4-(4-Nitro­benz­yl)pyridinium 5-nitro­salicylate

Graham Smith; Urs D Wermuth

doi:10.1107/S1600536810014698

. 2010 Apr 24;66(Pt 5):o1173. doi: 10.1107/S1600536810014698

4-(4-Nitrobenzyl)pyridinium 5-nitrosalicylate

Graham Smith ^a,^*, Urs D Wermuth ^a

PMCID: PMC2979186 PMID: 21579214

Abstract

In the title salt, C₁₂H₁₁N₂O₂ ⁺·C₇H₄NO₅ ⁻, the cations and anions interact through asymmetric cyclic pyridinium–carboxylate N—H⋯O,O′ hydrogen-bonding associations [graph set R ₁ ²(4)], giving discrete heterodimers having weak cation–anion π–π aromatic ring interactions [minimum ring centroid separation = 3.7116 (9) Å].

Related literature

For structural data on nitro-substituted 4-benzylpyridines and related compounds, see Seff & Trueblood (1968 ▶); Ottersen & Seff (1974 ▶); Scherl et al. (1996 ▶); Smith et al. (1997 ▶); Naumov et al. (2002 ▶). For structures of Lewis base salts of 5-nitrosalicylic acid, see: Smith et al. (1996 ▶, 2005 ▶, 2006 ▶). For graph-set motifs, see: Etter et al. (1990 ▶).

Experimental

Crystal data

C₁₂H₁₁N₂O₂ ⁺·C₇H₄NO₅ ⁻
M _r = 397.34
Triclinic,
a = 8.3287 (5) Å
b = 10.8219 (7) Å
c = 11.3896 (8) Å
α = 65.160 (6)°
β = 88.286 (5)°
γ = 70.553 (6)°
V = 871.17 (12) Å³
Z = 2
Mo Kα radiation
μ = 0.12 mm⁻¹
T = 200 K
0.25 × 0.25 × 0.20 mm

Data collection

Oxford Diffraction Gemini-S CCD-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.795, T _max = 0.900
10797 measured reflections
3419 independent reflections
2615 reflections with I > 2σ(I)
R _int = 0.021

Refinement

R[F ² > 2σ(F ²)] = 0.034
wR(F ²) = 0.091
S = 1.03
3419 reflections
270 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.15 e Å⁻³
Δρ_min = −0.19 e Å⁻³

Data collection: CrysAlis PRO (Oxford Diffraction, 2009 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶) within WinGX (Farrugia, 1999 ▶); molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: PLATON.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810014698/pv2273sup1.cif

e-66-o1173-sup1.cif^{(21.1KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810014698/pv2273Isup2.hkl

e-66-o1173-Isup2.hkl^{(164.2KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯O11A	0.97 (2)	1.612 (19)	2.5804 (16)	180 (2)
N1—H1⋯O12A	0.97 (2)	2.55 (2)	3.1464 (18)	120.2 (14)
O2A—H2A⋯O12A	1.00 (2)	1.48 (2)	2.4623 (17)	165 (2)

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Acknowledgments

The authors acknowledge financial support from the Australian Research Council and the Faculty of Science and Technology, Queensland University of Technology.

supplementary crystallographic information

Comment

The Lewis base 4-(4-nitrobenzyl)pyridine (NBP) is an analogue of 2-(2,4-dinitrobenzyl)pyridine (DNBP) which is significant because of its unusual photochromic behaviour in the solid state, although NBP does not possess such properties. The structure of DNBP has been determined (Seff & Trueblood, 1968; Scherl et al., 1996; Naumov et al., 2002), as well that of its isomer 4-(2,4-dinitrobenzyl)pyridine (Ottersen & Seff (1974), but the structure of NBP itself is not known. A structure of a cocrystal adduct of NBP with 4-aminobenzoic acid has been reported (Smith et al., 1997).

Our reaction of NBP with 5-nitrosalicylic acid (5-NSA) gave the title compound C₁₂H₁₁N₂O₂⁺ C₇H₄NO₅^- (I), the structure of which is reported here. The acid 5-NSA has proved useful for formation of crystalline salts with a number of Lewis bases (Smith et al., 1996; Smith et al., 2005; Smith et al., 2006). With the title compound (I) (Fig. 1), the NBP cations and 5-NSA anions interact through asymmetric cyclic N⁺–H···O,O'_carboxyl hydrogen-bonding associations (Table 1), giving discrete heterodimers [graph set R²₁(4) (Etter et al., 1990)]. There are weak cation–anion π–π aromatic ring interactions present in the crystal packing [minimum ring centroid separation between rings N1–C6 and C1A–C6A, 3.7166 (9) Å] (Fig. 2). With the NBP cation the two rings are approximately normal to each other [torsion angle C3–C4–C42–C11, -77.72 (17)°] with the nitro group close to coplanar with the benzene ring [torsion angle C31–C41–N41–O42, 170.27 (13)°]. The usual intramolecular phenolO—H···O_carboxyl hydrogen bond [2.4623 (17) Å] is present in the 5-NSA anion which, including the nitro group is close to planar [torsion angles C2A–C1A–C11A–O11A, -173.72 (13)°; C4A–C5A–N5A–O52A, 177.68 (13)°].

Experimental

The title compound was synthesized by heating together under reflux for 10 minutes, 1 mmol quantities of 4-(4-nitrobenzyl)pyridine with 5-nitrosalicylic acid in 50 ml of 50% ethanol–water. After concentration to ca. 30 ml, partial room temperature evaporation of the hot-filtered solution gave yellow crystal aggregates (m.p. 416–417 K) from which a block section was cleaved for the X-ray analysis.