Gabapentin-lactum-chloranilic acid (1/1).

In the title compound, C(9)H(15)NO·C(6)H(2)Cl(2)O(4) [sytematic name: 2-aza-spiro-[4.5]decan-3-one-chloranilic acid (1/1)], the cyclo-hexane ring of the lactam molecule adopts a slightly distorted normal chair conformation and the five-membered 3-aza-spiro ring is in a slightly distorted chair conformation. The dihedral angle between the least-squares planes of the cyclohexane and 3-azaspiro rings is 84.0 (3)°. In the crystal, the chloranilic acid mol-ecule and the gabapentin-lactum mol-ecules are held together by strong inter-molecular N-H⋯O and O-H⋯O hydrogen bonds with two bifurcated O acceptor atoms on the chloranilic acid mol-ecule and one on the gabapentin-lactum mol-ecule, each bonding with an inter- and intra-molecular hydrogen bond. The molecules are linked into chains parallel to (011) and propagating along the b axis.

Related literature

For the neuroprotective properties of gabapentin-lactam and related compounds, see: Lagreze et al. (2001 ▶); Henle et al. (2006 ▶); Bowery (1993 ▶). For the synthesis and spectroscopic studies of chloranilic acid charge-transfer complexes, see: Al-Attas et al. (2009 ▶). For related structures, see: Gotoh et al. (2008 ▶); Ibers (2001 ▶); Ishida (2004 ▶); Ishida & Kashino (2000 ▶); Jasinski et al. (2009 ▶). For density functional theory (DFT), see: Frisch et al. (2004 ▶); Hehre et al. (1986 ▶); Schmidt & Polik (2007 ▶).

Experimental

Crystal data

C9H15NO·C6H2Cl2O4

M = 362.20

Triclinic,

a = 6.6127 (9) Å

b = 9.5800 (11) Å

c = 13.0724 (13) Å

α = 102.679 (9)°

β = 91.934 (9)°

γ = 98.481 (10)°

V = 797.23 (16) Å3

Z = 2

Cu Kα radiation

μ = 3.90 mm−1

T = 110 K

0.47 × 0.42 × 0.15 mm

Data collection

Goniometer Xcalibur diffractometer with a Ruby (Gemini Cu) detector

Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2007 ▶) T min = 0.200, T max = 0.557

5138 measured reflections

3123 independent reflections

2731 reflections with I > 2σ(I)

R int = 0.025

Refinement

R[F 2 > 2σ(F 2)] = 0.042

wR(F 2) = 0.119

S = 1.05

3123 reflections

210 parameters

H-atom parameters constrained

Δρmax = 0.45 e Å−3

Δρmin = −0.40 e Å−3

Data collection: CrysAlis PRO (Oxford Diffraction, 2007 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809053410/ng2704sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809053410/ng2704Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C9H15NO·C6H2Cl2O4	Z = 2
Mr = 362.20	F(000) = 376
Triclinic, P1	Dx = 1.509 Mg m−3
Hall symbol: -P 1	Cu Kα radiation, λ = 1.54184 Å
a = 6.6127 (9) Å	Cell parameters from 3438 reflections
b = 9.5800 (11) Å	θ = 4.8–74.0°
c = 13.0724 (13) Å	µ = 3.90 mm−1
α = 102.679 (9)°	T = 110 K
β = 91.934 (9)°	Irregular plate, red-brown
γ = 98.481 (10)°	0.47 × 0.42 × 0.15 mm
V = 797.23 (16) Å3

Goniometer Xcalibur diffractometer with a Ruby (Gemini Cu) detector	3123 independent reflections
Radiation source: Enhance (Cu) X-ray Source	2731 reflections with I > 2σ(I)
graphite	Rint = 0.025
Detector resolution: 10.5081 pixels mm-1	θmax = 74.2°, θmin = 4.8°
ω scans	h = −8→5
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2007)	k = −10→11
Tmin = 0.200, Tmax = 0.557	l = −15→16
5138 measured reflections

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)] = 0.042	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.119	H-atom parameters constrained
S = 1.05	w = 1/[σ2(Fo2) + (0.0762P)2 + 0.4046P] where P = (Fo2 + 2Fc2)/3
3123 reflections	(Δ/σ)max = 0.001
210 parameters	Δρmax = 0.45 e Å−3
0 restraints	Δρmin = −0.40 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.

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.

	x	y	z	Uiso*/Ueq
Cl1	0.07819 (8)	0.35536 (5)	0.25360 (3)	0.02058 (15)
Cl2	0.30441 (7)	0.39346 (5)	0.73387 (3)	0.01894 (15)
O1A	0.0035 (2)	0.11592 (14)	0.36708 (11)	0.0185 (3)
H1A	−0.0101	0.0550	0.4048	0.022*
O2A	0.1030 (2)	0.13961 (14)	0.57058 (11)	0.0198 (3)
O3A	0.3781 (2)	0.63101 (14)	0.62265 (11)	0.0168 (3)
H3A	0.3800	0.6958	0.5885	0.020*
O4A	0.2633 (2)	0.61192 (14)	0.41806 (11)	0.0174 (3)
C1A	0.1342 (3)	0.3619 (2)	0.38385 (15)	0.0142 (4)
C2A	0.0914 (3)	0.2440 (2)	0.42497 (15)	0.0149 (4)
C3A	0.1454 (3)	0.25105 (19)	0.53885 (15)	0.0142 (4)
C4A	0.2436 (3)	0.3875 (2)	0.60388 (14)	0.0139 (4)
C5A	0.2870 (3)	0.50807 (19)	0.56472 (15)	0.0134 (4)
C6A	0.2301 (3)	0.50147 (19)	0.45017 (15)	0.0132 (4)
O1B	0.5433 (2)	1.13507 (14)	0.43096 (11)	0.0189 (3)
C1B	0.4590 (3)	1.03933 (19)	0.35294 (15)	0.0147 (4)
N2B	0.3806 (3)	0.90640 (16)	0.35775 (12)	0.0158 (3)
H2BA	0.3923	0.8731	0.4149	0.019*
C3B	0.2729 (3)	0.8193 (2)	0.26005 (14)	0.0163 (4)
H3BA	0.1226	0.8081	0.2654	0.020*
H3BB	0.3141	0.7220	0.2424	0.020*
C4B	0.3395 (3)	0.90694 (19)	0.17620 (14)	0.0155 (4)
C5B	0.1561 (3)	0.9111 (2)	0.10248 (16)	0.0214 (4)
H5BA	0.0461	0.9484	0.1448	0.026*
H5BB	0.1986	0.9785	0.0568	0.026*
C6B	0.0727 (4)	0.7610 (2)	0.03391 (17)	0.0288 (5)
H6BA	0.0190	0.6956	0.0791	0.035*
H6BB	−0.0418	0.7686	−0.0143	0.035*
C7B	0.2397 (4)	0.6977 (3)	−0.02991 (17)	0.0320 (5)
H7BA	0.2827	0.7577	−0.0805	0.038*
H7BB	0.1841	0.5986	−0.0705	0.038*
C8B	0.4253 (4)	0.6919 (2)	0.04056 (17)	0.0278 (5)
H8BA	0.5350	0.6579	−0.0036	0.033*
H8BB	0.3866	0.6216	0.0847	0.033*
C9B	0.5062 (3)	0.8409 (2)	0.11141 (16)	0.0198 (4)
H9BA	0.5625	0.9073	0.0674	0.024*
H9BB	0.6193	0.8318	0.1598	0.024*
C10B	0.4297 (3)	1.0593 (2)	0.24256 (15)	0.0175 (4)
H10A	0.5621	1.0955	0.2170	0.021*
H10B	0.3340	1.1288	0.2394	0.021*

	U11	U22	U33	U12	U13	U23
Cl1	0.0306 (3)	0.0172 (2)	0.0145 (2)	0.00588 (19)	−0.00172 (18)	0.00410 (18)
Cl2	0.0277 (3)	0.0151 (2)	0.0153 (2)	0.00428 (18)	−0.00131 (18)	0.00606 (17)
O1A	0.0265 (7)	0.0099 (6)	0.0176 (7)	−0.0005 (5)	0.0004 (6)	0.0026 (5)
O2A	0.0281 (8)	0.0111 (6)	0.0211 (7)	0.0016 (6)	0.0049 (6)	0.0057 (5)
O3A	0.0228 (7)	0.0093 (6)	0.0179 (7)	−0.0007 (5)	−0.0029 (5)	0.0048 (5)
O4A	0.0214 (7)	0.0131 (7)	0.0194 (7)	0.0022 (5)	0.0020 (5)	0.0076 (5)
C1A	0.0154 (9)	0.0149 (9)	0.0141 (9)	0.0062 (7)	0.0023 (7)	0.0042 (7)
C2A	0.0144 (9)	0.0112 (8)	0.0183 (9)	0.0032 (7)	0.0023 (7)	0.0008 (7)
C3A	0.0154 (9)	0.0107 (9)	0.0184 (9)	0.0048 (7)	0.0048 (7)	0.0047 (7)
C4A	0.0168 (9)	0.0125 (9)	0.0138 (9)	0.0051 (7)	0.0017 (7)	0.0042 (7)
C5A	0.0112 (9)	0.0113 (9)	0.0184 (9)	0.0036 (7)	0.0014 (7)	0.0037 (7)
C6A	0.0122 (8)	0.0108 (9)	0.0179 (9)	0.0043 (7)	0.0027 (7)	0.0044 (7)
O1B	0.0276 (8)	0.0112 (6)	0.0166 (7)	−0.0010 (5)	−0.0015 (6)	0.0036 (5)
C1B	0.0170 (9)	0.0110 (8)	0.0166 (9)	0.0029 (7)	0.0014 (7)	0.0037 (7)
N2B	0.0236 (8)	0.0109 (7)	0.0130 (8)	0.0012 (6)	−0.0001 (6)	0.0044 (6)
C3B	0.0245 (10)	0.0116 (8)	0.0123 (9)	0.0004 (7)	0.0009 (7)	0.0032 (7)
C4B	0.0224 (10)	0.0106 (9)	0.0138 (9)	0.0024 (7)	0.0013 (7)	0.0038 (7)
C5B	0.0251 (10)	0.0216 (10)	0.0192 (10)	0.0078 (8)	−0.0004 (8)	0.0058 (8)
C6B	0.0350 (12)	0.0279 (12)	0.0208 (10)	0.0012 (9)	−0.0075 (9)	0.0034 (9)
C7B	0.0492 (15)	0.0252 (11)	0.0174 (10)	0.0041 (10)	−0.0010 (10)	−0.0022 (8)
C8B	0.0413 (13)	0.0195 (10)	0.0229 (10)	0.0115 (9)	0.0078 (9)	0.0002 (8)
C9B	0.0245 (10)	0.0173 (9)	0.0193 (9)	0.0054 (8)	0.0042 (8)	0.0060 (8)
C10B	0.0268 (10)	0.0112 (9)	0.0155 (9)	0.0030 (7)	0.0024 (8)	0.0049 (7)

Cl1—C1A	1.7158 (19)	C3B—H3BB	0.9900
Cl2—C4A	1.7196 (18)	C4B—C5B	1.534 (3)
O1A—C2A	1.330 (2)	C4B—C9B	1.538 (3)
O1A—H1A	0.8400	C4B—C10B	1.546 (2)
O2A—C3A	1.227 (2)	C5B—C6B	1.530 (3)
O3A—C5A	1.301 (2)	C5B—H5BA	0.9900
O3A—H3A	0.8400	C5B—H5BB	0.9900
O4A—C6A	1.215 (2)	C6B—C7B	1.523 (3)
C1A—C2A	1.352 (3)	C6B—H6BA	0.9900
C1A—C6A	1.465 (3)	C6B—H6BB	0.9900
C2A—C3A	1.504 (3)	C7B—C8B	1.525 (3)
C3A—C4A	1.441 (3)	C7B—H7BA	0.9900
C4A—C5A	1.361 (3)	C7B—H7BB	0.9900
C5A—C6A	1.517 (3)	C8B—C9B	1.531 (3)
O1B—C1B	1.262 (2)	C8B—H8BA	0.9900
C1B—N2B	1.318 (2)	C8B—H8BB	0.9900
C1B—C10B	1.507 (2)	C9B—H9BA	0.9900
N2B—C3B	1.460 (2)	C9B—H9BB	0.9900
N2B—H2BA	0.8800	C10B—H10A	0.9900
C3B—C4B	1.558 (2)	C10B—H10B	0.9900
C3B—H3BA	0.9900
C2A—O1A—H1A	109.5	C10B—C4B—C3B	103.66 (14)
C5A—O3A—H3A	109.5	C6B—C5B—C4B	111.76 (17)
C2A—C1A—C6A	120.62 (17)	C6B—C5B—H5BA	109.3
C2A—C1A—Cl1	121.97 (15)	C4B—C5B—H5BA	109.3
C6A—C1A—Cl1	117.41 (14)	C6B—C5B—H5BB	109.3
O1A—C2A—C1A	122.13 (17)	C4B—C5B—H5BB	109.3
O1A—C2A—C3A	116.63 (16)	H5BA—C5B—H5BB	107.9
C1A—C2A—C3A	121.23 (16)	C7B—C6B—C5B	110.90 (19)
O2A—C3A—C4A	124.02 (17)	C7B—C6B—H6BA	109.5
O2A—C3A—C2A	117.66 (17)	C5B—C6B—H6BA	109.5
C4A—C3A—C2A	118.32 (16)	C7B—C6B—H6BB	109.5
C5A—C4A—C3A	121.67 (17)	C5B—C6B—H6BB	109.5
C5A—C4A—Cl2	120.66 (14)	H6BA—C6B—H6BB	108.0
C3A—C4A—Cl2	117.67 (14)	C6B—C7B—C8B	111.52 (18)
O3A—C5A—C4A	121.97 (17)	C6B—C7B—H7BA	109.3
O3A—C5A—C6A	118.01 (16)	C8B—C7B—H7BA	109.3
C4A—C5A—C6A	120.03 (16)	C6B—C7B—H7BB	109.3
O4A—C6A—C1A	123.11 (17)	C8B—C7B—H7BB	109.3
O4A—C6A—C5A	118.78 (16)	H7BA—C7B—H7BB	108.0
C1A—C6A—C5A	118.10 (15)	C7B—C8B—C9B	111.18 (17)
O1B—C1B—N2B	123.96 (17)	C7B—C8B—H8BA	109.4
O1B—C1B—C10B	125.82 (16)	C9B—C8B—H8BA	109.4
N2B—C1B—C10B	110.21 (16)	C7B—C8B—H8BB	109.4
C1B—N2B—C3B	114.19 (15)	C9B—C8B—H8BB	109.4
C1B—N2B—H2BA	122.9	H8BA—C8B—H8BB	108.0
C3B—N2B—H2BA	122.9	C8B—C9B—C4B	112.62 (17)
N2B—C3B—C4B	104.11 (15)	C8B—C9B—H9BA	109.1
N2B—C3B—H3BA	110.9	C4B—C9B—H9BA	109.1
C4B—C3B—H3BA	110.9	C8B—C9B—H9BB	109.1
N2B—C3B—H3BB	110.9	C4B—C9B—H9BB	109.1
C4B—C3B—H3BB	110.9	H9BA—C9B—H9BB	107.8
H3BA—C3B—H3BB	109.0	C1B—C10B—C4B	105.01 (15)
C5B—C4B—C9B	109.57 (15)	C1B—C10B—H10A	110.7
C5B—C4B—C10B	111.96 (15)	C4B—C10B—H10A	110.7
C9B—C4B—C10B	109.81 (16)	C1B—C10B—H10B	110.7
C5B—C4B—C3B	111.08 (16)	C4B—C10B—H10B	110.7
C9B—C4B—C3B	110.64 (15)	H10A—C10B—H10B	108.8
C6A—C1A—C2A—O1A	179.69 (16)	C4A—C5A—C6A—C1A	−1.8 (3)
Cl1—C1A—C2A—O1A	0.0 (3)	O1B—C1B—N2B—C3B	174.06 (18)
C6A—C1A—C2A—C3A	−1.6 (3)	C10B—C1B—N2B—C3B	−5.0 (2)
Cl1—C1A—C2A—C3A	178.76 (13)	C1B—N2B—C3B—C4B	14.0 (2)
O1A—C2A—C3A—O2A	−0.8 (3)	N2B—C3B—C4B—C5B	−136.89 (16)
C1A—C2A—C3A—O2A	−179.58 (18)	N2B—C3B—C4B—C9B	101.19 (17)
O1A—C2A—C3A—C4A	179.11 (16)	N2B—C3B—C4B—C10B	−16.48 (19)
C1A—C2A—C3A—C4A	0.3 (3)	C9B—C4B—C5B—C6B	55.7 (2)
O2A—C3A—C4A—C5A	−179.95 (18)	C10B—C4B—C5B—C6B	177.77 (17)
C2A—C3A—C4A—C5A	0.2 (3)	C3B—C4B—C5B—C6B	−66.9 (2)
O2A—C3A—C4A—Cl2	0.0 (3)	C4B—C5B—C6B—C7B	−57.1 (2)
C2A—C3A—C4A—Cl2	−179.94 (13)	C5B—C6B—C7B—C8B	55.9 (2)
C3A—C4A—C5A—O3A	−179.05 (16)	C6B—C7B—C8B—C9B	−54.4 (3)
Cl2—C4A—C5A—O3A	1.1 (3)	C7B—C8B—C9B—C4B	54.4 (2)
C3A—C4A—C5A—C6A	0.6 (3)	C5B—C4B—C9B—C8B	−54.5 (2)
Cl2—C4A—C5A—C6A	−179.28 (13)	C10B—C4B—C9B—C8B	−177.91 (16)
C2A—C1A—C6A—O4A	−176.63 (18)	C3B—C4B—C9B—C8B	68.3 (2)
Cl1—C1A—C6A—O4A	3.0 (3)	O1B—C1B—C10B—C4B	174.58 (18)
C2A—C1A—C6A—C5A	2.3 (3)	N2B—C1B—C10B—C4B	−6.4 (2)
Cl1—C1A—C6A—C5A	−178.02 (13)	C5B—C4B—C10B—C1B	133.80 (17)
O3A—C5A—C6A—O4A	−3.2 (3)	C9B—C4B—C10B—C1B	−104.25 (17)
C4A—C5A—C6A—O4A	177.16 (17)	C3B—C4B—C10B—C1B	13.99 (19)
O3A—C5A—C6A—C1A	177.86 (15)

D—H···A	D—H	H···A	D···A	D—H···A
O1A—H1A···O2Ai	0.84	1.97	2.7493 (19)	153
O1A—H1A···O2A	0.84	2.20	2.671 (2)	115
O3A—H3A···O1Bii	0.84	1.70	2.4807 (19)	153
O3A—H3A···O4A	0.84	2.26	2.7148 (19)	114
N2B—H2BA···O1Bii	0.88	2.07	2.913 (2)	161
N2B—H2BA···O4A	0.88	2.53	3.091 (2)	122

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1A—H1A⋯O2Ai	0.84	1.97	2.7493 (19)	153
O1A—H1A⋯O2A	0.84	2.20	2.671 (2)	115
O3A—H3A⋯O1Bii	0.84	1.70	2.4807 (19)	153
O3A—H3A⋯O4A	0.84	2.26	2.7148 (19)	114
N2B—H2BA⋯O1Bii	0.88	2.07	2.913 (2)	161
N2B—H2BA⋯O4A	0.88	2.53	3.091 (2)	122

Symmetry codes: (i) ; (ii) .