Tramadol hydro-chloride-benzoic acid (1/1).

In the cation of the title co-crystal salt {systematic name: [2-hydroxy-2-(3-meth-oxy-phen-yl)cyclo-hexyl-meth-yl]dimethyl-aza-nium chloride-benzoic acid (1/1)}, C(16)H(31)NO(2) (+)·Cl(-)·C(7)H(6)O(2), the N atom is protonated and the six-membered cyclo-hexane ring adopts a slightly distorted chair conformation. The dihedral angle between the mean planes of the benzene rings in the cation and the benzoic acid mol-ecule is 75.5 (9)°. The crystal packing is stabilized by weak inter-molecular O-H⋯Cl, N-H⋯Cl and C-H⋯π inter-actions, forming a two-dimensional chain network along the b axis. The benzoic acid mol-ecule is not involved in the usual head-to-tail dimer bonding, but instead is linked to the ammonium cation through mutual hydrogen-bonding inter-actions with the chloride anion.

Related literature

For the use of tramadol for perioperative pain relief, see: Scott & Perry (2000 ▶). For related structures, see: Arman et al. (2010 ▶); Hemamalini & Fun (2010 ▶); Tessler & Goldberg (2004 ▶). For standard bond lengths, see Allen et al. (1987 ▶).

Experimental

Crystal data

C16H26NO2 +·Cl−·C7H6O2

M = 421.95

Monoclinic,

a = 8.9721 (2) Å

b = 10.4086 (2) Å

c = 12.5189 (3) Å

β = 101.646 (2)°

V = 1145.03 (4) Å3

Z = 2

Mo Kα radiation

μ = 0.19 mm−1

T = 173 K

0.42 × 0.34 × 0.25 mm

Data collection

Oxford Diffraction Xcalibur Eos Gemini diffractometer

Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2010 ▶) T min = 0.923, T max = 0.953

11101 measured reflections

5354 independent reflections

5067 reflections with I > 2σ(I)

R int = 0.014

Refinement

R[F 2 > 2σ(F 2)] = 0.029

wR(F 2) = 0.077

S = 1.04

5354 reflections

267 parameters

2 restraints

H-atom parameters constrained

Δρmax = 0.21 e Å−3

Δρmin = −0.14 e Å−3

Absolute structure: Flack (1983 ▶), 2397 Friedel pairs

Flack parameter: −0.02 (4)

Data collection: CrysAlis PRO (Oxford Diffraction, 2010 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis RED (Oxford Diffraction, 2010 ▶); 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 datablock(s) global, I. DOI: 10.1107/S1600536811032181/bv2189sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811032181/bv2189Isup2.hkl

Supplementary material file. DOI: 10.1107/S1600536811032181/bv2189Isup3.cml

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

C16H26NO2+·Cl−·C7H6O2	F(000) = 452
Mr = 421.95	Dx = 1.224 Mg m−3
Monoclinic, Pc	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P -2yc	Cell parameters from 8856 reflections
a = 8.9721 (2) Å	θ = 3.2–32.3°
b = 10.4086 (2) Å	µ = 0.19 mm−1
c = 12.5189 (3) Å	T = 173 K
β = 101.646 (2)°	Block, colorless
V = 1145.03 (4) Å3	0.42 × 0.34 × 0.25 mm
Z = 2

Oxford Diffraction Xcalibur Eos Gemini diffractometer	5354 independent reflections
Radiation source: Enhance (Mo) X-ray Source	5067 reflections with I > 2σ(I)
graphite	Rint = 0.014
Detector resolution: 16.1500 pixels mm-1	θmax = 28.7°, θmin = 3.2°
ω scans	h = −12→12
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2010)	k = −13→14
Tmin = 0.923, Tmax = 0.953	l = −16→16
11101 measured reflections

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.029	H-atom parameters constrained
wR(F2) = 0.077	w = 1/[σ2(Fo2) + (0.0432P)2 + 0.0915P] where P = (Fo2 + 2Fc2)/3
S = 1.04	(Δ/σ)max = 0.001
5354 reflections	Δρmax = 0.21 e Å−3
267 parameters	Δρmin = −0.14 e Å−3
2 restraints	Absolute structure: Flack (1983), 2397 Friedel pairs
Primary atom site location: structure-invariant direct methods	Flack parameter: −0.02 (4)

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
O1	0.52336 (9)	0.94842 (8)	0.34245 (7)	0.02855 (17)
H1O	0.6170	0.9644	0.3579	0.034*
O2	0.50785 (17)	0.37596 (10)	0.40095 (13)	0.0647 (3)
N1	0.05818 (11)	0.84734 (11)	0.28462 (9)	0.0337 (2)
H1N	0.0310	0.9119	0.3284	0.040*
C1	0.0099 (2)	0.72349 (19)	0.32402 (18)	0.0637 (5)
H1A	−0.1006	0.7241	0.3189	0.096*
H1B	0.0610	0.7106	0.4002	0.096*
H1C	0.0371	0.6535	0.2792	0.096*
C2	−0.02187 (17)	0.87309 (19)	0.17005 (12)	0.0519 (4)
H2A	−0.1321	0.8698	0.1655	0.078*
H2B	0.0074	0.8080	0.1216	0.078*
H2C	0.0066	0.9584	0.1478	0.078*
C3	0.22703 (13)	0.85528 (12)	0.29216 (10)	0.0298 (2)
H3A	0.2504	0.9364	0.2577	0.036*
H3B	0.2586	0.7835	0.2498	0.036*
C4	0.32126 (12)	0.85020 (11)	0.40805 (9)	0.0254 (2)
H4A	0.2915	0.7718	0.4449	0.030*
C5	0.29134 (14)	0.96879 (14)	0.47321 (11)	0.0368 (3)
H5A	0.3075	1.0471	0.4321	0.044*
H5B	0.1838	0.9681	0.4812	0.044*
C6	0.39380 (16)	0.97406 (16)	0.58564 (12)	0.0445 (3)
H6A	0.3656	0.9037	0.6309	0.053*
H6B	0.3771	1.0565	0.6209	0.053*
C7	0.56191 (15)	0.96186 (14)	0.58141 (11)	0.0376 (3)
H7A	0.5947	1.0390	0.5460	0.045*
H7B	0.6230	0.9570	0.6566	0.045*
C8	0.59035 (13)	0.84261 (12)	0.51835 (9)	0.0310 (2)
H8A	0.5686	0.7653	0.5587	0.037*
H8B	0.6990	0.8398	0.5134	0.037*
C9	0.49169 (12)	0.83936 (10)	0.40268 (9)	0.02313 (19)
C10	0.52315 (12)	0.71504 (10)	0.34583 (9)	0.0254 (2)
C11	0.50053 (15)	0.59804 (12)	0.39240 (11)	0.0346 (3)
H11A	0.4621	0.5960	0.4577	0.041*
C12	0.53321 (16)	0.48312 (13)	0.34504 (13)	0.0405 (3)
C13	0.58753 (17)	0.48517 (15)	0.24902 (14)	0.0455 (3)
H13A	0.6103	0.4073	0.2161	0.055*
C14	0.60801 (17)	0.60191 (16)	0.20207 (12)	0.0458 (3)
H14A	0.6450	0.6037	0.1361	0.055*
C15	0.57602 (14)	0.71689 (13)	0.24871 (11)	0.0341 (3)
H15A	0.5901	0.7963	0.2146	0.041*
C16	0.5307 (3)	0.25388 (16)	0.3558 (2)	0.0713 (6)
H16A	0.5050	0.1860	0.4032	0.107*
H16B	0.6375	0.2453	0.3499	0.107*
H16C	0.4654	0.2463	0.2832	0.107*
O3	−0.10582 (14)	1.25355 (13)	0.22279 (12)	0.0598 (3)
H3O	−0.1056	1.1872	0.2611	0.072*
O4	0.13609 (18)	1.20037 (17)	0.23538 (18)	0.0883 (5)
C17	0.03083 (18)	1.27036 (16)	0.20051 (14)	0.0496 (4)
C18	0.04087 (16)	1.38280 (15)	0.12968 (13)	0.0434 (3)
C19	−0.08709 (18)	1.44113 (17)	0.06800 (15)	0.0508 (4)
H19A	−0.1856	1.4105	0.0718	0.061*
C20	−0.0714 (2)	1.54327 (19)	0.00136 (17)	0.0624 (5)
H20A	−0.1593	1.5816	−0.0419	0.075*
C21	0.0714 (2)	1.5907 (2)	−0.00322 (17)	0.0631 (5)
H21A	0.0813	1.6621	−0.0486	0.076*
C22	0.1979 (2)	1.53427 (19)	0.05796 (19)	0.0639 (5)
H22A	0.2960	1.5669	0.0554	0.077*
C23	0.18366 (19)	1.42998 (19)	0.12347 (17)	0.0584 (4)
H23A	0.2722	1.3902	0.1646	0.070*
Cl1	−0.13063 (4)	1.04083 (3)	0.38725 (3)	0.04431 (9)

	U11	U22	U33	U12	U13	U23
O1	0.0265 (4)	0.0253 (4)	0.0336 (4)	−0.0005 (3)	0.0054 (3)	0.0049 (3)
O2	0.0903 (9)	0.0227 (5)	0.0842 (9)	0.0030 (5)	0.0248 (7)	0.0023 (5)
N1	0.0243 (4)	0.0418 (6)	0.0331 (5)	0.0007 (4)	0.0013 (4)	−0.0013 (4)
C1	0.0418 (8)	0.0638 (11)	0.0802 (12)	−0.0202 (8)	−0.0003 (8)	0.0176 (9)
C2	0.0380 (7)	0.0747 (11)	0.0371 (7)	0.0095 (7)	−0.0066 (6)	−0.0041 (7)
C3	0.0243 (5)	0.0387 (6)	0.0264 (5)	0.0020 (4)	0.0051 (4)	−0.0016 (5)
C4	0.0224 (4)	0.0293 (5)	0.0248 (5)	−0.0002 (4)	0.0055 (4)	−0.0017 (4)
C5	0.0285 (6)	0.0442 (7)	0.0383 (6)	0.0051 (5)	0.0080 (5)	−0.0136 (6)
C6	0.0397 (7)	0.0594 (9)	0.0345 (7)	0.0020 (6)	0.0076 (6)	−0.0166 (6)
C7	0.0341 (6)	0.0456 (7)	0.0301 (6)	0.0004 (5)	−0.0003 (5)	−0.0103 (5)
C8	0.0293 (5)	0.0337 (6)	0.0272 (5)	0.0034 (4)	−0.0007 (4)	0.0009 (5)
C9	0.0228 (4)	0.0220 (5)	0.0245 (5)	0.0008 (4)	0.0046 (4)	0.0013 (4)
C10	0.0216 (4)	0.0246 (5)	0.0291 (5)	0.0029 (4)	0.0026 (4)	−0.0025 (4)
C11	0.0397 (6)	0.0265 (6)	0.0383 (6)	0.0021 (5)	0.0098 (5)	−0.0007 (5)
C12	0.0404 (7)	0.0253 (6)	0.0527 (8)	0.0039 (5)	0.0022 (6)	−0.0037 (6)
C13	0.0429 (7)	0.0362 (7)	0.0549 (8)	0.0076 (6)	0.0042 (6)	−0.0191 (6)
C14	0.0478 (8)	0.0518 (9)	0.0407 (7)	0.0073 (6)	0.0155 (6)	−0.0121 (6)
C15	0.0347 (6)	0.0343 (6)	0.0347 (6)	0.0026 (5)	0.0107 (5)	−0.0016 (5)
C16	0.0744 (12)	0.0241 (6)	0.1099 (17)	0.0061 (7)	0.0055 (11)	−0.0089 (9)
O3	0.0429 (5)	0.0625 (7)	0.0747 (8)	0.0057 (5)	0.0137 (5)	0.0121 (6)
O4	0.0559 (7)	0.0862 (11)	0.1261 (14)	0.0267 (7)	0.0263 (8)	0.0416 (10)
C17	0.0393 (7)	0.0523 (9)	0.0560 (9)	0.0069 (6)	0.0068 (6)	−0.0057 (7)
C18	0.0351 (6)	0.0461 (8)	0.0477 (8)	0.0028 (5)	0.0056 (6)	−0.0100 (6)
C19	0.0363 (7)	0.0567 (9)	0.0563 (9)	0.0032 (6)	0.0021 (6)	−0.0044 (8)
C20	0.0514 (10)	0.0654 (11)	0.0640 (11)	0.0065 (8)	−0.0039 (8)	0.0028 (9)
C21	0.0745 (12)	0.0568 (10)	0.0585 (10)	−0.0029 (9)	0.0146 (9)	−0.0013 (9)
C22	0.0487 (9)	0.0644 (11)	0.0808 (13)	−0.0068 (8)	0.0181 (9)	−0.0034 (10)
C23	0.0352 (7)	0.0655 (11)	0.0715 (11)	0.0032 (7)	0.0040 (7)	−0.0011 (10)
Cl1	0.02963 (13)	0.05385 (19)	0.05016 (18)	0.00276 (14)	0.00977 (11)	−0.00115 (16)

O1—C9	1.4228 (13)	C8—H8B	0.9900
O1—H1O	0.8400	C9—C10	1.5302 (15)
O2—C12	1.3601 (19)	C10—C11	1.3827 (17)
O2—C16	1.422 (2)	C10—C15	1.3916 (16)
N1—C1	1.476 (2)	C11—C12	1.3923 (18)
N1—C2	1.4930 (17)	C11—H11A	0.9500
N1—C3	1.5010 (14)	C12—C13	1.385 (2)
N1—H1N	0.9300	C13—C14	1.378 (2)
C1—H1A	0.9800	C13—H13A	0.9500
C1—H1B	0.9800	C14—C15	1.3868 (19)
C1—H1C	0.9800	C14—H14A	0.9500
C2—H2A	0.9800	C15—H15A	0.9500
C2—H2B	0.9800	C16—H16A	0.9800
C2—H2C	0.9800	C16—H16B	0.9800
C3—C4	1.5255 (15)	C16—H16C	0.9800
C3—H3A	0.9900	O3—C17	1.323 (2)
C3—H3B	0.9900	O3—H3O	0.8400
C4—C5	1.5329 (16)	O4—C17	1.203 (2)
C4—C9	1.5482 (14)	C17—C18	1.482 (2)
C4—H4A	1.0000	C18—C19	1.387 (2)
C5—C6	1.5188 (19)	C18—C23	1.389 (2)
C5—H5A	0.9900	C19—C20	1.376 (3)
C5—H5B	0.9900	C19—H19A	0.9500
C6—C7	1.5252 (19)	C20—C21	1.384 (3)
C6—H6A	0.9900	C20—H20A	0.9500
C6—H6B	0.9900	C21—C22	1.367 (3)
C7—C8	1.5199 (18)	C21—H21A	0.9500
C7—H7A	0.9900	C22—C23	1.382 (3)
C7—H7B	0.9900	C22—H22A	0.9500
C8—C9	1.5376 (15)	C23—H23A	0.9500
C8—H8A	0.9900
C9—O1—H1O	109.5	C9—C8—H8B	109.1
C12—O2—C16	118.40 (16)	H8A—C8—H8B	107.8
C1—N1—C2	111.16 (13)	O1—C9—C10	110.66 (9)
C1—N1—C3	112.82 (11)	O1—C9—C8	110.06 (9)
C2—N1—C3	109.53 (11)	C10—C9—C8	109.35 (9)
C1—N1—H1N	107.7	O1—C9—C4	105.64 (8)
C2—N1—H1N	107.7	C10—C9—C4	111.00 (8)
C3—N1—H1N	107.7	C8—C9—C4	110.09 (8)
N1—C1—H1A	109.5	C11—C10—C15	119.04 (11)
N1—C1—H1B	109.5	C11—C10—C9	119.48 (10)
H1A—C1—H1B	109.5	C15—C10—C9	121.47 (10)
N1—C1—H1C	109.5	C10—C11—C12	121.05 (12)
H1A—C1—H1C	109.5	C10—C11—H11A	119.5
H1B—C1—H1C	109.5	C12—C11—H11A	119.5
N1—C2—H2A	109.5	O2—C12—C13	125.71 (13)
N1—C2—H2B	109.5	O2—C12—C11	114.46 (13)
H2A—C2—H2B	109.5	C13—C12—C11	119.83 (14)
N1—C2—H2C	109.5	C14—C13—C12	118.96 (13)
H2A—C2—H2C	109.5	C14—C13—H13A	120.5
H2B—C2—H2C	109.5	C12—C13—H13A	120.5
N1—C3—C4	114.61 (9)	C13—C14—C15	121.64 (13)
N1—C3—H3A	108.6	C13—C14—H14A	119.2
C4—C3—H3A	108.6	C15—C14—H14A	119.2
N1—C3—H3B	108.6	C14—C15—C10	119.47 (13)
C4—C3—H3B	108.6	C14—C15—H15A	120.3
H3A—C3—H3B	107.6	C10—C15—H15A	120.3
C3—C4—C5	110.81 (10)	O2—C16—H16A	109.5
C3—C4—C9	108.90 (8)	O2—C16—H16B	109.5
C5—C4—C9	111.25 (9)	H16A—C16—H16B	109.5
C3—C4—H4A	108.6	O2—C16—H16C	109.5
C5—C4—H4A	108.6	H16A—C16—H16C	109.5
C9—C4—H4A	108.6	H16B—C16—H16C	109.5
C6—C5—C4	112.58 (11)	C17—O3—H3O	109.5
C6—C5—H5A	109.1	O4—C17—O3	122.46 (18)
C4—C5—H5A	109.1	O4—C17—C18	123.87 (16)
C6—C5—H5B	109.1	O3—C17—C18	113.67 (13)
C4—C5—H5B	109.1	C19—C18—C23	118.90 (16)
H5A—C5—H5B	107.8	C19—C18—C17	122.35 (14)
C5—C6—C7	112.49 (11)	C23—C18—C17	118.74 (14)
C5—C6—H6A	109.1	C20—C19—C18	120.06 (16)
C7—C6—H6A	109.1	C20—C19—H19A	120.0
C5—C6—H6B	109.1	C18—C19—H19A	120.0
C7—C6—H6B	109.1	C19—C20—C21	120.63 (17)
H6A—C6—H6B	107.8	C19—C20—H20A	119.7
C8—C7—C6	110.91 (11)	C21—C20—H20A	119.7
C8—C7—H7A	109.5	C22—C21—C20	119.60 (19)
C6—C7—H7A	109.5	C22—C21—H21A	120.2
C8—C7—H7B	109.5	C20—C21—H21A	120.2
C6—C7—H7B	109.5	C21—C22—C23	120.27 (18)
H7A—C7—H7B	108.0	C21—C22—H22A	119.9
C7—C8—C9	112.46 (10)	C23—C22—H22A	119.9
C7—C8—H8A	109.1	C22—C23—C18	120.52 (17)
C9—C8—H8A	109.1	C22—C23—H23A	119.7
C7—C8—H8B	109.1	C18—C23—H23A	119.7
C1—N1—C3—C4	−64.12 (16)	C15—C10—C11—C12	1.54 (17)
C2—N1—C3—C4	171.50 (12)	C9—C10—C11—C12	−177.65 (11)
N1—C3—C4—C5	−65.45 (13)	C16—O2—C12—C13	−3.5 (2)
N1—C3—C4—C9	171.88 (9)	C16—O2—C12—C11	176.86 (15)
C3—C4—C5—C6	−174.57 (11)	C10—C11—C12—O2	178.89 (13)
C9—C4—C5—C6	−53.27 (14)	C10—C11—C12—C13	−0.8 (2)
C4—C5—C6—C7	53.02 (17)	O2—C12—C13—C14	−179.73 (15)
C5—C6—C7—C8	−53.47 (17)	C11—C12—C13—C14	−0.1 (2)
C6—C7—C8—C9	55.64 (15)	C12—C13—C14—C15	0.2 (2)
C7—C8—C9—O1	59.94 (12)	C13—C14—C15—C10	0.6 (2)
C7—C8—C9—C10	−178.30 (10)	C11—C10—C15—C14	−1.41 (17)
C7—C8—C9—C4	−56.10 (13)	C9—C10—C15—C14	177.77 (11)
C3—C4—C9—O1	57.67 (11)	O4—C17—C18—C19	162.7 (2)
C5—C4—C9—O1	−64.74 (11)	O3—C17—C18—C19	−17.5 (2)
C3—C4—C9—C10	−62.33 (11)	O4—C17—C18—C23	−16.2 (3)
C5—C4—C9—C10	175.26 (10)	O3—C17—C18—C23	163.59 (16)
C3—C4—C9—C8	176.45 (9)	C23—C18—C19—C20	0.5 (3)
C5—C4—C9—C8	54.04 (12)	C17—C18—C19—C20	−178.32 (16)
O1—C9—C10—C11	179.40 (10)	C18—C19—C20—C21	−1.4 (3)
C8—C9—C10—C11	58.00 (13)	C19—C20—C21—C22	0.9 (3)
C4—C9—C10—C11	−63.64 (13)	C20—C21—C22—C23	0.4 (3)
O1—C9—C10—C15	0.22 (14)	C21—C22—C23—C18	−1.3 (3)
C8—C9—C10—C15	−121.17 (11)	C19—C18—C23—C22	0.8 (3)
C4—C9—C10—C15	117.18 (11)	C17—C18—C23—C22	179.69 (16)

Cg3 is the centroid of the C18–C23 ring.

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1O···Cl1i	0.84	2.36	3.1898 (9)	171.
O3—H3O···Cl1	0.84	2.24	3.0620 (14)	167.
N1—H1N···Cl1	0.93	2.21	3.0750 (12)	155.
C1—H1B···Cg3ii	0.98	2.90	3.662 (5)	135

Table 1

Hydrogen-bond geometry (Å, °)

Cg3 is the centroid of the C18–C23 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1O⋯Cl1i	0.84	2.36	3.1898 (9)	171
O3—H3O⋯Cl1	0.84	2.24	3.0620 (14)	167
N1—H1N⋯Cl1	0.93	2.21	3.0750 (12)	155
C1—H1B⋯Cg3ii	0.98	2.90	3.662 (5)	135

Symmetry codes: (i) ; (ii) .