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Logo of actae2this articlesearchopen accesssubmitActa Crystallographica Section E: Crystallographic CommunicationsActa Crystallographica Section E: Crystallographic Communications
 
Acta Crystallogr E Crystallogr Commun. 2017 March 1; 73(Pt 3): 383–386.
Published online 2017 February 17. doi:  10.1107/S2056989017002171
PMCID: PMC5347060

Supra­molecular hydrogen-bonding patterns in a 1:1 co-crystal of the N(7)—H tautomeric form of N 6-benzoyl­adenine with 4-hy­droxy­benzoic acid

Abstract

The asymmetric unit of the title co-crystal, C12H9N5O·C7H6O3, contains one mol­ecule of N 6-benzoyl­adenine (BA) and one mol­ecule of 4-hy­droxy­benzoic acid (HBA). The N 6-benzoyl­adenine (BA) has an N(7)—H tautomeric form with nonprotonated N-1 and N-3 atoms. This tautomeric form is stabilized by a typical intra­molecular N—H(...)O hydrogen bond between the carbonyl (C=O) group and the N(7)—H hydrogen on the Hoogsteen face of the purine ring, forming a graph-set S(7) ring motif. The primary robust R 2 2(8) ring motif is formed in the Watson–Crick face via N—H(...)O and O—H(...)N hydrogen bonds (involving N1, N6—H and the carboxyl group of HBA). Weak inter­actions, such as, C—H(...)π and π–π are also observed in this crystal structure.

Keywords: crystal structure, hydrogen bond, dihedral angle, coplanar, supra­molecular inter­action

Chemical context  

Adenine is one of the major nucleobases and some of its N 6-derivatives have plant hormone (kinetin) (Tr). They also offer a variety of hydrogen-bonding donor and acceptor sites (McHugh & Erxleben, 2011  ; Imaz et al., 2011  ). 4-Hy­droxy­benzoic acid is also a promising hydrogen-bond donor with the ability to form co-crystals with other organic mol­ecules (Vishweshwar et al., 2003  ). It is used as an anti­microbial paraben (Barker & Frost, 2001  ). The present study investigates co-crystal formation between N 6- benzoyl­adenine and 4-hy­droxy­benzoic acid.

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Object name is e-73-00383-scheme1.jpg

Structural commentary  

In the title co-crystal (I), the asymmetric unit contains one N 6-benzoyl­adenine (BA) mol­ecule and one 4-hy­droxy­benzoic acid (HBA) mol­ecule (Fig. 1  ). The bond angle at N7 [C8—N7—C5 = 106.93 (17)°] is wider than at N9 [C8—N9—C4 = 104.19 (16)°]. In addition, the C8—N7 bond [1.343 (2)Å] is longer than C8—N9 [1.319 (3) Å]. These values agree with those reported earlier for the crystal structure of N 6-benzoyl­adenine (Raghunathan & Pattabhi, 1981  ). In the title co-crystal, the N 6-benzoyl­adenine also exists in the N(7)—H tautomeric form with non-protonated N1, N3 and N9 atoms. In the crystal structures of N 6-benzoyl­adenine (Raghunathan & Pattabhi, 1981  ), N 6-benzoyl­adenine-3-hy­droxy­pyridinium-2-carboxyl­ate (1:1) and N 6-benzoyl adenine-dl-tartaric acid (1:1) (Karthikeyan et al., 2015  ), N 6-benzoyl­adeninium nitrate (1:1) (Karthikeyan et al., 2016  ), N 6-benzoyl adenine–adipic acid (1:0.5) (Swinton Darious et al., 2016  ) and the title compound (I), the N 6-substituent is distal to the N1 and syn to the adenine nitro­gen atom N7. This may be due to the participation of the N7 atom in N7—H7(...)O1A intra­molecular hydrogen bond (Table 1  ) with an S(7) ring motif in the Hoogsteen face. In contrast, it may be noted that in the crystal structure of N 6-benzyl­adenine, (where no intra­molecular hydrogen bond is present) the N 6-substituent is syn to N1 and distal to N7 and the adenine moiety exists in the N(9)—H tautomeric form (Raghunathan et al., 1983  ). The dihedral angle between the benzene ring and the carboxyl group of HBA is 1.5 (3)°, indicating that the benzene ring and the carboxyl group are nearly coplanar. A comparison of dihedral angles and the C6—N6—C10—C11 torsion angle reported for various N 6-benzoyl­adenine-containing crystal structures is given in Table 2  .

Figure 1
The asymmetric unit of the title compound, showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. Dashed lines represent hydrogen bonds.
Table 1
Hydrogen-bond geometry (Å, °)
Table 2
Comparison of dihedral angles and torsion angles (°) for various N 6-benzoyl­adenine-containing crystal structures

Supra­molecular features  

The robust An external file that holds a picture, illustration, etc.
Object name is e-73-00383-efi1.jpg(8) ring motif is formed in the Watson–Crick face (N1 and N6 atoms) via N—H(...)O and O—H(...)N hydrogen bonds involving the carboxyl group of HBA. The N7 atom is a bifurcated donor and the carbonyl oxygen atom acts as a double acceptor for the N—H(...)O hydrogen bonds. Inversion-related BA mol­ecules form dimers through an array of hydrogen bonds, generating ring motifs, and these dimers are doubly bridged by inversion-related HBA mol­ecules (Fig. 2  ). A large R 6 6(32) supra­molecular ring is formed along the c-axis direction. A weak C8—H8(...)π inter­action is also present. Further consolidation of the structure is provided by homo and hetero π–π stacking inter­actions [Cg1(...)Cg5(An external file that holds a picture, illustration, etc.
Object name is e-73-00383-efi3.jpg − x, An external file that holds a picture, illustration, etc.
Object name is e-73-00383-efi3.jpg + y, An external file that holds a picture, illustration, etc.
Object name is e-73-00383-efi5.jpg − z) = 3.5580 (13) Å, Cg2(...)Cg5(An external file that holds a picture, illustration, etc.
Object name is e-73-00383-efi3.jpg − x, −An external file that holds a picture, illustration, etc.
Object name is e-73-00383-efi3.jpg + y, An external file that holds a picture, illustration, etc.
Object name is e-73-00383-efi5.jpg − z) = 3.6508 (12) Å; Cg1, Cg2 and Cg5 are the centroids of the imidazole ring, the pyrimidine ring and the benzene ring of HBA, respectively] (Fig. 3  ).

Figure 2
The formation of a supra­molecular three-dimensional large ring structure in the title compound.
Figure 3
A view of the homo/hetero-stacking inter­actions in the title compound.

Database survey  

The neutral mol­ecule N 6-benzoyl­adenine was first reported by Raghunathan & Pattabhi (1981  ). Various salts and co-crystals of N 6-benzoyl­adenine have also been reported: N 6-benzoyl­adenine–3-hy­droxy­pyridinium-2-carboxyl­ate (1:1) and N 6-benzoyl­adenine–dl-tartaric acid (1:1) (Karthikeyan et al., 2015  ), N 6-benzoyl­adeninium nitrate (1:1) (Karthikeyan et al., 2015  ), N 6-benzoyl­adenine–adipic acid (1:0.5) (Swinton Darious et al., 2016  ). Similarly, various co-crystals of HBA have been reported: 2-amino-4,6-di­methyl­pyrimidine–4-hy­droxy­benzoic acid (Balasubramani et al., 2006  ), 4-hy­droxy­benzoic acid–1H-imidazole (Wang et al., 2009  ), 2-amino-5-bromo­pyridine–4-hy­droxy­benzoic acid (Quah et al., 2010  ) and 4,6-dimeth­oxy-2-(methyl­sulfan­yl)-pyrimidine–4-hy­droxy­benzoic acid (Thanigaimani et al., 2012  ).

Synthesis and crystallization  

The title co-crystal was prepared by mixing a hot ethanol solution of N 6-benzoyl­adenine (30 mg) and 4-hy­droxy­benzoic acid (35 mg) in an equimolar ratio in a total volume of 30 mL. The mixture was warmed over a water bath for 30 min, filtered, and left aside for a few days. Colourless plate-shaped crystals were collected from the mother solution following slow cooling at room temperature.

Refinement details  

Crystal data, data collection and structure refinement details are summarized in Table 3  . Hydrogen atoms were readily located in difference-Fourier maps and were subsequently treated as riding atoms in geometrically idealized positions, with C—H = 0.93, N—H = 0.86 and O—H = 0.82 Å, and with U iso(H) = kU eq(C,N,O), where k = 1.5 for hy­droxy and 1.2 for all other H atoms.

Table 3
Experimental details

Supplementary Material

Crystal structure: contains datablock(s) I. DOI: 10.1107/S2056989017002171/hg5481sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989017002171/hg5481Isup2.hkl

CCDC reference: 1531929

Additional supporting information: crystallographic information; 3D view; checkCIF report

Acknowledgments

RSD thanks the UGC–BSR India for the award of an RFSMS. PTM is thankful to the UGC, New Delhi, for a UGC–BSR one-time grant to Faculty. FP thanks the Slovenian Research Agency for financial support (P1–0230-0175), as well as the EN–FIST Centre of Excellence, Ljubljana, Slovenia, for the use of the SuperNova diffractometer.

supplementary crystallographic information

Crystal data

C12H9N5O·C7H6O3F(000) = 784
Mr = 377.36Dx = 1.447 Mg m3
Monoclinic, P21/nCu Kα radiation, λ = 1.54184 Å
a = 14.7579 (5) ÅCell parameters from 2120 reflections
b = 6.7930 (3) Åθ = 3.9–74.6°
c = 17.2873 (5) ŵ = 0.88 mm1
β = 91.287 (3)°T = 293 K
V = 1732.62 (11) Å3Plate, colorless
Z = 40.20 × 0.15 × 0.03 mm

Data collection

Agilent SuperNova, Dual, Cu at zero, Atlas diffractometer3284 independent reflections
Radiation source: SuperNova (Cu) X-ray Source2457 reflections with I > 2σ(I)
Detector resolution: 10.4933 pixels mm-1Rint = 0.028
ω scansθmax = 70.1°, θmin = 3.9°
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2013)h = −12→17
Tmin = 0.597, Tmax = 1.000k = −8→7
6790 measured reflectionsl = −19→21

Refinement

Refinement on F2Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: fullH-atom parameters constrained
R[F2 > 2σ(F2)] = 0.053w = 1/[σ2(Fo2) + (0.0934P)2 + 0.2078P] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.161(Δ/σ)max < 0.001
S = 1.02Δρmax = 0.44 e Å3
3284 reflectionsΔρmin = −0.30 e Å3
256 parametersExtinction correction: SHELXL2014 (Sheldrick, 2015), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraintsExtinction coefficient: 0.0007 (2)

Special details

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)

xyzUiso*/Ueq
O10.42682 (11)1.0650 (3)0.54392 (9)0.0705 (6)
N10.39444 (11)0.9505 (3)0.78054 (9)0.0441 (4)
N30.54449 (12)0.9582 (3)0.83693 (10)0.0507 (5)
N60.35504 (10)0.9706 (2)0.65248 (9)0.0398 (4)
H60.30240.93810.66860.048*
N70.57481 (11)0.9980 (3)0.63742 (10)0.0428 (4)
H70.55981.00530.58920.051*
N90.66312 (11)0.9887 (3)0.74394 (11)0.0466 (4)
C20.45586 (14)0.9466 (4)0.84004 (12)0.0522 (6)
H20.43220.93400.88920.063*
C40.57400 (13)0.9747 (3)0.76459 (12)0.0402 (4)
C60.42445 (13)0.9683 (3)0.70853 (11)0.0362 (4)
C50.51711 (12)0.9806 (3)0.69794 (11)0.0357 (4)
C80.65938 (13)1.0017 (3)0.66780 (13)0.0473 (5)
H80.71071.01250.63780.057*
C100.35828 (13)1.0163 (3)0.57653 (12)0.0430 (5)
C110.26848 (13)1.0088 (3)0.53510 (11)0.0448 (5)
C120.21996 (19)0.8373 (5)0.53086 (16)0.0774 (8)
H120.24150.72520.55610.093*
C130.1393 (2)0.8303 (7)0.4892 (2)0.1083 (14)
H130.10750.71240.48470.130*
C140.1062 (2)0.9956 (7)0.45466 (18)0.0950 (13)
H140.05100.99080.42770.114*
C150.15326 (18)1.1700 (6)0.45909 (15)0.0828 (10)
H150.12971.28280.43560.099*
C160.23613 (16)1.1771 (4)0.49876 (14)0.0621 (6)
H160.26941.29330.50090.075*
O20.22103 (10)0.9691 (3)0.83296 (9)0.0563 (4)
H2A0.27180.95300.81570.084*
O30.18126 (10)0.9349 (4)0.70936 (9)0.0734 (6)
O4−0.20332 (10)1.0061 (3)0.86009 (10)0.0608 (5)
H4−0.23730.99260.82230.091*
C170.15996 (13)0.9583 (3)0.77584 (11)0.0409 (4)
C180.06559 (12)0.9737 (3)0.79947 (11)0.0366 (4)
C190.04097 (14)1.0009 (3)0.87579 (11)0.0435 (5)
H190.08571.01120.91430.052*
C20−0.04879 (14)1.0128 (4)0.89506 (12)0.0499 (5)
H20−0.06431.03140.94640.060*
C21−0.11692 (13)0.9970 (3)0.83780 (12)0.0425 (5)
C22−0.09232 (13)0.9722 (3)0.76111 (12)0.0437 (5)
H22−0.13680.96370.72230.052*
C23−0.00281 (13)0.9602 (3)0.74278 (12)0.0433 (5)
H230.01270.94270.69140.052*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
O10.0375 (9)0.1294 (16)0.0446 (8)−0.0059 (9)−0.0021 (6)0.0179 (9)
N10.0314 (8)0.0663 (11)0.0343 (8)0.0027 (7)−0.0060 (6)−0.0018 (7)
N30.0361 (9)0.0755 (12)0.0400 (9)0.0026 (8)−0.0107 (7)−0.0030 (8)
N60.0240 (8)0.0597 (10)0.0353 (8)−0.0021 (6)−0.0076 (6)0.0019 (7)
N70.0287 (8)0.0592 (10)0.0403 (9)−0.0002 (7)−0.0034 (6)0.0011 (7)
N90.0264 (8)0.0624 (11)0.0503 (10)0.0015 (7)−0.0087 (7)−0.0032 (8)
C20.0379 (11)0.0841 (16)0.0344 (9)0.0035 (10)−0.0064 (8)−0.0016 (10)
C40.0302 (10)0.0476 (10)0.0424 (10)0.0019 (7)−0.0097 (7)−0.0034 (8)
C60.0296 (9)0.0430 (10)0.0355 (9)0.0010 (7)−0.0078 (7)−0.0021 (7)
C50.0302 (9)0.0401 (9)0.0365 (9)0.0011 (7)−0.0061 (7)−0.0012 (7)
C80.0259 (10)0.0649 (13)0.0511 (12)0.0005 (8)−0.0012 (8)0.0007 (10)
C100.0301 (10)0.0615 (12)0.0372 (10)0.0017 (8)−0.0048 (7)0.0011 (9)
C110.0311 (10)0.0710 (13)0.0320 (9)0.0012 (9)−0.0061 (7)0.0023 (9)
C120.0706 (17)0.0902 (19)0.0699 (16)−0.0204 (15)−0.0324 (13)0.0151 (15)
C130.086 (2)0.150 (3)0.086 (2)−0.053 (2)−0.0499 (18)0.030 (2)
C140.0481 (15)0.182 (4)0.0536 (15)−0.0141 (19)−0.0213 (12)0.0164 (19)
C150.0563 (15)0.135 (3)0.0564 (14)0.0353 (18)−0.0098 (11)0.0172 (17)
C160.0517 (13)0.0784 (16)0.0558 (12)0.0135 (12)−0.0075 (10)0.0073 (12)
O20.0294 (7)0.0975 (12)0.0416 (8)−0.0001 (7)−0.0052 (6)−0.0040 (8)
O30.0339 (8)0.1439 (18)0.0425 (8)−0.0016 (9)−0.0009 (6)−0.0160 (10)
O40.0290 (8)0.1037 (14)0.0497 (9)0.0011 (7)−0.0003 (6)−0.0057 (9)
C170.0317 (10)0.0510 (11)0.0398 (10)−0.0015 (8)−0.0052 (7)−0.0014 (8)
C180.0308 (10)0.0403 (9)0.0383 (9)−0.0009 (7)−0.0051 (7)0.0018 (7)
C190.0332 (10)0.0621 (12)0.0350 (9)−0.0004 (8)−0.0078 (7)0.0008 (8)
C200.0349 (10)0.0822 (15)0.0324 (9)0.0006 (10)−0.0023 (8)0.0000 (10)
C210.0294 (10)0.0540 (11)0.0439 (10)−0.0002 (8)−0.0034 (8)0.0009 (9)
C220.0330 (10)0.0578 (12)0.0397 (10)0.0009 (8)−0.0092 (7)−0.0036 (9)
C230.0346 (10)0.0602 (12)0.0349 (9)0.0014 (8)−0.0060 (7)−0.0029 (9)

Geometric parameters (Å, º)

O1—C101.215 (3)C13—H130.9300
N1—C61.336 (3)C14—C151.375 (5)
N1—C21.356 (2)C14—H140.9300
N3—C21.313 (3)C15—C161.389 (3)
N3—C41.338 (3)C15—H150.9300
N6—C101.351 (3)C16—H160.9300
N6—C61.394 (2)O2—C171.324 (2)
N6—H60.8600O2—H2A0.8200
N7—C81.343 (2)O3—C171.209 (3)
N7—C51.369 (3)O4—C211.342 (3)
N7—H70.8600O4—H40.8200
N9—C81.319 (3)C17—C181.464 (3)
N9—C41.374 (3)C18—C191.389 (3)
C2—H20.9300C18—C231.394 (2)
C4—C51.411 (2)C19—C201.376 (3)
C6—C51.386 (3)C19—H190.9300
C8—H80.9300C20—C211.399 (3)
C10—C111.493 (3)C20—H200.9300
C11—C121.369 (4)C21—C221.393 (3)
C11—C161.384 (3)C22—C231.368 (3)
C12—C131.379 (3)C22—H220.9300
C12—H120.9300C23—H230.9300
C13—C141.357 (5)
C6—N1—C2118.60 (18)C14—C13—H13120.0
C2—N3—C4112.88 (17)C12—C13—H13120.0
C10—N6—C6129.53 (17)C13—C14—C15120.8 (3)
C10—N6—H6115.2C13—C14—H14119.6
C6—N6—H6115.2C15—C14—H14119.6
C8—N7—C5106.93 (17)C14—C15—C16119.7 (3)
C8—N7—H7126.5C14—C15—H15120.2
C5—N7—H7126.5C16—C15—H15120.2
C8—N9—C4104.19 (16)C11—C16—C15119.1 (3)
N3—C2—N1128.1 (2)C11—C16—H16120.4
N3—C2—H2115.9C15—C16—H16120.4
N1—C2—H2115.9C17—O2—H2A109.5
N3—C4—N9125.60 (17)C21—O4—H4109.5
N3—C4—C5124.43 (18)O3—C17—O2121.96 (18)
N9—C4—C5109.97 (18)O3—C17—C18122.96 (17)
N1—C6—C5118.50 (16)O2—C17—C18115.08 (18)
N1—C6—N6113.25 (17)C19—C18—C23118.42 (18)
C5—C6—N6128.25 (18)C19—C18—C17123.06 (17)
N7—C5—C6137.61 (17)C23—C18—C17118.53 (18)
N7—C5—C4104.93 (16)C20—C19—C18120.79 (18)
C6—C5—C4117.46 (18)C20—C19—H19119.6
N9—C8—N7113.98 (18)C18—C19—H19119.6
N9—C8—H8123.0C19—C20—C21120.3 (2)
N7—C8—H8123.0C19—C20—H20119.8
O1—C10—N6124.15 (18)C21—C20—H20119.8
O1—C10—C11121.74 (18)O4—C21—C22123.28 (18)
N6—C10—C11114.07 (17)O4—C21—C20117.8 (2)
C12—C11—C16120.3 (2)C22—C21—C20118.97 (19)
C12—C11—C10120.8 (2)C23—C22—C21120.10 (17)
C16—C11—C10118.9 (2)C23—C22—H22119.9
C11—C12—C13120.1 (3)C21—C22—H22119.9
C11—C12—H12119.9C22—C23—C18121.40 (19)
C13—C12—H12119.9C22—C23—H23119.3
C14—C13—C12119.9 (3)C18—C23—H23119.3
C4—N3—C2—N1−0.4 (4)N6—C10—C11—C12−60.8 (3)
C6—N1—C2—N30.0 (4)O1—C10—C11—C16−56.9 (3)
C2—N3—C4—N9−179.7 (2)N6—C10—C11—C16121.2 (2)
C2—N3—C4—C50.4 (3)C16—C11—C12—C131.1 (5)
C8—N9—C4—N3179.9 (2)C10—C11—C12—C13−176.8 (3)
C8—N9—C4—C5−0.2 (2)C11—C12—C13—C14−2.4 (6)
C2—N1—C6—C50.4 (3)C12—C13—C14—C151.6 (6)
C2—N1—C6—N6−179.98 (19)C13—C14—C15—C160.6 (5)
C10—N6—C6—N1168.6 (2)C12—C11—C16—C151.0 (4)
C10—N6—C6—C5−11.9 (3)C10—C11—C16—C15179.0 (2)
C8—N7—C5—C6−179.9 (2)C14—C15—C16—C11−1.9 (4)
C8—N7—C5—C40.0 (2)O3—C17—C18—C19−179.9 (2)
N1—C6—C5—N7179.6 (2)O2—C17—C18—C191.0 (3)
N6—C6—C5—N70.0 (4)O3—C17—C18—C230.2 (3)
N1—C6—C5—C4−0.4 (3)O2—C17—C18—C23−178.92 (19)
N6—C6—C5—C4−179.93 (18)C23—C18—C19—C200.5 (3)
N3—C4—C5—N7179.99 (19)C17—C18—C19—C20−179.43 (19)
N9—C4—C5—N70.1 (2)C18—C19—C20—C210.2 (3)
N3—C4—C5—C60.0 (3)C19—C20—C21—O4178.8 (2)
N9—C4—C5—C6−179.93 (16)C19—C20—C21—C22−1.0 (3)
C4—N9—C8—N70.2 (2)O4—C21—C22—C23−178.7 (2)
C5—N7—C8—N9−0.2 (2)C20—C21—C22—C231.1 (3)
C6—N6—C10—O10.1 (4)C21—C22—C23—C18−0.4 (3)
C6—N6—C10—C11−177.92 (19)C19—C18—C23—C22−0.3 (3)
O1—C10—C11—C12121.1 (3)C17—C18—C23—C22179.55 (19)

Hydrogen-bond geometry (Å, º)

Cg3 is the centroid of the C11–C16 phenyl ring.

D—H···AD—HH···AD···AD—H···A
O2—H2A···N10.821.922.737 (2)172
O4—H4···N9i0.821.982.784 (2)168
N6—H6···O30.861.942.778 (2)166
N7—H7···O10.862.142.726 (2)126
N7—H7···O1ii0.862.363.164 (2)155
C8—H8···Cg3ii0.932.773.646 (2)157

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

References

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Articles from Acta Crystallographica Section E: Crystallographic Communications are provided here courtesy of International Union of Crystallography