Redetermined crystal structure of β-dl-me-thio-nine at 320 K.

The structure of β-dl-me-thio-nine, C5H11NO2S, in the space group C2/c, is here confirmed to be fully ordered all the way up to the phase transition at approximately 326 K, where displacive sliding of mol-ecular bilayers gives the disordered P21/c α form [data at 340 K; Görbitz (2014). Acta Cryst. E70, 341-343]. The geometry of hydrogen bonds in LD-LD hydrogen-bonding patterns [Görbitz et al. (2009). Acta Cryst. B65, 393-400] at the hydro-philic core of each mol-ecular bilayer are virtually unperturbed by the phase shift, but the C-C-S-C torsion angle of the side chain changes from trans at 320 K to gauche+ for the major conformation at 340 K.

Related literature

For previous investigations of dl-me­thio­nine (dl-Met), see: Mathieson (1952 ▸); Taniguchi et al. (1980 ▸); Alagar et al. (2005 ▸); Görbitz (2014 ▸); Görbitz et al. (2014 ▸). For a discussion of displacive phase transitions of amino acids with linear side chains and structures of quasiracemic complexes, see: Görbitz & Karen (2015 ▸). For the phase behaviour of the corresponding enanti­omeric substances, including l-Met and l-norvaline, see: Görbitz et al. (2015 ▸). For a discussion of hydrogen-bonding patterns in the crystal structures of hydrophobic amino acids, see: Görbitz et al. (2009 ▸).

Experimental

Crystal data

C5H11NO2S

M = 149.21

Monoclinic,

a = 31.774 (2) Å

b = 4.6969 (3) Å

c = 9.8939 (7) Å

β = 91.224 (2)°

V = 1476.20 (18) Å3

Z = 8

Mo Kα radiation

μ = 0.37 mm−1

T = 320 K

0.72 × 0.15 × 0.10 mm

Data collection

Bruker D8 Advance single-crystal CCD diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2014 ▸) T min = 0.924, T max = 1.000

10516 measured reflections

2060 independent reflections

1567 reflections with I > 2σ(I)

R int = 0.031

Refinement

R[F 2 > 2σ(F 2)] = 0.046

wR(F 2) = 0.116

S = 1.03

2060 reflections

92 parameters

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.34 e Å−3

Δρmin = −0.39 e Å−3

Data collection: APEX2 (Bruker, 2014 ▸); cell refinement: SAINT-Plus (Bruker, 2014 ▸); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS2014 (Sheldrick, 2008 ▸); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015 ▸); molecular graphics: Mercury (Macrae et al., 2008 ▸); software used to prepare material for publication: SHELXL2014.

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S2056989015008749/su5129sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989015008749/su5129Isup2.hkl

Click here for additional data file.

Supporting information file. DOI: 10.1107/S2056989015008749/su5129Isup3.cml

Click here for additional data file.

dl I a et al. et al. gauche trans trans l gauche trans gauche+ gaucsu5129.cif he trans gauche+ . . DOI: 10.1107/S2056989015008749/su5129fig1.tif

The mol­ecular structure of β-dl-me­thio­nine at 320 K, with atom labelling, flanked by the structures at 105 K (published with the alternative space group setting I2/a, Alagar et al., 2005; Görbitz, 2014) and 340 K (Görbitz et al., 2014). Thermal displacement ellipsoids are shown at the 50% probability level. Atoms of the minor side-chain conformation with occupancy 0.0491 (18) at 340 K (with H atoms omitted) are shown in a lighter tone. The side-chain conformation is gauche–, trans, trans (as defined by the N1—C2—C3—C4, C2—C3—C4—S1 and C3—C4—S1—C5 torsion angles of the l-enanti­omer shown) at 105 and 320 K, while the major and minor conformations at 340 K are gauche–, trans, gauche+ and gaucsu5129.cif he+, trans, gauche+, respectively.

CCDC reference: 1063335

Additional supporting information: crystallographic information; 3D view; checkCIF report

C5H11NO2S	F(000) = 640
Mr = 149.21	Dx = 1.343 Mg m−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 31.774 (2) Å	Cell parameters from 4136 reflections
b = 4.6969 (3) Å	θ = 2.6–29.5°
c = 9.8939 (7) Å	µ = 0.37 mm−1
β = 91.224 (2)°	T = 320 K
V = 1476.20 (18) Å3	Needle, colourless
Z = 8	0.72 × 0.15 × 0.10 mm

Bruker D8 Advance single-crystal CCD diffractometer	2060 independent reflections
Radiation source: fine-focus sealed tube	1567 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.031
Detector resolution: 8.3 pixels mm-1	θmax = 29.5°, θmin = 2.6°
Sets of exposures each taken over 0.5° ω rotation scans	h = −44→39
Absorption correction: multi-scan (SADABS; Bruker, 2014)	k = −6→6
Tmin = 0.924, Tmax = 1.000	l = −13→13
10516 measured reflections

Refinement on F2	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.046	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.116	w = 1/[σ2(Fo2) + (0.0458P)2 + 1.6546P] where P = (Fo2 + 2Fc2)/3
S = 1.03	(Δ/σ)max = 0.001
2060 reflections	Δρmax = 0.34 e Å−3
92 parameters	Δρmin = −0.39 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. Final R-factor is 0.0364 for a refinement based on 1300 reflections with 2 theta < 50 °.

	x	y	z	Uiso*/Ueq
S1	0.44096 (2)	0.65785 (16)	0.45693 (7)	0.0684 (2)
O1	0.28350 (4)	0.4246 (2)	0.19616 (11)	0.0316 (3)
N1	0.29732 (4)	0.7975 (3)	0.39652 (12)	0.0252 (3)
H1	0.2705 (6)	0.826 (4)	0.3685 (19)	0.038*
H2	0.2998 (6)	0.627 (5)	0.441 (2)	0.038*
H3	0.3042 (6)	0.926 (4)	0.461 (2)	0.038*
C1	0.30472 (4)	0.6339 (3)	0.16326 (14)	0.0225 (3)
C2	0.32477 (5)	0.8093 (3)	0.27735 (13)	0.0229 (3)
H21	0.3278	1.0073	0.2479	0.028*
O2	0.31323 (4)	0.7062 (3)	0.04532 (10)	0.0383 (3)
C3	0.36823 (5)	0.6847 (4)	0.31133 (16)	0.0318 (3)
H31	0.3651	0.4828	0.3293	0.038*
H32	0.3858	0.7044	0.2329	0.038*
C4	0.39054 (5)	0.8220 (4)	0.43157 (19)	0.0406 (4)
H41	0.3739	0.7986	0.5118	0.049*
H42	0.3940	1.0242	0.4153	0.049*
C5	0.45831 (8)	0.8257 (7)	0.6094 (3)	0.0750 (8)
H51	0.4861	0.7596	0.6334	0.113*
H52	0.4393	0.7799	0.6804	0.113*
H53	0.4589	1.0282	0.5965	0.113*

	U11	U22	U33	U12	U13	U23
S1	0.0405 (3)	0.0825 (5)	0.0809 (4)	0.0201 (3)	−0.0269 (3)	−0.0255 (4)
O1	0.0365 (6)	0.0287 (6)	0.0295 (6)	−0.0081 (5)	−0.0036 (4)	−0.0017 (4)
N1	0.0289 (6)	0.0278 (6)	0.0189 (6)	0.0044 (5)	−0.0031 (5)	−0.0035 (5)
C1	0.0270 (7)	0.0198 (6)	0.0204 (6)	0.0041 (5)	−0.0051 (5)	−0.0015 (5)
C2	0.0308 (7)	0.0192 (6)	0.0186 (6)	−0.0018 (5)	−0.0028 (5)	0.0008 (5)
O2	0.0657 (8)	0.0314 (6)	0.0176 (5)	−0.0024 (6)	−0.0001 (5)	0.0011 (4)
C3	0.0278 (7)	0.0356 (8)	0.0318 (8)	0.0003 (7)	−0.0033 (6)	−0.0050 (7)
C4	0.0336 (8)	0.0417 (10)	0.0458 (10)	0.0047 (7)	−0.0144 (7)	−0.0078 (8)
C5	0.0579 (14)	0.104 (2)	0.0620 (14)	0.0004 (14)	−0.0292 (12)	−0.0068 (15)

S1—C5	1.779 (2)	C2—H21	0.9800
S1—C4	1.7907 (17)	C3—C4	1.516 (2)
O1—C1	1.2398 (18)	C3—H31	0.9700
N1—C2	1.4825 (18)	C3—H32	0.9700
N1—H1	0.90 (2)	C4—H41	0.9700
N1—H2	0.92 (2)	C4—H42	0.9700
N1—H3	0.90 (2)	C5—H51	0.9600
C1—O2	1.2504 (18)	C5—H52	0.9600
C1—C2	1.5258 (19)	C5—H53	0.9600
C2—C3	1.530 (2)
C5—S1—C4	100.84 (11)	C4—C3—H31	108.6
C2—N1—H1	108.6 (12)	C2—C3—H31	108.6
C2—N1—H2	111.8 (12)	C4—C3—H32	108.6
H1—N1—H2	110.3 (17)	C2—C3—H32	108.6
C2—N1—H3	113.4 (12)	H31—C3—H32	107.6
H1—N1—H3	109.4 (17)	C3—C4—S1	109.19 (12)
H2—N1—H3	103.2 (16)	C3—C4—H41	109.8
O1—C1—O2	126.16 (13)	S1—C4—H41	109.8
O1—C1—C2	117.06 (12)	C3—C4—H42	109.8
O2—C1—C2	116.66 (13)	S1—C4—H42	109.8
N1—C2—C1	108.95 (12)	H41—C4—H42	108.3
N1—C2—C3	110.76 (11)	S1—C5—H51	109.5
C1—C2—C3	108.45 (12)	S1—C5—H52	109.5
N1—C2—H21	109.6	H51—C5—H52	109.5
C1—C2—H21	109.6	S1—C5—H53	109.5
C3—C2—H21	109.6	H51—C5—H53	109.5
C4—C3—C2	114.47 (13)	H52—C5—H53	109.5
O1—C1—C2—N1	−31.43 (17)	C2—C3—C4—S1	−179.16 (12)
O2—C1—C2—N1	152.41 (13)	C3—C4—S1—C5	−174.55 (16)
O1—C1—C2—C3	89.21 (16)	H1—N1—C2—C1	−44.4 (13)
O2—C1—C2—C3	−86.95 (16)	H2—N1—C2—C1	76.5 (13)
N1—C2—C3—C4	−55.52 (18)	H3—N1—C2—C1	−167.3 (14)
C1—C2—C3—C4	−175.03 (14)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1i	0.90 (2)	1.88 (2)	2.7732 (17)	173.7 (19)
N1—H2···O2ii	0.92 (2)	1.92 (2)	2.8264 (18)	171.0 (18)
N1—H3···O2iii	0.90 (2)	1.94 (2)	2.7973 (18)	159.2 (18)

Table 1

Hydrogen-bond geometry (, )

DHA	DH	HA	D A	DHA
N1H1O1i	0.90(2)	1.88(2)	2.7732(17)	173.7(19)
N1H2O2ii	0.92(2)	1.92(2)	2.8264(18)	171.0(18)
N1H3O2iii	0.90(2)	1.94(2)	2.7973(18)	159.2(18)

Symmetry codes: (i) ; (ii) ; (iii) .

Table 2

Selected torsion angles ()

Torsion angle	-DL-Met, 320K	-DL-Met, 340Ka	-DL-Met, 340Kb
N1C2C3C4	55.52(18)	59.3(4)	73(8)
C1C2C3C4	175.03 (14)	178.0(2)	78(5)
C2C3C4S1	179.16(12)	176.7(2)	178(5)
C3C4S1C5	174.55(16)	69.4(3)	60(3)

Notes: (a) major conformation, occupancy 0.9509(18) (Grbitz et al., 2014 ▸); (a) minor conformation, occupancy 0.0491(18).