A top–down approach to crystal engineering of a racemic Δ²-isoxazoline

The crystal structure of racemic dimethyl (4RS,5RS)-3-(4-nitrophenyl)-4,5-dihydroisoxazole-4,5-dicarboxylate, C₁₃H₁₂N₂O₇, has been determined by single-crystal X-ray diffraction. By analysing the degree of growth of the morphologically important crystal faces, a ranking of the most relevant non-covalent interactions determining the crystal structure can be inferred. The morphological information is considered with an approach opposite to the conventional one: instead of searching inside the structure for the potential key interactions and using them to calculate the crystal habit, the observed crystal morphology is used to define the preferential lines of growth of the crystal, and then this information is interpreted by means of density functional theory (DFT) calculations. Comparison with the X-ray structure confirms the validity of the strategy, thus suggesting this top–down approach to be a useful tool for crystal engineering.

Computing details

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2008); molecular graphics: SHELXTL (Bruker, 2008); software used to prepare material for publication: SHELXL2013 (Sheldrick, 2008) and WinGX (Farrugia, 1999).

Figures

Dimethyl (4RS,5RS)-3-(4-nitrophenyl)-4,5-dihydroisoxazole-4,5-dicarboxylate

Crystal data

C13H12N2O7	F(000) = 640
Mr = 308.25	Dx = 1.494 Mg m^−3
Monoclinic, P21/c	Cu Kα radiation, λ = 1.54178 Å
a = 7.2032 (2) Å	Cell parameters from 4957 reflections
b = 6.9183 (3) Å	θ = 3.2–69.8°
c = 27.515 (2) Å	µ = 1.07 mm^−1
β = 92.134 (4)°	T = 293 K
V = 1370.23 (12) Å^3	Prism, colorless
Z = 4	0.90 × 0.45 × 0.25 mm

Data collection

Bruker APEX-II CCD diffractometer	2596 independent reflections
Radiation source: fine-focus sealed tube	2490 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.016
φ and ω scans	θmax = 69.8°, θmin = 3.2°
Absorption correction: multi-scan SADABS (Bruker, 2008)	h = −8→8
Tmin = 0.98, Tmax = 0.99	k = −8→1
4957 measured reflections	l = −32→33

Refinement

Refinement on F^2	Hydrogen site location: difference Fourier map
Least-squares matrix: full	All H-atom parameters refined
R[F^2 > 2σ(F^2)] = 0.040	w = 1/[σ^2(Fo^2) + (0.0613P)^2 + 0.4588P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.114	(Δ/σ)max < 0.001
S = 1.05	Δρmax = 0.30 e Å^−3
2596 reflections	Δρmin = −0.24 e Å^−3
248 parameters	Extinction correction: SHELXL, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
3 restraints	Extinction coefficient: 0.0090 (7)

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
N1	0.1514 (2)	0.1930 (2)	−0.06205 (5)	0.0538 (4)
N2	0.40842 (18)	0.84188 (19)	0.09400 (5)	0.0430 (3)
O1	0.1488 (3)	0.0178 (2)	−0.05648 (6)	0.0821 (5)
O2	0.1104 (2)	0.2730 (2)	−0.10048 (5)	0.0743 (4)
O3	0.43675 (16)	0.93415 (17)	0.13944 (4)	0.0495 (3)
O4	0.59575 (17)	0.42401 (19)	0.14255 (4)	0.0543 (3)
O5	0.5048 (2)	0.4656 (3)	0.21773 (5)	0.0876 (6)
O6	0.11028 (19)	1.07368 (18)	0.17241 (5)	0.0600 (4)
O7	0.05328 (16)	0.79192 (17)	0.20942 (4)	0.0510 (3)
C1	0.2054 (2)	0.3150 (2)	−0.02012 (5)	0.0417 (4)
C2	0.2380 (2)	0.5091 (2)	−0.02755 (5)	0.0439 (4)
C3	0.2866 (2)	0.6236 (2)	0.01190 (5)	0.0403 (3)
C4	0.29951 (19)	0.5448 (2)	0.05864 (5)	0.0349 (3)
C5	0.2636 (2)	0.3482 (2)	0.06492 (6)	0.0432 (4)
C6	0.2183 (2)	0.2323 (2)	0.02550 (6)	0.0470 (4)
C7	0.34806 (18)	0.6699 (2)	0.10043 (5)	0.0347 (3)
C8	0.3312 (2)	0.6186 (2)	0.15339 (5)	0.0355 (3)
C9	0.3426 (2)	0.8226 (2)	0.17495 (5)	0.0403 (4)
C10	0.4867 (2)	0.4927 (2)	0.17506 (5)	0.0409 (4)
C11	0.1549 (2)	0.9142 (2)	0.18422 (5)	0.0412 (4)
C12	0.7500 (3)	0.3034 (4)	0.15973 (8)	0.0684 (6)
C13	−0.1297 (3)	0.8578 (3)	0.22185 (8)	0.0596 (5)
H8	0.220 (3)	0.553 (2)	0.1599 (6)	0.039 (4)*
H5	0.268 (3)	0.293 (3)	0.0972 (7)	0.055 (5)*
H2	0.230 (3)	0.561 (3)	−0.0582 (8)	0.055 (5)*
H6	0.192 (3)	0.099 (3)	0.0300 (7)	0.055 (5)*
H3	0.314 (3)	0.758 (3)	0.0075 (7)	0.052 (5)*
H121	0.791 (5)	0.229 (5)	0.1359 (10)	0.121 (11)*
H122	0.704 (4)	0.222 (4)	0.1839 (11)	0.104 (10)*
H133	−0.180 (3)	0.757 (4)	0.2416 (10)	0.081 (7)*
H131	−0.201 (3)	0.881 (4)	0.1921 (10)	0.075 (7)*
H132	−0.126 (4)	0.983 (4)	0.2392 (10)	0.088 (8)*
H123	0.836 (4)	0.381 (4)	0.1734 (11)	0.106 (11)*
H9	0.414 (3)	0.827 (3)	0.2054 (7)	0.051 (5)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0537 (8)	0.0654 (10)	0.0423 (8)	−0.0091 (7)	0.0009 (6)	−0.0122 (7)
N2	0.0487 (7)	0.0416 (7)	0.0386 (7)	−0.0011 (5)	0.0016 (5)	−0.0008 (5)
O1	0.1212 (14)	0.0595 (9)	0.0653 (9)	−0.0237 (9)	−0.0023 (9)	−0.0174 (7)
O2	0.0896 (10)	0.0886 (11)	0.0433 (7)	−0.0087 (8)	−0.0142 (6)	−0.0109 (7)
O3	0.0560 (7)	0.0461 (6)	0.0467 (6)	−0.0109 (5)	0.0037 (5)	−0.0090 (5)
O4	0.0573 (7)	0.0662 (8)	0.0391 (6)	0.0304 (6)	−0.0012 (5)	0.0069 (5)
O5	0.1002 (12)	0.1259 (14)	0.0368 (7)	0.0538 (11)	0.0029 (7)	0.0226 (8)
O6	0.0652 (8)	0.0451 (7)	0.0698 (8)	0.0140 (6)	0.0044 (6)	0.0049 (6)
O7	0.0523 (6)	0.0531 (7)	0.0482 (6)	0.0166 (5)	0.0102 (5)	0.0071 (5)
C1	0.0382 (7)	0.0502 (9)	0.0367 (8)	0.0000 (6)	−0.0006 (6)	−0.0078 (6)
C2	0.0487 (8)	0.0529 (9)	0.0300 (7)	0.0051 (7)	−0.0006 (6)	0.0033 (6)
C3	0.0483 (8)	0.0373 (8)	0.0353 (7)	0.0053 (6)	−0.0001 (6)	0.0037 (6)
C4	0.0346 (6)	0.0384 (7)	0.0315 (7)	0.0064 (5)	−0.0006 (5)	0.0020 (5)
C5	0.0532 (9)	0.0413 (8)	0.0347 (7)	−0.0001 (7)	−0.0032 (6)	0.0050 (6)
C6	0.0552 (9)	0.0397 (8)	0.0458 (9)	−0.0042 (7)	−0.0014 (7)	−0.0001 (7)
C7	0.0346 (6)	0.0359 (7)	0.0333 (7)	0.0064 (5)	−0.0008 (5)	0.0028 (5)
C8	0.0375 (7)	0.0390 (7)	0.0301 (7)	0.0038 (6)	0.0001 (5)	−0.0008 (5)
C9	0.0440 (8)	0.0432 (8)	0.0332 (7)	0.0026 (6)	−0.0042 (6)	−0.0046 (6)
C10	0.0470 (8)	0.0420 (8)	0.0336 (7)	0.0049 (6)	−0.0021 (6)	0.0053 (6)
C11	0.0498 (8)	0.0418 (8)	0.0317 (7)	0.0066 (6)	−0.0035 (6)	−0.0047 (6)
C12	0.0682 (13)	0.0737 (14)	0.0624 (12)	0.0381 (12)	−0.0096 (10)	0.0067 (11)
C13	0.0536 (10)	0.0612 (12)	0.0648 (12)	0.0152 (9)	0.0158 (9)	0.0046 (10)

Geometric parameters (Å, º)

N1—O2	1.220 (2)	C4—C5	1.396 (2)
N1—O1	1.222 (2)	C4—C7	1.471 (2)
N1—C1	1.470 (2)	C5—C6	1.378 (2)
N2—C7	1.2811 (19)	C5—H5	0.97 (2)
N2—O3	1.4117 (17)	C6—H6	0.95 (2)
O3—C9	1.4353 (19)	C7—C8	1.5090 (19)
O4—C10	1.3018 (19)	C8—C10	1.5232 (19)
O4—C12	1.454 (2)	C8—C9	1.532 (2)
O5—C10	1.1912 (19)	C8—H8	0.947 (18)
O6—C11	1.1912 (19)	C9—C11	1.523 (2)
O7—C11	1.330 (2)	C9—H9	0.97 (2)
O7—C13	1.448 (2)	C12—H121	0.89 (3)
C1—C6	1.380 (2)	C12—H122	0.94 (3)
C1—C2	1.380 (2)	C12—H123	0.89 (3)
C2—C3	1.378 (2)	C13—H133	0.96 (3)
C2—H2	0.92 (2)	C13—H131	0.96 (3)
C3—C4	1.397 (2)	C13—H132	0.99 (3)
C3—H3	0.96 (2)
O2—N1—O1	123.65 (16)	C7—C8—C9	98.74 (11)
O2—N1—C1	117.92 (16)	C10—C8—C9	110.33 (12)
O1—N1—C1	118.43 (15)	C7—C8—H8	113.3 (10)
C7—N2—O3	109.64 (12)	C10—C8—H8	105.5 (10)
N2—O3—C9	107.65 (11)	C9—C8—H8	113.8 (10)
C10—O4—C12	117.33 (14)	O3—C9—C11	109.59 (12)
C11—O7—C13	116.52 (14)	O3—C9—C8	104.57 (11)
C6—C1—C2	122.18 (14)	C11—C9—C8	114.41 (12)
C6—C1—N1	118.86 (15)	O3—C9—H9	108.8 (11)
C2—C1—N1	118.95 (14)	C11—C9—H9	106.7 (11)
C3—C2—C1	118.81 (14)	C8—C9—H9	112.7 (11)
C3—C2—H2	120.4 (12)	O5—C10—O4	124.97 (15)
C1—C2—H2	120.8 (12)	O5—C10—C8	121.85 (14)
C2—C3—C4	120.48 (15)	O4—C10—C8	113.16 (12)
C2—C3—H3	120.4 (11)	O6—C11—O7	125.66 (15)
C4—C3—H3	119.1 (11)	O6—C11—C9	124.89 (15)
C5—C4—C3	119.20 (14)	O7—C11—C9	109.38 (12)
C5—C4—C7	121.09 (13)	O4—C12—H121	111 (2)
C3—C4—C7	119.71 (13)	O4—C12—H122	106.7 (19)
C6—C5—C4	120.60 (14)	H121—C12—H122	108 (2)
C6—C5—H5	119.5 (12)	O4—C12—H123	108 (2)
C4—C5—H5	119.9 (12)	H121—C12—H123	115 (3)
C5—C6—C1	118.72 (15)	H122—C12—H123	108 (2)
C5—C6—H6	120.2 (12)	O7—C13—H133	105.6 (15)
C1—C6—H6	121.0 (12)	O7—C13—H131	108.1 (15)
N2—C7—C4	120.70 (13)	H133—C13—H131	114 (2)
N2—C7—C8	113.07 (13)	O7—C13—H132	112.5 (17)
C4—C7—C8	126.22 (13)	H133—C13—H132	111 (2)
C7—C8—C10	115.36 (12)	H131—C13—H132	106 (2)