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The side chains of L-alanyl-L-me­thionine hemihydrate, C8H16N2O3S·0.5H2O, form hydro­phobic columns within a three-dimensional hydrogen-bond network that includes extended polymers of cocrystallized water mol­ecules and C[alpha]-H...S interactions.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270103025782/sk1679sup1.cif
Contains datablocks I, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270103025782/sk1679Isup2.hkl
Contains datablock I

CCDC reference: 229123

Comment top

The crystal structure of L-Val-L-Ala (VA; Görbitz & Gundersen, 1996) was the first example of nanotube formation by such a small molecule. Subsequently, the reteroanalogue L-Ala-L-Val (Görbitz, 2002) and a series of other dipeptides with L-Ala, L-Val and L-Ile residues (Görbitz, 2003a) were found to form structures very similar to VA, differing only in the way that side chains partly fill the channels along the hexagonal axes, which translates directly to pore size.

To investigate whether crystallization in the VA class is compatible with dipeptides incorporating unbranched side chains (apart from the methyl group of L-Ala), crystallization and structure determination have been carried out for L-Met-L-Ala (MA) and L-Ala-L-Met (AM). The structure of MA is indeed closely related to the VA-class, but with seven molecules in the asymmetric unit (Görbitz, 2003b).

The asymmetric unit of AM, with two peptide molecules and one water molecule, is shown in Fig. 1. There are no signs of any kind of disorder. Bond lengths and bond angles are normal. Peptide molecule A has an elongated main-chain conformation, in which the carboxylate group is coplanar with the N atom of the peptide bond (Table 1). The L-Met side chain has an unusual gauche+,trans,trans conformation for χ1,χ2 and χ3 (N2A—C4A—C5A—C6A, C4A—C5A—C6A—S1A and C5A—C6A—S1A—C7A, respectively), which has been found previously only for D-Ala-L-Met (in the racemate; Stenkamp & Jensen, 1974; Guillot et al., 2001), for one of the two side chains in cyclo(L-Met-L-Met) (Valle et al., 1990) and for N-formyl-L-Met (Chen & Parthasarathy, 1977).

The main chain of peptide molecule B differs from A mainly in the carboxylate orientation defined by N2B—C4B—C8B—O2B [−57.8 (2)°]. The side-chain gauche- rotamer for χ1 (N2B—C4B—C5B—C6B) and the trans rotamer for χ3 (C5B—C6B—S1B—C7B) are both quite common, but the gauche+ orientation for χ2 (C4B—C5B—C6B—S1B) is very rare, and the gauche-,gauche+,trans combination for χ1,χ2 and χ3 yields a conformation that has not been observed previously for amino acids or peptides in the Cambridge Structural Database (CSD; Allen & Motherwell, 2002).

The packing diagram in Fig. 2 shows that even though some features are shared, like the aggregation of side chains into hydrophobic columns, AM is clearly not a member of the VA class. As was also evident from the P212121 space group, AM lacks hexagonal symmetry, and furthermore, the open channels at the center of each hydrophobic column are missing. In the VA class, these channels are either empty or filled non-stoichiometrically with solvent molecules that can be removed by drying with complete retention of the peptide scaffold (Görbitz & Gundersen, 1996; Görbitz, 2002). The cocrystallized solvent water molecules of AM are located close to the twofold screw axes parallel to the short 5.0809 (2) Å a axis; they form an integral part of the hydrogen-bond network and cannot be removed by drying without destroying the crystal. Hydrogen bonds between water molecules give rise to polymers along the a axis that are surrounded by peptide B molecules, as seen in Fig. 3. Similar columns, with carboxylate groups as acceptors for water H atoms rather than peptide carbonyl groups, have been found for L-Asp-Gly·H2O (Eggleston et al., 1981), for L-Arg-L-Asp·2H2O (Ramakrishnan & Viswamitra, 1988) and twice in the 1:1 complex L-His-L-Ser:Gly-L-Glu·6H2O (Suresh & Vijayan, 1985). L-Pro-Gly (Narasimhan & Chacko, 1982) and L-Pro-Val (Narasimhan et al., 1982) have polymers in which water molecules do not accept amino H atoms.

It was no surprise to find that the structure of AM is completely different from the monoclinic structure of D,L-Ala-L,D-Met (Stenkamp & Jensen, 1974; Guillot et al., 2001), the difference being due to the different directions in which side chains are disposed relative to the main chain for L—L and D,L—L,D diastereomers (Görbitz & Etter, 1992).

The hydrogen-bond geometry is detailed in Table 2. A l l amino H atoms of molecule A are donated to molecule B carboxylate groups and vice verca (including a three-center interaction for H2B; Table 2), except for atom H1B, which is accepted by the water molecule. Neighboring molecules of type A or type B are connected by hydrogen bonds, with the >N—H peptide bond as the donor, and by a number of weak interactions with Cα—H donors (including C4B—H41B···S1B; Fig. 3). A search of the CSD revealed that C—H···S(L-Met) contacts are surprisingly ubiquitous, with H···S distances starting at 2.85 Å. The most common donor is, however, not Cα—H, as in AM, but the terminal methyl group of another L-Met side chain.

In summary, the hydrogen-bond network in AM incorporates two peptide molecules in the asymmetric unit, both with unusual L-Met side-chain conformations, together with a solvent water molecule that forms extended hydrogen-bonded polymers along the shortest crystallographic axis.

Experimental top

The title compound was obtained from BACHEM and used as received. Crystals were grown by slow diffusion of acetonitrile into an aqueous solution (30 µl) containing the peptide (approximately 1 mg).

Refinement top

Data were collected by measuring three sets of exposures (with the detector set at 2θ = 29°; crystal-to-detector distance = 5.00 cm). Coordinates for water H atoms, which were found in an electron density map, were refined; other H atoms were placed geometrically and treated in the refinement with constraints. Free rotation of amine and methyl groups was permitted. Uiso values for H atoms were set to 1.2Ueq of the carrier atom, or 1.5Ueq for water, methyl and amine groups. The Flack (1983) parameter [−0.04 (8)] confirmed the known absolute structure; Friedel pairs were not merged in the final refinements.

Computing details top

Data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Bruker, 2000); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Figures top
[Figure 1] Fig. 1. : The asymmetric unit of L-Ala-L-Met, with peptide molecules A and B and a solvent water molecule. Displacement ellipsoids are shown at the 50% probability level and H atoms are shown as spheres of arbitrary size.
[Figure 2] Fig. 2. : The molecular packing and unit cell viewed along the a axis. Molecules in the asymmetric unit are identified by the suffixes A, B and W.
[Figure 3] Fig. 3. : A stereoview of the chains of water molecules, related by twofold screw symetry, along the a axis. Peptide B molecules surround the column. H atoms not involved in hydrogen bonds have been omitted for clarity. For peptide A molecules, only line drawings of the carboxylate groups are included.
L-Alanyl-L-methionine hemihydrate top
Crystal data top
C8H16N2O3S·0.5H2OF(000) = 984
Mr = 229.31Dx = 1.365 Mg m3
Orthorhombic, P212121Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2abCell parameters from 5401 reflections
a = 5.0809 (2) Åθ = 1.7–27.1°
b = 17.9228 (9) ŵ = 0.28 mm1
c = 24.5005 (11) ÅT = 105 K
V = 2231.11 (17) Å3Needle, colourless
Z = 80.58 × 0.05 × 0.03 mm
Data collection top
Siemens SMART CCD
diffractometer
4661 independent reflections
Radiation source: fine-focus sealed tube3741 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.099
Detector resolution: 8.3 pixels mm-1θmax = 27.1°, θmin = 1.7°
Sets of exposures each taken over 0.3° ω rotation scansh = 66
Absorption correction: multi-scan
SADABS (Sheldrick, 1996)
k = 2121
Tmin = 0.829, Tmax = 0.992l = 3131
13921 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)] = 0.040H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.090 w = 1/[σ2(Fo2) + (0.0356P)2]
where P = (Fo2 + 2Fc2)/3
S = 0.99(Δ/σ)max = 0.001
4661 reflectionsΔρmax = 0.29 e Å3
290 parametersΔρmin = 0.35 e Å3
0 restraintsAbsolute structure: Flack (1983)
Primary atom site location: structure-invariant direct methodsAbsolute structure parameter: 0.04 (8)
Crystal data top
C8H16N2O3S·0.5H2OV = 2231.11 (17) Å3
Mr = 229.31Z = 8
Orthorhombic, P212121Mo Kα radiation
a = 5.0809 (2) ŵ = 0.28 mm1
b = 17.9228 (9) ÅT = 105 K
c = 24.5005 (11) Å0.58 × 0.05 × 0.03 mm
Data collection top
Siemens SMART CCD
diffractometer
4661 independent reflections
Absorption correction: multi-scan
SADABS (Sheldrick, 1996)
3741 reflections with I > 2σ(I)
Tmin = 0.829, Tmax = 0.992Rint = 0.099
13921 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.040H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.090Δρmax = 0.29 e Å3
S = 0.99Δρmin = 0.35 e Å3
4661 reflectionsAbsolute structure: Flack (1983)
290 parametersAbsolute structure parameter: 0.04 (8)
0 restraints
Special details top

Refinement. Refinement of F2 against ALL reflections.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
S1A0.00812 (16)0.42636 (4)0.76208 (3)0.02919 (18)
O1A0.2719 (4)0.69891 (10)0.65014 (6)0.0191 (4)
O2A0.4030 (4)0.68803 (12)0.78347 (6)0.0304 (5)
O3A0.1017 (4)0.64020 (9)0.83967 (6)0.0250 (4)
N1A0.0406 (4)0.72992 (10)0.55620 (7)0.0147 (5)
H1A0.0150.77030.53560.022*
H2A0.2090.72750.56620.022*
H3A0.0010.68920.53710.022*
N2A0.1111 (5)0.67829 (11)0.69541 (7)0.0165 (5)
H4A0.2710.678660.69340.020*
C1A0.1286 (6)0.73448 (13)0.60562 (8)0.0156 (5)
H11A0.2890.70440.59990.019*
C2A0.2054 (6)0.81481 (14)0.61705 (9)0.0247 (6)
H21A0.3000.83490.58590.037*
H22A0.3180.81670.64910.037*
H23A0.0480.84420.62350.037*
C3A0.0304 (5)0.70142 (13)0.65273 (8)0.0141 (5)
C4A0.0143 (6)0.65213 (13)0.74612 (8)0.0181 (5)
H41A0.1760.68560.75400.022*
C5A0.1071 (5)0.57157 (14)0.74186 (9)0.0196 (5)
H51A0.2320.56720.71000.023*
H52A0.2080.55850.77600.023*
C6A0.1149 (6)0.51502 (14)0.73445 (10)0.0223 (6)
H61A0.2700.53170.75310.027*
H62A0.1560.50980.69650.027*
C7A0.2883 (6)0.36853 (17)0.74804 (12)0.0369 (8)
H71A0.2560.31890.76120.055*
H72A0.4400.38860.76610.055*
H73A0.3190.36710.70940.055*
C8A0.1842 (6)0.66180 (15)0.79313 (9)0.0210 (6)
S1B0.59102 (16)0.59987 (4)1.08894 (3)0.03015 (19)
O1B0.9833 (4)0.60955 (9)0.96639 (6)0.0170 (4)
O2B0.9721 (4)0.34854 (9)1.01264 (6)0.0167 (4)
O3B1.3731 (3)0.39718 (9)1.00395 (6)0.0209 (4)
N1B0.6177 (5)0.64273 (11)0.89371 (7)0.0195 (5)
H1B0.6260.68270.91750.029*
H2B0.4800.64970.86950.029*
H3B0.7740.63930.87460.029*
N2B0.8080 (4)0.49850 (11)0.99211 (7)0.0144 (4)
H4B0.6800.46850.98830.017*
C1B0.5739 (5)0.57253 (13)0.92526 (9)0.0160 (5)
H11B0.4210.57840.94670.019*
C2B0.5298 (6)0.50791 (13)0.88594 (9)0.0223 (6)
H21B0.3900.51940.86240.033*
H22B0.4890.46470.90580.033*
H23B0.6830.49990.86540.033*
C3B0.8082 (5)0.56245 (13)0.96325 (8)0.0126 (5)
C4B1.0208 (6)0.47859 (13)1.02985 (8)0.0146 (5)
H41B1.1630.51621.02690.018*
C5B0.9229 (6)0.47606 (13)1.08968 (9)0.0210 (6)
H51B0.7580.44761.09100.025*
H52B1.0530.44921.11180.025*
C6B0.8759 (6)0.55269 (14)1.11528 (9)0.0208 (6)
H61B1.0260.58301.10910.025*
H62B0.8560.54691.15360.025*
C7B0.6229 (7)0.68536 (15)1.12659 (10)0.0375 (8)
H71B0.4780.71391.12130.056*
H72B0.7670.71051.11490.056*
H73B0.6400.67491.16270.056*
C8B1.1306 (5)0.40232 (13)1.01375 (8)0.0137 (5)
O1W1.1342 (5)0.73326 (11)1.02722 (7)0.0274 (5)
H1W1.277 (7)0.7356 (19)1.0126 (13)0.041*
H2W1.097 (7)0.6961 (17)1.0185 (12)0.041*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
S1A0.0327 (4)0.0212 (4)0.0337 (3)0.0013 (4)0.0087 (3)0.0074 (3)
O1A0.0184 (11)0.0238 (10)0.0150 (8)0.0002 (9)0.0003 (7)0.0033 (7)
O2A0.0210 (11)0.0481 (14)0.0221 (9)0.0003 (11)0.0032 (9)0.0079 (8)
O3A0.0389 (12)0.0223 (10)0.0137 (8)0.0070 (10)0.0032 (8)0.0020 (7)
N1A0.0192 (13)0.0126 (10)0.0123 (8)0.0007 (9)0.0001 (8)0.0002 (7)
N2A0.0152 (11)0.0202 (12)0.0142 (9)0.0010 (10)0.0008 (9)0.0031 (7)
C1A0.0180 (14)0.0157 (14)0.0132 (11)0.0012 (12)0.0005 (10)0.0009 (8)
C2A0.0365 (17)0.0203 (15)0.0173 (12)0.0084 (13)0.0050 (12)0.0009 (10)
C3A0.0185 (15)0.0121 (12)0.0116 (10)0.0001 (12)0.0008 (10)0.0015 (8)
C4A0.0205 (14)0.0218 (14)0.0120 (10)0.0016 (12)0.0020 (10)0.0015 (9)
C5A0.0223 (14)0.0222 (14)0.0142 (10)0.0026 (13)0.0017 (11)0.0024 (9)
C6A0.0277 (15)0.0169 (14)0.0224 (12)0.0025 (13)0.0020 (12)0.0026 (9)
C7A0.0339 (19)0.0259 (17)0.0510 (18)0.0056 (15)0.0010 (15)0.0081 (13)
C8A0.0271 (18)0.0189 (15)0.0170 (12)0.0111 (13)0.0029 (11)0.0033 (9)
S1B0.0330 (4)0.0281 (4)0.0294 (3)0.0123 (3)0.0062 (3)0.0128 (3)
O1B0.0204 (10)0.0126 (9)0.0179 (8)0.0042 (9)0.0029 (7)0.0018 (6)
O2B0.0183 (10)0.0125 (9)0.0191 (8)0.0020 (8)0.0015 (7)0.0016 (6)
O3B0.0173 (10)0.0153 (9)0.0301 (9)0.0001 (8)0.0034 (8)0.0038 (7)
N1B0.0313 (13)0.0108 (11)0.0163 (9)0.0038 (11)0.0100 (9)0.0005 (7)
N2B0.0170 (11)0.0113 (11)0.0150 (9)0.0028 (9)0.0020 (8)0.0014 (7)
C1B0.0196 (14)0.0122 (13)0.0161 (10)0.0007 (11)0.0009 (10)0.0011 (8)
C2B0.0330 (17)0.0135 (13)0.0203 (11)0.0019 (13)0.0092 (12)0.0002 (9)
C3B0.0145 (13)0.0121 (13)0.0112 (10)0.0029 (11)0.0039 (9)0.0035 (8)
C4B0.0193 (14)0.0088 (12)0.0158 (11)0.0008 (12)0.0011 (10)0.0007 (8)
C5B0.0334 (17)0.0154 (13)0.0143 (10)0.0059 (12)0.0033 (11)0.0003 (9)
C6B0.0264 (16)0.0183 (14)0.0176 (11)0.0019 (13)0.0019 (11)0.0058 (9)
C7B0.060 (2)0.0214 (16)0.0316 (14)0.0095 (17)0.0069 (16)0.0077 (11)
C8B0.0186 (14)0.0158 (13)0.0067 (9)0.0006 (12)0.0021 (9)0.0025 (8)
O1W0.0311 (13)0.0187 (11)0.0324 (10)0.0056 (10)0.0036 (9)0.0092 (8)
Geometric parameters (Å, º) top
S1A—C7A1.794 (3)S1B—C6B1.796 (3)
S1A—C6A1.810 (3)O1B—C3B1.229 (3)
O1A—C3A1.229 (3)O2B—C8B1.256 (3)
O2A—C8A1.230 (3)O3B—C8B1.259 (3)
O3A—C8A1.275 (3)N1B—C1B1.493 (3)
N1A—C1A1.487 (3)N1B—H1B0.9230
N1A—H1A0.8920N1B—H2B0.9230
N1A—H2A0.8920N1B—H3B0.9230
N1A—H3A0.8920N2B—C3B1.347 (3)
N2A—C3A1.335 (3)N2B—C4B1.467 (3)
N2A—C4A1.473 (3)N2B—H4B0.8501
N2A—H4A0.8128C1B—C3B1.522 (3)
C1A—C2A1.518 (3)C1B—C2B1.523 (3)
C1A—C3A1.528 (3)C1B—H11B0.9427
C1A—H11A0.9870C2B—H21B0.9374
C2A—H21A0.9699C2B—H22B0.9374
C2A—H22A0.9699C2B—H23B0.9374
C2A—H23A0.9699C4B—C8B1.528 (3)
C4A—C5A1.523 (3)C4B—C5B1.549 (3)
C4A—C8A1.540 (3)C4B—H41B0.9884
C4A—H41A1.0369C5B—C6B1.529 (3)
C5A—C6A1.527 (4)C5B—H51B0.9803
C5A—H51A1.0100C5B—H52B0.9803
C5A—H52A1.0100C6B—H61B0.9493
C6A—H61A0.9569C6B—H62B0.9493
C6A—H62A0.9569C7B—H71B0.9072
C7A—H71A0.9603C7B—H72B0.9072
C7A—H72A0.9603C7B—H73B0.9072
C7A—H73A0.9603O1W—H1W0.81 (3)
S1B—C7B1.796 (3)O1W—H2W0.72 (3)
C7A—S1A—C6A101.40 (14)C1B—N1B—H1B109.5
C1A—N1A—H1A109.5C1B—N1B—H2B109.5
C1A—N1A—H2A109.5H1B—N1B—H2B109.5
H1A—N1A—H2A109.5C1B—N1B—H3B109.5
C1A—N1A—H3A109.5H1B—N1B—H3B109.5
H1A—N1A—H3A109.5H2B—N1B—H3B109.5
H2A—N1A—H3A109.5C3B—N2B—C4B122.5 (2)
C3A—N2A—C4A121.8 (2)C3B—N2B—H4B118.7
C3A—N2A—H4A119.1C4B—N2B—H4B118.7
C4A—N2A—H4A119.1N1B—C1B—C3B107.5 (2)
N1A—C1A—C2A110.56 (19)N1B—C1B—C2B109.58 (17)
N1A—C1A—C3A106.7 (2)C3B—C1B—C2B114.3 (2)
C2A—C1A—C3A111.37 (19)N1B—C1B—H11B108.5
N1A—C1A—H11A109.4C3B—C1B—H11B108.5
C2A—C1A—H11A109.4C2B—C1B—H11B108.5
C3A—C1A—H11A109.4C1B—C2B—H21B109.5
C1A—C2A—H21A109.5C1B—C2B—H22B109.5
C1A—C2A—H22A109.5H21B—C2B—H22B109.5
H21A—C2A—H22A109.5C1B—C2B—H23B109.5
C1A—C2A—H23A109.5H21B—C2B—H23B109.5
H21A—C2A—H23A109.5H22B—C2B—H23B109.5
H22A—C2A—H23A109.5O1B—C3B—N2B123.5 (2)
O1A—C3A—N2A124.5 (2)O1B—C3B—C1B121.5 (2)
O1A—C3A—C1A120.2 (2)N2B—C3B—C1B115.0 (2)
N2A—C3A—C1A115.3 (2)N2B—C4B—C8B108.91 (18)
N2A—C4A—C5A112.21 (18)N2B—C4B—C5B111.5 (2)
N2A—C4A—C8A108.2 (2)C8B—C4B—C5B109.60 (18)
C5A—C4A—C8A111.14 (19)N2B—C4B—H41B108.9
N2A—C4A—H41A108.4C8B—C4B—H41B108.9
C5A—C4A—H41A108.4C5B—C4B—H41B108.9
C8A—C4A—H41A108.4C6B—C5B—C4B114.3 (2)
C4A—C5A—C6A114.1 (2)C6B—C5B—H51B108.7
C4A—C5A—H51A108.7C4B—C5B—H51B108.7
C6A—C5A—H51A108.7C6B—C5B—H52B108.7
C4A—C5A—H52A108.7C4B—C5B—H52B108.7
C6A—C5A—H52A108.7H51B—C5B—H52B107.6
H51A—C5A—H52A107.6C5B—C6B—S1B113.66 (19)
C5A—C6A—S1A108.47 (18)C5B—C6B—H61B108.8
C5A—C6A—H61A110.0S1B—C6B—H61B108.8
S1A—C6A—H61A110.0C5B—C6B—H62B108.8
C5A—C6A—H62A110.0S1B—C6B—H62B108.8
S1A—C6A—H62A110.0H61B—C6B—H62B107.7
H61A—C6A—H62A108.4S1B—C7B—H71B109.5
S1A—C7A—H71A109.5S1B—C7B—H72B109.5
S1A—C7A—H72A109.5H71B—C7B—H72B109.5
H71A—C7A—H72A109.5S1B—C7B—H73B109.5
S1A—C7A—H73A109.5H71B—C7B—H73B109.5
H71A—C7A—H73A109.5H72B—C7B—H73B109.5
H72A—C7A—H73A109.5O2B—C8B—O3B124.5 (2)
O2A—C8A—O3A125.8 (2)O2B—C8B—C4B117.3 (2)
O2A—C8A—C4A119.4 (2)O3B—C8B—C4B118.2 (2)
O3A—C8A—C4A114.8 (2)H1W—O1W—H2W99 (4)
C7B—S1B—C6B98.30 (14)
N1A—C1A—C3A—N2A159.11 (19)N1B—C1B—C3B—N2B175.58 (19)
C1A—C3A—N2A—C4A173.8 (2)C1B—C3B—N2B—C4B178.65 (19)
C3A—N2A—C4A—C8A156.2 (2)C3B—N2B—C4B—C8B124.4 (2)
N2A—C4A—C8A—O2A0.2 (3)N2B—C4B—C8B—O2B57.8 (2)
N2A—C4A—C5A—C6A64.5 (3)N2B—C4B—C5B—C6B74.5 (3)
C4A—C5A—C6A—S1A152.83 (15)C4B—C5B—C6B—S1B71.8 (3)
C5A—C6A—S1A—C7A178.66 (17)C5B—C6B—S1B—C7B177.3 (2)
C4A—N2A—C3A—O1A4.7 (4)C4B—N2B—C3B—O1B0.8 (3)
N1A—C1A—C3A—O1A22.4 (3)N1B—C1B—C3B—O1B3.8 (3)
C2A—C1A—C3A—O1A98.4 (3)C2B—C1B—C3B—O1B125.7 (2)
C2A—C1A—C3A—N2A80.1 (3)C2B—C1B—C3B—N2B53.7 (3)
C3A—N2A—C4A—C5A80.9 (3)C3B—N2B—C4B—C5B114.5 (2)
C8A—C4A—C5A—C6A56.7 (3)C8B—C4B—C5B—C6B164.8 (2)
C5A—C4A—C8A—O2A123.8 (3)C5B—C4B—C8B—O2B64.4 (3)
N2A—C4A—C8A—O3A179.1 (2)N2B—C4B—C8B—O3B124.0 (2)
C5A—C4A—C8A—O3A55.5 (3)C5B—C4B—C8B—O3B113.7 (2)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1A—H1A···O2Bi0.891.852.736 (2)175
N1A—H2A···O2Bii0.892.322.815 (3)115
N1A—H3A···O3Biii0.891.862.748 (2)172
N2A—H4A···O1Aiv0.812.583.346 (3)158
C1A—H11A···O1Aiv0.992.553.300 (3)132
C4A—H41A···O2Av1.042.263.165 (4)145
N1B—H1B···O1Wvi0.922.032.950 (3)177
N1B—H2B···O3A0.922.072.937 (3)157
N1B—H2B···O2A0.922.253.024 (2)141
N1B—H3B···O3Aiv0.921.872.793 (3)175
N2B—H4B···O3Bv0.852.052.875 (3)163
C1B—H11B···O1Bv0.942.343.234 (3)157
C4B—H41B···S1Biv0.993.053.901 (3)145
O1W—H1W···O1Wvii0.81 (3)2.14 (3)2.931 (2)167 (3)
O1W—H2W···O1B0.72 (3)2.09 (3)2.779 (3)159 (3)
Symmetry codes: (i) x+1, y+1/2, z+3/2; (ii) x+1/2, y+1, z1/2; (iii) x+3/2, y+1, z1/2; (iv) x+1, y, z; (v) x1, y, z; (vi) x1/2, y+3/2, z+2; (vii) x+1/2, y+3/2, z+2.

Experimental details

Crystal data
Chemical formulaC8H16N2O3S·0.5H2O
Mr229.31
Crystal system, space groupOrthorhombic, P212121
Temperature (K)105
a, b, c (Å)5.0809 (2), 17.9228 (9), 24.5005 (11)
V3)2231.11 (17)
Z8
Radiation typeMo Kα
µ (mm1)0.28
Crystal size (mm)0.58 × 0.05 × 0.03
Data collection
DiffractometerSiemens SMART CCD
diffractometer
Absorption correctionMulti-scan
SADABS (Sheldrick, 1996)
Tmin, Tmax0.829, 0.992
No. of measured, independent and
observed [I > 2σ(I)] reflections
13921, 4661, 3741
Rint0.099
(sin θ/λ)max1)0.641
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.040, 0.090, 0.99
No. of reflections4661
No. of parameters290
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.29, 0.35
Absolute structureFlack (1983)
Absolute structure parameter0.04 (8)

Computer programs: SMART (Bruker, 1998), SAINT (Bruker, 2001), SAINT, SHELXTL (Bruker, 2000), SHELXTL.

Selected geometric parameters (Å, º) top
S1A—C7A1.794 (3)S1B—C7B1.796 (3)
S1A—C6A1.810 (3)S1B—C6B1.796 (3)
O1A—C3A1.229 (3)O1B—C3B1.229 (3)
O2A—C8A1.230 (3)O2B—C8B1.256 (3)
O3A—C8A1.275 (3)O3B—C8B1.259 (3)
N1A—C1A1.487 (3)N1B—C1B1.493 (3)
N2A—C3A1.335 (3)N2B—C3B1.347 (3)
C7A—S1A—C6A101.40 (14)H1W—O1W—H2W99 (4)
C7B—S1B—C6B98.30 (14)
N1A—C1A—C3A—N2A159.11 (19)N1B—C1B—C3B—N2B175.58 (19)
C1A—C3A—N2A—C4A173.8 (2)C1B—C3B—N2B—C4B178.65 (19)
C3A—N2A—C4A—C8A156.2 (2)C3B—N2B—C4B—C8B124.4 (2)
N2A—C4A—C8A—O2A0.2 (3)N2B—C4B—C8B—O2B57.8 (2)
N2A—C4A—C5A—C6A64.5 (3)N2B—C4B—C5B—C6B74.5 (3)
C4A—C5A—C6A—S1A152.83 (15)C4B—C5B—C6B—S1B71.8 (3)
C5A—C6A—S1A—C7A178.66 (17)C5B—C6B—S1B—C7B177.3 (2)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1A—H1A···O2Bi0.891.852.736 (2)175
N1A—H2A···O2Bii0.892.322.815 (3)115
N1A—H3A···O3Biii0.891.862.748 (2)172
N2A—H4A···O1Aiv0.812.583.346 (3)158
C1A—H11A···O1Aiv0.992.553.300 (3)132
C4A—H41A···O2Av1.042.263.165 (4)145
N1B—H1B···O1Wvi0.922.032.950 (3)177
N1B—H2B···O3A0.922.072.937 (3)157
N1B—H2B···O2A0.922.253.024 (2)141
N1B—H3B···O3Aiv0.921.872.793 (3)175
N2B—H4B···O3Bv0.852.052.875 (3)163
C1B—H11B···O1Bv0.942.343.234 (3)157
C4B—H41B···S1Biv0.993.053.901 (3)145
O1W—H1W···O1Wvii0.81 (3)2.14 (3)2.931 (2)167 (3)
O1W—H2W···O1B0.72 (3)2.09 (3)2.779 (3)159 (3)
Symmetry codes: (i) x+1, y+1/2, z+3/2; (ii) x+1/2, y+1, z1/2; (iii) x+3/2, y+1, z1/2; (iv) x+1, y, z; (v) x1, y, z; (vi) x1/2, y+3/2, z+2; (vii) x+1/2, y+3/2, z+2.
 

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