organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2056-9890
Volume 68| Part 5| May 2012| Page o1416

(R)-(3-Carb­­oxy-2-hy­dr­oxy­prop­yl)tri­methyl­aza­nium chloride

aDepartment of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia, and bChemistry Department, Faculty of Science, King Abdulaziz University, PO Box 80203 Jeddah, Saudi Arabia
*Correspondence e-mail: seikweng@um.edu.my

(Received 8 April 2012; accepted 12 April 2012; online 18 April 2012)

In the title salt (common name L-carnitine hydro­chloride), C7H16NO3+·Cl, the organic cation features a carb­oxy­lic part (–CO2H) having unambigous single- and double-bonds [1.336 (2), 1.211 (2) Å]. There is a large N—C—C bond angle [115.9 (1)°] for the C atom connected to the bulky trimethyl­amino substituent. In the crystal, the acid H atom forms a hydrogen bond to the chloride anion, whereas the hydroxyl H atom forms a longer hydrogen bond to the anion, generating a helical chain running along [001].

Related literature

For racemic carnitine hydro­chloride, see: Tomita et al. (1974[Tomita, K.-I., Urabe, K., Kim, Y. B. & Fujiwara, T. (1974). Bull. Chem. Soc. Jpn, 47, 1988-1993.]); Yunuskhodzhaev et al. (1991[Yunuskhodzhaev, A. N., Shamuratov, E. B., Batsanov, A. S. & Talipov, S. A. (1991). Chem. Nat. Compd. (Engl. Transl.), 27, 743-744.]). For R-carnitine, see: Gandour et al. (1985[Gandour, R. D., Colucci, W. J. & Fronczek, F. R. (1985). Bioorg. Chem. 13, 197-208.]).

[Scheme 1]

Experimental

Crystal data
  • C7H16NO3+·Cl

  • Mr = 197.66

  • Orthorhombic, P 21 21 21

  • a = 6.3043 (3) Å

  • b = 11.5256 (7) Å

  • c = 13.4905 (8) Å

  • V = 980.23 (10) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.36 mm−1

  • T = 100 K

  • 0.40 × 0.30 × 0.20 mm

Data collection
  • Agilent Technologies SuperNova Dual diffractometer with Atlas detector

  • Absorption correction: multi-scan CrysAlis PRO (Agilent, 2012[Agilent (2012). CrysAlis PRO. Agilent Technologies, Yarnton, England.]) Tmin = 0.869, Tmax = 0.931

  • 6682 measured reflections

  • 2251 independent reflections

  • 2191 reflections with I > 2σ(I)

  • Rint = 0.033

Refinement
  • R[F2 > 2σ(F2)] = 0.027

  • wR(F2) = 0.072

  • S = 1.09

  • 2251 reflections

  • 117 parameters

  • 2 restraints

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.28 e Å−3

  • Δρmin = −0.19 e Å−3

  • Absolute structure: Flack (1983[Flack, H. D. (1983). Acta Cryst. A39, 876-881.]), 926 Friedel pairs

  • Flack parameter: 0.01 (5)

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
O1—H1⋯Cl1 0.85 (1) 2.18 (1) 3.022 (1) 176 (2)
O3—H3⋯Cl1i 0.83 (1) 2.51 (2) 3.209 (1) 142 (2)
Symmetry code: (i) [-x+{\script{1\over 2}}, -y, z-{\script{1\over 2}}].

Data collection: CrysAlis PRO (Agilent, 2012[Agilent (2012). CrysAlis PRO. Agilent Technologies, Yarnton, England.]); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: X-SEED (Barbour, 2001[Barbour, L. J. (2001). J. Supramol. Chem. 1, 189-191.]); software used to prepare material for publication: publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]).

Supporting information


Comment top

A model for the binding of L-carnitine to the carnitine acetyltransferase enzyme has been proposed on the basis of the crystal structure of L-carnitine (Gandour et al., 1985). L-Carnitine, a zwitterionic compound that is biosynthesized from lysine and methinonine, is the vitamin BT; it is also avaliable commerically as the hydrochloride salt. The crystal structure of racemic carnitine hydrochloride has been previously reported (Tomita et al., 1974; Yunuskhodzhaev et al., 1991). In the crystal structure of L-carnitine hydrochloride (Scheme I), the carboxyl –CO2 part carries the acid hydrogen (Fig. 1). This part has unambigous single- and double-bonds [1.336 (2), 1.211 (2) Å]. The three-atom CcarboxylC–Ctrimethylamino unit shows a large angle [115.9 (1) °] for the atom connected to the bulky trimethylamino substituent. The acid hydrogen forms a hydrogen bond to the chloride anion (Table 1). Oddly, the hydroxy group does not engage in any hydrogen bonding interactions.

Related literature top

For racemic carnitine hydrochloride, see: Tomita et al. (1974); Yunuskhodzhaev et al. (1991). For R-carnitine, see: Gandour et al. (1985).

Experimental top

L-Carnithine hydrochloride as supplied by Sigma Chemical Company consists of colorless prismatic crystals, and was used without purification.

Refinement top

Carbon-bound H-atoms were placed in calculated positions [C–H 0.98 to 1.00 Å, Uiso(H) 1.2 to 1.5Ueq(C)] and were included in the refinement in the riding model approximation.

The hydroxy and acid H-atoms were located in a difference Fourier map, and were refined with a distance restraint of O–H 0.84±0.01 Å; their temperature factors were refined.

Computing details top

Data collection: CrysAlis PRO (Agilent, 2012); cell refinement: CrysAlis PRO (Agilent, 2012); data reduction: CrysAlis PRO (Agilent, 2012); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures top
[Figure 1] Fig. 1. Thermal ellipsoid plot (Barbour, 2001) of C7H16NO3+.Cl- at the 70% probability level; hydrogen atoms are drawn as spheres of arbitrary radius.
(R)-(3-Carboxy-2-hydroxypropyl)trimethylazanium chloride top
Crystal data top
C7H16NO3+·ClF(000) = 424
Mr = 197.66Dx = 1.339 Mg m3
Orthorhombic, P212121Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2abCell parameters from 3837 reflections
a = 6.3043 (3) Åθ = 2.3–27.5°
b = 11.5256 (7) ŵ = 0.36 mm1
c = 13.4905 (8) ÅT = 100 K
V = 980.23 (10) Å3Prism, colorless
Z = 40.40 × 0.30 × 0.20 mm
Data collection top
Agilent Technologies SuperNova Dual
diffractometer with Atlas detector
2251 independent reflections
Radiation source: SuperNova (Mo) X-ray Source2191 reflections with I > 2σ(I)
Mirror monochromatorRint = 0.033
Detector resolution: 10.4041 pixels mm-1θmax = 27.5°, θmin = 2.3°
ω scanh = 88
Absorption correction: multi-scan
CrysAlis PRO (Agilent, 2012)
k = 1215
Tmin = 0.869, Tmax = 0.931l = 1617
6682 measured reflections
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.027H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.072 w = 1/[σ2(Fo2) + (0.0381P)2 + 0.129P]
where P = (Fo2 + 2Fc2)/3
S = 1.09(Δ/σ)max = 0.001
2251 reflectionsΔρmax = 0.28 e Å3
117 parametersΔρmin = 0.19 e Å3
2 restraintsAbsolute structure: Flack (1983), 926 Friedel pairs
Primary atom site location: structure-invariant direct methodsAbsolute structure parameter: 0.01 (5)
Crystal data top
C7H16NO3+·ClV = 980.23 (10) Å3
Mr = 197.66Z = 4
Orthorhombic, P212121Mo Kα radiation
a = 6.3043 (3) ŵ = 0.36 mm1
b = 11.5256 (7) ÅT = 100 K
c = 13.4905 (8) Å0.40 × 0.30 × 0.20 mm
Data collection top
Agilent Technologies SuperNova Dual
diffractometer with Atlas detector
2251 independent reflections
Absorption correction: multi-scan
CrysAlis PRO (Agilent, 2012)
2191 reflections with I > 2σ(I)
Tmin = 0.869, Tmax = 0.931Rint = 0.033
6682 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.027H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.072Δρmax = 0.28 e Å3
S = 1.09Δρmin = 0.19 e Å3
2251 reflectionsAbsolute structure: Flack (1983), 926 Friedel pairs
117 parametersAbsolute structure parameter: 0.01 (5)
2 restraints
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Cl10.16829 (6)0.02923 (3)1.11989 (3)0.01599 (10)
O10.11377 (16)0.20168 (9)1.01683 (8)0.0153 (2)
H10.123 (3)0.1372 (11)1.0468 (14)0.032 (6)*
O20.09374 (17)0.09692 (9)0.87751 (9)0.0164 (2)
O30.03544 (17)0.23605 (10)0.69856 (8)0.0146 (2)
H30.066 (4)0.1658 (10)0.6948 (18)0.047 (7)*
N10.38932 (18)0.40990 (10)0.62406 (10)0.0107 (2)
C10.1083 (2)0.19013 (12)0.91830 (11)0.0113 (3)
C20.1258 (2)0.30406 (12)0.86490 (11)0.0120 (3)
H2A0.22870.35420.90010.014*
H2B0.01380.34350.86590.014*
C30.1976 (2)0.28843 (12)0.75711 (10)0.0103 (3)
H3A0.32790.23900.75520.012*
C40.2485 (2)0.40787 (13)0.71538 (11)0.0109 (3)
H4A0.11320.44700.69890.013*
H4B0.31820.45400.76800.013*
C50.6024 (2)0.35642 (13)0.64467 (12)0.0151 (3)
H5A0.68870.35820.58430.023*
H5B0.58340.27580.66610.023*
H5C0.67410.40030.69710.023*
C60.2902 (3)0.35091 (15)0.53684 (11)0.0198 (4)
H6A0.38670.35520.48000.030*
H6B0.15630.38950.52030.030*
H6C0.26280.26940.55310.030*
C70.4241 (3)0.53502 (13)0.59814 (12)0.0187 (3)
H7A0.51260.54020.53860.028*
H7B0.49540.57420.65330.028*
H7C0.28710.57230.58560.028*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cl10.02265 (18)0.01262 (16)0.01271 (18)0.00108 (14)0.00145 (14)0.00228 (14)
O10.0237 (6)0.0118 (5)0.0104 (5)0.0005 (5)0.0008 (4)0.0021 (4)
O20.0218 (5)0.0124 (5)0.0150 (5)0.0037 (4)0.0005 (5)0.0013 (4)
O30.0161 (5)0.0142 (5)0.0135 (6)0.0021 (5)0.0049 (4)0.0009 (4)
N10.0103 (6)0.0117 (5)0.0102 (6)0.0002 (5)0.0010 (5)0.0014 (5)
C10.0073 (6)0.0149 (7)0.0118 (7)0.0007 (6)0.0006 (5)0.0008 (6)
C20.0126 (7)0.0121 (6)0.0112 (7)0.0013 (6)0.0002 (5)0.0003 (5)
C30.0095 (6)0.0109 (6)0.0106 (7)0.0008 (5)0.0011 (5)0.0004 (6)
C40.0114 (6)0.0115 (6)0.0099 (7)0.0010 (6)0.0024 (5)0.0004 (6)
C50.0118 (7)0.0180 (7)0.0155 (8)0.0044 (6)0.0011 (6)0.0008 (6)
C60.0210 (8)0.0305 (9)0.0081 (8)0.0080 (7)0.0022 (6)0.0002 (6)
C70.0167 (7)0.0134 (7)0.0260 (9)0.0003 (7)0.0062 (6)0.0078 (7)
Geometric parameters (Å, º) top
O1—C11.3363 (18)C3—C41.521 (2)
O1—H10.848 (9)C3—H3A1.0000
O2—C11.2105 (18)C4—H4A0.9900
O3—C31.4262 (18)C4—H4B0.9900
O3—H30.833 (9)C5—H5A0.9800
N1—C61.4956 (19)C5—H5B0.9800
N1—C71.5000 (19)C5—H5C0.9800
N1—C51.5042 (18)C6—H6A0.9800
N1—C41.5188 (18)C6—H6B0.9800
C1—C21.5018 (19)C6—H6C0.9800
C2—C31.534 (2)C7—H7A0.9800
C2—H2A0.9900C7—H7B0.9800
C2—H2B0.9900C7—H7C0.9800
C1—O1—H1112.9 (14)N1—C4—H4A108.3
C3—O3—H3106.3 (18)C3—C4—H4A108.3
C6—N1—C7108.35 (12)N1—C4—H4B108.3
C6—N1—C5109.41 (12)C3—C4—H4B108.3
C7—N1—C5107.84 (12)H4A—C4—H4B107.4
C6—N1—C4112.76 (11)N1—C5—H5A109.5
C7—N1—C4106.82 (11)N1—C5—H5B109.5
C5—N1—C4111.47 (11)H5A—C5—H5B109.5
O2—C1—O1122.86 (14)N1—C5—H5C109.5
O2—C1—C2124.29 (14)H5A—C5—H5C109.5
O1—C1—C2112.83 (12)H5B—C5—H5C109.5
C1—C2—C3111.95 (11)N1—C6—H6A109.5
C1—C2—H2A109.2N1—C6—H6B109.5
C3—C2—H2A109.2H6A—C6—H6B109.5
C1—C2—H2B109.2N1—C6—H6C109.5
C3—C2—H2B109.2H6A—C6—H6C109.5
H2A—C2—H2B107.9H6B—C6—H6C109.5
O3—C3—C4109.21 (11)N1—C7—H7A109.5
O3—C3—C2111.29 (11)N1—C7—H7B109.5
C4—C3—C2107.87 (11)H7A—C7—H7B109.5
O3—C3—H3A109.5N1—C7—H7C109.5
C4—C3—H3A109.5H7A—C7—H7C109.5
C2—C3—H3A109.5H7B—C7—H7C109.5
N1—C4—C3115.93 (12)
O2—C1—C2—C319.23 (19)C7—N1—C4—C3178.16 (13)
O1—C1—C2—C3159.77 (12)C5—N1—C4—C360.59 (16)
C1—C2—C3—O370.19 (14)O3—C3—C4—N178.63 (15)
C1—C2—C3—C4170.02 (12)C2—C3—C4—N1160.28 (11)
C6—N1—C4—C362.93 (16)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1···Cl10.85 (1)2.18 (1)3.022 (1)176 (2)
O3—H3···Cl1i0.83 (1)2.51 (2)3.209 (1)142 (2)
Symmetry code: (i) x+1/2, y, z1/2.

Experimental details

Crystal data
Chemical formulaC7H16NO3+·Cl
Mr197.66
Crystal system, space groupOrthorhombic, P212121
Temperature (K)100
a, b, c (Å)6.3043 (3), 11.5256 (7), 13.4905 (8)
V3)980.23 (10)
Z4
Radiation typeMo Kα
µ (mm1)0.36
Crystal size (mm)0.40 × 0.30 × 0.20
Data collection
DiffractometerAgilent Technologies SuperNova Dual
diffractometer with Atlas detector
Absorption correctionMulti-scan
CrysAlis PRO (Agilent, 2012)
Tmin, Tmax0.869, 0.931
No. of measured, independent and
observed [I > 2σ(I)] reflections
6682, 2251, 2191
Rint0.033
(sin θ/λ)max1)0.650
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.027, 0.072, 1.09
No. of reflections2251
No. of parameters117
No. of restraints2
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.28, 0.19
Absolute structureFlack (1983), 926 Friedel pairs
Absolute structure parameter0.01 (5)

Computer programs: CrysAlis PRO (Agilent, 2012), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), X-SEED (Barbour, 2001), publCIF (Westrip, 2010).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1···Cl10.85 (1)2.18 (1)3.022 (1)176 (2)
O3—H3···Cl1i0.83 (1)2.51 (2)3.209 (1)142 (2)
Symmetry code: (i) x+1/2, y, z1/2.
 

Acknowledgements

I thank the Ministry of Higher Education of Malaysia (grant No. UM·C/HIR/MOHE/SC/12) for supporting this study.

References

First citationAgilent (2012). CrysAlis PRO. Agilent Technologies, Yarnton, England.  Google Scholar
First citationBarbour, L. J. (2001). J. Supramol. Chem. 1, 189–191.  CrossRef CAS Google Scholar
First citationFlack, H. D. (1983). Acta Cryst. A39, 876–881.  CrossRef CAS Web of Science IUCr Journals Google Scholar
First citationGandour, R. D., Colucci, W. J. & Fronczek, F. R. (1985). Bioorg. Chem. 13, 197–208.  CSD CrossRef CAS Web of Science Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationTomita, K.-I., Urabe, K., Kim, Y. B. & Fujiwara, T. (1974). Bull. Chem. Soc. Jpn, 47, 1988–1993.  CrossRef CAS Web of Science Google Scholar
First citationWestrip, S. P. (2010). J. Appl. Cryst. 43, 920–925.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationYunuskhodzhaev, A. N., Shamuratov, E. B., Batsanov, A. S. & Talipov, S. A. (1991). Chem. Nat. Compd. (Engl. Transl.), 27, 743–744.  CrossRef Google Scholar

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Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 68| Part 5| May 2012| Page o1416
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