Crystal structure of the co-crystal butyl-paraben-isonicotinamide (1/1).

The title 1:1 co-crystal, C11H14O3·C6H6N2O [systematic name: butyl 4-hy-droxy-benzoate-isonicotinamide (1/1)], crystallizes with one mol-ecule of butyl-paraben (BPN) and one mol-ecule of isonicotinamide (ISN) in the asymmetric unit. In the crystal, BPN and ISN mol-ecules form hydrogen-bonded (O-H⋯N and N-H⋯O) dimers of paired BPN and ISN mol-ecules. These dimers are further connected to each other via N-H⋯O=C hydrogen bonds, creating ribbons in [011] which further stack along the a axis to form a layered structure with short C⋯C contacts of 3.285 (3) Å. Packing inter-actions within the crystal structure were assessed using PIXEL calculations.

Chemical context

Butyl­paraben (butyl 4-hy­droxy­benzoate, BPN), a naturally derived preservative, is widely used in pharmaceutical products and cosmetics (Charnock & Finsrud, 2007 ▸), and generally considered to be safe (Hossaini et al., 2000 ▸). The solubility of BPN has been reported in various solvents (Yang & Rasmuson, 2010 ▸; 2012 ▸; 2013 ▸). Isonicotinamide (ISN) is a widely used coformer (Aakeröy et al., 2003 ▸) and is known to form hydrogen-bonded co-crystals with phenolic compounds (Vishweshwar et al., 2003 ▸; McKellar et al., 2014 ▸). The sample of butyl paraben–isonicotinamide (BPIN) co-crystals was isolated during an experimental co-crystal screening of BPN. The sample was identified as a novel form using multi-sample foil transmission X-ray powder diffraction analysis (Florence et al., 2003 ▸). A suitable sample for single crystal X-ray diffraction analysis was obtained from slow evaporation of 1:1 molar solution of BPN with ISN in ethanol at room temperature.

Structural commentary

The title co-crystal crystallizes with one mol­ecule of BPN and a mol­ecule of ISN in the asymmetric unit (Fig. 1 ▸). In the solid state, the BPN mol­ecule exhibits a planar conformation with a fully extended trans zigzag butyl ester group.

Figure 1

A view of the mol­ecular structure of the asymmetric unit of the title co-crystal, showing the atom labelling. Displacement ellipsoids are drawn at the 50% probability level.

Supra­molecular features

The crystal structure is defined by hydrogen-bonded BPN–ISN–ISN–BPN dimers of paired BPN⋯ISN mol­ecules connected via O—H⋯N hydrogen bonds (Fig. 2 ▸ a). These BPN–ISN–ISN–BPN dimers are further connected to each other via N—H⋯O=C hydrogen-bonds extending the structure to form ribbons in [011]; see Fig. 2 ▸ b and Table 1 ▸. These ribbons further stack along a axis to produce a layered structure (Fig. 3 ▸) which is stabilized by various van der Waals inter­actions and exhibits short C⋯C contacts of 3.285 (3) Å. PIXEL (Gavezzotti, 2002 ▸; 2003 ▸) calculations revealed that the largest contribution to crystal stabilization comes from the dispersion energy (Ed, −98.5 kJ mol−1). The next greatest contribution comes from electrostatic (Coulombic) energy, (EC, −67.3 kJ mol−1) and then from polarization energy (Ep, −32.2 kJ mol−1).

Figure 2

Hydrogen bonds in the title compound: (a) hydrogen-bonded (thin grey lines) dimer of paired BPN⋯ISN mol­ecules; (b) hydrogen-bonded (thin orange lines) ribbon of dimers extended in [011]. Atom colour code: C, N, O and H are grey, blue, red and white, respectively. Hydrogen atoms not involved in hydrogen bonding have been omitted for clarity.

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H3O⋯N2	0.95 (3)	1.79 (3)	2.721 (2)	165 (2)
N1—H1N⋯O1i	0.91 (2)	1.97 (2)	2.880 (2)	175.3 (15)
N1—H2N⋯O3ii	0.94 (2)	2.02 (2)	2.948 (2)	168.3 (18)

Symmetry codes: (i) ; (ii) .

Figure 3

A portion of the crystal packing showing the layered structure of the title co-crystal. H atoms have been omitted for clarity.

Database survey

The crystal structures of BPN (CSD refcode: UDOMIL) (Yang & Rasmuson, 2013 ▸) and its clathrate hydrate (CSD refcode: VOFKIL) have been reported in the literature (de Vries & Caira, 2008 ▸). In UDOMIL, the BPN mol­ecule exhibits a planar conformation except for the terminal ethyl moiety of butyl ester group which is in a cis orientation with respect to the ester group.

Synthesis and crystallization

Plate shaped crystals were grown from the saturated 1:1 molar solution of BPN with ISN in ethanol by isothermal solvent evaporation at 298 K.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2 ▸. The N and O bound H atoms were located in a difference Fourier map and isotropically refined. The C-bound H atoms were placed in calculated positions and refined as riding atoms: C—H = 0.95–0.99 Å with U iso(H) = 1.5U eq(C) for methyl H atoms and = 1.2U eq(C) for other H atoms.

Table 2

Experimental details

Crystal data
Chemical formula	C11H14O3·C6H6N2O
M r	316.35
Crystal system, space group	Triclinic, P
Temperature (K)	150
a, b, c (Å)	5.6257 (6), 9.8661 (11), 14.3979 (15)
α, β, γ (°)	90.834 (7), 91.431 (7), 91.645 (7)
V (Å3)	798.47 (15)
Z	2
Radiation type	Mo Kα
μ (mm−1)	0.09
Crystal size (mm)	0.45 × 0.36 × 0.21
Data collection
Diffractometer	Bruker APEXII CCD
Absorption correction	Multi-scan (SADABS; Bruker, 2007 ▸)
T min, T max	0.625, 0.745
No. of measured, independent and observed [I > 2σ(I)] reflections	10444, 3225, 2344
R int	0.039
(sin θ/λ)max (Å−1)	0.627
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.045, 0.116, 1.05
No. of reflections	3225
No. of parameters	221
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3)	0.26, −0.27

Computer programs: APEX2 and SAINT (Bruker, 2007 ▸), SHELXS97 (Sheldrick, 2008 ▸), SHELXL2014 (Sheldrick, 2015 ▸), Mercury (Macrae et al., 2008 ▸), ORTEP-3 for Windows (Farrugia, 2012 ▸), enCIFer (Allen et al., 2004 ▸) and publCIF (Westrip, 2010 ▸).

Crystal structure: contains datablock(s) I. DOI: 10.1107/S2056989015023518/cv5494sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989015023518/cv5494Isup2.hkl

Click here for additional data file.

Supporting information file. DOI: 10.1107/S2056989015023518/cv5494Isup3.cml

CCDC reference: 1440986

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

C11H14O3·C6H6N2O	Z = 2
Mr = 316.35	F(000) = 336
Triclinic, P1	Dx = 1.316 Mg m−3
a = 5.6257 (6) Å	Mo Kα radiation, λ = 0.71073 Å
b = 9.8661 (11) Å	Cell parameters from 4038 reflections
c = 14.3979 (15) Å	θ = 2.5–26.4°
α = 90.834 (7)°	µ = 0.09 mm−1
β = 91.431 (7)°	T = 150 K
γ = 91.645 (7)°	Plate, colourless
V = 798.47 (15) Å3	0.45 × 0.36 × 0.21 mm

Bruker APEXII CCD diffractometer	3225 independent reflections
Radiation source: fine-focus sealed tube	2344 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.039
φ and ω scans	θmax = 26.5°, θmin = 2.1°
Absorption correction: multi-scan (SADABS; Bruker, 2007)	h = −6→7
Tmin = 0.625, Tmax = 0.745	k = −12→12
10444 measured reflections	l = −18→18

Refinement on F2	0 restraints
Least-squares matrix: full	Hydrogen site location: mixed
R[F2 > 2σ(F2)] = 0.045	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.116	w = 1/[σ2(Fo2) + (0.0482P)2 + 0.3682P] where P = (Fo2 + 2Fc2)/3
S = 1.05	(Δ/σ)max = 0.001
3225 reflections	Δρmax = 0.26 e Å−3
221 parameters	Δρmin = −0.27 e Å−3

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

	x	y	z	Uiso*/Ueq
H1N	−0.623 (3)	1.480 (2)	1.4226 (13)	0.019 (5)*
H2N	−0.626 (4)	1.399 (2)	1.3256 (16)	0.035 (6)*
H3O	0.140 (5)	0.939 (3)	1.1807 (17)	0.054 (7)*
O4	0.1197 (2)	0.47988 (13)	0.82145 (8)	0.0227 (3)
O1	−0.2641 (2)	1.38157 (14)	1.49057 (9)	0.0275 (3)
N1	−0.5594 (3)	1.41555 (17)	1.38514 (11)	0.0238 (4)
O2	0.2637 (2)	0.88155 (15)	1.16227 (9)	0.0308 (4)
N2	−0.0392 (3)	1.05682 (16)	1.24155 (10)	0.0234 (4)
O3	−0.2134 (2)	0.59634 (14)	0.80166 (9)	0.0297 (3)
C13	−0.0315 (3)	0.57543 (19)	0.84578 (12)	0.0207 (4)
C7	0.2633 (3)	0.63083 (19)	0.97609 (12)	0.0220 (4)
H8	0.3619	0.5641	0.9542	0.026*
C6	−0.3631 (3)	1.35566 (18)	1.41440 (12)	0.0194 (4)
C12	0.0462 (3)	0.65243 (18)	0.93023 (12)	0.0190 (4)
C14	0.0586 (3)	0.40447 (19)	0.73615 (12)	0.0223 (4)
H15A	0.0438	0.4660	0.6845	0.027*
H15B	−0.0918	0.3552	0.7423	0.027*
C8	0.3330 (3)	0.7076 (2)	1.05364 (13)	0.0239 (4)
H9	0.4775	0.6920	1.0839	0.029*
C2	−0.0520 (3)	1.18936 (19)	1.38204 (13)	0.0234 (4)
H2	0.0162	1.2121	1.4399	0.028*
C10	−0.0302 (3)	0.83018 (19)	1.04128 (12)	0.0229 (4)
H11	−0.1290	0.8969	1.0631	0.027*
C16	0.2264 (3)	0.2420 (2)	0.62252 (13)	0.0242 (4)
H17A	0.0722	0.1955	0.6171	0.029*
H17B	0.2306	0.3126	0.5764	0.029*
C5	−0.3533 (3)	1.21153 (19)	1.26476 (12)	0.0213 (4)
H6	−0.4918	1.2498	1.2420	0.026*
C15	0.2548 (3)	0.30708 (19)	0.71924 (12)	0.0220 (4)
H16A	0.2511	0.2370	0.7658	0.026*
H16B	0.4075	0.3551	0.7248	0.026*
C1	−0.2580 (3)	1.25031 (18)	1.35125 (12)	0.0185 (4)
C9	0.1866 (3)	0.80852 (19)	1.08652 (12)	0.0221 (4)
C11	−0.0986 (3)	0.75279 (19)	0.96404 (12)	0.0223 (4)
H12	−0.2437	0.7680	0.9342	0.027*
C3	0.0504 (3)	1.0945 (2)	1.32551 (13)	0.0251 (4)
H3	0.1888	1.0544	1.3467	0.030*
C4	−0.2387 (3)	1.11486 (19)	1.21283 (13)	0.0240 (4)
H5	−0.3042	1.0892	1.1551	0.029*
C17	0.4194 (4)	0.1414 (2)	0.60224 (14)	0.0314 (5)
H18A	0.5725	0.1869	0.6068	0.047*
H18B	0.3946	0.1042	0.5407	0.047*
H18C	0.4130	0.0696	0.6465	0.047*

	U11	U22	U33	U12	U13	U23
O4	0.0233 (7)	0.0256 (7)	0.0192 (7)	0.0096 (6)	−0.0068 (5)	−0.0082 (5)
O1	0.0308 (7)	0.0313 (8)	0.0203 (7)	0.0134 (6)	−0.0072 (6)	−0.0097 (6)
N1	0.0260 (9)	0.0268 (9)	0.0185 (8)	0.0106 (7)	−0.0047 (7)	−0.0089 (7)
O2	0.0272 (7)	0.0367 (8)	0.0279 (7)	0.0099 (6)	−0.0072 (6)	−0.0183 (6)
N2	0.0251 (8)	0.0230 (8)	0.0223 (8)	0.0055 (7)	0.0000 (6)	−0.0049 (7)
O3	0.0284 (7)	0.0376 (8)	0.0229 (7)	0.0145 (6)	−0.0098 (6)	−0.0089 (6)
C13	0.0215 (9)	0.0228 (10)	0.0181 (9)	0.0066 (8)	−0.0013 (7)	−0.0014 (8)
C7	0.0227 (9)	0.0230 (10)	0.0205 (9)	0.0081 (8)	−0.0021 (7)	−0.0043 (8)
C6	0.0209 (9)	0.0199 (9)	0.0173 (9)	0.0022 (8)	−0.0009 (7)	−0.0019 (7)
C12	0.0211 (9)	0.0195 (9)	0.0164 (9)	0.0033 (7)	−0.0010 (7)	−0.0006 (7)
C14	0.0257 (10)	0.0252 (10)	0.0157 (9)	0.0049 (8)	−0.0061 (7)	−0.0061 (8)
C8	0.0190 (9)	0.0311 (11)	0.0215 (9)	0.0076 (8)	−0.0060 (7)	−0.0061 (8)
C2	0.0234 (9)	0.0270 (10)	0.0195 (9)	0.0037 (8)	−0.0046 (7)	−0.0050 (8)
C10	0.0226 (9)	0.0241 (10)	0.0222 (9)	0.0090 (8)	0.0014 (7)	−0.0035 (8)
C16	0.0281 (10)	0.0246 (10)	0.0199 (9)	0.0060 (8)	−0.0034 (8)	−0.0053 (8)
C5	0.0234 (9)	0.0230 (10)	0.0176 (9)	0.0068 (8)	−0.0040 (7)	−0.0013 (8)
C15	0.0233 (9)	0.0232 (10)	0.0194 (9)	0.0062 (8)	−0.0042 (7)	−0.0027 (8)
C1	0.0200 (9)	0.0176 (9)	0.0179 (9)	0.0017 (7)	0.0009 (7)	−0.0015 (7)
C9	0.0239 (10)	0.0239 (10)	0.0184 (9)	0.0031 (8)	−0.0009 (7)	−0.0067 (8)
C11	0.0196 (9)	0.0276 (10)	0.0199 (9)	0.0079 (8)	−0.0037 (7)	−0.0010 (8)
C3	0.0225 (9)	0.0263 (10)	0.0265 (10)	0.0095 (8)	−0.0033 (8)	−0.0059 (8)
C4	0.0277 (10)	0.0269 (11)	0.0173 (9)	0.0055 (8)	−0.0029 (7)	−0.0058 (8)
C17	0.0348 (11)	0.0310 (11)	0.0287 (11)	0.0096 (9)	0.0016 (9)	−0.0062 (9)

O4—C13	1.336 (2)	C12—C11	1.391 (2)
O4—C14	1.455 (2)	C14—C15	1.506 (2)
O1—C6	1.238 (2)	C8—C9	1.395 (2)
N1—C6	1.330 (2)	C2—C3	1.379 (2)
O2—C9	1.354 (2)	C2—C1	1.387 (2)
N2—C4	1.334 (2)	C10—C11	1.380 (3)
N2—C3	1.341 (2)	C10—C9	1.392 (3)
O3—C13	1.215 (2)	C16—C17	1.523 (3)
C13—C12	1.475 (2)	C16—C15	1.528 (2)
C7—C8	1.382 (3)	C5—C4	1.387 (2)
C7—C12	1.397 (2)	C5—C1	1.388 (2)
C6—C1	1.514 (2)
C13—O4—C14	115.95 (13)	C3—C2—C1	118.97 (17)
C4—N2—C3	117.20 (15)	C11—C10—C9	120.08 (16)
O3—C13—O4	122.73 (16)	C17—C16—C15	112.76 (15)
O3—C13—C12	123.99 (16)	C4—C5—C1	118.94 (16)
O4—C13—C12	113.28 (14)	C14—C15—C16	110.66 (15)
C8—C7—C12	120.73 (16)	C2—C1—C5	118.09 (16)
O1—C6—N1	123.13 (16)	C2—C1—C6	117.54 (16)
O1—C6—C1	118.87 (15)	C5—C1—C6	124.37 (15)
N1—C6—C1	117.99 (16)	O2—C9—C10	122.75 (16)
C11—C12—C7	118.73 (16)	O2—C9—C8	117.70 (16)
C11—C12—C13	118.87 (15)	C10—C9—C8	119.55 (16)
C7—C12—C13	122.38 (15)	C10—C11—C12	120.95 (17)
O4—C14—C15	107.55 (14)	N2—C3—C2	123.48 (17)
C7—C8—C9	119.96 (17)	N2—C4—C5	123.31 (17)
C14—O4—C13—O3	2.3 (3)	O1—C6—C1—C2	−1.0 (3)
C14—O4—C13—C12	−177.25 (15)	N1—C6—C1—C2	179.41 (18)
C8—C7—C12—C11	0.0 (3)	O1—C6—C1—C5	179.42 (18)
C8—C7—C12—C13	178.19 (18)	N1—C6—C1—C5	−0.2 (3)
O3—C13—C12—C11	2.0 (3)	C11—C10—C9—O2	179.70 (18)
O4—C13—C12—C11	−178.52 (16)	C11—C10—C9—C8	−0.4 (3)
O3—C13—C12—C7	−176.20 (19)	C7—C8—C9—O2	−179.54 (17)
O4—C13—C12—C7	3.3 (3)	C7—C8—C9—C10	0.6 (3)
C13—O4—C14—C15	177.62 (16)	C9—C10—C11—C12	0.1 (3)
C12—C7—C8—C9	−0.4 (3)	C7—C12—C11—C10	0.1 (3)
O4—C14—C15—C16	−170.00 (15)	C13—C12—C11—C10	−178.09 (17)
C17—C16—C15—C14	−179.45 (17)	C4—N2—C3—C2	−0.4 (3)
C3—C2—C1—C5	0.6 (3)	C1—C2—C3—N2	−0.2 (3)
C3—C2—C1—C6	−179.01 (17)	C3—N2—C4—C5	0.7 (3)
C4—C5—C1—C2	−0.4 (3)	C1—C5—C4—N2	−0.3 (3)
C4—C5—C1—C6	179.21 (17)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H3O···N2	0.95 (3)	1.79 (3)	2.721 (2)	165 (2)
N1—H1N···O1i	0.91 (2)	1.97 (2)	2.880 (2)	175.3 (15)
N1—H2N···O3ii	0.94 (2)	2.02 (2)	2.948 (2)	168.3 (18)