β-DL-Methio­nine at 105 K

In the title compound, C₅H₁₁NO₂S, the conformation of the terminal meth­yl C atom with respect to the β-C atom is trans. The crystal structure is stabilized by a network of characteristic head-to-tail DL1 and DL2 sequences.

Key indicators

• Single-crystal X-ray study
• T = 105 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.041
• wR factor = 0.100
• Data-to-parameter ratio = 17.5

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT128_ALERT_4_C Non-standard setting of Space group C2/c    ....    I2/a

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

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

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Computing details

Data collection: SMART (Bruker 1999); cell refinement: SMART; data reduction: SAINT (Bruker 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXL97.

DL-methionine

Crystal data

C5H11NO2S	F(000) = 640
Mr = 149.21	Dx = 1.367 Mg m^−3 Dm = 1.36 Mg m^−3 Dm measured by flotation in a mixture of xylene and bromoform
Monoclinic, I2/a	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -I 2ya	Cell parameters from 1012 reflections
a = 9.877 (2) Å	θ = 2.6–26.1°
b = 4.6915 (10) Å	µ = 0.38 mm^−1
c = 32.603 (6) Å	T = 105 K
β = 106.25 (1)°	Block, colourless
V = 1450.4 (5) Å^3	0.32 × 0.24 × 0.22 mm
Z = 8

Data collection

Bruker SMART CCD area-detector diffractometer	1436 independent reflections
Radiation source: fine-focus sealed tube	1373 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.023
Detector resolution: 8 pixels mm^-1	θmax = 26.3°, θmin = 2.6°
ω scans	h = −12→12
Absorption correction: multi-scan (SADABS; Bruker, 1998)	k = −5→5
Tmin = 0.85, Tmax = 0.92	l = −40→40
6469 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.041	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.100	H-atom parameters constrained
S = 1.23	w = 1/[σ^2(Fo^2) + (0.028P)^2 + 3.0328P] where P = (Fo^2 + 2Fc^2)/3
1436 reflections	(Δ/σ)max = 0.001
82 parameters	Δρmax = 0.36 e Å^−3
0 restraints	Δρmin = −0.34 e Å^−3

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
S1	0.39654 (6)	0.15678 (13)	0.442915 (17)	0.0328 (2)
O1	−0.14522 (14)	0.2025 (3)	0.31402 (5)	0.0239 (3)
O2	−0.01845 (14)	−0.0810 (3)	0.28409 (4)	0.0216 (3)
N1	0.19303 (17)	0.3001 (3)	0.29735 (5)	0.0193 (4)
H1A	0.1478	0.3730	0.2720	0.029*
H1B	0.2169	0.1203	0.2941	0.029*
H1C	0.2704	0.4018	0.3088	0.029*
C1	−0.0329 (2)	0.1302 (4)	0.30560 (6)	0.0184 (4)
C2	0.09968 (19)	0.3086 (4)	0.32589 (6)	0.0181 (4)
H2	0.0725	0.5061	0.3293	0.022*
C3	0.1764 (2)	0.1830 (4)	0.36982 (6)	0.0214 (4)
H3A	0.1161	0.2031	0.3885	0.026*
H3B	0.1909	−0.0192	0.3665	0.026*
C4	0.3196 (2)	0.3214 (4)	0.39142 (6)	0.0246 (4)
H4A	0.3070	0.5239	0.3951	0.030*
H4B	0.3823	0.2980	0.3735	0.030*
C5	0.5659 (2)	0.3325 (6)	0.45831 (7)	0.0349 (5)
H5A	0.6196	0.2639	0.4858	0.052*
H5B	0.5524	0.5345	0.4597	0.052*
H5C	0.6158	0.2924	0.4376	0.052*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0350 (3)	0.0336 (3)	0.0230 (3)	−0.0067 (2)	−0.0031 (2)	0.0074 (2)
O1	0.0223 (7)	0.0168 (7)	0.0334 (8)	0.0011 (5)	0.0090 (6)	−0.0004 (6)
O2	0.0254 (7)	0.0155 (7)	0.0220 (7)	−0.0011 (5)	0.0037 (5)	−0.0028 (5)
N1	0.0212 (8)	0.0164 (8)	0.0191 (8)	−0.0009 (6)	0.0036 (6)	0.0007 (6)
C1	0.0213 (9)	0.0136 (9)	0.0182 (9)	0.0007 (7)	0.0020 (7)	0.0034 (7)
C2	0.0211 (9)	0.0125 (8)	0.0208 (9)	0.0007 (7)	0.0058 (7)	−0.0008 (7)
C3	0.0248 (10)	0.0188 (9)	0.0195 (9)	−0.0006 (8)	0.0045 (8)	−0.0002 (7)
C4	0.0276 (10)	0.0214 (10)	0.0213 (9)	−0.0014 (8)	0.0010 (8)	0.0015 (8)
C5	0.0307 (11)	0.0415 (14)	0.0268 (11)	−0.0024 (10)	−0.0011 (9)	0.0012 (10)

Geometric parameters (Å, º)

S1—C5	1.806 (2)	C2—H2	0.9800
S1—C4	1.811 (2)	C3—C4	1.536 (3)
O1—C1	1.261 (2)	C3—H3A	0.9700
O2—C1	1.245 (2)	C3—H3B	0.9700
N1—C2	1.483 (2)	C4—H4A	0.9700
N1—H1A	0.8900	C4—H4B	0.9700
N1—H1B	0.8900	C5—H5A	0.9600
N1—H1C	0.8900	C5—H5B	0.9600
C1—C2	1.539 (3)	C5—H5C	0.9600
C2—C3	1.538 (3)
C5—S1—C4	100.30 (10)	C4—C3—H3A	108.6
C2—N1—H1A	109.5	C2—C3—H3A	108.6
C2—N1—H1B	109.5	C4—C3—H3B	108.6
H1A—N1—H1B	109.5	C2—C3—H3B	108.6
C2—N1—H1C	109.5	H3A—C3—H3B	107.6
H1A—N1—H1C	109.5	C3—C4—S1	109.79 (14)
H1B—N1—H1C	109.5	C3—C4—H4A	109.7
O2—C1—O1	125.64 (18)	S1—C4—H4A	109.7
O2—C1—C2	117.20 (16)	C3—C4—H4B	109.7
O1—C1—C2	117.06 (17)	S1—C4—H4B	109.7
N1—C2—C3	110.07 (15)	H4A—C4—H4B	108.2
N1—C2—C1	108.62 (15)	S1—C5—H5A	109.5
C3—C2—C1	109.29 (15)	S1—C5—H5B	109.5
N1—C2—H2	109.6	H5A—C5—H5B	109.5
C3—C2—H2	109.6	S1—C5—H5C	109.5
C1—C2—H2	109.6	H5A—C5—H5C	109.5
C4—C3—C2	114.56 (16)	H5B—C5—H5C	109.5
O2—C1—C2—N1	32.6 (2)	N1—C2—C3—C4	54.4 (2)
O1—C1—C2—N1	−150.95 (16)	C1—C2—C3—C4	173.58 (16)
O2—C1—C2—C3	−87.6 (2)	C2—C3—C4—S1	179.23 (13)
O1—C1—C2—C3	88.9 (2)	C5—S1—C4—C3	174.99 (15)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O2^i	0.89	1.93	2.788 (2)	162
N1—H1B···O1^ii	0.89	2.02	2.814 (2)	148
N1—H1C···O1^iii	0.89	2.02	2.794 (2)	144

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