Redetermination of (+)-methamphetamine hydro­chloride at 90 K

The title crystal structure (systematic name: N-methyl-1-phenyl­propan-2-aminium chloride), C₁₀H₁₆N⁺·Cl⁻, was orginally determined by Simon, Bocskei & Torok [Acta Pharm. Hung. (1992). 62, 225–230] and Yao, Kan & Wang [Huaxue Shijie (1999). 40, 568–570] at room temperature but no atomic coordinates are available for these determinations. The mol­ecule has inter­est with respect to biological activity. In the crystal structure, inter­molecular N—H...Cl hydrogen bonds form one-dimensional chains.

Key indicators

• Single-crystal X-ray study
• T = 90 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.052
• wR factor = 0.118
• Data-to-parameter ratio = 15.6

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT245_ALERT_2_C U(iso) H4B     Smaller than U(eq) C4      by ...       0.01 AngSq
PLAT391_ALERT_3_C Deviating Methyl C2      H-C-H Bond Angle ......     101.00 Deg.
PLAT850_ALERT_2_C Check Flack Parameter Exact Value 0.00 and su ..       0.10

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           28.23
           From the CIF: _reflns_number_total               2720
           Count of symmetry unique reflns         1485
           Completeness (_total/calc)            183.16%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured      1235
           Fraction of Friedel pairs measured     0.832
           Are heavy atom types Z>Si present        yes
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C3     ...          R
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          1

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   4 ALERT level C = Check and explain
   3 ALERT level G = General alerts; check

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   2 ALERT type 2 Indicator that the structure model may be wrong or deficient
   2 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

The compound, (+)-methamphetamine hydrochloride has been reinvestigated in this study by single-crystal x-ray diffraction to provide a complete determination of the atomic coordinates and lattice dimensions at 90 (2) K. Earlier structural studies on this compound by Simon et al. (1992) and by Yanhong et al. (1999) were performed at or near room temperature and did not include atomic coordinates. The determination of crystallographic data at cryogenic temperatures improves the precision of the atomic coordinates and also provides insight into temperature-induced lattice changes. This information is important in the complete understanding of the molecular solid and is particularly useful for validation of first-principles solid-state modeling.

The compound studied is a synthetic sympathomimetic drug and is specified as a controlled substance by the United States Federal government (O'Neil et al., 2001). The substance is a strong stimulant that affects the central nervous system (CNS) and contributes cardiactoxicity (Yu et al., 2003). The use of methamphetamine has increased substantially and is becoming a problem nation wide with its use increasing across all age groups (Cho & Melega, 2002). The compound has a more potent effect on the CNS than structurally similar amphetamine due to its increased penetration of the CNS (Davis & Swalwell,1994). The potency of methamphetamine is also dependent upon its chirality, as its dextrorotatory enantiomer exhibits an effect roughly fives times greater than that provided by the levorotatory enantiomer (Cho, 1990). The stimulant effects of methamphetamine can be compared to the effects brought on by the use of cocaine, however, the duration of the effects can be much greater for the methamphetamine than for cocaine (Cho, 1990).

The (+)-methamphetamine hydrochloride form of methamphetamine has become the primary form used (Cho & Melega, 2002). This highlights the importance of complete characterization of the substance. Knowledge of the solid-state Crystal Structure of this compound is imperative for its identification and detection via various spectroscopic methods, such as solid-state NMR and terahertz. The unit-cell dimensions determined by this study are slightly smaller than those published by Simon et al., (1992) leading to a reduction in the unit cell volume of approximately 2.4% from the previously calculated value. Overall the basic structural parameters, such as the space group, P2₁, are in agreement with earlier work (Simon et al., 1992).

Related literature

For related literature, see: Cho (1990); Cho & Melega (2002); Davis & Swalwell (1994); O'Neil et al. (2001); Simon et al. (1992); Yao et al. (1999); Yu et al. (2003).

S2. Experimental

The material for this work was purchased from Sigma-Aldrich and was used without any further purification.

S3. Refinement

H atoms were located in a difference map and refined freely.

Computing details

Data collection: SMART (Bruker, 2002); cell refinement: SAINT (Bruker, 2002); data reduction: SAINT (Bruker, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: CrystalMaker (Palmer, 2006); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

	Fig. 1. The molecular structure of the title compound, with the atom numbering scheme and thermal ellipsoids drawn at 50% probability level.
	Fig. 2. The crystal packing of the title compound viewed in the ac plane, showing hydrogen bonds as dashed lines. H atoms not involved in hydrogen bonding have been omitted.
	Fig. 3. The crystal packing of the title compound, showing hydrogen bonds as dashed lines. H atoms not involved in hydrogen bonding have been omitted.

(+)-methamphetamine hydrochloride

Crystal data

C10H16N^+·Cl^−	F(000) = 200
Mr = 185.69	Dx = 1.110 Mg m^−3
Monoclinic, P21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2yb	Cell parameters from 964 reflections
a = 7.1022 (11) Å	θ = 2.9–22.5°
b = 7.2949 (11) Å	µ = 0.30 mm^−1
c = 10.8121 (17) Å	T = 90 K
β = 97.293 (4)°	Block, colorless
V = 555.64 (15) Å^3	0.28 × 0.14 × 0.10 mm
Z = 2

Data collection

Bruker APEX CCD area-detector diffractometer	2720 independent reflections
Radiation source: fine-focus sealed tube	2379 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.047
Detector resolution: 512 pixels mm^-1	θmax = 28.2°, θmin = 1.9°
ϕ and ω scans	h = −9→9
Absorption correction: multi-scan (SADABS; Bruker, 2002)	k = −9→9
Tmin = 0.922, Tmax = 0.971	l = −14→14
5892 measured reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.051	All H-atom parameters refined
wR(F^2) = 0.117	w = 1/[σ^2(Fo^2) + (0.0575P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.05	(Δ/σ)max < 0.001
2720 reflections	Δρmax = 0.43 e Å^−3
174 parameters	Δρmin = −0.46 e Å^−3
1 restraint	Absolute structure: Flack (1983), 1235 Freidel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.00 (10)

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.

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 (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.23185 (8)	0.78305 (9)	0.55574 (6)	0.02213 (16)
N1	0.8031 (3)	0.6811 (3)	0.5363 (2)	0.0172 (4)
C1	0.6896 (4)	0.7867 (6)	0.4357 (2)	0.0224 (5)
C2	0.7510 (5)	0.8922 (5)	0.7083 (3)	0.0256 (6)
C3	0.7409 (4)	0.6944 (4)	0.6644 (3)	0.0187 (5)
C4	0.8700 (4)	0.5637 (4)	0.7481 (3)	0.0236 (6)
C5	0.8089 (4)	0.5381 (4)	0.8763 (2)	0.0202 (5)
C6	0.8940 (4)	0.6384 (4)	0.9782 (3)	0.0228 (6)
C7	0.8402 (4)	0.6117 (4)	1.0956 (3)	0.0249 (6)
C8	0.7005 (4)	0.4842 (4)	1.1138 (3)	0.0262 (6)
C9	0.6134 (4)	0.3862 (4)	1.0127 (3)	0.0281 (6)
C10	0.6678 (4)	0.4130 (4)	0.8947 (3)	0.0248 (6)
H1A	0.718 (5)	0.908 (6)	0.446 (3)	0.039 (10)*
H1D	0.791 (4)	0.560 (5)	0.509 (3)	0.024 (8)*
H1B	0.558 (4)	0.754 (4)	0.436 (2)	0.018 (7)*
H1E	0.925 (4)	0.717 (4)	0.541 (3)	0.020 (8)*
H1C	0.733 (4)	0.747 (5)	0.356 (3)	0.027 (9)*
H2A	0.650 (5)	0.967 (5)	0.659 (3)	0.026 (9)*
H2B	0.880 (5)	0.945 (5)	0.718 (3)	0.030 (10)*
H2C	0.724 (5)	0.895 (5)	0.791 (3)	0.034 (9)*
H3A	0.622 (5)	0.651 (5)	0.654 (3)	0.023 (8)*
H4A	0.863 (4)	0.446 (4)	0.701 (3)	0.017 (7)*
H4B	0.996 (4)	0.626 (4)	0.757 (3)	0.013 (7)*
H6	0.980 (4)	0.725 (4)	0.965 (3)	0.017 (7)*
H7	0.900 (4)	0.680 (4)	1.164 (3)	0.021 (7)*
H8	0.681 (5)	0.457 (5)	1.193 (3)	0.027 (9)*
H9	0.521 (4)	0.278 (7)	1.025 (3)	0.030 (7)*
H10	0.611 (4)	0.337 (4)	0.827 (3)	0.017 (8)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0193 (3)	0.0208 (3)	0.0275 (3)	−0.0001 (3)	0.0077 (2)	0.0022 (3)
N1	0.0186 (11)	0.0200 (12)	0.0139 (10)	−0.0016 (9)	0.0064 (8)	0.0003 (9)
C1	0.0263 (12)	0.0248 (12)	0.0166 (11)	−0.0002 (17)	0.0055 (9)	0.0004 (15)
C2	0.0345 (17)	0.0268 (15)	0.0167 (14)	0.0038 (13)	0.0082 (12)	−0.0019 (11)
C3	0.0191 (13)	0.0265 (14)	0.0114 (12)	−0.0008 (11)	0.0052 (10)	0.0006 (11)
C4	0.0268 (14)	0.0282 (16)	0.0172 (13)	0.0038 (12)	0.0076 (11)	0.0011 (11)
C5	0.0193 (12)	0.0226 (13)	0.0192 (13)	0.0032 (10)	0.0049 (10)	0.0024 (10)
C6	0.0222 (13)	0.0260 (14)	0.0205 (13)	−0.0036 (12)	0.0041 (10)	0.0017 (11)
C7	0.0266 (14)	0.0293 (15)	0.0184 (13)	−0.0006 (11)	0.0016 (11)	−0.0043 (11)
C8	0.0280 (14)	0.0352 (16)	0.0172 (13)	0.0045 (12)	0.0094 (11)	0.0061 (11)
C9	0.0267 (15)	0.0294 (16)	0.0292 (15)	−0.0050 (12)	0.0070 (12)	0.0057 (12)
C10	0.0254 (14)	0.0270 (14)	0.0222 (13)	−0.0025 (11)	0.0034 (11)	−0.0017 (11)

Geometric parameters (Å, º)

N1—C1	1.485 (4)	C4—H4A	1.00 (3)
N1—C3	1.510 (3)	C4—H4B	1.00 (3)
N1—H1D	0.93 (3)	C5—C10	1.388 (4)
N1—H1E	0.90 (3)	C5—C6	1.395 (4)
C1—H1A	0.91 (4)	C6—C7	1.386 (4)
C1—H1B	0.97 (3)	C6—H6	0.90 (3)
C1—H1C	0.99 (3)	C7—C8	1.392 (4)
C2—C3	1.518 (4)	C7—H7	0.95 (3)
C2—H2A	1.00 (3)	C8—C9	1.384 (4)
C2—H2B	0.99 (4)	C8—H8	0.90 (3)
C2—H2C	0.94 (3)	C9—C10	1.393 (4)
C3—C4	1.536 (4)	C9—H9	1.05 (4)
C3—H3A	0.89 (3)	C10—H10	0.96 (3)
C4—C5	1.515 (4)
C1—N1—C3	116.4 (2)	C5—C4—C3	113.4 (2)
C1—N1—H1D	104 (2)	C5—C4—H4A	111.2 (18)
C3—N1—H1D	109 (2)	C3—C4—H4A	104.2 (17)
C1—N1—H1E	108.9 (19)	C5—C4—H4B	109.2 (17)
C3—N1—H1E	108.5 (19)	C3—C4—H4B	103.6 (16)
H1D—N1—H1E	110 (3)	H4A—C4—H4B	115 (2)
N1—C1—H1A	109 (2)	C10—C5—C6	118.7 (2)
N1—C1—H1B	107.8 (17)	C10—C5—C4	120.5 (3)
H1A—C1—H1B	116 (3)	C6—C5—C4	120.8 (2)
N1—C1—H1C	106.5 (18)	C7—C6—C5	120.5 (3)
H1A—C1—H1C	108 (3)	C7—C6—H6	120.9 (19)
H1B—C1—H1C	110 (2)	C5—C6—H6	118.5 (19)
C3—C2—H2A	110 (2)	C6—C7—C8	120.5 (3)
C3—C2—H2B	114 (2)	C6—C7—H7	119.6 (19)
H2A—C2—H2B	116 (3)	C8—C7—H7	119.8 (19)
C3—C2—H2C	108 (2)	C9—C8—C7	119.3 (3)
H2A—C2—H2C	106 (3)	C9—C8—H8	122 (2)
H2B—C2—H2C	101 (3)	C7—C8—H8	119 (2)
N1—C3—C2	109.9 (2)	C8—C9—C10	120.2 (3)
N1—C3—C4	106.2 (2)	C8—C9—H9	120.9 (16)
C2—C3—C4	113.9 (3)	C10—C9—H9	118.3 (17)
N1—C3—H3A	104 (2)	C5—C10—C9	120.8 (3)
C2—C3—H3A	113 (2)	C5—C10—H10	120.6 (17)
C4—C3—H3A	109 (2)	C9—C10—H10	118.4 (18)
C1—N1—C3—C2	−60.4 (3)	C4—C5—C6—C7	−178.7 (3)
C1—N1—C3—C4	176.0 (3)	C5—C6—C7—C8	0.1 (4)
N1—C3—C4—C5	−171.5 (2)	C6—C7—C8—C9	−1.1 (4)
C2—C3—C4—C5	67.5 (3)	C7—C8—C9—C10	1.2 (5)
C3—C4—C5—C10	82.9 (3)	C6—C5—C10—C9	−0.8 (4)
C3—C4—C5—C6	−97.6 (3)	C4—C5—C10—C9	178.8 (3)
C10—C5—C6—C7	0.8 (4)	C8—C9—C10—C5	−0.2 (5)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1D···Cl1^i	0.93 (4)	2.14 (4)	3.069 (2)	179 (4)
N1—H1E···Cl1^ii	0.90 (3)	2.22 (3)	3.116 (2)	176 (3)

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