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In the title compound, C7H11Cl2NO3·0.41H2O, the D and L forms are linked by N—H...O and C—H...O hydrogen bonds to form centrosymmetric dimers. These hydrogen bonds form rings of graph-set motif R22(14), R22(10) and R21(6). The dimers are linked together by O—H...O hydrogen bonds to form two-dimensional molecular networks.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536803013850/ci6227sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536803013850/ci6227Isup2.hkl
Contains datablock I

CCDC reference: 210250

Key indicators

  • Single-crystal X-ray study
  • T = 293 K
  • Mean [sigma](C-C) = 0.003 Å
  • Disorder in solvent or counterion
  • R factor = 0.040
  • wR factor = 0.095
  • Data-to-parameter ratio = 17.9

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


Yellow Alert Alert Level C:
PLAT_302 Alert C Anion/Solvent Disorder ......................... 41.00 Perc.
0 Alert Level A = Potentially serious problem
0 Alert Level B = Potential problem
1 Alert Level C = Please check

Comment top

Valine is an important amino acid and the structures of L-valine (Torii & Iitaka, 1970), DL-Valine (Mallikarjunan & Rao, 1969) L-valine hydrochloride (Ando et al., 1967), DL-valine hydrochloride (Blasio et al., 1977) and L-valine L-valinium perchlorate monohydrate (Pandiarajan et al., 2001) have been reported. The structures of the model peptides N-acetyl-D,L-valine (Carroll et al., 1990) and N-carboxy-L-valine anhydride (Kanazawa et al., 1984) have also been reported. We report here the structure of the title compound, (I), a valine derivative.

The C1—C2—N1—C3 torsion angle, which describes the planarity of the peptide unit, is 176.95 (17)°. The torsion angle ϕ1 (C4—C3—N1—C2) is −128.83 (19)°. The torsion angles around the C3—C4 and C3—C5 bonds (Fig.1 and Table 1) are comparable to those observed for DL-valine hydrochloride (Blasio et al., 1977). In the crystal structure, the enantiomers are linked by centrosymmetric N1—H1A···O3i and C1—H1···O3i hydrogen bonds to form dimers. In a dimer, the N—H···O and C—H···O hydrogen bonds form rings of graph-set motif (Etter, 1990) R22(10) and R22(14), respectively. In addition, the N—H···O and C—H···O hydrogen bonds together form a ring of graph-set motif R21(6) (Fig. 2). The dimers are linked together by O2—H2···O1ii hydrogen bonds to form two-dimensional molecular networks parallel to the bc plane. [Symmetry codes are given in Table 2.]

Experimental top

L-valine and dichloroacetic acid in equal molar ratio were mixed together, and kept at 443 K for 5 h. The resulting solution was kept at room temperature overnight to obtain the title compound. Single crystals suitable for an X-ray diffraction study were obtained by recrystallizing the title compound from 70% aqueous ethanol.

Refinement top

A solvent water O atom with partial occupancy was found in the crystal. The occupancy of this atom was initially refined and later fixed at 0.41(su?). This atom lies at a distance of 2.239 (5) Å from O2(1 − x, y − 1/2, 1/2 − z). The positional and isotropic displacement parameters of solvent water H atoms were refined [O—H = 0.84 (5) or 0.93 Å and Uiso(H) = 0.08 (2) or 0.034 (14) Å2]. All other H atoms were fixed geometrically and allowed to ride on their parent atoms, with SHELXTL (Bruker, 2000) defaults for the bond distances and isotropic displacement parameters.

Computing details top

Data collection: SMART (Bruker, 2000); cell refinement: SMART; data reduction: SAINT (Bruker, 2000); 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 molecular structure of (I), showing 50% probability displacement ellipsoids and the atom-numbering scheme.
[Figure 2] Fig. 2. A view of the hydrogen-bonded network parallel to the bc plane. Solvent water molecules with partial occupancy have been omitted.
2-(2,2-dichloroacetylamino)-3-methyl butyric acid hydrate (1/0.41) top
Crystal data top
C7H11Cl2NO3·0.41H2OF(000) = 488.4
Mr = 235.45Dx = 1.403 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 785 reflections
a = 9.298 (2) Åθ = 2.6–19.5°
b = 9.011 (1) ŵ = 0.57 mm1
c = 13.990 (2) ÅT = 293 K
β = 108.07 (1)°Prism, colorless
V = 1114.3 (3) Å30.28 × 0.15 × 0.15 mm
Z = 4
Data collection top
Bruker Smart Apex CCD area-detector diffactometer
diffractometer
2417 independent reflections
Radiation source: sealed tube1788 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.016
ϕ and ω scansθmax = 27.0°, θmin = 2.7°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 1111
Tmin = 0.90, Tmax = 0.91k = 1111
6265 measured reflectionsl = 1717
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.040Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.095H atoms treated by a mixture of independent and constrained refinement
S = 1.14 w = 1/[σ2(Fo2) + (0.0388P)2 + 0.1217P]
where P = (Fo2 + 2Fc2)/3
2417 reflections(Δ/σ)max < 0.001
135 parametersΔρmax = 0.30 e Å3
0 restraintsΔρmin = 0.16 e Å3
Crystal data top
C7H11Cl2NO3·0.41H2OV = 1114.3 (3) Å3
Mr = 235.45Z = 4
Monoclinic, P21/cMo Kα radiation
a = 9.298 (2) ŵ = 0.57 mm1
b = 9.011 (1) ÅT = 293 K
c = 13.990 (2) Å0.28 × 0.15 × 0.15 mm
β = 108.07 (1)°
Data collection top
Bruker Smart Apex CCD area-detector diffactometer
diffractometer
2417 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
1788 reflections with I > 2σ(I)
Tmin = 0.90, Tmax = 0.91Rint = 0.016
6265 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0400 restraints
wR(F2) = 0.095H atoms treated by a mixture of independent and constrained refinement
S = 1.14Δρmax = 0.30 e Å3
2417 reflectionsΔρmin = 0.16 e Å3
135 parameters
Special details top

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 (Å2) top
xyzUiso*/UeqOcc. (<1)
C11.0096 (3)0.4937 (2)0.23560 (15)0.0468 (5)
H11.03780.41040.28270.056*
C20.8755 (2)0.5754 (2)0.25229 (14)0.0371 (4)
C30.7364 (2)0.6161 (2)0.37047 (15)0.0418 (5)
H30.69740.69970.32500.050*
C40.8014 (2)0.6775 (2)0.47481 (14)0.0382 (4)
C50.6029 (3)0.5107 (3)0.36352 (18)0.0574 (6)
H50.52760.56700.38440.069*
C60.5291 (3)0.4636 (3)0.25586 (18)0.0610 (7)
H6A0.44600.39830.25230.091*
H6B0.60180.41300.23170.091*
H6C0.49260.54970.21510.091*
C70.6482 (3)0.3819 (3)0.43219 (19)0.0630 (7)
H7A0.56180.31950.42540.094*
H7B0.68690.41640.50030.094*
H7C0.72510.32630.41540.094*
Cl10.96075 (7)0.42561 (7)0.11181 (4)0.0600 (2)
Cl21.16245 (7)0.61549 (7)0.25804 (5)0.0675 (2)
N10.85305 (17)0.54462 (17)0.33871 (11)0.0348 (4)
H1A0.90990.47960.37760.042*
O10.80101 (17)0.66421 (17)0.19258 (11)0.0532 (4)
O20.70716 (17)0.76853 (17)0.49730 (11)0.0552 (4)
H20.73810.78800.55750.083*
O30.92209 (17)0.64560 (16)0.53092 (10)0.0496 (4)
O40.3307 (5)0.5128 (5)0.0274 (3)0.0485 (9)0.41
H4A0.237 (8)0.485 (7)0.032 (5)0.08 (2)*0.41
H4B0.313 (5)0.586 (6)0.012 (4)0.034 (14)*0.41
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0625 (14)0.0456 (12)0.0385 (12)0.0084 (10)0.0246 (11)0.0012 (9)
C20.0382 (11)0.0431 (11)0.0286 (10)0.0016 (9)0.0083 (9)0.0065 (9)
C30.0398 (12)0.0434 (11)0.0438 (12)0.0045 (9)0.0154 (10)0.0023 (9)
C40.0441 (12)0.0408 (11)0.0351 (11)0.0033 (9)0.0200 (10)0.0002 (9)
C50.0562 (15)0.0645 (15)0.0647 (16)0.0009 (12)0.0382 (13)0.0153 (13)
C60.0550 (15)0.0699 (16)0.0694 (17)0.0018 (12)0.0358 (13)0.0185 (13)
C70.0644 (17)0.0661 (16)0.0744 (17)0.0038 (12)0.0447 (14)0.0146 (13)
Cl10.0652 (4)0.0667 (4)0.0613 (4)0.0042 (3)0.0387 (3)0.0131 (3)
Cl20.0562 (4)0.0684 (4)0.0874 (5)0.0003 (3)0.0362 (4)0.0003 (3)
N10.0380 (9)0.0420 (9)0.0275 (8)0.0100 (7)0.0145 (7)0.0049 (6)
O10.0620 (10)0.0590 (9)0.0444 (9)0.0095 (8)0.0248 (8)0.0104 (7)
O20.0558 (9)0.0698 (10)0.0402 (9)0.0054 (8)0.0152 (7)0.0146 (7)
O30.0515 (10)0.0519 (9)0.0402 (8)0.0091 (7)0.0067 (7)0.0078 (7)
O40.051 (3)0.054 (2)0.036 (2)0.0013 (19)0.0064 (18)0.0068 (18)
Geometric parameters (Å, º) top
C1—C21.527 (3)C5—C61.509 (3)
C1—Cl21.745 (2)C5—H50.98
C1—Cl11.759 (2)C6—H6A0.96
C1—H10.98C6—H6B0.96
C2—O11.208 (2)C6—H6C0.96
C2—N11.319 (2)C7—H7A0.96
C3—N11.445 (2)C7—H7B0.96
C3—C41.502 (3)C7—H7C0.96
C3—C51.542 (3)N1—H1A0.86
C3—H30.98O2—H20.82
C4—O31.188 (2)O4—H4A0.93 (7)
C4—O21.308 (2)O4—H4B0.84 (5)
C5—C71.482 (3)
C2—C1—Cl2109.11 (14)C7—C5—H5107.3
C2—C1—Cl1110.19 (15)C6—C5—H5107.3
Cl2—C1—Cl1110.11 (11)C3—C5—H5107.3
C2—C1—H1109.1C5—C6—H6A109.5
Cl2—C1—H1109.1C5—C6—H6B109.5
Cl1—C1—H1109.1H6A—C6—H6B109.5
O1—C2—N1123.61 (18)C5—C6—H6C109.5
O1—C2—C1122.27 (17)H6A—C6—H6C109.5
N1—C2—C1114.06 (17)H6B—C6—H6C109.5
N1—C3—C4110.41 (16)C5—C7—H7A109.5
N1—C3—C5111.88 (16)C5—C7—H7B109.5
C4—C3—C5111.21 (17)H7A—C7—H7B109.5
N1—C3—H3107.7C5—C7—H7C109.5
C4—C3—H3107.7H7A—C7—H7C109.5
C5—C3—H3107.7H7B—C7—H7C109.5
O3—C4—O2123.97 (18)C2—N1—C3122.38 (16)
O3—C4—C3124.48 (18)C2—N1—H1A118.8
O2—C4—C3111.54 (17)C3—N1—H1A118.8
C7—C5—C6112.1 (2)C4—O2—H2109.5
C7—C5—C3112.3 (2)H4A—O4—H4B105 (5)
C6—C5—C3110.10 (18)
Cl2—C1—C2—O175.0 (2)N1—C3—C5—C763.7 (2)
Cl1—C1—C2—O146.0 (2)C4—C3—C5—C760.3 (2)
Cl2—C1—C2—N1102.43 (17)N1—C3—C5—C662.1 (2)
Cl1—C1—C2—N1136.57 (16)C4—C3—C5—C6173.93 (18)
N1—C3—C4—O314.7 (3)O1—C2—N1—C30.5 (3)
C5—C3—C4—O3110.1 (2)C1—C2—N1—C3176.95 (17)
N1—C3—C4—O2166.68 (16)C4—C3—N1—C2128.83 (19)
C5—C3—C4—O268.5 (2)C5—C3—N1—C2106.7 (2)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···O3i0.862.032.876 (2)169
O2—H2···O1ii0.821.852.667 (2)178
C1—H1···O3i0.982.573.371 (3)139
C3—H3···O10.982.362.769 (3)104
Symmetry codes: (i) x+2, y+1, z+1; (ii) x, y+3/2, z+1/2.

Experimental details

Crystal data
Chemical formulaC7H11Cl2NO3·0.41H2O
Mr235.45
Crystal system, space groupMonoclinic, P21/c
Temperature (K)293
a, b, c (Å)9.298 (2), 9.011 (1), 13.990 (2)
β (°) 108.07 (1)
V3)1114.3 (3)
Z4
Radiation typeMo Kα
µ (mm1)0.57
Crystal size (mm)0.28 × 0.15 × 0.15
Data collection
DiffractometerBruker Smart Apex CCD area-detector diffactometer
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.90, 0.91
No. of measured, independent and
observed [I > 2σ(I)] reflections
6265, 2417, 1788
Rint0.016
(sin θ/λ)max1)0.639
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.040, 0.095, 1.14
No. of reflections2417
No. of parameters135
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.30, 0.16

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

Selected geometric parameters (Å, º) top
C1—C21.527 (3)C3—C51.542 (3)
C2—O11.208 (2)C4—O31.188 (2)
C2—N11.319 (2)C4—O21.308 (2)
C3—N11.445 (2)C5—C71.482 (3)
C3—C41.502 (3)C5—C61.509 (3)
N1—C3—C4—O314.7 (3)N1—C3—C5—C662.1 (2)
C5—C3—C4—O3110.1 (2)C4—C3—C5—C6173.93 (18)
N1—C3—C4—O2166.68 (16)O1—C2—N1—C30.5 (3)
C5—C3—C4—O268.5 (2)C1—C2—N1—C3176.95 (17)
N1—C3—C5—C763.7 (2)C4—C3—N1—C2128.83 (19)
C4—C3—C5—C760.3 (2)C5—C3—N1—C2106.7 (2)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···O3i0.862.032.876 (2)169
O2—H2···O1ii0.821.852.667 (2)178
C1—H1···O3i0.982.573.371 (3)139
C3—H3···O10.982.362.769 (3)104
Symmetry codes: (i) x+2, y+1, z+1; (ii) x, y+3/2, z+1/2.
 

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