DL-Me­thioninium tri­chloro­acetate at 123 K

In the title compound, C₅H₁₂NO₂S⁺·C₂Cl₃O₂⁻, the me­thionine mol­ecule exists as a cation with a protonated amino group and an uncharged carboxyl­ic acid group, while the tri­chloro­acetic acid mol­ecule exists as an anion. The assembly of meth­ioninium and tri­chloro­acetate ions, leading to layers parallel to the ab plane, is characterized by a strong O—H...O-type hydrogen bond between the carboxyl­ic acid and carboxyl­ate groups of the respective ions. A head-to-tail hydrogen bond is also observed between the me­thioninium cations, in addition to S...Cl, Cl...Cl and Cl...O short contacts.

Key indicators

• Single-crystal X-ray study
• T = 123 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.029
• wR factor = 0.092
• Data-to-parameter ratio = 20.7

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry

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Computing details

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

DL-methiononium trichloroacetate at 123 K

Crystal data

C5H12NO2S^+·C2Cl3O2^−	Z = 2
Mr = 312.60	F(000) = 320
Triclinic, P1	Dx = 1.578 Mg m^−3 Dm = 1.58 Mg m^−3 Dm measured by floatation in a mixture of xylene and bromoform
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 6.1359 (12) Å	Cell parameters from 1024 reflections
b = 8.9746 (18) Å	θ = 1.7–27.5°
c = 12.731 (3) Å	µ = 0.85 mm^−1
α = 70.54 (3)°	T = 123 K
β = 85.95 (3)°	Prism, colourless
γ = 85.08 (3)°	0.5 × 0.3 × 0.2 mm
V = 657.9 (3) Å^3

Data collection

Bruker SMART diffractometer	2999 independent reflections
Radiation source: fine-focus sealed tube	2628 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.019
Detector resolution: 8 pixels mm^-1	θmax = 27.5°, θmin = 1.7°
ω scans	h = −7→7
Absorption correction: multi-scan (SADABS; Bruker, 1998)	k = −11→11
Tmin = 0.743, Tmax = 0.843	l = −14→16
7442 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)] = 0.029	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.092	H-atom parameters constrained
S = 1.17	w = 1/[σ^2(Fo^2) + (0.0385P)^2 + 0.4522P] where P = (Fo^2 + 2Fc^2)/3
2999 reflections	(Δ/σ)max < 0.001
145 parameters	Δρmax = 0.39 e Å^−3
0 restraints	Δρmin = −0.41 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	0.28221 (9)	0.36780 (6)	0.40975 (4)	0.03244 (14)
Cl1	1.04062 (9)	0.74883 (6)	0.31890 (4)	0.03306 (13)
Cl2	1.02444 (11)	1.04591 (7)	0.35800 (4)	0.04089 (16)
Cl3	0.72973 (8)	1.00052 (7)	0.20404 (5)	0.04054 (15)
N1	0.5430 (3)	0.70793 (18)	0.05645 (13)	0.0215 (3)
H1A	0.4798	0.7889	0.0754	0.032*
H1B	0.4407	0.6467	0.0508	0.032*
H1C	0.6166	0.7445	−0.0088	0.032*
O1	0.9458 (2)	0.39321 (17)	0.17917 (12)	0.0275 (3)
H1	1.0022	0.3211	0.1583	0.041*
O2	0.7537 (2)	0.45138 (16)	0.02522 (12)	0.0252 (3)
O3	1.1650 (2)	1.17240 (17)	0.11985 (13)	0.0330 (3)
O4	1.2738 (3)	0.93047 (19)	0.11946 (14)	0.0400 (4)
C1	0.8018 (3)	0.4764 (2)	0.10851 (15)	0.0202 (3)
C2	0.6973 (3)	0.6134 (2)	0.14354 (15)	0.0203 (3)
H2	0.8130	0.6811	0.1455	0.024*
C3	0.5836 (3)	0.5559 (2)	0.26014 (15)	0.0233 (4)
H3A	0.6939	0.5079	0.3146	0.028*
H3B	0.5129	0.6466	0.2770	0.028*
C4	0.4132 (3)	0.4363 (3)	0.27201 (17)	0.0284 (4)
H4A	0.4835	0.3458	0.2545	0.034*
H4B	0.3020	0.4845	0.2181	0.034*
C5	0.5048 (5)	0.2502 (4)	0.4873 (2)	0.0549 (7)
H5A	0.4575	0.2050	0.5641	0.082*
H5B	0.6239	0.3156	0.4816	0.082*
H5C	0.5524	0.1669	0.4576	0.082*
C6	1.1631 (3)	1.0240 (2)	0.15541 (15)	0.0223 (4)
C7	0.9984 (3)	0.9557 (2)	0.25646 (15)	0.0225 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0326 (3)	0.0329 (3)	0.0279 (3)	−0.0051 (2)	0.0084 (2)	−0.0059 (2)
Cl1	0.0390 (3)	0.0213 (2)	0.0343 (3)	−0.00138 (18)	−0.0036 (2)	−0.00284 (18)
Cl2	0.0672 (4)	0.0349 (3)	0.0223 (2)	0.0050 (2)	−0.0010 (2)	−0.0141 (2)
Cl3	0.0209 (2)	0.0428 (3)	0.0470 (3)	−0.0003 (2)	−0.0038 (2)	−0.0003 (2)
N1	0.0219 (7)	0.0193 (7)	0.0232 (8)	0.0019 (6)	0.0026 (6)	−0.0083 (6)
O1	0.0263 (7)	0.0270 (7)	0.0290 (7)	0.0086 (5)	−0.0034 (5)	−0.0109 (6)
O2	0.0225 (7)	0.0272 (7)	0.0298 (7)	0.0012 (5)	0.0001 (5)	−0.0157 (6)
O3	0.0332 (8)	0.0227 (7)	0.0372 (8)	0.0016 (6)	0.0138 (6)	−0.0059 (6)
O4	0.0450 (9)	0.0328 (8)	0.0401 (9)	0.0115 (7)	0.0124 (7)	−0.0153 (7)
C1	0.0165 (8)	0.0192 (8)	0.0245 (9)	−0.0019 (6)	0.0038 (6)	−0.0073 (7)
C2	0.0199 (8)	0.0195 (8)	0.0226 (9)	−0.0008 (6)	0.0009 (6)	−0.0089 (7)
C3	0.0241 (9)	0.0248 (9)	0.0222 (9)	−0.0017 (7)	0.0027 (7)	−0.0101 (7)
C4	0.0281 (10)	0.0331 (10)	0.0241 (9)	−0.0075 (8)	0.0026 (7)	−0.0093 (8)
C5	0.0535 (16)	0.0614 (17)	0.0328 (13)	0.0020 (13)	−0.0009 (11)	0.0053 (12)
C6	0.0200 (8)	0.0239 (9)	0.0219 (8)	0.0031 (7)	0.0008 (7)	−0.0077 (7)
C7	0.0219 (9)	0.0216 (8)	0.0227 (9)	0.0024 (7)	−0.0008 (7)	−0.0068 (7)

Geometric parameters (Å, º)

S1—C5	1.789 (3)	O4—C6	1.220 (2)
S1—C4	1.807 (2)	C1—C2	1.521 (2)
Cl1—C7	1.7634 (19)	C2—C3	1.537 (2)
Cl2—C7	1.761 (2)	C2—H2	0.98
Cl3—C7	1.786 (2)	C3—C4	1.527 (3)
N1—C2	1.493 (2)	C3—H3A	0.97
N1—H1A	0.89	C3—H3B	0.97
N1—H1B	0.89	C4—H4A	0.97
N1—H1C	0.89	C4—H4B	0.97
O1—C1	1.304 (2)	C5—H5A	0.96
O1—H1	0.82	C5—H5B	0.96
O2—C1	1.215 (2)	C5—H5C	0.96
O3—C6	1.257 (2)	C6—C7	1.565 (3)
C5—S1—C4	100.28 (12)	H3A—C3—H3B	107.7
C2—N1—H1A	109.5	C3—C4—S1	113.45 (14)
C2—N1—H1B	109.5	C3—C4—H4A	108.9
H1A—N1—H1B	109.5	S1—C4—H4A	108.9
C2—N1—H1C	109.5	C3—C4—H4B	108.9
H1A—N1—H1C	109.5	S1—C4—H4B	108.9
H1B—N1—H1C	109.5	H4A—C4—H4B	107.7
C1—O1—H1	109.5	S1—C5—H5A	109.5
O2—C1—O1	126.14 (17)	S1—C5—H5B	109.5
O2—C1—C2	123.04 (17)	H5A—C5—H5B	109.5
O1—C1—C2	110.82 (16)	S1—C5—H5C	109.5
N1—C2—C1	107.99 (14)	H5A—C5—H5C	109.5
N1—C2—C3	112.22 (15)	H5B—C5—H5C	109.5
C1—C2—C3	111.87 (15)	O4—C6—O3	127.07 (18)
N1—C2—H2	108.2	O4—C6—C7	117.98 (17)
C1—C2—H2	108.2	O3—C6—C7	114.94 (16)
C3—C2—H2	108.2	C6—C7—Cl2	109.80 (13)
C4—C3—C2	113.75 (15)	C6—C7—Cl1	112.47 (13)
C4—C3—H3A	108.8	Cl2—C7—Cl1	108.67 (10)
C2—C3—H3A	108.8	C6—C7—Cl3	107.04 (12)
C4—C3—H3B	108.8	Cl2—C7—Cl3	109.97 (10)
C2—C3—H3B	108.8	Cl1—C7—Cl3	108.86 (11)
O2—C1—C2—N1	−2.7 (2)	C5—S1—C4—C3	−70.20 (19)
O1—C1—C2—N1	177.21 (14)	O4—C6—C7—Cl2	132.81 (18)
O2—C1—C2—C3	121.28 (19)	O3—C6—C7—Cl2	−47.4 (2)
O1—C1—C2—C3	−58.8 (2)	O4—C6—C7—Cl1	11.7 (2)
N1—C2—C3—C4	66.1 (2)	O3—C6—C7—Cl1	−168.56 (14)
C1—C2—C3—C4	−55.4 (2)	O4—C6—C7—Cl3	−107.84 (19)
C2—C3—C4—S1	179.46 (13)	O3—C6—C7—Cl3	71.92 (19)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O3^i	0.82	1.78	2.589 (2)	171
N1—H1A···O4^ii	0.89	1.90	2.771 (2)	164
N1—H1B···O2^iii	0.89	2.01	2.854 (2)	157
N1—H1C···O3^iv	0.89	1.89	2.749 (2)	163

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