N3—N2 | 106.0 (2) | C9—C8—C7 | 120.2 (2) |
N3—N4—C7 | 106.5 (2) | C13—C8—C7 | 120.6 (2) |
H5A—N5—H5B | 103 (8) | C10—C9—C8 | 119.9 (2) |
C6—C1—C2 | 121.9 (3) | C10—C9—H9 | 120.1 |
C6—C1—N2 | 119.4 (2) | C8—C9—H9 | 120.1 |
C2—C1—N2 | 118.7 (2) | C9—C10—C11 | 121.2 (2) |
C3—C2—C1 | 117.8 (3) | C9—C10—H10 | 119.4 |
C3—C2—H2 | 121.1 | C11—C10—H10 | 119.4 |
C1—C2—H2 | 121.1 | C12—C11—C10 | 118.5 (2) |
C4—C3—C2 | 121.4 (3) | C12—C11—C14 | 121.6 (2) |
C4—C3—H3 | 119.3 | C10—C11—C14 | 119.8 (2) |
C2—C3—H3 | 119.3 | C13—C12—C11 | 120.9 (2) |
C3—C4—C5 | 119.7 (3) | C13—C12—H12 | 119.6 |
C3—C4—H4 | 120.2 | C11—C12—H12 | 119.6 |
C5—C4—H4 | 120.2 | C12—C13—C8 | 120.3 (2) |
C6—C5—C4 | 120.3 (3) | C12—C13—H13 | 119.9 |
C6—C5—H5 | 119.8 | C8—C13—H13 | 119.9 |
C4—C5—H5 | 119.9 | O2—C14—O1 | 124.3 (2) |
C5—C6—C1 | 119.0 (3) | O2—C14—C11 | 119.9 (2) |
C5—C6—H6 | 120.5 | O1—C14—C11 | 115.8 (2) |
C1—C6—H6 | 120.5 | ||
C7—N1—N2—N3 | 0.2 (3) | N3—N4—C7—C8 | −179.8 (3) |
C7—N1—N2—C1 | 179.5 (2) | N1—C7—C8—C9 | 6.1 (4) |
N1—N2—N3—N4 | −0.2 (3) | N4—C7—C8—C9 | −174.2 (3) |
C1—N2—N3—N4 | −179.5 (2) | N1—C7—C8—C13 | −173.7 (3) |
N2—N3—N4—C7 | 0.1 (3) | N4—C7—C8—C13 | 6.1 (4) |
N1—N2—C1—C6 | 177.7 (3) | C13—C8—C9—C10 | 0.0 (4) |
N3—N2—C1—C6 | −3.1 (4) | C7—C8—C9—C10 | −179.8 (3) |
N1—N2—C1—C2 | −1.7 (4) | C8—C9—C10—C11 | 0.3 (4) |
N3—N2—C1—C2 | 177.6 (3) | C9—C10—C11—C12 | −0.6 (4) |
C6—C1—C2—C3 | 1.3 (4) | C9—C10—C11—C14 | −179.5 (2) |
N2—C1—C2—C3 | −179.4 (3) | C10—C11—C12—C13 | 0.6 (4) |
C1—C2—C3—C4 | −0.7 (4) | C14—C11—C12—C13 | 179.5 (3) |
C2—C3—C4—C5 | −0.1 (5) | C11—C12—C13—C8 | −0.4 (4) |
C3—C4—C5—C6 | 0.4 (5) | C9—C8—C13—C12 | 0.1 (4) |
C4—C5—C6—C1 | 0.2 (4) | C7—C8—C13—C12 | 179.9 (3) |
C2—C1—C6—C5 | −1.1 (4) | C12—C11—C14—O2 | 169.8 (3) |
N2—C1—C6—C5 | 179.6 (3) | C10—C11—C14—O2 | −11.3 (4) |
N2—N1—C7—N4 | −0.1 (3) | C12—C11—C14—O1 | −9.5 (4) |
N2—N1—C7—C8 | 179.7 (2) | C10—C11—C14—O1 | 169.3 (2) |
N3—N4—C7—N1 | 0.0 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1A···O1i | 1.28 | 1.28 | 2.561 (3) | 180 |
N5—H5A···O2ii | 0.80 (8) | 2.09 (8) | 2.815 (4) | 151 (7) |
N5—H5B···O1iii | 0.84 (11) | 2.15 (10) | 2.8513 (18) | 140 (9) |
Symmetry codes: (i) −x+1, −y−2, −z+1; (ii) x+1/2, −y−1, z; (iii) −x+3/2, y+1, −z+1. |
Acknowledgements
The authors acknowledge St. Catherine University and NSF-MRI award No. 1125975 `MRI Consortium: Acquisition of a Single Crystal X-ray Diffractometer for a Regional PUI Molecular Structure Facility', as well as an NSF–CHE award No. 1308655 `Quantification and Visualization of the Prenylome'.
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