Crystal structures of the 1:1 salts of 2-amino-4-nitro­benzoate with each of (2-hy­droxy­eth­yl)di­methyl­aza­nium, tert-but­yl(2-hy­droxy­eth­yl)aza­nium and 1,3-dihy­droxy-2-(hy­droxy­meth­yl)propan-2-aminium

Wardell, J.L.; Tiekink, E.R.T.

doi:10.1107/S2056989018015578

research communications

CRYSTALLOGRAPHIC
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ISSN: 2056-9890

Volume 74| Part 12| December 2018| Pages 1735-1740

https://doi.org/10.1107/S2056989018015578

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Crystal structures of the 1:1 salts of 2-amino-4-nitrobenzoate with each of (2-hydroxyethyl)dimethylazanium, tert-butyl(2-hydroxyethyl)azanium and 1,3-dihydroxy-2-(hydroxymethyl)propan-2-aminium

James L. Wardell ^a ‡ and Edward R. T. Tiekink ^b ^*

^aDepartment of Chemistry, University of Aberdeen, Old Aberdeen, AB24 3UE, Scotland, and ^bResearch Centre for Crystalline Materials, School of Science and Technology, Sunway University, 47500 Bandar Sunway, Selangor Darul Ehsan, Malaysia
^*Correspondence e-mail: edwardt@sunway.edu.my

Edited by W. T. A. Harrison, University of Aberdeen, Scotland (Received 2 November 2018; accepted 2 November 2018; online 9 November 2018)

The crystal and molecular structures of the title molecular salts, C₄H₁₂NO⁺·C₇H₅N₂O₄⁻, (I), C₆H₁₆NO⁺·C₇H₅N₂O₄⁻, (II), and C₄H₁₂NO₃⁺·C₇H₅N₂O₄⁻, (III), are described. The common feature of these salts is the presence of the 2-amino-4-nitrobenzoate anion, which exhibit non-chemically significant variations in the conformational relationships between the carboxylate and nitro groups, and between these and the benzene rings they are connected to. The number of ammonium-N—H H atoms in the cations increases from one to three in (I) to (III), respectively, and this variation significantly influences the supramolecular aggregation patterns in the respective crystals. Thus, a linear supramolecular chain along [100] sustained by charge-assisted tertiary-ammonium-N—H⋯O(carboxylate), hydroxy-O—H⋯O(carboxylate) and amino-N—H⋯O(carboxylate) hydrogen-bonds is apparent in the crystal of (I). Chains are connected into a three-dimensional architecture by methyl-C—H⋯O(hydroxy) and π–π interactions, the latter between benzene rings [inter-centroid separation = 3.5796 (10) Å]. In the crystal of (II), a supramolecular tube propagating along [901] arises as a result of charge-assisted secondary-ammonium-N—H⋯O(carboxylate) and hydroxy-O—H⋯O(carboxylate) hydrogen-bonding. These are connected by methylene- and methyl-C—H⋯O(nitro) and π–π stacking between benzene rings [inter-centroid separation = 3.5226 (10) Å]. Finally, double-layers parallel to (100) sustained by charge-assisted ammonium-N—H⋯O(carboxylate), ammonium-N—H⋯O(hydroxy) and hydroxy-O—H⋯O(carboxylate) hydrogen-bonds are apparent in the crystal of (III). These are connected in a three-dimensional architecture by amine-N—H⋯O(nitro) hydrogen-bonds.

Keywords: crystal structure; carboxylate; molecular salt; hydrogen-bonding.

CCDC references: 1876928; 1876927; 1876926

1. Chemical context

Despite being tetramorphic (Wardell & Tiekink, 2011 ; Wardell & Wardell, 2016 ), readily forming co-crystals (Wardell & Tiekink, 2011) and providing systematic series of crystals of alkali metal, e.g. Na⁺, K⁺ (Smith, 2013 ), Rb⁺ (Smith, 2014a ) and Cs⁺ (Smith & Wermuth, 2011 ), and ammonium salts, see below, studies of the relatively small benzoic acid derivative, 2-amino-4-nitrobenzoic acid, are still comparatively limited. Most crystallographic investigations of the acid have focused upon an evaluation of the hydrogen-bonding propensities occurring in derived ammonium salts of the 2-amino-4-nitrobenzoate anion. Thus, studies have been described with a range of salts, starting with the simplest, i.e. N⁽⁺⁾H₄ (Smith, 2014b ), H₂NN⁽⁺⁾H₃ (Wardell et al., 2017 ) and (H₂N)₂C=N⁽⁺⁾H₂ (Smith et al., 2007 ) to R₂N⁽⁺⁾H₂, i.e. R = Me, n-Bu (Wardell et al., 2016 ), cyclohexyl (Smith et al., 2004 ) and R₂ = (CH₂CH₂)₂O (Smith & Lynch, 2016 ), and more complicated ammonium cations such as 4-(4-acetylphenyl)piperazin-1-ium (Jotani et al., 2018 ) and the dication, H₃N⁽⁺⁾CH₂CH₂N⁽⁺⁾H₃ (Smith et al., 2002 ). As a continuation of on-going interest in this area, the results of co-crystallization experiments between 2-amino-4-nitrobenzoic acid (LH) and amines substituted with hydroxy groups, i.e. each of Me₂N(CH₂CH₂OH), (t-Bu)N(H)CH₂CH₂OH and (HOCH₂)₃CNH₂ are described whereupon the anhydrous 1:1 salts, i.e. [Me₂N⁽⁺⁾H(CH₂CH₂OH)]L (I), [(t-Bu)N⁽⁺⁾H₂(CH₂CH₂OH)]L (II) and [(HOCH₂)₃CN⁽⁺⁾H₃]L (III), were isolated. Herein, a description of the crystal and molecular structures of (I)–(III) are presented.

2. Structural commentary

The molecular structures of the constituent ions in (I) are shown in Fig. 1 and selected geometric data for this and for (II) and (III), are collected in Table 1. That proton transfer occurred during co-crystallization is confirmed by the experimental equivalence of the C7 O1, O2 bond lengths of 1.270 (2) and 1.258 (2) Å, respectively, in the 2-amino-4-nitrobenzoate anion and in the pattern of hydrogen-bonding interactions, as described below in Supramolecular features. In the anion, the carboxylate group is tilted out of the plane of the benzene ring to which it is connected with the dihedral angle being 6.7 (3)°. Similarly, the nitro group lies out of the plane of the benzene ring, forming a dihedral angle of 6.6 (3)°. A dis-rotatory relationship between the carboxylate and nitro substituents is indicated by the dihedral angle between them of 11.5 (4)°. An intramolecular amine-N1—H⋯O1(carboxylate) hydrogen-bond is noted which closes an S(6) loop, Table 2. In the Me₂N⁽⁺⁾(H)CH₂CH₂OH cation, the N3—C8—C9—O5 torsion angle of −71.15 (19)° is indicative of a −syn-clinal conformation.

Table 1
Selected geometric data (Å, °) for (I)–(III)

Parameter	(I)	(II)	(III)
C7 O1	1.270 (2)	1.259 (2)	1.270 (2)
C7 O2	1.258 (2)	1.2678 (19)	1.264 (2)
CO₂/C₆	6.7 (3)	6.21 (13)	14.80 (17)
NO₂/C₆	6.6 (3)	3.28 (13)	6.58 (18)
CO₂/NO₂	11.5 (4)	2.94 (17)	9.7 (3)

Table 2
Hydrogen-bond geometry (Å, °) for (I)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1N⋯O1	0.89 (2)	1.97 (2)	2.6698 (19)	135 (2)
N1—H2N⋯O2ⁱ	0.88 (1)	2.24 (2)	3.010 (2)	146 (2)
N3—H3N⋯O1	0.90 (1)	1.82 (1)	2.6722 (18)	156 (2)
O5—H5O⋯O2	0.84 (2)	1.83 (2)	2.6731 (19)	179 (3)
C10—H10B⋯O5ⁱⁱ	0.98	2.48	3.406 (2)	157
Symmetry codes: (i) x-1, y, z; (ii) $[x-{\script{3\over 2}}, -y-{\script{1\over 2}}, z-{\script{3\over 2}}]$ .

Figure 1
The molecular structures of the ions comprising the asymmetric unit of (I)

showing the atom-labelling scheme and displacement ellipsoids at the 70% probability level. Dashed lines indicate a hydrogen bonds.

The anion in (II), Fig. 2, presents essentially the same features as just described for (I), Tables 1 and 3, with the exception of the con-rotatory relationship between the carboxylate and nitro substituents. The (t-Bu)N⁽⁺⁾H₂(CH₂CH₂OH) cation is relatively rare, being reported for the first time in its salt with sulfathiazolate only in 2012 (Arman et al., 2012 ). As for the cation in (I), the N3—C12—C13—O5 torsion angle for the cation in (II) of −55.18 (18)° is indicative of a −syn-clinal conformation.

Table 3
Hydrogen-bond geometry (Å, °) for (II)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1N⋯O1	0.87 (2)	2.00 (2)	2.665 (2)	132 (2)
N1—H2N⋯O5	0.89 (2)	2.17 (2)	3.058 (2)	176 (2)
N3—H3N⋯O1ⁱ	0.90 (2)	1.73 (2)	2.637 (2)	178 (2)
N3—H4N⋯O2ⁱⁱ	0.89 (2)	1.98 (2)	2.849 (2)	166 (2)
O5—H5O⋯O2ⁱ	0.84 (2)	1.92 (2)	2.7546 (18)	173 (2)
C11—H11A⋯O4ⁱⁱⁱ	0.98	2.49	3.450 (3)	165
C12—H12A⋯O3	0.99	2.50	3.445 (2)	159
Symmetry codes: (i) $[x+{\script{1\over 2}}, -y+{\script{3\over 2}}, z-{\script{1\over 2}}]$ ; (ii) $[-x+1, y, -z+{\script{1\over 2}}]$ ; (iii) $[x+{\script{1\over 2}}, -y+{\script{1\over 2}}, z-{\script{1\over 2}}]$ .

Figure 2
The molecular structures of the ions comprising the asymmetric unit of (II)

showing the atom-labelling scheme and displacement ellipsoids at the 70% probability level. The dashed line indicates a hydrogen bond.

The anion in (III), Fig. 3, exhibits the greatest twist between the carboxylate and benzene groups among the series but, a con-rotatory relationship between the carboxylate and nitro substituents means the dihedral angle between them is not as great as in the anion of (I), Tables 1 and 4. The (HOCH₂)₃CN⁽⁺⁾H₃ cation exhibits N3—C8—C9—O5, N3—C8—C10—O6 and N3—C8—C11—O7 torsion angles of −59.01 (18), −49.84 (19) and −58.12 (18)°, respectively, indicating −syn-clinal relationships.

Table 4
Hydrogen-bond geometry (Å, °) for (III)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1N⋯O1	0.88 (2)	2.02 (2)	2.678 (2)	131 (2)
N1—H1N⋯O3ⁱ	0.88 (2)	2.50 (2)	3.210 (2)	138 (1)
N1—H2N⋯O4ⁱⁱ	0.88 (1)	2.56 (2)	3.094 (2)	120 (2)
N3—H3N⋯O6ⁱⁱⁱ	0.89 (2)	2.34 (2)	2.934 (2)	124 (1)
N3—H3N⋯O7^iv	0.89 (2)	2.44 (2)	3.065 (2)	128 (2)
N3—H4N⋯O5^v	0.89 (1)	2.08 (1)	2.945 (2)	165 (2)
N3—H5N⋯O2^vi	0.89 (2)	1.92 (2)	2.773 (2)	160 (2)
O5—H5O⋯O2^vii	0.85 (2)	1.90 (2)	2.7453 (18)	175 (2)
O6—H6O⋯O1^viii	0.84 (2)	1.88 (2)	2.6993 (19)	163 (2)
O7—H7O⋯O1^ix	0.84 (2)	2.07 (2)	2.8905 (18)	164 (2)
Symmetry codes: (i) $[-x+1, y+{\script{1\over 2}}, -z+{\script{3\over 2}}]$ ; (ii) $[x, -y+{\script{1\over 2}}, z-{\script{1\over 2}}]$ ; (iii) $[-x+2, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]$ ; (iv) -x+2, -y+1, -z+1; (v) $[-x+2, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]$ ; (vi) $[x+1, -y+{\script{1\over 2}}, z-{\script{3\over 2}}]$ ; (vii) $[-x+1, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]$ ; (viii) -x+1, -y+2, -z+1; (ix) $[-x+1, y-{\script{1\over 2}}, -z+{\script{3\over 2}}]$ .

Figure 3
The molecular structures of the ions comprising the asymmetric unit of (III)

showing the atom-labelling scheme and displacement ellipsoids at the 70% probability level.

3. Supramolecular features

As expected from the chemical compositions of (I)–(III), significant charge-assisted hydrogen-bonding is apparent in their respective crystals. Geometric data characterizing these and other identified interactions are collated in Tables 2–4 , respectively.

As indicated in Fig. 1, the anion and cation in (I) are linked via charge-assisted ammonium-N3—H⋯O(carboxylate) and hydroxy-O—H⋯O(carboxylate) hydrogen-bonds to form a nine-membered {⋯OCO⋯HNC₂OH} heterosynthon. These are connected into a linear, supramolecular chain along the a-axis direction via amino-N—H⋯O(carboxylate) hydrogen-bonds, Fig. 4(a). The chains are linked along the b axis via π–π interactions between benzene rings [inter-centroid separation = 3.5796 (10) Å for symmetry operation: −x, −y, 1 − z], and methyl-C—H⋯O(hydroxy) interactions link molecules along the c-axis to consolidate the three-dimensional packing, Fig. 4(b).

Figure 4
The molecular packing in (I)

: (a) linear, supramolecular chain along the a axis sustained by charge-assisted amine-N—H⋯O(carboxylate) and hydroxy-O—H⋯O(carboxylate) hydrogen-bonding interactions shown as blue and orange dashed lines, respectively; intramolecular amine-N—H⋯O(carboxylate) hydrogen bonds are represented by pink dashed lines, and (b) a view of the unit-cell contents in projection down the a axis. The methyl-C—H⋯O(hydroxy) and π–π interactions are shown as green and purple dashed lines, respectively.

In the crystal of (II), the charge-assisted ammonium-N3—H⋯O(carboxylate) and hydroxy-O—H⋯O(carboxylate) hydrogen-bonds, that lead to the formation of a nine-membered {⋯OCO⋯HNC₂OH} heterosynthon, observed in (I) persist, Fig. 5(a). However, in (II), through the agency of having two ammonium-N—H H atoms, the second H atom bridges a neighbouring carboxylate-O2 atom leading to the formation of a supramolecular tube, as highlighted in Fig. 5(b). As seen from Fig. 5(b), the benzene rings are aligned to be proximate and, indeed, they interact via π–π stacking with the inter-centroid separation being 3.4944 (9) Å (symmetry operation: 1 − x, y, $[{1\over 2}]$ − z). The carboxylate-O2 atom forms two hydrogen-bonds. The connections between the tubes are of the type methylene- and methyl-C—H⋯O(nitro), involving both nitro-O atoms, as well as π–π stacking between benzene rings [inter-centroid separation = 3.5226 (10) Å for symmetry operation: 1 − x, 1 − y, −z]. A view of the unit-cell contents is shown in Fig. 5(c), highlighting the intra- and inter-tube π–π stacking along the c-axis direction.

Figure 5
The molecular packing in (II)

: (a) linear, supramolecular tube along [901] sustained by charge-assisted amine-N—H⋯O(carboxylate) and hydroxy-O—H⋯O(carboxylate) hydrogen-bonding interactions shown as blue and orange dashed lines, respectively; intramolecular amine-N—H⋯O(carboxylate) hydrogen bonds are represented by pink dashed lines, (b) end-on view of the supramolecular tube and (c) a view of the unit-cell contents in projection down the c axis. The methylene-, methyl-C—H⋯O(nitro) and π–π interactions are shown as green and purple dashed lines, respectively. In each of (a) and (b), non-participating H atoms are omitted.

In the crystal of (III), supramolecular double-layers in the bc-plane are formed as a result of charge-assisted ammonium-N3—H⋯O(carboxylate), ammonium-N3—H⋯O(hydroxy) and hydroxy-O—H⋯O(carboxylate) hydrogen-bonds. The ammonium-N3—H3N atom is bifurcated, forming two weak ammonium-N3—H⋯O(hydroxy) hydrogen-bonds. A view normal to the plane of the double-layer and a side-on view are shown in Fig. 6(a) and (b), respectively. From the latter, the intra-layer region comprises the ammonium groups, each of which forms four N—H⋯O hydrogen-bonds to carboxylate and hydroxy groups on either side. Each hydroxy group of the cation forms a hydroxy-O—H⋯O(carboxylate) hydrogen-bond with a carboxylate-O atom derived from a different anion, and each accepts an ammonium-N—H atom derived from a different cation. Each carboxylate-O atom forms two hydrogen-bonds, the O1 accepts hydrogen-bonds from different hydroxy groups, and the O2 atom accept hydrogen-bonds from hydroxy and ammonium groups. Projecting to either side of the double-layer are the nitrobenzene groups, Fig. 6(c) and (d). These provide the links to construct the three-dimensional architecture, i.e. via amine-N—H⋯O(nitro) interactions, involving both nitro-O atoms.

Figure 6
The molecular packing in (III)

: (a) plan and (b) views of the double-layer sustained by charge-assisted ammonium-N3—H⋯O(carboxylate), ammonium-N3—H⋯O(hydroxy) (blue dashed lines) and hydroxy-O—H⋯O(carboxylate) (orange dashed lines) hydrogen bonds, and views of the unit-cell contents in projection down the (c) c axis and (d) b axis. In (c) and (d), the intramolecular amine-N—H⋯O(carboxylate) and amine-N—H⋯O(nitro) interactions are represented by pink and brown dashed lines, respectively. In each of (a)–(d), non-participating H atoms are omitted.

The obvious trend from the present study is the increase in dimensionality of the supramolecular aggregation pattern, i.e. chain in (I), tube in (II) and double-layer in (III), as the number of acidic ammonium-N—H atoms increases.

4. Database survey

As indicated in the Chemical context, a number of ammonium salts of the anion derived from 2-amino-4-nitrobenzoic acid have now been described. The key conformational indicators for the anion are the dihedral angles formed between CO₂/C₆/NO₂. The smallest dihedral angles between the CO₂/C₆, C₆/NO₂ and CO₂/NO₂ pairs of least-squares planes of 3.44 (14), 0.69 (11) and 3.2 (2)° are found for the anion in the salt with H₃N⁽⁺⁾CH₂CH₂N⁽⁺⁾H₃ (Smith et al., 2002). Conversely, the greatest CO₂/C₆, C₆/NO₂ and CO₂/NO₂ dihedral angles of 26.4 (3), 12.6 (3) and 26.73 (14)°, respectively, are found in the N⁽⁺⁾H₄ (Smith, 2014b), n-Bu₂N⁽⁺⁾H₂ (Wardell et al., 2016) and H₂NN⁽⁺⁾H₃ (Wardell et al., 2017) salts, respectively. The respective dihedral angles in (I)–(III), described herein, fall within these ranges.

5. Synthesis and crystallization

Preparation of dimethyl(2-hydroxyethyl)ammonium 2-amino-4-nitrobenzoate (I). To a solution of 2-amino-4-nitrobenzoic acid (1 mmol) in methanol (10 ml) was added a solution of dimethyl(2-hydroxyethyl)amine (1 mmol) in methanol (10 ml). The reaction mixture was refluxed for 15 mins, and then maintained at room temperature. Crystals of (I) were collected after three days. M.p. 444–447 K. Anal. calcd.: C, 48.89; H, 5.97, N, 15.54. Found: C, 48.81; H, 5.89; N, 14.68%. IR (KBr, cm⁻¹): 3500–2700 (br, s; with maxima at 3439, 3324, 3219, 2978, 2826), 1632, 1537, 1433, 1381, 1346, 1329, 1279, 1263, 1209, 1140, 1099, 1072, 1022, 918, 858, 823, 785, 731, 692, 684, 577, 513, 486.

Preparation of tert-butyl(2-hydroxyethyl)ammonium 2-amino-4-nitrobenzoate (II). To a solution of 2-amino-4-nitrobenzoic acid (1 mmol) in methanol (10 ml) was added a solution of tert-butyl(2-hydroxyethyl)amine (1 mmol) in methanol (10 ml). The reaction mixture was refluxed for 15 mins, and then maintained at room temperature. Crystals of (II) were collected after 3 days. M.p. 429–431 K. Anal. calcd.: C, 52.34; H, 6.76, N, 14.09. Found: C, 52.27; H, 6.89; N, 13.99%. IR (KBr, cm⁻¹): 3550–2700 (br, s, with maxima at 3430, 3327, 3224, 2968, 2810), 1640, 1446, 1370, 1351, 1329, 1269, 1221 1137, 1085, 1034, 858, 8245, 739, 687, 587.

Preparation of tris(hydroxymethyl)methylammonium 2-amino-4-nitrobenzoate (III): To a solution of 2-amino-4-nitrobenzoic acid (1 mmol) in ethanol (10 ml) was added a solution of tris(hydroxymethyl)methylamine (1 mmol) in ethanol (10 ml). The reaction mixture was refluxed for 10 mins, and then maintained at room temperature. Crystals of (III) were collected after two days. M.p. 460–463 K. Anal. calcd.: C, 51.06; H, 5.71, N, 14.89. Found: C, 50.94; H, 5.80; N, 14.79% IR (KBr, cm⁻¹): 3700–2400 (br, s, with maxima at 3514, 3477, 3398, 3314, 3256, 3078, 2823 and 2538), 1647, 1431, 1350 1250, 1146, 1115, 1063, 1010, 872, 827, 736, 689, 596, 578 511, 484, 1549, 1356.

6. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 5. Carbon-bound H atoms were placed in calculated positions (C—H = 0.95–0.99 Å) and were included in the refinement in the riding-model approximation, with U_iso(H) set to 1.2–1.5U_eq(C). The O- and N-bound H atoms were located from difference maps, but refined with O—H = 0.84±0.01 Å and U_iso(H) = 1.5U_eq(O), and with N—H = 0.86–0.88±0.01 Å and U_iso(H) = 1.2U_eq(N), respectively. In the refinement of (II), owing to poor agreement, a reflection, i.e. (0 2 0), was omitted from the final cycles of refinement.

Table 5
Experimental details

	(I)	(II)	(III)
Crystal data
Chemical formula	C₄H₁₂NO⁺·C₇H₅N₂O₄⁻	C₆H₁₆NO⁺·C₇H₅N₂O₄⁻	C₄H₁₂NO₃⁺·C₇H₅N₂O₄⁻
M_r	271.27	299.33	303.27
Crystal system, space group	Monoclinic, P2₁/n	Monoclinic, C2/c	Monoclinic, P2₁/c
Temperature (K)	120	120	120
a, b, c (Å)	6.6816 (2), 22.8286 (8), 8.6570 (3)	21.1138 (5), 12.3635 (5), 13.1909 (4)	13.6269 (6), 9.4976 (3), 10.2042 (4)
β (°)	104.551 (2)	120.627 (2)	90.355 (2)
V (Å³)	1278.11 (7)	2963.02 (17)	1320.63 (9)
Z	4	8	4
Radiation type	Mo Kα	Mo Kα	Mo Kα
μ (mm⁻¹)	0.11	0.10	0.13
Crystal size (mm)	0.22 × 0.10 × 0.06	0.62 × 0.26 × 0.10	0.38 × 0.22 × 0.09

Data collection
Diffractometer	Bruker–Nonius Roper CCD camera on κ-goniostat	Bruker–Nonius Roper CCD camera on κ-goniostat	Bruker–Nonius Roper CCD camera on κ-goniostat
Absorption correction	Multi-scan (SADABS; Sheldrick, 2007 )	Multi-scan (SADABS; Sheldrick, 2007)	Multi-scan (SADABS; Sheldrick, 2007)
T_min, T_max	0.847, 1.000	0.652, 0.746	0.656, 0.746
No. of measured, independent and observed [I > 2σ(I)] reflections	9689, 2911, 2380	18353, 3406, 2349	16747, 3027, 2183
R_int	0.043	0.065	0.069
(sin θ/λ)_max (Å⁻¹)	0.649	0.651	0.651

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.054, 0.123, 1.07	0.050, 0.135, 1.02	0.048, 0.122, 1.04
No. of reflections	2911	3406	3027
No. of parameters	186	208	214
No. of restraints	4	5	8
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement	H atoms treated by a mixture of independent and constrained refinement	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.27, −0.32	0.24, −0.33	0.31, −0.26
Computer programs: DENZO (Otwinowski & Minor, 1997 ), COLLECT (Hooft, 1998 ), SHELXS97 (Sheldrick, 2008 ), SHELXL2014 (Sheldrick, 2015 ), ORTEP-3 for Windows (Farrugia, 2012 ), DIAMOND (Brandenburg, 2006 ) and publCIF (Westrip, 2010 ).

Supporting information

CCDC references: 1876928; 1876927; 1876926

Crystal structure: contains datablocks I, II, III, global. DOI: https://doi.org/10.1107/S2056989018015578/hb7785sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989018015578/hb7785Isup2.hkl

Structure factors: contains datablock II. DOI: https://doi.org/10.1107/S2056989018015578/hb7785IIsup3.hkl

Structure factors: contains datablock III. DOI: https://doi.org/10.1107/S2056989018015578/hb7785IIIsup4.hkl

Supporting information file. DOI: https://doi.org/10.1107/S2056989018015578/hb7785Isup5.cml

Supporting information file. DOI: https://doi.org/10.1107/S2056989018015578/hb7785IIsup6.cml

Supporting information file. DOI: https://doi.org/10.1107/S2056989018015578/hb7785IIIsup7.cml

checkCIF report

Computing details top

For all structures, data collection: COLLECT (Hooft, 1998); cell refinement: DENZO (Otwinowski & Minor, 1997) and COLLECT (Hooft, 1998); data reduction: DENZO (Otwinowski & Minor, 1997) and COLLECT (Hooft, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012) and DIAMOND (Brandenburg, 2006); software used to prepare material for publication: publCIF (Westrip, 2010).

2-Amino-4-nitrobenzoate (2-hydroxyethyl)dimethylazanium (I) top

Crystal data top

C₄H₁₂NO⁺·C₇H₅N₂O₄⁻	F(000) = 576
M_r = 271.27	D_x = 1.410 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
a = 6.6816 (2) Å	Cell parameters from 8678 reflections
b = 22.8286 (8) Å	θ = 2.9–27.5°
c = 8.6570 (3) Å	µ = 0.11 mm⁻¹
β = 104.551 (2)°	T = 120 K
V = 1278.11 (7) Å³	Blade, yellow
Z = 4	0.22 × 0.10 × 0.06 mm

Data collection top

Bruker–Nonius Roper CCD camera on κ-goniostat diffractometer	2911 independent reflections
Radiation source: Bruker–Nonius FR591 rotating anode	2380 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.043
Detector resolution: 9.091 pixels mm^-1	θ_max = 27.5°, θ_min = 3.0°
φ & ω scans	h = −8→8
Absorption correction: multi-scan (SADABS; Sheldrick, 2007)	k = −29→29
T_min = 0.847, T_max = 1.000	l = −11→10
9689 measured reflections

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Hydrogen site location: mixed
R[F² > 2σ(F²)] = 0.054	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.123	w = 1/[σ²(F_o²) + (0.0305P)² + 1.1579P] where P = (F_o² + 2F_c²)/3
S = 1.07	(Δ/σ)_max < 0.001
2911 reflections	Δρ_max = 0.27 e Å⁻³
186 parameters	Δρ_min = −0.31 e Å⁻³
4 restraints

Special details top

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.

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

	x	y	z	U_iso*/U_eq
O1	0.16272 (19)	0.18360 (5)	0.56894 (15)	0.0234 (3)
O2	0.3854 (2)	0.15398 (6)	0.43175 (16)	0.0276 (3)
O3	−0.4660 (3)	−0.04973 (8)	0.2249 (3)	0.0617 (6)
O4	−0.2616 (3)	−0.06559 (8)	0.0708 (2)	0.0553 (5)
N1	−0.1707 (2)	0.11839 (7)	0.5634 (2)	0.0270 (4)
H1N	−0.101 (3)	0.1513 (6)	0.593 (3)	0.032*
H2N	−0.3042 (16)	0.1187 (10)	0.558 (3)	0.032*
N2	−0.3090 (3)	−0.03927 (8)	0.1803 (2)	0.0385 (4)
C1	0.0836 (3)	0.09665 (7)	0.4120 (2)	0.0188 (3)
C2	−0.1058 (3)	0.08640 (7)	0.4521 (2)	0.0205 (4)
C3	−0.2321 (3)	0.04031 (8)	0.3743 (2)	0.0258 (4)
H3	−0.3606	0.0324	0.3984	0.031*
C4	−0.1684 (3)	0.00696 (8)	0.2634 (2)	0.0275 (4)
C5	0.0187 (3)	0.01502 (8)	0.2244 (2)	0.0283 (4)
H5	0.0602	−0.0094	0.1491	0.034*
C6	0.1419 (3)	0.06031 (8)	0.3006 (2)	0.0237 (4)
H6	0.2711	0.0670	0.2765	0.028*
C7	0.2213 (3)	0.14808 (7)	0.4763 (2)	0.0190 (3)
O5	0.59794 (19)	0.25309 (6)	0.51573 (16)	0.0249 (3)
H5O	0.529 (3)	0.2221 (7)	0.489 (3)	0.037*
N3	0.1711 (2)	0.29912 (6)	0.52114 (17)	0.0189 (3)
H3N	0.206 (3)	0.2616 (5)	0.548 (2)	0.023*
C8	0.3578 (3)	0.33333 (8)	0.5092 (2)	0.0250 (4)
H8A	0.4401	0.3433	0.6180	0.030*
H8B	0.3126	0.3705	0.4520	0.030*
C9	0.4932 (3)	0.30024 (8)	0.4229 (2)	0.0256 (4)
H9A	0.4067	0.2848	0.3209	0.031*
H9B	0.5960	0.3274	0.3976	0.031*
C10	0.0140 (3)	0.29638 (9)	0.3653 (2)	0.0252 (4)
H10A	−0.1042	0.2729	0.3768	0.038*
H10B	0.0753	0.2783	0.2853	0.038*
H10C	−0.0327	0.3361	0.3311	0.038*
C11	0.0766 (3)	0.32355 (8)	0.6464 (2)	0.0251 (4)
H11A	0.0397	0.3647	0.6223	0.038*
H11B	0.1760	0.3208	0.7508	0.038*
H11C	−0.0481	0.3012	0.6482	0.038*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0236 (6)	0.0214 (6)	0.0258 (7)	−0.0023 (5)	0.0074 (5)	−0.0044 (5)
O2	0.0251 (7)	0.0280 (7)	0.0326 (7)	−0.0051 (5)	0.0126 (6)	−0.0029 (6)
O3	0.0404 (10)	0.0457 (10)	0.0971 (16)	−0.0189 (8)	0.0135 (10)	−0.0275 (10)
O4	0.0809 (13)	0.0412 (9)	0.0422 (10)	−0.0246 (9)	0.0125 (9)	−0.0190 (8)
N1	0.0216 (8)	0.0259 (8)	0.0358 (9)	−0.0034 (6)	0.0115 (7)	−0.0050 (7)
N2	0.0422 (11)	0.0233 (8)	0.0432 (11)	−0.0063 (8)	−0.0018 (8)	−0.0034 (8)
C1	0.0206 (8)	0.0158 (8)	0.0182 (8)	0.0004 (6)	0.0015 (6)	0.0023 (6)
C2	0.0206 (8)	0.0171 (8)	0.0214 (8)	0.0016 (6)	0.0009 (6)	0.0034 (7)
C3	0.0214 (9)	0.0200 (8)	0.0328 (10)	−0.0014 (7)	0.0005 (7)	0.0039 (8)
C4	0.0332 (10)	0.0169 (8)	0.0266 (9)	−0.0031 (7)	−0.0028 (8)	−0.0002 (7)
C5	0.0388 (11)	0.0197 (9)	0.0253 (9)	0.0016 (8)	0.0061 (8)	−0.0015 (7)
C6	0.0269 (9)	0.0219 (9)	0.0217 (9)	0.0030 (7)	0.0052 (7)	0.0019 (7)
C7	0.0196 (8)	0.0177 (8)	0.0185 (8)	0.0005 (6)	0.0025 (6)	0.0046 (6)
O5	0.0202 (6)	0.0237 (6)	0.0296 (7)	−0.0017 (5)	0.0041 (5)	0.0036 (5)
N3	0.0183 (7)	0.0195 (7)	0.0186 (7)	−0.0002 (6)	0.0042 (5)	−0.0013 (6)
C8	0.0218 (9)	0.0229 (9)	0.0304 (10)	−0.0054 (7)	0.0067 (7)	−0.0026 (7)
C9	0.0225 (9)	0.0256 (9)	0.0307 (10)	−0.0007 (7)	0.0106 (7)	0.0070 (8)
C10	0.0208 (8)	0.0318 (10)	0.0209 (9)	−0.0013 (7)	0.0014 (7)	−0.0028 (7)
C11	0.0288 (9)	0.0273 (9)	0.0211 (9)	0.0027 (8)	0.0099 (7)	−0.0034 (7)

Geometric parameters (Å, º) top

O1—C7	1.270 (2)	O5—C9	1.418 (2)
O2—C7	1.258 (2)	O5—H5O	0.843 (10)
O3—N2	1.229 (3)	N3—C10	1.488 (2)
O4—N2	1.229 (3)	N3—C11	1.493 (2)
N1—C2	1.363 (2)	N3—C8	1.498 (2)
N1—H1N	0.886 (10)	N3—H3N	0.902 (9)
N1—H2N	0.881 (9)	C8—C9	1.512 (3)
N2—C4	1.474 (2)	C8—H8A	0.9900
C1—C6	1.399 (2)	C8—H8B	0.9900
C1—C2	1.413 (2)	C9—H9A	0.9900
C1—C7	1.509 (2)	C9—H9B	0.9900
C2—C3	1.410 (2)	C10—H10A	0.9800
C3—C4	1.374 (3)	C10—H10B	0.9800
C3—H3	0.9500	C10—H10C	0.9800
C4—C5	1.387 (3)	C11—H11A	0.9800
C5—C6	1.382 (3)	C11—H11B	0.9800
C5—H5	0.9500	C11—H11C	0.9800
C6—H6	0.9500

C2—N1—H1N	115.2 (14)	C10—N3—C8	111.68 (14)
C2—N1—H2N	117.5 (15)	C11—N3—C8	111.54 (14)
H1N—N1—H2N	117 (2)	C10—N3—H3N	105.8 (13)
O3—N2—O4	123.56 (18)	C11—N3—H3N	107.4 (13)
O3—N2—C4	118.39 (19)	C8—N3—H3N	110.1 (13)
O4—N2—C4	118.05 (19)	N3—C8—C9	112.70 (14)
C6—C1—C2	119.52 (16)	N3—C8—H8A	109.1
C6—C1—C7	117.77 (15)	C9—C8—H8A	109.1
C2—C1—C7	122.59 (15)	N3—C8—H8B	109.1
N1—C2—C3	118.61 (16)	C9—C8—H8B	109.1
N1—C2—C1	123.25 (15)	H8A—C8—H8B	107.8
C3—C2—C1	118.14 (16)	O5—C9—C8	111.72 (15)
C4—C3—C2	119.58 (17)	O5—C9—H9A	109.3
C4—C3—H3	120.2	C8—C9—H9A	109.3
C2—C3—H3	120.2	O5—C9—H9B	109.3
C3—C4—C5	123.60 (17)	C8—C9—H9B	109.3
C3—C4—N2	117.77 (18)	H9A—C9—H9B	107.9
C5—C4—N2	118.63 (18)	N3—C10—H10A	109.5
C6—C5—C4	116.63 (18)	N3—C10—H10B	109.5
C6—C5—H5	121.7	H10A—C10—H10B	109.5
C4—C5—H5	121.7	N3—C10—H10C	109.5
C5—C6—C1	122.49 (18)	H10A—C10—H10C	109.5
C5—C6—H6	118.8	H10B—C10—H10C	109.5
C1—C6—H6	118.8	N3—C11—H11A	109.5
O2—C7—O1	123.80 (16)	N3—C11—H11B	109.5
O2—C7—C1	117.90 (15)	H11A—C11—H11B	109.5
O1—C7—C1	118.28 (15)	N3—C11—H11C	109.5
C9—O5—H5O	108.9 (16)	H11A—C11—H11C	109.5
C10—N3—C11	110.07 (14)	H11B—C11—H11C	109.5

C6—C1—C2—N1	177.60 (16)	C3—C4—C5—C6	−1.6 (3)
C7—C1—C2—N1	−6.6 (3)	N2—C4—C5—C6	177.51 (17)
C6—C1—C2—C3	−1.6 (2)	C4—C5—C6—C1	0.1 (3)
C7—C1—C2—C3	174.24 (15)	C2—C1—C6—C5	1.5 (3)
N1—C2—C3—C4	−179.05 (17)	C7—C1—C6—C5	−174.52 (16)
C1—C2—C3—C4	0.2 (2)	C6—C1—C7—O2	−3.1 (2)
C2—C3—C4—C5	1.5 (3)	C2—C1—C7—O2	−178.95 (15)
C2—C3—C4—N2	−177.62 (16)	C6—C1—C7—O1	175.26 (15)
O3—N2—C4—C3	−7.2 (3)	C2—C1—C7—O1	−0.6 (2)
O4—N2—C4—C3	173.39 (19)	C10—N3—C8—C9	−73.87 (19)
O3—N2—C4—C5	173.7 (2)	C11—N3—C8—C9	162.49 (15)
O4—N2—C4—C5	−5.7 (3)	N3—C8—C9—O5	−71.15 (19)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O1	0.89 (2)	1.97 (2)	2.6698 (19)	135 (2)
N1—H2N···O2ⁱ	0.88 (1)	2.24 (2)	3.010 (2)	146 (2)
N3—H3N···O1	0.90 (1)	1.82 (1)	2.6722 (18)	156 (2)
O5—H5O···O2	0.84 (2)	1.83 (2)	2.6731 (19)	179 (3)
C10—H10B···O5ⁱⁱ	0.98	2.48	3.406 (2)	157

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

2-Amino-4-nitrobenzoate tert-butyl(2-hydroxyethyl)azanium (II) top

Crystal data top

C₆H₁₆NO⁺·C₇H₅N₂O₄⁻	F(000) = 1280
M_r = 299.33	D_x = 1.342 Mg m⁻³
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 21.1138 (5) Å	Cell parameters from 8229 reflections
b = 12.3635 (5) Å	θ = 2.9–27.5°
c = 13.1909 (4) Å	µ = 0.10 mm⁻¹
β = 120.627 (2)°	T = 120 K
V = 2963.02 (17) Å³	Slab, orange
Z = 8	0.62 × 0.26 × 0.10 mm

Data collection top

Bruker–Nonius Roper CCD camera on κ-goniostat diffractometer	3406 independent reflections
Radiation source: Bruker–Nonius FR591 rotating anode	2349 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.065
Detector resolution: 9.091 pixels mm^-1	θ_max = 27.6°, θ_min = 3.0°
φ & ω scans	h = −27→27
Absorption correction: multi-scan (SADABS; Sheldrick, 2007)	k = −16→15
T_min = 0.652, T_max = 0.746	l = −17→17
18353 measured reflections

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Hydrogen site location: mixed
R[F² > 2σ(F²)] = 0.050	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.135	w = 1/[σ²(F_o²) + (0.0712P)² + 0.7685P] where P = (F_o² + 2F_c²)/3
S = 1.02	(Δ/σ)_max < 0.001
3406 reflections	Δρ_max = 0.24 e Å⁻³
208 parameters	Δρ_min = −0.33 e Å⁻³
5 restraints

Special details top

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

	x	y	z	U_iso*/U_eq
O1	0.38287 (6)	0.76025 (10)	0.01169 (10)	0.0301 (3)
O2	0.29310 (6)	0.63783 (10)	−0.04670 (10)	0.0263 (3)
O3	0.63480 (6)	0.33794 (10)	0.24135 (11)	0.0305 (3)
O4	0.54488 (7)	0.22405 (10)	0.17418 (13)	0.0400 (4)
N1	0.52324 (7)	0.69991 (12)	0.14202 (13)	0.0241 (3)
N2	0.56872 (7)	0.31665 (12)	0.18823 (12)	0.0241 (3)
C1	0.41726 (8)	0.57689 (13)	0.05554 (13)	0.0188 (4)
C2	0.49416 (8)	0.59915 (13)	0.12014 (12)	0.0187 (4)
C3	0.54245 (8)	0.51022 (13)	0.16275 (13)	0.0192 (4)
H3	0.5941	0.5221	0.2073	0.023*
C4	0.51565 (8)	0.40665 (13)	0.14053 (13)	0.0195 (4)
C5	0.44091 (8)	0.38249 (14)	0.07707 (13)	0.0215 (4)
H5	0.4235	0.3101	0.0624	0.026*
C6	0.39357 (8)	0.46956 (14)	0.03667 (13)	0.0214 (4)
H6	0.3421	0.4558	−0.0063	0.026*
C7	0.36039 (8)	0.66455 (14)	0.00382 (13)	0.0216 (4)
O5	0.69062 (6)	0.71809 (10)	0.29593 (11)	0.0303 (3)
N3	0.79731 (7)	0.56819 (12)	0.45647 (12)	0.0231 (3)
C8	0.84793 (9)	0.47891 (15)	0.53503 (16)	0.0292 (4)
C9	0.80464 (11)	0.37480 (16)	0.5120 (2)	0.0444 (5)
H9A	0.7623	0.3876	0.5219	0.067*
H9B	0.8363	0.3192	0.5678	0.067*
H9C	0.7873	0.3503	0.4313	0.067*
C10	0.87684 (12)	0.51860 (17)	0.66040 (17)	0.0448 (5)
H10A	0.8355	0.5298	0.6732	0.067*
H10B	0.9032	0.5870	0.6724	0.067*
H10C	0.9104	0.4646	0.7163	0.067*
C11	0.91074 (10)	0.46495 (17)	0.51089 (19)	0.0402 (5)
H11A	0.9478	0.4160	0.5696	0.060*
H11B	0.9333	0.5355	0.5155	0.060*
H11C	0.8916	0.4344	0.4320	0.060*
C12	0.75766 (9)	0.54960 (16)	0.32642 (15)	0.0310 (4)
H12A	0.7141	0.5033	0.3028	0.037*
H12B	0.7905	0.5118	0.3049	0.037*
C13	0.73361 (9)	0.65690 (16)	0.26214 (15)	0.0301 (4)
H13A	0.7777	0.6992	0.2789	0.036*
H13B	0.7046	0.6434	0.1762	0.036*
H1N	0.4925 (9)	0.7539 (12)	0.1137 (17)	0.036*
H2N	0.5715 (5)	0.7082 (16)	0.1885 (15)	0.036*
H5O	0.7197 (10)	0.7625 (14)	0.3464 (15)	0.045*
H3N	0.8263 (9)	0.6272 (11)	0.4739 (16)	0.036*
H4N	0.7637 (8)	0.5810 (16)	0.4767 (16)	0.036*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0220 (6)	0.0240 (7)	0.0377 (7)	0.0031 (5)	0.0104 (6)	0.0033 (5)
O2	0.0159 (6)	0.0339 (7)	0.0272 (6)	0.0023 (5)	0.0096 (5)	0.0055 (5)
O3	0.0197 (6)	0.0276 (7)	0.0389 (7)	0.0024 (5)	0.0112 (5)	−0.0006 (6)
O4	0.0337 (7)	0.0186 (7)	0.0580 (9)	−0.0016 (6)	0.0163 (7)	0.0032 (6)
N1	0.0169 (7)	0.0189 (8)	0.0318 (8)	−0.0002 (6)	0.0089 (6)	−0.0009 (6)
N2	0.0223 (7)	0.0237 (8)	0.0254 (7)	0.0007 (6)	0.0114 (6)	0.0000 (6)
C1	0.0181 (8)	0.0232 (9)	0.0162 (7)	0.0006 (7)	0.0096 (6)	0.0000 (6)
C2	0.0192 (8)	0.0221 (9)	0.0158 (7)	−0.0003 (7)	0.0097 (6)	−0.0004 (6)
C3	0.0160 (7)	0.0246 (9)	0.0177 (7)	−0.0009 (6)	0.0090 (6)	−0.0006 (6)
C4	0.0206 (8)	0.0194 (9)	0.0194 (7)	0.0028 (7)	0.0110 (6)	0.0018 (6)
C5	0.0222 (8)	0.0208 (9)	0.0229 (8)	−0.0042 (7)	0.0125 (7)	−0.0024 (7)
C6	0.0172 (7)	0.0294 (10)	0.0182 (7)	−0.0029 (7)	0.0095 (6)	−0.0022 (7)
C7	0.0200 (8)	0.0271 (10)	0.0174 (7)	0.0036 (7)	0.0093 (6)	0.0022 (7)
O5	0.0202 (6)	0.0296 (8)	0.0306 (7)	−0.0012 (5)	0.0053 (5)	−0.0053 (5)
N3	0.0181 (7)	0.0210 (8)	0.0295 (7)	−0.0011 (6)	0.0114 (6)	−0.0027 (6)
C8	0.0236 (8)	0.0234 (10)	0.0378 (10)	0.0060 (7)	0.0136 (8)	0.0037 (8)
C9	0.0352 (10)	0.0261 (11)	0.0740 (15)	0.0047 (9)	0.0295 (11)	0.0084 (10)
C10	0.0526 (12)	0.0396 (12)	0.0357 (11)	0.0156 (10)	0.0178 (10)	0.0129 (9)
C11	0.0247 (9)	0.0367 (12)	0.0578 (13)	0.0075 (8)	0.0200 (9)	0.0040 (10)
C12	0.0227 (8)	0.0326 (11)	0.0304 (9)	−0.0014 (7)	0.0083 (7)	−0.0104 (8)
C13	0.0250 (9)	0.0379 (11)	0.0232 (8)	−0.0032 (8)	0.0093 (7)	−0.0060 (8)

Geometric parameters (Å, º) top

O1—C7	1.259 (2)	N3—C8	1.519 (2)
O2—C7	1.2678 (19)	N3—H3N	0.903 (9)
O3—N2	1.2292 (17)	N3—H4N	0.890 (9)
O4—N2	1.2262 (18)	C8—C9	1.517 (3)
N1—C2	1.353 (2)	C8—C11	1.523 (3)
N1—H1N	0.872 (9)	C8—C10	1.523 (3)
N1—H2N	0.887 (9)	C9—H9A	0.9800
N2—C4	1.473 (2)	C9—H9B	0.9800
C1—C6	1.395 (2)	C9—H9C	0.9800
C1—C2	1.424 (2)	C10—H10A	0.9800
C1—C7	1.499 (2)	C10—H10B	0.9800
C2—C3	1.407 (2)	C10—H10C	0.9800
C3—C4	1.370 (2)	C11—H11A	0.9800
C3—H3	0.9500	C11—H11B	0.9800
C4—C5	1.391 (2)	C11—H11C	0.9800
C5—C6	1.378 (2)	C12—C13	1.516 (3)
C5—H5	0.9500	C12—H12A	0.9900
C6—H6	0.9500	C12—H12B	0.9900
O5—C13	1.417 (2)	C13—H13A	0.9900
O5—H5O	0.841 (10)	C13—H13B	0.9900
N3—C12	1.494 (2)

C2—N1—H1N	117.1 (13)	C9—C8—C11	111.21 (16)
C2—N1—H2N	119.3 (13)	N3—C8—C11	108.94 (15)
H1N—N1—H2N	123.4 (19)	C9—C8—C10	111.00 (17)
O4—N2—O3	123.05 (14)	N3—C8—C10	105.08 (14)
O4—N2—C4	118.44 (13)	C11—C8—C10	110.70 (16)
O3—N2—C4	118.50 (14)	C8—C9—H9A	109.5
C6—C1—C2	119.11 (14)	C8—C9—H9B	109.5
C6—C1—C7	118.37 (13)	H9A—C9—H9B	109.5
C2—C1—C7	122.50 (14)	C8—C9—H9C	109.5
N1—C2—C3	118.44 (13)	H9A—C9—H9C	109.5
N1—C2—C1	124.09 (14)	H9B—C9—H9C	109.5
C3—C2—C1	117.46 (14)	C8—C10—H10A	109.5
C4—C3—C2	120.56 (14)	C8—C10—H10B	109.5
C4—C3—H3	119.7	H10A—C10—H10B	109.5
C2—C3—H3	119.7	C8—C10—H10C	109.5
C3—C4—C5	123.22 (15)	H10A—C10—H10C	109.5
C3—C4—N2	118.23 (13)	H10B—C10—H10C	109.5
C5—C4—N2	118.54 (14)	C8—C11—H11A	109.5
C6—C5—C4	116.24 (15)	C8—C11—H11B	109.5
C6—C5—H5	121.9	H11A—C11—H11B	109.5
C4—C5—H5	121.9	C8—C11—H11C	109.5
C5—C6—C1	123.40 (14)	H11A—C11—H11C	109.5
C5—C6—H6	118.3	H11B—C11—H11C	109.5
C1—C6—H6	118.3	N3—C12—C13	109.85 (14)
O1—C7—O2	124.24 (15)	N3—C12—H12A	109.7
O1—C7—C1	117.45 (13)	C13—C12—H12A	109.7
O2—C7—C1	118.31 (15)	N3—C12—H12B	109.7
C13—O5—H5O	105.7 (15)	C13—C12—H12B	109.7
C12—N3—C8	117.35 (14)	H12A—C12—H12B	108.2
C12—N3—H3N	109.1 (12)	O5—C13—C12	112.15 (15)
C8—N3—H3N	105.3 (12)	O5—C13—H13A	109.2
C12—N3—H4N	107.8 (12)	C12—C13—H13A	109.2
C8—N3—H4N	108.4 (13)	O5—C13—H13B	109.2
H3N—N3—H4N	108.6 (18)	C12—C13—H13B	109.2
C9—C8—N3	109.71 (14)	H13A—C13—H13B	107.9

C6—C1—C2—N1	178.92 (14)	N2—C4—C5—C6	178.59 (13)
C7—C1—C2—N1	0.6 (2)	C4—C5—C6—C1	0.7 (2)
C6—C1—C2—C3	−0.6 (2)	C2—C1—C6—C5	−0.3 (2)
C7—C1—C2—C3	−178.87 (13)	C7—C1—C6—C5	178.09 (14)
N1—C2—C3—C4	−178.52 (14)	C6—C1—C7—O1	−173.13 (14)
C1—C2—C3—C4	1.0 (2)	C2—C1—C7—O1	5.2 (2)
C2—C3—C4—C5	−0.6 (2)	C6—C1—C7—O2	5.6 (2)
C2—C3—C4—N2	−179.45 (13)	C2—C1—C7—O2	−176.12 (14)
O4—N2—C4—C3	176.00 (14)	C12—N3—C8—C9	−58.0 (2)
O3—N2—C4—C3	−3.2 (2)	C12—N3—C8—C11	63.99 (19)
O4—N2—C4—C5	−2.9 (2)	C12—N3—C8—C10	−177.36 (15)
O3—N2—C4—C5	177.91 (14)	C8—N3—C12—C13	−159.11 (14)
C3—C4—C5—C6	−0.2 (2)	N3—C12—C13—O5	−55.18 (18)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O1	0.87 (2)	2.00 (2)	2.665 (2)	132 (2)
N1—H2N···O5	0.89 (2)	2.17 (2)	3.058 (2)	176 (2)
N3—H3N···O1ⁱ	0.90 (2)	1.73 (2)	2.637 (2)	178 (2)
N3—H4N···O2ⁱⁱ	0.89 (2)	1.98 (2)	2.849 (2)	166 (2)
O5—H5O···O2ⁱ	0.84 (2)	1.92 (2)	2.7546 (18)	173 (2)
C11—H11A···O4ⁱⁱⁱ	0.98	2.49	3.450 (3)	165
C12—H12A···O3	0.99	2.50	3.445 (2)	159

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

2-Amino-4-nitrobenzoate 1,3-dihydroxy-2-(hydroxymethyl)propan-2-aminium (III) top

Crystal data top

C₄H₁₂NO₃⁺·C₇H₅N₂O₄⁻	F(000) = 640
M_r = 303.27	D_x = 1.525 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
a = 13.6269 (6) Å	Cell parameters from 10585 reflections
b = 9.4976 (3) Å	θ = 2.9–27.5°
c = 10.2042 (4) Å	µ = 0.13 mm⁻¹
β = 90.355 (2)°	T = 120 K
V = 1320.63 (9) Å³	Slab, orange
Z = 4	0.38 × 0.22 × 0.09 mm

Data collection top

Bruker–Nonius Roper CCD camera on κ-goniostat diffractometer	3027 independent reflections
Radiation source: Bruker–Nonius FR591 rotating anode	2183 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.069
Detector resolution: 9.091 pixels mm^-1	θ_max = 27.5°, θ_min = 2.9°
φ & ω scans	h = −17→17
Absorption correction: multi-scan (SADABS; Sheldrick, 2007)	k = −11→12
T_min = 0.656, T_max = 0.746	l = −11→13
16747 measured reflections

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Hydrogen site location: mixed
R[F² > 2σ(F²)] = 0.048	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.122	w = 1/[σ²(F_o²) + (0.055P)² + 0.4405P] where P = (F_o² + 2F_c²)/3
S = 1.04	(Δ/σ)_max < 0.001
3027 reflections	Δρ_max = 0.31 e Å⁻³
214 parameters	Δρ_min = −0.26 e Å⁻³
8 restraints

Special details top

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

	x	y	z	U_iso*/U_eq
O1	0.23149 (10)	1.04393 (14)	0.76677 (13)	0.0214 (3)
O2	0.14548 (9)	0.92617 (13)	0.61598 (12)	0.0175 (3)
O3	0.65621 (10)	0.73923 (15)	0.52281 (13)	0.0255 (3)
O4	0.56887 (10)	0.60326 (14)	0.39818 (13)	0.0226 (3)
N1	0.42471 (12)	1.07055 (17)	0.72756 (15)	0.0187 (4)
H1N	0.3741 (11)	1.100 (2)	0.7735 (18)	0.022*
H2N	0.4832 (9)	1.086 (2)	0.7608 (19)	0.022*
N2	0.57664 (12)	0.69917 (16)	0.47821 (14)	0.0179 (4)
C1	0.31934 (13)	0.89761 (19)	0.61872 (16)	0.0147 (4)
C2	0.41270 (14)	0.95131 (18)	0.65438 (16)	0.0144 (4)
C3	0.49671 (14)	0.88243 (19)	0.60661 (16)	0.0156 (4)
H3	0.5603	0.9150	0.6306	0.019*
C4	0.48646 (13)	0.76770 (19)	0.52504 (17)	0.0155 (4)
C5	0.39602 (14)	0.71363 (19)	0.48678 (17)	0.0167 (4)
H5	0.3910	0.6348	0.4298	0.020*
C6	0.31356 (14)	0.78010 (19)	0.53561 (17)	0.0160 (4)
H6	0.2507	0.7448	0.5120	0.019*
C7	0.22586 (14)	0.96075 (18)	0.66953 (16)	0.0151 (4)
O5	0.93618 (10)	0.33420 (13)	0.11526 (12)	0.0172 (3)
H5O	0.9100 (15)	0.357 (2)	0.0431 (13)	0.026*
O6	0.91226 (10)	0.77428 (13)	0.16735 (13)	0.0186 (3)
H6O	0.8659 (12)	0.820 (2)	0.201 (2)	0.028*
O7	0.85135 (10)	0.48735 (14)	0.47852 (12)	0.0212 (3)
H7O	0.8181 (15)	0.511 (2)	0.5444 (16)	0.032*
N3	0.99779 (11)	0.55298 (16)	0.30064 (15)	0.0137 (3)
H3N	1.0132 (15)	0.4938 (17)	0.3649 (15)	0.016*
H4N	1.0077 (15)	0.6377 (13)	0.3343 (18)	0.016*
H5N	1.0380 (12)	0.542 (2)	0.2325 (14)	0.016*
C8	0.89311 (13)	0.53736 (18)	0.25643 (16)	0.0144 (4)
C9	0.87415 (14)	0.38355 (18)	0.21779 (17)	0.0158 (4)
H9A	0.8839	0.3232	0.2959	0.019*
H9B	0.8049	0.3738	0.1894	0.019*
C10	0.87791 (14)	0.63603 (18)	0.13984 (17)	0.0163 (4)
H10A	0.9132	0.5982	0.0630	0.020*
H10B	0.8072	0.6399	0.1174	0.020*
C11	0.82764 (14)	0.5772 (2)	0.37062 (17)	0.0180 (4)
H11A	0.8386	0.6769	0.3951	0.022*
H11B	0.7578	0.5655	0.3457	0.022*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0188 (7)	0.0239 (7)	0.0215 (7)	0.0012 (6)	0.0027 (5)	−0.0081 (6)
O2	0.0149 (7)	0.0211 (7)	0.0165 (6)	0.0007 (5)	0.0004 (5)	−0.0007 (5)
O3	0.0150 (7)	0.0364 (8)	0.0250 (7)	0.0032 (6)	−0.0015 (6)	−0.0061 (6)
O4	0.0234 (8)	0.0204 (7)	0.0241 (7)	0.0033 (6)	0.0029 (6)	−0.0061 (6)
N1	0.0156 (9)	0.0203 (9)	0.0202 (8)	−0.0006 (7)	−0.0004 (7)	−0.0060 (7)
N2	0.0178 (9)	0.0195 (8)	0.0165 (8)	0.0016 (7)	0.0014 (6)	0.0008 (6)
C1	0.0164 (10)	0.0151 (9)	0.0125 (8)	0.0018 (7)	0.0014 (7)	0.0027 (7)
C2	0.0161 (10)	0.0145 (9)	0.0126 (8)	−0.0001 (7)	0.0004 (7)	0.0017 (7)
C3	0.0138 (9)	0.0193 (10)	0.0137 (8)	−0.0002 (7)	−0.0009 (7)	0.0011 (7)
C4	0.0142 (9)	0.0172 (9)	0.0150 (9)	0.0036 (7)	0.0018 (7)	0.0033 (7)
C5	0.0200 (10)	0.0136 (9)	0.0167 (9)	0.0010 (7)	0.0007 (7)	−0.0008 (7)
C6	0.0149 (9)	0.0162 (9)	0.0170 (9)	−0.0016 (7)	−0.0005 (7)	−0.0005 (7)
C7	0.0197 (10)	0.0121 (9)	0.0136 (8)	0.0008 (7)	0.0017 (7)	0.0031 (7)
O5	0.0225 (8)	0.0160 (7)	0.0132 (6)	0.0040 (5)	−0.0004 (5)	−0.0014 (5)
O6	0.0208 (8)	0.0108 (6)	0.0242 (7)	0.0015 (5)	0.0000 (6)	0.0002 (5)
O7	0.0264 (8)	0.0231 (7)	0.0143 (6)	−0.0016 (6)	0.0053 (6)	−0.0010 (5)
N3	0.0149 (8)	0.0133 (8)	0.0129 (7)	0.0010 (6)	0.0009 (6)	0.0006 (6)
C8	0.0143 (9)	0.0134 (9)	0.0156 (8)	0.0009 (7)	−0.0007 (7)	−0.0005 (7)
C9	0.0186 (10)	0.0131 (9)	0.0157 (8)	0.0004 (7)	0.0015 (7)	0.0000 (7)
C10	0.0193 (10)	0.0129 (9)	0.0167 (9)	0.0004 (7)	−0.0020 (7)	−0.0006 (7)
C11	0.0162 (10)	0.0197 (10)	0.0181 (9)	0.0005 (8)	0.0027 (7)	−0.0016 (7)

Geometric parameters (Å, º) top

O1—C7	1.270 (2)	O5—H5O	0.844 (9)
O2—C7	1.264 (2)	O6—C10	1.421 (2)
O3—N2	1.233 (2)	O6—H6O	0.841 (10)
O4—N2	1.228 (2)	O7—C11	1.429 (2)
N1—C2	1.366 (2)	O7—H7O	0.844 (10)
N1—H1N	0.882 (9)	N3—C8	1.501 (2)
N1—H2N	0.877 (10)	N3—H3N	0.888 (9)
N2—C4	1.473 (2)	N3—H4N	0.885 (9)
C1—C6	1.404 (3)	N3—H5N	0.894 (9)
C1—C2	1.416 (3)	C8—C11	1.520 (2)
C1—C7	1.503 (3)	C8—C10	1.528 (2)
C2—C3	1.408 (3)	C8—C9	1.535 (2)
C3—C4	1.378 (3)	C9—H9A	0.9900
C3—H3	0.9500	C9—H9B	0.9900
C4—C5	1.389 (3)	C10—H10A	0.9900
C5—C6	1.384 (3)	C10—H10B	0.9900
C5—H5	0.9500	C11—H11A	0.9900
C6—H6	0.9500	C11—H11B	0.9900
O5—C9	1.428 (2)

C2—N1—H1N	117.5 (14)	C8—N3—H3N	112.3 (13)
C2—N1—H2N	117.1 (15)	C8—N3—H4N	110.4 (13)
H1N—N1—H2N	117 (2)	H3N—N3—H4N	104.7 (18)
O4—N2—O3	123.12 (16)	C8—N3—H5N	109.9 (13)
O4—N2—C4	118.36 (15)	H3N—N3—H5N	111.1 (19)
O3—N2—C4	118.51 (15)	H4N—N3—H5N	108.2 (19)
C6—C1—C2	119.25 (17)	N3—C8—C11	107.84 (14)
C6—C1—C7	118.76 (16)	N3—C8—C10	107.31 (14)
C2—C1—C7	121.97 (16)	C11—C8—C10	111.52 (15)
N1—C2—C3	118.65 (17)	N3—C8—C9	109.24 (14)
N1—C2—C1	122.93 (17)	C11—C8—C9	109.60 (15)
C3—C2—C1	118.34 (16)	C10—C8—C9	111.22 (14)
C4—C3—C2	119.80 (17)	O5—C9—C8	113.65 (15)
C4—C3—H3	120.1	O5—C9—H9A	108.8
C2—C3—H3	120.1	C8—C9—H9A	108.8
C3—C4—C5	123.28 (17)	O5—C9—H9B	108.8
C3—C4—N2	117.63 (16)	C8—C9—H9B	108.8
C5—C4—N2	119.09 (16)	H9A—C9—H9B	107.7
C6—C5—C4	116.82 (17)	O6—C10—C8	111.71 (14)
C6—C5—H5	121.6	O6—C10—H10A	109.3
C4—C5—H5	121.6	C8—C10—H10A	109.3
C5—C6—C1	122.50 (17)	O6—C10—H10B	109.3
C5—C6—H6	118.7	C8—C10—H10B	109.3
C1—C6—H6	118.7	H10A—C10—H10B	107.9
O2—C7—O1	123.17 (17)	O7—C11—C8	108.12 (15)
O2—C7—C1	118.74 (16)	O7—C11—H11A	110.1
O1—C7—C1	118.06 (16)	C8—C11—H11A	110.1
C9—O5—H5O	107.9 (15)	O7—C11—H11B	110.1
C10—O6—H6O	108.1 (16)	C8—C11—H11B	110.1
C11—O7—H7O	109.4 (16)	H11A—C11—H11B	108.4

C6—C1—C2—N1	175.53 (16)	C2—C1—C6—C5	0.1 (3)
C7—C1—C2—N1	−5.8 (3)	C7—C1—C6—C5	−178.55 (16)
C6—C1—C2—C3	−1.2 (2)	C6—C1—C7—O2	−14.4 (2)
C7—C1—C2—C3	177.46 (15)	C2—C1—C7—O2	166.90 (16)
N1—C2—C3—C4	−175.49 (16)	C6—C1—C7—O1	163.83 (16)
C1—C2—C3—C4	1.4 (3)	C2—C1—C7—O1	−14.8 (2)
C2—C3—C4—C5	−0.5 (3)	N3—C8—C9—O5	−59.01 (18)
C2—C3—C4—N2	−179.78 (15)	C11—C8—C9—O5	−176.96 (14)
O4—N2—C4—C3	−174.88 (15)	C10—C8—C9—O5	59.3 (2)
O3—N2—C4—C3	6.3 (2)	N3—C8—C10—O6	−49.84 (19)
O4—N2—C4—C5	5.8 (2)	C11—C8—C10—O6	68.0 (2)
O3—N2—C4—C5	−173.00 (16)	C9—C8—C10—O6	−169.27 (15)
C3—C4—C5—C6	−0.5 (3)	N3—C8—C11—O7	−58.12 (18)
N2—C4—C5—C6	178.72 (15)	C10—C8—C11—O7	−175.70 (14)
C4—C5—C6—C1	0.7 (3)	C9—C8—C11—O7	60.70 (18)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O1	0.88 (2)	2.02 (2)	2.678 (2)	131 (2)
N1—H1N···O3ⁱ	0.88 (2)	2.50 (2)	3.210 (2)	138 (1)
N1—H2N···O4ⁱⁱ	0.88 (1)	2.56 (2)	3.094 (2)	120 (2)
N3—H3N···O6ⁱⁱⁱ	0.89 (2)	2.34 (2)	2.934 (2)	124 (1)
N3—H3N···O7^iv	0.89 (2)	2.44 (2)	3.065 (2)	128 (2)
N3—H4N···O5^v	0.89 (1)	2.08 (1)	2.945 (2)	165 (2)
N3—H5N···O2^vi	0.89 (2)	1.92 (2)	2.773 (2)	160 (2)
O5—H5O···O2^vii	0.85 (2)	1.90 (2)	2.7453 (18)	175 (2)
O6—H6O···O1^viii	0.84 (2)	1.88 (2)	2.6993 (19)	163 (2)
O7—H7O···O1^ix	0.84 (2)	2.07 (2)	2.8905 (18)	164 (2)

Symmetry codes: (i) −x+1, y+1/2, −z+3/2; (ii) x, −y+1/2, z−1/2; (iii) −x+2, y−1/2, −z+1/2; (iv) −x+2, −y+1, −z+1; (v) −x+2, y+1/2, −z+1/2; (vi) x+1, −y+1/2, z−3/2; (vii) −x+1, y−1/2, −z+1/2; (viii) −x+1, −y+2, −z+1; (ix) −x+1, y−1/2, −z+3/2.

Selected geometric data (Å, °) for (I)–(III) top

Parameter	(I)	(II)	(III)
C7≐O1	1.270 (2)	1.259 (2)	1.270 (2)
C7≐O2	1.258 (2)	1.2678 (19)	1.264 (2)
CO₂/C₆	6.7 (3)	6.21 (13)	14.80 (17)
NO₂/C₆	6.6 (3)	3.28 (13)	6.58 (18)
CO₂/NO₂	11.5 (4)	2.94 (17)	9.7 (3)

Footnotes

‡Additional correspondence author, e-mail: j.wardell@abdn.ac.uk.

Acknowledgements

The authors thank the National Crystallographic Service, based at the University of Southampton, for collecting the data.

Funding information

JLW thanks CNPq, Brazil, for a grant. The authors are also grateful to Sunway University (INT-RRO-2017-096) for support of this research.

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Volume 74| Part 12| December 2018| Pages 1735-1740

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research communications\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Crystal structures of the 1:1 salts of 2-amino-4-nitro­benzoate with each of (2-hy­dr­oxy­eth­yl)di­methyl­aza­nium, tert-but­yl(2-hy­dr­oxy­eth­yl)aza­nium and 1,3-dihy­dr­oxy-2-(hy­dr­oxy­meth­yl)propan-2-aminium

1. Chemical context

2. Structural commentary

3. Supra­molecular features

4. Database survey

5. Synthesis and crystallization

6. Refinement

Supporting information

Footnotes

Acknowledgements

Funding information

References

research communications

Crystal structures of the 1:1 salts of 2-amino-4-nitrobenzoate with each of (2-hydroxyethyl)dimethylazanium, tert-butyl(2-hydroxyethyl)azanium and 1,3-dihydroxy-2-(hydroxymethyl)propan-2-aminium

3. Supramolecular features