The 1:1 proton-transfer complex of 3,5-di­nitro­salicylic acid with (8-quinolinyl)­urea

In the crystal structure of the proton-transfer complex of (8-quinolinyl)­urea (QUR) with 3,5-di­nitro­salicylic acid (DNSA), 8-ureidoquinolinium 3,5-di­nitro­salicylate, [(QUR)⁺ (DNSA)⁻] or C₁₀H₁₀N₃O⁺·C₇H₃N₂O₇⁻, the hetero–N atom of QUR is protonated and, together with all urea protons, is involved in extensive hydrogen-bonding associations which result in a three-dimensional network polymer [N...O 2.711–3.251 (2) Å]. In addition, the quinolinium proton is involved in an intramolecular hydrogen bond with a urea–N atom [N—N 2.841 (2) Å] and within the DNSA anions a short intramolecular O(carboxyl)...O(hydroxy) hydrogen bond is also present [O...O 2.492 (2) Å].

Key indicators

• Single-crystal X-ray study
• T = 295 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.045
• wR factor = 0.125
• Data-to-parameter ratio = 13.9

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry

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S1. Comment

The nitro-substituted aromatic acid 3,5-dinitrosalicylic acid (DNSA) has proved a very useful compound for structure formation, giving a number of complexes which acquire stable crystalline lattices through hydrogen-bonding associations. These compounds may be either neutral or ionic, the latter involving proton transfer to a Lewis base acceptor. In addition, association may involve π–π interactions through the aromatic ring and its interactive nitro substituents, although the majority of reported examples primarily interact via the carboxylate group, the ortho-related hydroxy group, and to a lesser extent, the nitro groups. Issa and co-workers have categorized a large number of examples using IR spectroscopy (Hindawey et al., 1980; Issa et al., 1980, 1981), while those characterized to date by our group using X-ray diffraction are the compounds with 3-amino-1H-1,2,4-triazole (Smith et al., 1995), 8-aminoquinoline (Smith, Wermuth, Bott et al., 2001), 8-hydroxyquinoline (Smith, Wermuth & White, 2001), guanidine (Smith, Bott & Wermuth, 2001) and the isomeric aminobenzoic acids (Smith et al., 1995). In the case of the compound with 4-aminobenzoic acid, the only example is a 1:2 adduct. Neutral compounds are less common but the 1:1 adducts with urea (Smith, Baldry et al., 1997), 1,1-diethylurea (Smith et al., 2000), and a series of polymorphic solvates with dioxane (1:1) (two) and (2:1) (two) (Kumar et al., 1999) have been characterized. A series of four polymorphs is also known for the hydrates [all (1:1)] (Smith et al., 1995; Kumar et al., 1999)].

Taking into account the potential for proton transfer and the associative nature of the urea molecule, we expected the structure of the product of the interaction of the unsymmetrically substituted urea, 8-quinolinylurea (QUR) with DNSA, the (1:1) proton-transfer complex [(QUR)⁺(DNSA)^-], to be of considerable interest. QUR is also known for its biological effects, such as cytotoxicity or mutagenic properties (Pagani et al., 1983: Smith, Hansch & Morton, 1997).

The structure (Fig. 1) shows that the hetero-N atom of QUR is protonated and gives strong intermolecular hydrogen-bonding associations with a hydroxyl O atom [N11···O2ⁱ 2.711 (2) Å; symmetry code: (i) 1 - x, -y, 1 - z] and a nitro-O atom of the same DNSA anion [N11···O31ⁱ 2.837 (2) Å]. Completing a four-centre association about the quinolinium proton is an intramolecular hydrogen bond to the first urea-N atom [N11–H11···N1 2.841 (2) Å]. The urea residue is twisted out of the plane of the quinolinyl ring [torsion angles: C17–C18–N1–C182 115.2 (2)°; C18–N1–C182–N2 - 167.3 (2)°]. All available hydrogen-bonding sites on the urea residue are utilized [N1···O182 2.800 (2) Å; N2···O71 2.981 (2) Å; N2···O71 3.251 (2) Å; N2···O72 3.101 (2) Å], giving a three-dimensional network polymer (Fig. 2). A number of C–H···O associations (Table 1) add to the stability of the structure.

The intramolecular hydrogen bond between the carboxylate group and the ortho-related hydroxyl group is dimensionally similar to those found in all of the complexes and adducts of DNSA [O72—O2 2.492 (2) Å; range 2.409–2.464 Å]. The type of intramolecular bond found here places this compound in a minor category within the series of those compounds in which the hydroxyl proton is anti-located adjacent to the carboxyl oxygen within the hydrogen bond, rather than being on the hydroxyl oxygen (this type of hydrogen bonds was also reported in the proton-transfer compounds with 3-amino-1H-1,2,4-triazole, 3-aminobenzoic acid and 4-aminobenzoic acid).

S2. Experimental

Synthesis was carried out by initially mixing together equimolar quantities (1 mmol) of 3,5-dinitrosalicylic acid and (8-quinolinyl)urea at which stage reaction was observed as a colour change to orange-yellow. 50 ml of 80% ethanol/water were added to the product and the mixture was heated with stirring until the volume was reduced to ca 40 ml. Crystals were obtained after partial room temperature evaporation of the filtered solution.

S3. Refinement

The positional parameters only for those atoms which are involved in hydrogen bonding (H1, H11, H21, H22 and H72; located by difference methods) were refined. All other H atoms were placed in calculated positions and included in the refinement in the riding-model approximation.

Computing details

Data collection: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1999a).; cell refinement: MSC/AFC Diffractometer Control Software; data reduction: TEXSAN for Windows (Molecular Structure Corporation, 1999b); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON for Windows (Spek, 1999); software used to prepare material for publication: TEXSAN for Windows.

Figures

	Fig. 1. The (8-quinolinyl)urea cation and the 3,5-dinitrosalicylate anion in the structure of [QUR^+][DNSA^-]. Atoms are shown as 30% probability ellipsoids.
	Fig. 2. The hydrogen-bonding scheme (hydrogen bonds shown as broken lines) viewed down the a axis of the crystal.

(I)

Crystal data

C10H10N3O^+·C7H3N2O7^−	Z = 2
Mr = 415.32	F(000) = 428
Triclinic, P1	Dx = 1.594 Mg m^−3
Hall symbol: -P 1	Melting point = 512–517 K
a = 13.061 (2) Å	Mo Kα radiation, λ = 0.71069 Å
b = 13.898 (2) Å	Cell parameters from 25 reflections
c = 4.8910 (17) Å	θ = 12.6–17.7°
α = 93.33 (2)°	µ = 0.13 mm^−1
β = 93.21 (2)°	T = 295 K
γ = 101.764 (14)°	Blocky prism, yellow
V = 865.6 (4) Å^3	0.45 × 0.42 × 0.20 mm

Data collection

Rigaku AFC-7R diffractometer	Rint = 0.058
Radiation source: Rigaku rotating anode	θmax = 27.5°, θmin = 3.0°
Graphite monochromator	h = −16→16
ω–2θ scans	k = −18→18
4728 measured reflections	l = −6→2
3980 independent reflections	3 standard reflections every 150 reflections
3117 reflections with I > 2σ(I)	intensity decay: 1.4%

Refinement

Refinement on F^2	0 constraints
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F^2 > 2σ(F^2)] = 0.045	w = 1/[σ^2(Fo^2) + (0.0527P)^2 + 0.3656P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.125	(Δ/σ)max < 0.001
S = 1.04	Δρmax = 0.30 e Å^−3
3980 reflections	Δρmin = −0.20 e Å^−3
287 parameters	Extinction correction: SHELXL97, FC^*=KFC[1+0.001XFC^2Λ^3/SIN(2Θ)]^-1/4
0 restraints	Extinction coefficient: 0.024 (4)

Special details

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All e.s.d.'s are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O2	0.78301 (10)	0.20887 (8)	0.3893 (3)	0.0393 (4)
O31	0.91186 (12)	0.30995 (9)	0.0466 (3)	0.0524 (4)
O32	1.02715 (15)	0.23432 (13)	−0.0948 (5)	0.0863 (7)
O51	0.91153 (15)	−0.10639 (12)	−0.4119 (4)	0.0655 (5)
O52	0.77274 (14)	−0.19269 (10)	−0.2574 (4)	0.0641 (5)
O71	0.60217 (11)	−0.06037 (10)	0.4942 (3)	0.0468 (4)
O72	0.64625 (10)	0.09837 (10)	0.6262 (3)	0.0414 (4)
N3	0.94176 (12)	0.23420 (11)	−0.0062 (3)	0.0395 (4)
N5	0.83816 (14)	−0.11582 (11)	−0.2629 (3)	0.0433 (5)
C1	0.73654 (12)	0.03735 (11)	0.2635 (3)	0.0282 (4)
C2	0.79740 (12)	0.13500 (11)	0.2375 (3)	0.0284 (4)
C3	0.87482 (12)	0.14005 (11)	0.0394 (3)	0.0309 (4)
C4	0.89063 (13)	0.05914 (12)	−0.1164 (3)	0.0332 (5)
C5	0.82707 (13)	−0.03127 (12)	−0.0861 (3)	0.0324 (5)
C6	0.75062 (13)	−0.04258 (11)	0.1025 (3)	0.0306 (4)
C7	0.65524 (13)	0.02073 (12)	0.4699 (3)	0.0314 (4)
O182	0.43791 (10)	−0.29935 (9)	0.6084 (2)	0.0382 (3)
N1	0.38575 (12)	−0.31732 (10)	1.0419 (3)	0.0334 (4)
N2	0.48421 (14)	−0.17027 (12)	0.9232 (3)	0.0441 (5)
N11	0.22207 (11)	−0.40209 (9)	0.6391 (3)	0.0314 (4)
C12	0.14806 (14)	−0.43657 (13)	0.4414 (4)	0.0388 (5)
C13	0.11796 (15)	−0.53707 (14)	0.3695 (4)	0.0441 (6)
C14	0.16347 (15)	−0.60047 (13)	0.5134 (4)	0.0419 (5)
C15	0.28873 (17)	−0.62749 (13)	0.8874 (4)	0.0451 (6)
C16	0.36099 (16)	−0.58817 (15)	1.0964 (4)	0.0466 (6)
C17	0.39303 (14)	−0.48532 (14)	1.1474 (4)	0.0390 (5)
C18	0.35236 (13)	−0.42061 (12)	0.9929 (3)	0.0314 (4)
C19	0.27294 (12)	−0.46119 (11)	0.7850 (3)	0.0294 (4)
C110	0.24178 (14)	−0.56459 (12)	0.7264 (4)	0.0348 (5)
C182	0.43746 (12)	−0.26271 (12)	0.8434 (3)	0.0298 (4)
H4	0.9465	0.0648	−0.2457	0.0340*
H6	0.7098	−0.1034	0.1195	0.0340*
H72	0.697 (2)	0.149 (2)	0.570 (6)	0.069*
H1	0.4043 (17)	−0.2990 (16)	1.205 (5)	0.049*
H11	0.2348 (18)	−0.3373 (16)	0.677 (5)	0.051*
H12	0.1211	−0.3892	0.3562	0.0340*
H13	0.0602	−0.5568	0.2208	0.0340*
H14	0.1409	−0.6775	0.4651	0.0340*
H15	0.2744	−0.7017	0.8441	0.0340*
H16	0.3921	−0.6323	1.2265	0.0340*
H17	0.4390	−0.4578	1.2720	0.0340*
H21	0.5174 (18)	−0.1329 (17)	0.802 (5)	0.050*
H22	0.4795 (19)	−0.1461 (18)	1.080 (6)	0.057*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O2	0.0519 (7)	0.0261 (6)	0.0395 (7)	0.0053 (5)	0.0147 (5)	−0.0020 (5)
O31	0.0616 (9)	0.0281 (6)	0.0656 (9)	0.0007 (6)	0.0193 (7)	0.0037 (6)
O32	0.0673 (11)	0.0536 (10)	0.1358 (19)	−0.0062 (8)	0.0629 (12)	0.0030 (10)
O51	0.0839 (12)	0.0546 (9)	0.0649 (10)	0.0233 (8)	0.0402 (9)	−0.0041 (7)
O52	0.0858 (12)	0.0294 (7)	0.0744 (11)	0.0052 (7)	0.0227 (9)	−0.0100 (7)
O71	0.0488 (8)	0.0400 (7)	0.0477 (8)	−0.0046 (6)	0.0176 (6)	0.0059 (6)
O72	0.0455 (7)	0.0408 (7)	0.0383 (7)	0.0067 (6)	0.0175 (6)	−0.0004 (5)
N3	0.0411 (8)	0.0329 (7)	0.0415 (8)	−0.0021 (6)	0.0123 (6)	0.0023 (6)
N5	0.0593 (10)	0.0318 (7)	0.0426 (8)	0.0170 (7)	0.0124 (7)	−0.0004 (6)
C1	0.0297 (7)	0.0278 (7)	0.0271 (7)	0.0048 (6)	0.0047 (6)	0.0035 (6)
C2	0.0311 (8)	0.0248 (7)	0.0288 (7)	0.0049 (6)	0.0027 (6)	0.0016 (6)
C3	0.0318 (8)	0.0266 (7)	0.0330 (8)	0.0015 (6)	0.0058 (6)	0.0030 (6)
C4	0.0340 (8)	0.0342 (8)	0.0327 (8)	0.0087 (6)	0.0081 (6)	0.0030 (6)
C5	0.0404 (9)	0.0273 (7)	0.0310 (8)	0.0105 (6)	0.0049 (6)	−0.0005 (6)
C6	0.0345 (8)	0.0240 (7)	0.0326 (8)	0.0038 (6)	0.0040 (6)	0.0039 (6)
C7	0.0319 (8)	0.0337 (8)	0.0284 (7)	0.0047 (6)	0.0050 (6)	0.0046 (6)
O182	0.0518 (7)	0.0381 (6)	0.0210 (5)	0.0011 (5)	0.0059 (5)	−0.0022 (5)
N1	0.0437 (8)	0.0327 (7)	0.0194 (6)	−0.0016 (6)	0.0051 (5)	−0.0025 (5)
N2	0.0557 (10)	0.0385 (8)	0.0290 (7)	−0.0118 (7)	0.0144 (7)	−0.0069 (6)
N11	0.0371 (7)	0.0239 (6)	0.0318 (7)	0.0034 (5)	0.0045 (5)	−0.0012 (5)
C12	0.0387 (9)	0.0373 (9)	0.0384 (9)	0.0046 (7)	0.0000 (7)	0.0011 (7)
C13	0.0390 (9)	0.0428 (10)	0.0441 (10)	−0.0022 (8)	0.0015 (8)	−0.0103 (8)
C14	0.0444 (10)	0.0286 (8)	0.0490 (10)	−0.0014 (7)	0.0152 (8)	−0.0085 (7)
C15	0.0555 (11)	0.0291 (8)	0.0546 (11)	0.0126 (8)	0.0210 (9)	0.0062 (8)
C16	0.0539 (11)	0.0451 (10)	0.0493 (11)	0.0218 (9)	0.0181 (9)	0.0187 (9)
C17	0.0406 (9)	0.0459 (10)	0.0322 (8)	0.0103 (8)	0.0076 (7)	0.0070 (7)
C18	0.0367 (8)	0.0328 (8)	0.0251 (7)	0.0057 (6)	0.0108 (6)	0.0028 (6)
C19	0.0341 (8)	0.0259 (7)	0.0285 (7)	0.0051 (6)	0.0113 (6)	0.0004 (6)
C110	0.0403 (9)	0.0256 (7)	0.0386 (9)	0.0047 (6)	0.0155 (7)	−0.0005 (6)
C182	0.0322 (8)	0.0329 (8)	0.0224 (7)	0.0026 (6)	0.0035 (6)	−0.0011 (6)

Geometric parameters (Å, º)

O2—C2	1.283 (2)	C1—C2	1.443 (2)
O31—N3	1.214 (2)	C2—C3	1.433 (2)
O32—N3	1.219 (3)	C3—C4	1.379 (2)
O51—N5	1.227 (3)	C4—C5	1.378 (2)
O52—N5	1.227 (2)	C5—C6	1.389 (2)
O71—C7	1.213 (2)	C4—H4	0.99
O72—C7	1.315 (2)	C6—H6	0.91
O72—H72	0.93 (3)	C12—C13	1.390 (3)
O182—C182	1.2306 (18)	C13—C14	1.365 (3)
N3—C3	1.454 (2)	C14—C110	1.412 (3)
N5—C5	1.454 (2)	C15—C110	1.416 (3)
N1—C18	1.415 (2)	C15—C16	1.361 (3)
N1—C182	1.387 (2)	C16—C17	1.408 (3)
N2—C182	1.331 (2)	C17—C18	1.375 (3)
N11—C19	1.365 (2)	C18—C19	1.416 (2)
N11—C12	1.323 (2)	C19—C110	1.419 (2)
N1—H1	0.83 (2)	C12—H12	0.92
N2—H22	0.83 (3)	C13—H13	1.00
N2—H21	0.88 (2)	C14—H14	1.06
N11—H11	0.89 (2)	C15—H15	1.02
C1—C6	1.373 (2)	C16—H16	1.03
C1—C7	1.499 (2)	C17—H17	0.85
C7—O72—H72	104.1 (17)	C3—C4—H4	121
O31—N3—O32	121.99 (17)	C5—C6—H6	120
O32—N3—C3	118.44 (15)	C1—C6—H6	120
O31—N3—C3	119.56 (15)	N11—C12—C13	120.98 (17)
O51—N5—O52	123.40 (17)	C12—C13—C14	118.80 (18)
O51—N5—C5	118.45 (16)	C13—C14—C110	120.67 (17)
O52—N5—C5	118.14 (17)	C16—C15—C110	119.76 (17)
C18—N1—C182	119.66 (14)	C15—C16—C17	120.74 (18)
C12—N11—C19	123.13 (14)	C16—C17—C18	122.05 (18)
C18—N1—H1	113.9 (15)	C17—C18—C19	117.39 (15)
C182—N1—H1	117.3 (16)	N1—C18—C17	121.96 (15)
C182—N2—H21	118.7 (15)	N1—C18—C19	120.63 (14)
H21—N2—H22	120 (2)	N11—C19—C110	117.85 (14)
C182—N2—H22	121.6 (17)	N11—C19—C18	120.98 (14)
C19—N11—H11	121 (2)	C18—C19—C110	121.15 (15)
C12—N11—H11	115 (2)	C14—C110—C15	122.74 (16)
C2—C1—C7	120.22 (13)	C14—C110—C19	118.48 (16)
C6—C1—C7	118.05 (14)	C15—C110—C19	118.77 (17)
C2—C1—C6	121.73 (14)	N11—C12—H12	114
O2—C2—C3	124.58 (14)	C13—C12—H12	124
C1—C2—C3	114.52 (13)	C12—C13—H13	116
O2—C2—C1	120.87 (14)	C14—C13—H13	125
N3—C3—C2	120.06 (13)	C13—C14—H14	120
C2—C3—C4	123.52 (14)	C110—C14—H14	119
N3—C3—C4	116.42 (14)	C110—C15—H15	122
C3—C4—C5	118.55 (15)	C16—C15—H15	118
N5—C5—C4	119.00 (15)	C15—C16—H16	121
C4—C5—C6	121.51 (15)	C17—C16—H16	118
N5—C5—C6	119.45 (15)	C16—C17—H17	124
C1—C6—C5	120.11 (15)	C18—C17—H17	114
O72—C7—C1	116.34 (14)	O182—C182—N2	123.37 (15)
O71—C7—C1	121.63 (15)	N1—C182—N2	116.05 (14)
O71—C7—O72	122.02 (16)	O182—C182—N1	120.57 (15)
C5—C4—H4	120
O31—N3—C3—C4	155.18 (16)	C1—C2—C3—N3	−179.79 (14)
O32—N3—C3—C2	154.66 (19)	C1—C2—C3—C4	0.3 (2)
O31—N3—C3—C2	−24.7 (2)	C2—C3—C4—C5	1.7 (2)
O32—N3—C3—C4	−25.4 (2)	N3—C3—C4—C5	−178.18 (14)
O51—N5—C5—C6	−174.05 (17)	C3—C4—C5—N5	175.75 (15)
O51—N5—C5—C4	8.1 (2)	C3—C4—C5—C6	−2.1 (2)
O52—N5—C5—C6	6.8 (2)	N5—C5—C6—C1	−177.51 (15)
O52—N5—C5—C4	−171.07 (17)	C4—C5—C6—C1	0.3 (2)
C18—N1—C182—O182	13.3 (2)	N11—C12—C13—C14	2.4 (3)
C182—N1—C18—C19	−66.4 (2)	C12—C13—C14—C110	−1.7 (3)
C18—N1—C182—N2	−167.31 (16)	C13—C14—C110—C15	177.82 (19)
C182—N1—C18—C17	115.24 (19)	C13—C14—C110—C19	−0.8 (3)
C12—N11—C19—C18	179.37 (17)	C16—C15—C110—C14	−177.5 (2)
C19—N11—C12—C13	−0.3 (3)	C110—C15—C16—C17	−2.7 (3)
C12—N11—C19—C110	−2.2 (2)	C16—C15—C110—C19	1.1 (3)
C6—C1—C7—O71	−0.7 (2)	C15—C16—C17—C18	0.9 (3)
C7—C1—C2—C3	177.93 (14)	C16—C17—C18—N1	−179.06 (17)
C2—C1—C7—O72	−2.1 (2)	C16—C17—C18—C19	2.6 (3)
C2—C1—C6—C5	1.9 (2)	C17—C18—C19—N11	174.15 (16)
C6—C1—C2—O2	179.85 (15)	C17—C18—C19—C110	−4.2 (2)
C6—C1—C2—C3	−2.1 (2)	N1—C18—C19—C110	177.40 (16)
C2—C1—C7—O71	179.20 (16)	N1—C18—C19—N11	−4.2 (2)
C7—C1—C6—C5	−178.16 (15)	N11—C19—C110—C15	−175.94 (17)
C7—C1—C2—O2	−0.1 (2)	C18—C19—C110—C15	2.5 (3)
C6—C1—C7—O72	177.93 (15)	N11—C19—C110—C14	2.7 (2)
O2—C2—C3—N3	−1.9 (2)	C18—C19—C110—C14	−178.88 (17)
O2—C2—C3—C4	178.25 (16)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O182^i	0.83 (2)	2.00 (2)	2.800 (2)	162 (2)
N11—H11···N1	0.89 (2)	2.54 (2)	2.841 (2)	100.3 (17)
N11—H11···O2^ii	0.89 (2)	1.89 (2)	2.7111 (19)	152.7 (17)
N11—H11···O31^ii	0.89 (2)	2.48 (2)	2.837 (2)	104.4 (17)
N2—H21···O71	0.88 (2)	2.10 (2)	2.981 (2)	173 (2)
N2—H22···O71^i	0.83 (3)	2.58 (3)	3.251 (2)	139 (2)
N2—H22···O72^iii	0.83 (3)	2.41 (3)	3.101 (2)	142 (2)
O72—H72···O2	0.93 (3)	1.60 (3)	2.492 (2)	161 (3)
C4—H4···O51^iv	0.989	2.57	3.547 (3)	171
C12—H12···O31^v	0.92	2.37	3.201 (3)	150
C13—H13···O31^vi	1.00	2.47	3.326 (3)	144
C14—H14···O52^vii	1.06	2.52	3.347 (3)	135
C15—H15···O52^viii	1.02	2.60	3.168 (3)	115

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