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Crystal structure of the co-crystal butyl­paraben–isonicotinamide (1/1)

aStrathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, Scotland
*Correspondence e-mail: alastair.florence@strath.ac.uk

Edited by V. V. Chernyshev, Moscow State University, Russia (Received 31 August 2015; accepted 7 December 2015; online 1 January 2016)

The title 1:1 co-crystal, C11H14O3·C6H6N2O [systematic name: butyl 4-hy­droxy­benzoate–isonicotinamide (1/1)], crystallizes with one mol­ecule of butyl­paraben (BPN) and one mol­ecule of isonicotinamide (ISN) in the asymmetric unit. In the crystal, BPN and ISN mol­ecules form hydrogen-bonded (O—H⋯N and N—H⋯O) dimers of paired BPN and ISN mol­ecules. 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 inter­actions within the crystal structure were assessed using PIXEL calculations.

1. Chemical context

Butyl­paraben (butyl 4-hy­droxy­benzoate, BPN), a naturally derived preservative, is widely used in pharmaceutical products and cosmetics (Charnock & Finsrud, 2007[Charnock, C. & Finsrud, T. (2007). J. Clin. Pharm. Ther. 32, 567-572.]), and generally considered to be safe (Hossaini et al., 2000[Hossaini, A., Larsen, J. J. & Larsen, J. C. (2000). Food Chem. Toxicol. 38, 319-323.]). The solubility of BPN has been reported in various solvents (Yang & Rasmuson, 2010[Yang, H. Y. & Rasmuson, A. C. (2010). J. Chem. Eng. Data, 55, 5091-5093.]; 2012[Yang, H. & Rasmuson, A. C. (2012). Org. Process Res. Dev. 16, 1212-1224.]; 2013[Yang, H. Y. & Rasmuson, A. C. (2013). Cryst. Growth Des. 13, 4226-4238.]). Isonicotinamide (ISN) is a widely used coformer (Aakeröy et al., 2003[Aakeröy, C. B., Beatty, A. M., Helfrich, B. A. & Nieuwenhuyzen, M. (2003). Cryst. Growth Des. 3, 159-165.]) and is known to form hydrogen-bonded co-crystals with phenolic compounds (Vishweshwar et al., 2003[Vishweshwar, P., Nangia, A. & Lynch, V. M. (2003). CrystEngComm, 5, 164-168.]; McKellar et al., 2014[McKellar, S. C., Kennedy, A. R., McCloy, N. C., McBride, E. & Florence, A. J. (2014). Cryst. Growth Des. 14, 2422-2430.]). 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[Florence, A. J., Baumgartner, B., Weston, C., Shankland, N., Kennedy, A. R., Shankland, K. & David, W. I. F. (2003). J. Pharm. Sci. 92, 1930-1938.]). 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.

[Scheme 1]

2. Structural commentary

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

[Figure 1]
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.

3. 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[link]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[link]b and Table 1[link]. These ribbons further stack along a axis to produce a layered structure (Fig. 3[link]) which is stabilized by various van der Waals inter­actions and exhibits short C⋯C contacts of 3.285 (3) Å. PIXEL (Gavezzotti, 2002[Gavezzotti, A. (2002). J. Phys. Chem. B, 106, 4145-4154.]; 2003[Gavezzotti, A. (2003). J. Phys. Chem. B, 107, 2344-2353.]) 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).

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA 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) -x-1, -y+3, -z+3; (ii) -x-1, -y+2, -z+2.
[Figure 2]
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.
[Figure 3]
Figure 3
A portion of the crystal packing showing the layered structure of the title co-crystal. H atoms have been omitted for clarity.

4. Database survey

The crystal structures of BPN (CSD refcode: UDOMIL) (Yang & Rasmuson, 2013[Yang, H. Y. & Rasmuson, A. C. (2013). Cryst. Growth Des. 13, 4226-4238.]) and its clathrate hydrate (CSD refcode: VOFKIL) have been reported in the literature (de Vries & Caira, 2008[Vries, E. J. C. de & Caira, M. R. (2008). Carbohydr. Res. 343, 2433-2438.]). 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.

5. 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.

6. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2[link]. 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 Uiso(H) = 1.5Ueq(C) for methyl H atoms and = 1.2Ueq(C) for other H atoms.

Table 2
Experimental details

Crystal data
Chemical formula C11H14O3·C6H6N2O
Mr 316.35
Crystal system, space group Triclinic, P[\overline{1}]
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)
V3) 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[Bruker (2007). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.])
Tmin, Tmax 0.625, 0.745
No. of measured, independent and observed [I > 2σ(I)] reflections 10444, 3225, 2344
Rint 0.039
(sin θ/λ)max−1) 0.627
 
Refinement
R[F2 > 2σ(F2)], wR(F2), 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[Bruker (2007). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]), SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]), SHELXL2014 (Sheldrick, 2015[Sheldrick, G. M. (2015). Acta Cryst. C71, 3-8.]), Mercury (Macrae et al., 2008[Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466-470.]), ORTEP-3 for Windows (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]), enCIFer (Allen et al., 2004[Allen, F. H., Johnson, O., Shields, G. P., Smith, B. R. & Towler, M. (2004). J. Appl. Cryst. 37, 335-338.]) and publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]).

Supporting information


Computing details top

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: Mercury (Macrae et al., 2008) and ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: enCIFer (Allen et al., 2004) and publCIF (Westrip, 2010).

Butyl 4-hydroxybenzoate–isonicotinamide (1/1) top
Crystal data top
C11H14O3·C6H6N2OZ = 2
Mr = 316.35F(000) = 336
Triclinic, P1Dx = 1.316 Mg m3
a = 5.6257 (6) ÅMo Kα radiation, λ = 0.71073 Å
b = 9.8661 (11) ÅCell parameters from 4038 reflections
c = 14.3979 (15) Åθ = 2.5–26.4°
α = 90.834 (7)°µ = 0.09 mm1
β = 91.431 (7)°T = 150 K
γ = 91.645 (7)°Plate, colourless
V = 798.47 (15) Å30.45 × 0.36 × 0.21 mm
Data collection top
Bruker APEXII CCD
diffractometer
3225 independent reflections
Radiation source: fine-focus sealed tube2344 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.039
φ and ω scansθmax = 26.5°, θmin = 2.1°
Absorption correction: multi-scan
(SADABS; Bruker, 2007)
h = 67
Tmin = 0.625, Tmax = 0.745k = 1212
10444 measured reflectionsl = 1818
Refinement top
Refinement on F20 restraints
Least-squares matrix: fullHydrogen site location: mixed
R[F2 > 2σ(F2)] = 0.045H 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 reflectionsΔρmax = 0.26 e Å3
221 parametersΔρmin = 0.27 e Å3
Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
H1N0.623 (3)1.480 (2)1.4226 (13)0.019 (5)*
H2N0.626 (4)1.399 (2)1.3256 (16)0.035 (6)*
H3O0.140 (5)0.939 (3)1.1807 (17)0.054 (7)*
O40.1197 (2)0.47988 (13)0.82145 (8)0.0227 (3)
O10.2641 (2)1.38157 (14)1.49057 (9)0.0275 (3)
N10.5594 (3)1.41555 (17)1.38514 (11)0.0238 (4)
O20.2637 (2)0.88155 (15)1.16227 (9)0.0308 (4)
N20.0392 (3)1.05682 (16)1.24155 (10)0.0234 (4)
O30.2134 (2)0.59634 (14)0.80166 (9)0.0297 (3)
C130.0315 (3)0.57543 (19)0.84578 (12)0.0207 (4)
C70.2633 (3)0.63083 (19)0.97609 (12)0.0220 (4)
H80.36190.56410.95420.026*
C60.3631 (3)1.35566 (18)1.41440 (12)0.0194 (4)
C120.0462 (3)0.65243 (18)0.93023 (12)0.0190 (4)
C140.0586 (3)0.40447 (19)0.73615 (12)0.0223 (4)
H15A0.04380.46600.68450.027*
H15B0.09180.35520.74230.027*
C80.3330 (3)0.7076 (2)1.05364 (13)0.0239 (4)
H90.47750.69201.08390.029*
C20.0520 (3)1.18936 (19)1.38204 (13)0.0234 (4)
H20.01621.21211.43990.028*
C100.0302 (3)0.83018 (19)1.04128 (12)0.0229 (4)
H110.12900.89691.06310.027*
C160.2264 (3)0.2420 (2)0.62252 (13)0.0242 (4)
H17A0.07220.19550.61710.029*
H17B0.23060.31260.57640.029*
C50.3533 (3)1.21153 (19)1.26476 (12)0.0213 (4)
H60.49181.24981.24200.026*
C150.2548 (3)0.30708 (19)0.71924 (12)0.0220 (4)
H16A0.25110.23700.76580.026*
H16B0.40750.35510.72480.026*
C10.2580 (3)1.25031 (18)1.35125 (12)0.0185 (4)
C90.1866 (3)0.80852 (19)1.08652 (12)0.0221 (4)
C110.0986 (3)0.75279 (19)0.96404 (12)0.0223 (4)
H120.24370.76800.93420.027*
C30.0504 (3)1.0945 (2)1.32551 (13)0.0251 (4)
H30.18881.05441.34670.030*
C40.2387 (3)1.11486 (19)1.21283 (13)0.0240 (4)
H50.30421.08921.15510.029*
C170.4194 (4)0.1414 (2)0.60224 (14)0.0314 (5)
H18A0.57250.18690.60680.047*
H18B0.39460.10420.54070.047*
H18C0.41300.06960.64650.047*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O40.0233 (7)0.0256 (7)0.0192 (7)0.0096 (6)0.0068 (5)0.0082 (5)
O10.0308 (7)0.0313 (8)0.0203 (7)0.0134 (6)0.0072 (6)0.0097 (6)
N10.0260 (9)0.0268 (9)0.0185 (8)0.0106 (7)0.0047 (7)0.0089 (7)
O20.0272 (7)0.0367 (8)0.0279 (7)0.0099 (6)0.0072 (6)0.0183 (6)
N20.0251 (8)0.0230 (8)0.0223 (8)0.0055 (7)0.0000 (6)0.0049 (7)
O30.0284 (7)0.0376 (8)0.0229 (7)0.0145 (6)0.0098 (6)0.0089 (6)
C130.0215 (9)0.0228 (10)0.0181 (9)0.0066 (8)0.0013 (7)0.0014 (8)
C70.0227 (9)0.0230 (10)0.0205 (9)0.0081 (8)0.0021 (7)0.0043 (8)
C60.0209 (9)0.0199 (9)0.0173 (9)0.0022 (8)0.0009 (7)0.0019 (7)
C120.0211 (9)0.0195 (9)0.0164 (9)0.0033 (7)0.0010 (7)0.0006 (7)
C140.0257 (10)0.0252 (10)0.0157 (9)0.0049 (8)0.0061 (7)0.0061 (8)
C80.0190 (9)0.0311 (11)0.0215 (9)0.0076 (8)0.0060 (7)0.0061 (8)
C20.0234 (9)0.0270 (10)0.0195 (9)0.0037 (8)0.0046 (7)0.0050 (8)
C100.0226 (9)0.0241 (10)0.0222 (9)0.0090 (8)0.0014 (7)0.0035 (8)
C160.0281 (10)0.0246 (10)0.0199 (9)0.0060 (8)0.0034 (8)0.0053 (8)
C50.0234 (9)0.0230 (10)0.0176 (9)0.0068 (8)0.0040 (7)0.0013 (8)
C150.0233 (9)0.0232 (10)0.0194 (9)0.0062 (8)0.0042 (7)0.0027 (8)
C10.0200 (9)0.0176 (9)0.0179 (9)0.0017 (7)0.0009 (7)0.0015 (7)
C90.0239 (10)0.0239 (10)0.0184 (9)0.0031 (8)0.0009 (7)0.0067 (8)
C110.0196 (9)0.0276 (10)0.0199 (9)0.0079 (8)0.0037 (7)0.0010 (8)
C30.0225 (9)0.0263 (10)0.0265 (10)0.0095 (8)0.0033 (8)0.0059 (8)
C40.0277 (10)0.0269 (11)0.0173 (9)0.0055 (8)0.0029 (7)0.0058 (8)
C170.0348 (11)0.0310 (11)0.0287 (11)0.0096 (9)0.0016 (9)0.0062 (9)
Geometric parameters (Å, º) top
O4—C131.336 (2)C12—C111.391 (2)
O4—C141.455 (2)C14—C151.506 (2)
O1—C61.238 (2)C8—C91.395 (2)
N1—C61.330 (2)C2—C31.379 (2)
O2—C91.354 (2)C2—C11.387 (2)
N2—C41.334 (2)C10—C111.380 (3)
N2—C31.341 (2)C10—C91.392 (3)
O3—C131.215 (2)C16—C171.523 (3)
C13—C121.475 (2)C16—C151.528 (2)
C7—C81.382 (3)C5—C41.387 (2)
C7—C121.397 (2)C5—C11.388 (2)
C6—C11.514 (2)
C13—O4—C14115.95 (13)C3—C2—C1118.97 (17)
C4—N2—C3117.20 (15)C11—C10—C9120.08 (16)
O3—C13—O4122.73 (16)C17—C16—C15112.76 (15)
O3—C13—C12123.99 (16)C4—C5—C1118.94 (16)
O4—C13—C12113.28 (14)C14—C15—C16110.66 (15)
C8—C7—C12120.73 (16)C2—C1—C5118.09 (16)
O1—C6—N1123.13 (16)C2—C1—C6117.54 (16)
O1—C6—C1118.87 (15)C5—C1—C6124.37 (15)
N1—C6—C1117.99 (16)O2—C9—C10122.75 (16)
C11—C12—C7118.73 (16)O2—C9—C8117.70 (16)
C11—C12—C13118.87 (15)C10—C9—C8119.55 (16)
C7—C12—C13122.38 (15)C10—C11—C12120.95 (17)
O4—C14—C15107.55 (14)N2—C3—C2123.48 (17)
C7—C8—C9119.96 (17)N2—C4—C5123.31 (17)
C14—O4—C13—O32.3 (3)O1—C6—C1—C21.0 (3)
C14—O4—C13—C12177.25 (15)N1—C6—C1—C2179.41 (18)
C8—C7—C12—C110.0 (3)O1—C6—C1—C5179.42 (18)
C8—C7—C12—C13178.19 (18)N1—C6—C1—C50.2 (3)
O3—C13—C12—C112.0 (3)C11—C10—C9—O2179.70 (18)
O4—C13—C12—C11178.52 (16)C11—C10—C9—C80.4 (3)
O3—C13—C12—C7176.20 (19)C7—C8—C9—O2179.54 (17)
O4—C13—C12—C73.3 (3)C7—C8—C9—C100.6 (3)
C13—O4—C14—C15177.62 (16)C9—C10—C11—C120.1 (3)
C12—C7—C8—C90.4 (3)C7—C12—C11—C100.1 (3)
O4—C14—C15—C16170.00 (15)C13—C12—C11—C10178.09 (17)
C17—C16—C15—C14179.45 (17)C4—N2—C3—C20.4 (3)
C3—C2—C1—C50.6 (3)C1—C2—C3—N20.2 (3)
C3—C2—C1—C6179.01 (17)C3—N2—C4—C50.7 (3)
C4—C5—C1—C20.4 (3)C1—C5—C4—N20.3 (3)
C4—C5—C1—C6179.21 (17)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2—H3O···N20.95 (3)1.79 (3)2.721 (2)165 (2)
N1—H1N···O1i0.91 (2)1.97 (2)2.880 (2)175.3 (15)
N1—H2N···O3ii0.94 (2)2.02 (2)2.948 (2)168.3 (18)
Symmetry codes: (i) x1, y+3, z+3; (ii) x1, y+2, z+2.
 

References

First citationAakeröy, C. B., Beatty, A. M., Helfrich, B. A. & Nieuwenhuyzen, M. (2003). Cryst. Growth Des. 3, 159–165.  Web of Science CSD CrossRef Google Scholar
First citationAllen, F. H., Johnson, O., Shields, G. P., Smith, B. R. & Towler, M. (2004). J. Appl. Cryst. 37, 335–338.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
First citationBruker (2007). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationCharnock, C. & Finsrud, T. (2007). J. Clin. Pharm. Ther. 32, 567–572.  CrossRef PubMed CAS Google Scholar
First citationFarrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationFlorence, A. J., Baumgartner, B., Weston, C., Shankland, N., Kennedy, A. R., Shankland, K. & David, W. I. F. (2003). J. Pharm. Sci. 92, 1930–1938.  Web of Science CSD CrossRef PubMed CAS Google Scholar
First citationGavezzotti, A. (2002). J. Phys. Chem. B, 106, 4145–4154.  Web of Science CrossRef CAS Google Scholar
First citationGavezzotti, A. (2003). J. Phys. Chem. B, 107, 2344–2353.  Web of Science CrossRef CAS Google Scholar
First citationHossaini, A., Larsen, J. J. & Larsen, J. C. (2000). Food Chem. Toxicol. 38, 319–323.  CrossRef PubMed CAS Google Scholar
First citationMacrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466–470.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
First citationMcKellar, S. C., Kennedy, A. R., McCloy, N. C., McBride, E. & Florence, A. J. (2014). Cryst. Growth Des. 14, 2422–2430.  CSD CrossRef CAS Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSheldrick, G. M. (2015). Acta Cryst. C71, 3–8.  Web of Science CrossRef IUCr Journals Google Scholar
First citationVishweshwar, P., Nangia, A. & Lynch, V. M. (2003). CrystEngComm, 5, 164–168.  Web of Science CSD CrossRef CAS Google Scholar
First citationVries, E. J. C. de & Caira, M. R. (2008). Carbohydr. Res. 343, 2433–2438.  PubMed Google Scholar
First citationWestrip, S. P. (2010). J. Appl. Cryst. 43, 920–925.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationYang, H. Y. & Rasmuson, A. C. (2010). J. Chem. Eng. Data, 55, 5091–5093.  CrossRef CAS Google Scholar
First citationYang, H. & Rasmuson, A. C. (2012). Org. Process Res. Dev. 16, 1212–1224.  CrossRef CAS Google Scholar
First citationYang, H. Y. & Rasmuson, A. C. (2013). Cryst. Growth Des. 13, 4226–4238.  CrossRef CAS Google Scholar

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