Carbamazepine N,N-di­methyl­form­amide solvate

Johnston, A.; Florence, A.J.; Kennedy, A.R.

doi:10.1107/S1600536805012535

organic compounds

CRYSTALLOGRAPHIC
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ISSN: 2056-9890

Volume 61| Part 5| May 2005| Pages o1509-o1511

https://doi.org/10.1107/S1600536805012535

Carbamazepine N,N-dimethylformamide solvate

Andrea Johnston,^a Alastair J. Florence ^a ^* and Alan R. Kennedy ^b

^aDepartment of Pharmaceutical Sciences, University of Strathclyde, 27 Taylor Street, Glasgow G4 0NR, Scotland, and ^bDepartment of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, Scotland
^*Correspondence e-mail: alastair.florence@strath.ac.uk

(Received 6 April 2005; accepted 20 April 2005; online 30 April 2005)

In the title compound, C₁₅H₁₂N₂O·C₃H₇NO, carbamazepine molecules form the R₂²(8) N—H⋯O hydrogen-bonded dimer arrangement observed in the crystal structures of each of the four known anhydrous polymorphs. The molecules of N,N-dimethylformamide are located between adjacent carbamazepine dimers and form an N—H⋯O hydrogen bond to the anti-oriented NH group of the carboxamide moiety of carbamazepine.

Comment

The antiepileptic compound carbamazepine (CBZ) is known to crystallize in at least four anhydrous polymorphic forms (Grzesiak et al., 2003 ) and the crystal structures of several solvates and co-crystals have also been reported (Fleischman et al., 2003 ). The title solvate, (I), was produced during an automated parallel crystallization polymorph screen on CBZ. The sample was identified as a new form using multi-sample X-ray powder diffraction analysis of all recrystallized samples (Florence et al., 2003 ). Subsequent manual recrystallization from a saturated N,N-dimethylformamide (DMF) solution by slow evaporation at 278 K yielded samples suitable for single-crystal X-ray analysis (Fig. 1).

In the crystal structure of (I), CBZ molecules form the centrosymmetric hydrogen-bonded R₂²(8) dimer motif observed in all of the known polymorphs and the majority of CBZ solvate crystal structures (Fleischman et al., 2003) (Fig. 2). CBZ also forms a second N—H⋯O contact to atom O2 of the solvent molecule. Two C—H⋯O contacts exist between the DMF methyl H atoms (H17C and H18B) and atom O1 of CBZ. Atom O2 of DMF is further involved in a third C—H⋯O contact with an adjacent DMF molecule, forming a centrosymmetric R₂²(10) motif (Fig. 2). The CBZ dimers pack back-to-back, forming offset face-to-face hydrophobic interactions between adjacent azepine ring systems (Fig. 3).

Figure 1
The molecular structure of (I

), shown with 50% probability displacement ellipsoids.

Figure 2
Packing diagram illustrating the non-covalent intermolecular network formed by (1) N2—H2B⋯O1 [N2⋯O1 = 2.9719 (19)Å O1 in the molecule at 2 − x, −y, 1 − z]; (2) N2—H2A⋯O2 [N2⋯O2 = 2.822 (2) Å; O2 in the molecule at 2 − x, 1 − y, 1 − z]; (3) C18—H18C⋯O2 [C18⋯O = 3.435 (3) Å; C18 in the molecule at 1 + x, y, z]; (4) C18—H18B⋯O1 [C18⋯O1 = 3.259 (2) Å; O1 in the molecule at 2 − x, −y, 1 − z] [calculated and illustrated using PLATON (Spek, 2003

), program version 280604]. These interactions combine to produce three ring motifs: (A) the R₂²(8) CBZ dimer; (B) an R₄²(8) motif between CBZ dimers and molecules of DMF and (C) an R₂²(10) motif connecting DMF molecules in a centrosymmetric dimer configuration.

Figure 3
Hydrophobic packing interactions between nearest neighbour CBZ molecules with a centroid–centroid distance of 3.801 (1) Å (the carboxamide groups have been omitted for clarity).

Experimental

A single-crystal sample of the title compound was recrystallized from DMF solution by slow evaporation at 278 K.

Crystal data

C₁₅H₁₂N₂O·C₃H₇NO
M_r = 309.36
Triclinic, $[P\overline 1]$
a = 7.7118 (4) Å
b = 9.1503 (4) Å
c = 11.6969 (6) Å
α = 100.192 (3)°
β = 95.379 (2)°
γ = 101.908 (3)°
V = 787.58 (7) Å³
Z = 2
D_x = 1.305 Mg m⁻³
Mo Kα radiation
Cell parameters from 3432 reflections
θ = 2.9–27.0°
μ = 0.09 mm⁻¹
T = 123 (2) K
Fragment, colourless
0.20 × 0.20 × 0.05 mm

Data collection

Nonius KappaCCD diffractometer
ω and φ scans
Absorption correction: none
15107 measured reflections
3476 independent reflections
2475 reflections with I > 2σ(I)
R_int = 0.054
θ_max = 27.2°
h = −9 → 9
k = −11 → 11
l = −14 → 14

Refinement

Refinement on F²
R[F² > 2σ(F²)] = 0.048
wR(F²) = 0.117
S = 1.03
3476 reflections
230 parameters
H atoms treated by a mixture of independent and constrained refinement
w = 1/[σ²(F_o²) + (0.0505P)² + 0.208P] where P = (F_o² + 2F_c²)/3
(Δ/σ)_max = 0.002
Δρ_max = 0.23 e Å⁻³
Δρ_min = −0.21 e Å⁻³

Table 1
Hydrogen-bonding geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H2A⋯O2ⁱ	0.921 (18)	1.963 (19)	2.822 (2)	154.5 (18)
N2—H2B⋯O1ⁱⁱ	0.884 (19)	2.103 (19)	2.9719 (19)	167.4 (15)
C17—H17C⋯O1ⁱⁱ	0.98	2.51	3.373 (3)	147
C18—H18B⋯O1ⁱⁱⁱ	0.98	2.43	3.259 (2)	142
C18—H18C⋯O2^iv	0.98	2.49	3.435 (3)	163
Symmetry codes: (i) 2-x,1-y,1-z; (ii) 2-x,-y,1-z; (iii) 1-x,-y,1-z; (iv) 1-x,1-y,1-z.

Five H atoms (H2A, H2B, H8, H9 and H16) were located in difference maps and refined isotropically, but all other H atoms were constrained to idealized geometry using a riding model; for CH₃ groups, U_iso(H) = 1.5U_eq(C) and C—H = 0.98 Å, while for CH groups, U_iso(H) = 1.2U_eq(C) and C—H = 0.95 Å.

Data collection: COLLECT (Hooft, 1988 ) and DENZO (Otwinowski & Minor, 1997 ); cell refinement: DENZO and COLLECT; data reduction: DENZO; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks global, I. DOI: https://doi.org/10.1107/S1600536805012535/sg6004sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536805012535/sg6004Isup2.hkl

Computing details top

Data collection: COLLECT (Hooft, 1988) and DENZO (Otwinowski & Minor, 1997); cell refinement: DENZO and COLLECT; data reduction: DENZO; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97.

carbamazepine N,N-dimethylformamide solvate top

Crystal data top

C₁₅H₁₂N₂O·C₃H₇NO	Z = 2
M_r = 309.36	F(000) = 328
Triclinic, P1	D_x = 1.305 Mg m⁻³
a = 7.7118 (4) Å	Mo Kα radiation, λ = 0.71073 Å
b = 9.1503 (4) Å	Cell parameters from 3432 reflections
c = 11.6969 (6) Å	θ = 2.9–27.0°
α = 100.192 (3)°	µ = 0.09 mm⁻¹
β = 95.379 (2)°	T = 123 K
γ = 101.908 (3)°	Fragment, colourless
V = 787.58 (7) Å³	0.20 × 0.20 × 0.05 mm

Data collection top

Nonius KappaCCD diffractometer	2475 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.054
Graphite monochromator	θ_max = 27.2°, θ_min = 3.1°
ω and φ scans	h = −9→9
15107 measured reflections	k = −11→11
3476 independent reflections	l = −14→14

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.048	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.117	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	w = 1/[σ²(F_o²) + (0.0505P)² + 0.208P] where P = (F_o² + 2F_c²)/3
3476 reflections	(Δ/σ)_max = 0.002
230 parameters	Δρ_max = 0.23 e Å⁻³
0 restraints	Δρ_min = −0.21 e Å⁻³

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.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
O1	0.86234 (15)	−0.08670 (12)	0.35964 (10)	0.0275 (3)
O2	0.76776 (19)	0.54750 (14)	0.56447 (13)	0.0482 (4)
N1	0.84593 (17)	0.07785 (14)	0.23638 (11)	0.0228 (3)
N2	1.06578 (19)	0.13981 (17)	0.39877 (13)	0.0251 (3)
N3	0.68494 (19)	0.30325 (15)	0.58731 (13)	0.0269 (3)
C1	0.9231 (2)	0.03844 (18)	0.33519 (14)	0.0220 (3)
C2	0.6856 (2)	−0.02317 (17)	0.17131 (14)	0.0225 (4)
C3	0.6971 (2)	−0.15694 (19)	0.09830 (15)	0.0278 (4)
H3	0.8107	−0.1791	0.0895	0.033*
C4	0.5434 (2)	−0.2582 (2)	0.03832 (15)	0.0312 (4)
H4	0.5515	−0.3499	−0.0115	0.037*
C5	0.3778 (2)	−0.2257 (2)	0.05097 (15)	0.0302 (4)
H5	0.2721	−0.2951	0.0100	0.036*
C6	0.3666 (2)	−0.09263 (19)	0.12297 (15)	0.0277 (4)
H6	0.2523	−0.0715	0.1311	0.033*
C7	0.5203 (2)	0.01298 (18)	0.18488 (14)	0.0240 (4)
C8	0.5007 (2)	0.15180 (19)	0.26111 (15)	0.0263 (4)
C9	0.6154 (2)	0.28859 (19)	0.28799 (15)	0.0260 (4)
C10	0.7853 (2)	0.33202 (18)	0.24291 (14)	0.0242 (4)
C11	0.8920 (2)	0.22866 (18)	0.21166 (14)	0.0228 (4)
C12	1.0437 (2)	0.27058 (19)	0.15885 (15)	0.0261 (4)
H12	1.1135	0.1987	0.1366	0.031*
C13	1.0930 (2)	0.41757 (19)	0.13867 (15)	0.0296 (4)
H13	1.1958	0.4459	0.1017	0.036*
C14	0.9924 (2)	0.52293 (19)	0.17237 (15)	0.0295 (4)
H14	1.0276	0.6241	0.1600	0.035*
C15	0.8412 (2)	0.48080 (18)	0.22387 (14)	0.0269 (4)
H15	0.7733	0.5540	0.2470	0.032*
C16	0.7986 (3)	0.4210 (2)	0.56419 (16)	0.0332 (4)
C17	0.7293 (3)	0.1566 (2)	0.58202 (18)	0.0377 (5)
H17A	0.6608	0.0850	0.5123	0.057*
H17B	0.6997	0.1179	0.6524	0.057*
H17C	0.8575	0.1674	0.5777	0.057*
C18	0.5100 (3)	0.3173 (2)	0.6171 (2)	0.0510 (6)
H18A	0.5225	0.3760	0.6972	0.077*
H18B	0.4342	0.2155	0.6117	0.077*
H18C	0.4551	0.3698	0.5625	0.077*
H2B	1.102 (2)	0.1196 (19)	0.4670 (17)	0.024 (5)*
H2A	1.096 (3)	0.240 (2)	0.3909 (16)	0.038 (5)*
H16	0.917 (3)	0.399 (2)	0.5475 (18)	0.044 (6)*
H8	0.386 (2)	0.1441 (19)	0.2895 (15)	0.028 (5)*
H9	0.578 (2)	0.372 (2)	0.3334 (16)	0.029 (5)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0302 (6)	0.0237 (6)	0.0275 (7)	0.0010 (5)	−0.0002 (5)	0.0107 (5)
O2	0.0570 (9)	0.0264 (7)	0.0524 (9)	−0.0058 (6)	−0.0159 (7)	0.0148 (6)
N1	0.0256 (7)	0.0214 (7)	0.0211 (7)	0.0033 (6)	0.0005 (6)	0.0075 (6)
N2	0.0263 (8)	0.0251 (8)	0.0233 (8)	0.0017 (6)	−0.0007 (6)	0.0107 (6)
N3	0.0253 (7)	0.0242 (7)	0.0313 (8)	0.0032 (6)	0.0038 (6)	0.0091 (6)
C1	0.0224 (8)	0.0233 (8)	0.0222 (9)	0.0064 (7)	0.0066 (7)	0.0063 (7)
C2	0.0263 (9)	0.0218 (8)	0.0189 (8)	0.0016 (7)	0.0010 (7)	0.0086 (6)
C3	0.0317 (10)	0.0290 (9)	0.0243 (9)	0.0073 (7)	0.0040 (7)	0.0087 (7)
C4	0.0436 (11)	0.0257 (9)	0.0222 (9)	0.0042 (8)	0.0024 (8)	0.0043 (7)
C5	0.0334 (10)	0.0304 (9)	0.0224 (9)	−0.0028 (8)	−0.0031 (7)	0.0094 (7)
C6	0.0252 (9)	0.0319 (9)	0.0258 (9)	0.0020 (7)	0.0014 (7)	0.0115 (7)
C7	0.0298 (9)	0.0252 (9)	0.0184 (8)	0.0041 (7)	0.0035 (7)	0.0100 (7)
C8	0.0256 (9)	0.0327 (10)	0.0231 (9)	0.0077 (8)	0.0063 (7)	0.0093 (7)
C9	0.0315 (9)	0.0270 (9)	0.0215 (9)	0.0100 (8)	0.0052 (7)	0.0055 (7)
C10	0.0284 (9)	0.0254 (9)	0.0171 (8)	0.0036 (7)	−0.0009 (7)	0.0051 (7)
C11	0.0262 (9)	0.0229 (8)	0.0184 (8)	0.0025 (7)	−0.0011 (7)	0.0073 (7)
C12	0.0270 (9)	0.0287 (9)	0.0235 (9)	0.0054 (7)	0.0032 (7)	0.0089 (7)
C13	0.0274 (9)	0.0329 (9)	0.0283 (9)	0.0004 (7)	0.0039 (7)	0.0126 (8)
C14	0.0363 (10)	0.0231 (9)	0.0273 (10)	0.0007 (7)	0.0004 (8)	0.0096 (7)
C15	0.0333 (10)	0.0232 (8)	0.0234 (9)	0.0063 (7)	0.0001 (7)	0.0046 (7)
C16	0.0366 (11)	0.0315 (10)	0.0260 (10)	−0.0053 (8)	−0.0045 (8)	0.0108 (8)
C17	0.0455 (12)	0.0310 (10)	0.0434 (12)	0.0129 (9)	0.0173 (9)	0.0151 (9)
C18	0.0340 (12)	0.0440 (12)	0.0823 (17)	0.0133 (10)	0.0153 (11)	0.0227 (12)

Geometric parameters (Å, º) top

O1—C1	1.2379 (18)	C8—C9	1.341 (2)
O2—C16	1.228 (2)	C8—H8	0.964 (18)
N1—C1	1.388 (2)	C9—C10	1.464 (2)
N1—C2	1.437 (2)	C9—H9	0.960 (18)
N1—C11	1.4395 (19)	C10—C11	1.400 (2)
N2—C1	1.343 (2)	C10—C15	1.404 (2)
N2—H2B	0.884 (19)	C11—C12	1.390 (2)
N2—H2A	0.92 (2)	C12—C13	1.388 (2)
N3—C16	1.327 (2)	C12—H12	0.9500
N3—C17	1.444 (2)	C13—C14	1.385 (2)
N3—C18	1.449 (2)	C13—H13	0.9500
C2—C3	1.387 (2)	C14—C15	1.378 (2)
C2—C7	1.398 (2)	C14—H14	0.9500
C3—C4	1.384 (2)	C15—H15	0.9500
C3—H3	0.9500	C16—H16	1.01 (2)
C4—C5	1.385 (3)	C17—H17A	0.9800
C4—H4	0.9500	C17—H17B	0.9800
C5—C6	1.376 (2)	C17—H17C	0.9800
C5—H5	0.9500	C18—H18A	0.9800
C6—C7	1.408 (2)	C18—H18B	0.9800
C6—H6	0.9500	C18—H18C	0.9800
C7—C8	1.461 (2)

C1—N1—C2	118.24 (13)	C10—C9—H9	114.5 (10)
C1—N1—C11	122.93 (13)	C11—C10—C15	117.76 (15)
C2—N1—C11	117.16 (12)	C11—C10—C9	122.68 (14)
C1—N2—H2B	115.4 (11)	C15—C10—C9	119.48 (15)
C1—N2—H2A	123.1 (12)	C12—C11—C10	120.85 (14)
H2B—N2—H2A	116.9 (16)	C12—C11—N1	119.50 (14)
C16—N3—C17	121.52 (16)	C10—C11—N1	119.64 (14)
C16—N3—C18	120.79 (16)	C13—C12—C11	119.94 (16)
C17—N3—C18	117.69 (15)	C13—C12—H12	120.0
O1—C1—N2	123.12 (15)	C11—C12—H12	120.0
O1—C1—N1	119.92 (14)	C14—C13—C12	120.07 (16)
N2—C1—N1	116.94 (14)	C14—C13—H13	120.0
C3—C2—C7	121.07 (15)	C12—C13—H13	120.0
C3—C2—N1	119.42 (15)	C15—C14—C13	119.90 (15)
C7—C2—N1	119.49 (14)	C15—C14—H14	120.0
C4—C3—C2	120.15 (16)	C13—C14—H14	120.0
C4—C3—H3	119.9	C14—C15—C10	121.41 (16)
C2—C3—H3	119.9	C14—C15—H15	119.3
C3—C4—C5	119.93 (16)	C10—C15—H15	119.3
C3—C4—H4	120.0	O2—C16—N3	124.8 (2)
C5—C4—H4	120.0	O2—C16—H16	121.5 (11)
C6—C5—C4	119.87 (16)	N3—C16—H16	113.7 (11)
C6—C5—H5	120.1	N3—C17—H17A	109.5
C4—C5—H5	120.1	N3—C17—H17B	109.5
C5—C6—C7	121.62 (16)	H17A—C17—H17B	109.5
C5—C6—H6	119.2	N3—C17—H17C	109.5
C7—C6—H6	119.2	H17A—C17—H17C	109.5
C2—C7—C6	117.35 (15)	H17B—C17—H17C	109.5
C2—C7—C8	123.25 (15)	N3—C18—H18A	109.5
C6—C7—C8	119.39 (15)	N3—C18—H18B	109.5
C9—C8—C7	127.99 (16)	H18A—C18—H18B	109.5
C9—C8—H8	117.3 (10)	N3—C18—H18C	109.5
C7—C8—H8	114.5 (10)	H18A—C18—H18C	109.5
C8—C9—C10	126.91 (16)	H18B—C18—H18C	109.5
C8—C9—H9	118.1 (10)

C2—N1—C1—O1	5.9 (2)	C7—C8—C9—C10	2.6 (3)
C11—N1—C1—O1	170.75 (14)	C8—C9—C10—C11	−31.2 (3)
C2—N1—C1—N2	−175.61 (14)	C8—C9—C10—C15	145.31 (18)
C11—N1—C1—N2	−10.8 (2)	C15—C10—C11—C12	−2.8 (2)
C1—N1—C2—C3	−76.47 (19)	C9—C10—C11—C12	173.83 (15)
C11—N1—C2—C3	117.80 (16)	C15—C10—C11—N1	176.11 (14)
C1—N1—C2—C7	101.90 (17)	C9—C10—C11—N1	−7.3 (2)
C11—N1—C2—C7	−63.84 (19)	C1—N1—C11—C12	82.2 (2)
C7—C2—C3—C4	−0.7 (2)	C2—N1—C11—C12	−112.76 (17)
N1—C2—C3—C4	177.63 (14)	C1—N1—C11—C10	−96.67 (18)
C2—C3—C4—C5	0.2 (2)	C2—N1—C11—C10	68.34 (19)
C3—C4—C5—C6	0.1 (2)	C10—C11—C12—C13	1.3 (2)
C4—C5—C6—C7	0.1 (2)	N1—C11—C12—C13	−177.57 (15)
C3—C2—C7—C6	0.9 (2)	C11—C12—C13—C14	0.8 (2)
N1—C2—C7—C6	−177.44 (13)	C12—C13—C14—C15	−1.3 (3)
C3—C2—C7—C8	179.64 (15)	C13—C14—C15—C10	−0.2 (2)
N1—C2—C7—C8	1.3 (2)	C11—C10—C15—C14	2.3 (2)
C5—C6—C7—C2	−0.6 (2)	C9—C10—C15—C14	−174.47 (15)
C5—C6—C7—C8	−179.39 (15)	C17—N3—C16—O2	178.25 (17)
C2—C7—C8—C9	31.3 (3)	C18—N3—C16—O2	−0.8 (3)
C6—C7—C8—C9	−150.03 (17)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2A···O2ⁱ	0.921 (18)	1.963 (19)	2.822 (2)	154.5 (18)
N2—H2B···O1ⁱⁱ	0.884 (19)	2.103 (19)	2.9719 (19)	167.4 (15)
C17—H17C···O1ⁱⁱ	0.98	2.51	3.373 (3)	147
C18—H18B···O1ⁱⁱⁱ	0.98	2.43	3.259 (2)	142
C18—H18C···O2^iv	0.98	2.49	3.435 (3)	163

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

Acknowledgements

We thank the Basic Technology programme of The Research Councils for funding this work under the project Control and Prediction of the Organic Solid State (URL: www.cposs.org.uk).

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