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In the title compound, C4H7NO4·H2O, the screw-related aspartic acid molecules are linked along the a axis by N—H...O hydrogen bonds to form helical structures. The adjacent helices are inter-linked through O—H...O hydrogen bonds and also by the water mol­ecules through N—H...O(W) and O(W)—H...O hydrogen bonds, to form a three-dimensional network.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536803014041/ci6237sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536803014041/ci6237Isup2.hkl
Contains datablock I

CCDC reference: 217624

Key indicators

  • Single-crystal X-ray study
  • T = 293 K
  • Mean [sigma](C-C) = 0.004 Å
  • R factor = 0.061
  • wR factor = 0.173
  • Data-to-parameter ratio = 12.2

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


Yellow Alert Alert Level C:
RADNW_01 Alert C The radiation wavelength lies outside the expected range for the supplied radiation type. Expected range 0.71065-0.71075 Wavelength given = 0.70165 General Notes
REFLT_03 From the CIF: _diffrn_reflns_theta_max 24.63 From the CIF: _reflns_number_total 1132 Count of symmetry unique reflns 691 Completeness (_total/calc) 163.82% TEST3: Check Friedels for noncentro structure Estimate of Friedel pairs measured 441 Fraction of Friedel pairs measured 0.638 Are heavy atom types Z>Si present no ALERT: MoKa measured Friedel data cannot be used to determine absolute structure in a light-atom study EXCEPT under VERY special conditions. It is preferred that Friedel data is merged in such cases.
0 Alert Level A = Potentially serious problem
0 Alert Level B = Potential problem
1 Alert Level C = Please check

Comment top

Aspartic acid is non-essential amino acid, widely distributed in proteins, which plays a major role in the energy cycle of the human body. The crystal structures of L-aspartic acid (Derissen et al., 1968), DL-aspartic acid (Rao, 1973; Sequeria et al., 1989), DL-aspartic acid nitrate monohydrate (Asath Bahadur & Rajaram, 1995), bis(DL-aspartic acid) sulfate (Srinivasan et al., 2001) and L-aspartic acid nitrate–L-aspartic acid (1/1) (Sridhar et al., 2002) have been reported. In the present paper, the crystal structure of L-aspartic acid monohydrate, (I), is reported.

The asymmetric unit of (I) contains one aspartic acid residue and one water molecule (Fig. 1). The equality of C—O bond distances [1.240 (4) and 1.259 (4) Å] and O—C—C bond angles [118.3 (3) and 115.3 (3)°] (Table 1) represent the deprotonated carboxylate group. The backbone conformation angle ψ1 of −10.8 (4)° indicates the cis form. The side chain shows a gauche II conformation [χ1 = −71.8 (3)°]. The branched chain conformation angles χ11 and χ21 are in cis and trans form. The Cγ atom is in the gauche I [52.7 (3)°] conformation with respect to C' atom. The molecular structure is stabilized by a weak intramolecular N1—H1B···O3 hydrogen bond.

The screw-related aspartic acid molecules are linked along the a axis by N1—H1A···O1i hydrogen bonds to form a helical structure (Table 2 and Fig.1). This helical structure is further stabilized by N1—H1C···O3ii hydrogen bonds which link the molecules translated a unit along the a axis. The adjacent helices are interlinked through O4—H4···O2iii hydrogen bonds and also by the water molecules through N1—H1B···O11iv, O11—H11···O2v and O11—H12···O2i hydrogen bonds, to form a three-dimensional network. Within the network, the O4—H4···O2iii hydrogen bonds link the screw related molecules, to form zigzag chains along the c axis. Class II hydrogen-bonding pattern is observed in the present structure having two two-centered hydrogen bonding and one three-centered hydrogen bonding (Jeffrey & Saegner, 1991). In the present study, the water molecule shows planar 1B-1/one-dimensional orientation (Jeffrey & Saegner, 1991). All the symmetry codes are as in Table 2. A view of the molecular packing down the a axis is shown in Fig. 2.

Experimental top

The title compound was crystallized from the aqueous solution when attempts were made to grow the single crystals of L-aspartic acid with sulfuric acid.

Refinement top

The H atoms of the water molecule were located from a difference Fourier map and their isotropic displacement parameters were refined [Uiso(H) = 0.04 (1) and 0.07 (2) Å2]. All other H atoms were placed in geometrically calculated positions and included in the refinement in the riding-model approximation, with Uiso equal to 1.2Ueq of the carrier atom. Intensities for 442 Friedel pairs were measured, resulting in a Flack parameter of 0(3). Though the absolute structure could not be confirmed as a result of weak anamalous signal, the Friedel pairs were not merged due to resulting low r/p ratio.

Computing details top

Data collection: CAD-4 Software (Enraf-Nonius, 1989); cell refinement: CAD-4 Software; data reduction: CAD-4 Software; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 1999); software used to prepare material for publication: SHELXL97.

Figures top
[Figure 1] Fig. 1. The structure of the title compound, showing 50% probability displacement ellipsoids (Johnson, 1976) and the atom-numbering scheme.
[Figure 2] Fig. 2. A view of the helical structures formed along the a axis. For clarity, all H atoms except H1A have been omitted.
[Figure 3] Fig. 3. Hydrogen-bonding network viewed down the a axis.
'L-aspartic acid monohydrate' top
Crystal data top
C4H7NO4·H2OF(000) = 320
Mr = 151.12Dx = 1.548 Mg m3
Dm = 1.54 Mg m3
Dm measured by Flotation in a mixture of carbon tetrachloride and xylene
Orthorhombic, P212121Mo Kα radiation, λ = 0.70165 Å
Hall symbol: P 2ac 2abCell parameters from 25 reflections
a = 5.587 (4) Åθ = 8.0–13.8°
b = 9.822 (5) ŵ = 0.14 mm1
c = 11.813 (9) ÅT = 293 K
V = 648.2 (8) Å3Block, colorless
Z = 40.3 × 0.3 × 0.3 mm
Data collection top
Enraf-Nonius CAD-4
diffractometer
1091 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.085
Graphite monochromatorθmax = 24.6°, θmin = 2.7°
ω–2θ scansh = 06
Absorption correction: ψ scan
(North et al., 1968)
k = 011
Tmin = 0.958, Tmax = 0.958l = 1414
1318 measured reflections3 standard reflections every 60 min
1132 independent reflections intensity decay: none
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)] = 0.061Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.173H atoms treated by a mixture of independent and constrained refinement
S = 1.06 w = 1/[σ2(Fo2) + (0.136P)2 + 0.3381P]
where P = (Fo2 + 2Fc2)/3
1132 reflections(Δ/σ)max < 0.001
93 parametersΔρmax = 0.33 e Å3
0 restraintsΔρmin = 0.54 e Å3
Crystal data top
C4H7NO4·H2OV = 648.2 (8) Å3
Mr = 151.12Z = 4
Orthorhombic, P212121Mo Kα radiation
a = 5.587 (4) ŵ = 0.14 mm1
b = 9.822 (5) ÅT = 293 K
c = 11.813 (9) Å0.3 × 0.3 × 0.3 mm
Data collection top
Enraf-Nonius CAD-4
diffractometer
1091 reflections with I > 2σ(I)
Absorption correction: ψ scan
(North et al., 1968)
Rint = 0.085
Tmin = 0.958, Tmax = 0.9583 standard reflections every 60 min
1318 measured reflections intensity decay: none
1132 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0610 restraints
wR(F2) = 0.173H atoms treated by a mixture of independent and constrained refinement
S = 1.06Δρmax = 0.33 e Å3
1132 reflectionsΔρmin = 0.54 e Å3
93 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*/Ueq
O10.8829 (4)0.1742 (2)0.00394 (19)0.0281 (6)
O20.9943 (4)0.0435 (2)0.0011 (2)0.0322 (6)
C10.8759 (5)0.0573 (3)0.0356 (2)0.0211 (7)
C20.6928 (5)0.0265 (3)0.1294 (2)0.0204 (7)
H20.56350.02660.09480.025*
N10.5849 (5)0.1570 (3)0.1709 (2)0.0225 (6)
H1A0.52890.20430.11230.034*
H1B0.69610.20570.20660.034*
H1C0.46560.13860.21840.034*
C30.7905 (5)0.0570 (3)0.2273 (3)0.0236 (7)
H3A0.82400.14840.20080.028*
H3B0.66860.06340.28550.028*
C41.0170 (6)0.0020 (3)0.2793 (3)0.0215 (7)
O31.1118 (4)0.1059 (2)0.2390 (2)0.0301 (6)
O41.1037 (5)0.0630 (3)0.3683 (2)0.0451 (7)
H41.22470.02420.39070.068*
O110.3015 (6)0.7701 (3)0.1132 (2)0.0430 (7)
H110.20370.81620.08550.037 (11)*
H120.33900.71420.06740.072 (19)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0359 (11)0.0217 (11)0.0268 (11)0.0021 (9)0.0069 (10)0.0077 (10)
O20.0363 (12)0.0256 (11)0.0348 (12)0.0058 (10)0.0098 (11)0.0020 (10)
C10.0208 (14)0.0244 (14)0.0179 (13)0.0016 (11)0.0004 (11)0.0007 (12)
C20.0206 (14)0.0162 (14)0.0246 (15)0.0016 (12)0.0014 (12)0.0001 (11)
N10.0232 (12)0.0187 (12)0.0256 (13)0.0034 (10)0.0022 (10)0.0019 (10)
C30.0257 (15)0.0171 (14)0.0280 (15)0.0026 (12)0.0053 (13)0.0077 (12)
C40.0220 (13)0.0180 (14)0.0244 (14)0.0025 (11)0.0054 (12)0.0027 (12)
O30.0275 (11)0.0237 (12)0.0391 (12)0.0059 (9)0.0041 (10)0.0068 (10)
O40.0454 (16)0.0453 (16)0.0445 (14)0.0009 (14)0.0070 (14)0.0067 (13)
O110.0516 (16)0.0395 (14)0.0380 (14)0.0107 (13)0.0034 (13)0.0022 (12)
Geometric parameters (Å, º) top
O1—C11.240 (4)C3—C41.522 (5)
O2—C11.259 (4)C3—H3A0.97
C1—C21.538 (4)C3—H3B0.97
C2—N11.499 (3)C4—O31.244 (4)
C2—C31.519 (4)C4—O41.322 (4)
C2—H20.98O4—H40.82
N1—H1A0.89O11—H110.78
N1—H1B0.89O11—H120.80
N1—H1C0.89
O1—C1—O2126.2 (3)H1A—N1—H1C109.5
O1—C1—C2118.3 (3)H1B—N1—H1C109.5
O2—C1—C2115.3 (3)C2—C3—C4113.6 (2)
N1—C2—C3110.9 (2)C2—C3—H3A108.8
N1—C2—C1109.5 (2)C4—C3—H3A108.8
C3—C2—C1114.6 (2)C2—C3—H3B108.8
N1—C2—H2107.2C4—C3—H3B108.8
C3—C2—H2107.2H3A—C3—H3B107.7
C1—C2—H2107.2O3—C4—O4123.0 (3)
C2—N1—H1A109.5O3—C4—C3120.8 (3)
C2—N1—H1B109.5O4—C4—C3116.2 (3)
H1A—N1—H1B109.5C4—O4—H4109.5
C2—N1—H1C109.5H11—O11—H12107.5
O1—C1—C2—N110.8 (4)N1—C2—C3—C471.9 (3)
O2—C1—C2—N1173.9 (3)C1—C2—C3—C452.8 (3)
O1—C1—C2—C3136.2 (3)C2—C3—C4—O32.9 (4)
O2—C1—C2—C348.5 (3)C2—C3—C4—O4177.0 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···O1i0.891.932.813 (4)171
N1—H1C···O3ii0.892.022.809 (4)147
O4—H4···O2iii0.822.152.933 (4)161
N1—H1B···O11iv0.892.222.854 (4)128
O11—H11···O2v0.782.062.837 (4)170
O11—H12···O2i0.802.052.817 (4)160
N1—H1B···O30.892.553.093 (4)120
Symmetry codes: (i) x1/2, y+1/2, z; (ii) x1, y, z; (iii) x+5/2, y, z+1/2; (iv) x+1, y1/2, z+1/2; (v) x1, y+1, z.

Experimental details

Crystal data
Chemical formulaC4H7NO4·H2O
Mr151.12
Crystal system, space groupOrthorhombic, P212121
Temperature (K)293
a, b, c (Å)5.587 (4), 9.822 (5), 11.813 (9)
V3)648.2 (8)
Z4
Radiation typeMo Kα
µ (mm1)0.14
Crystal size (mm)0.3 × 0.3 × 0.3
Data collection
DiffractometerEnraf-Nonius CAD-4
diffractometer
Absorption correctionψ scan
(North et al., 1968)
Tmin, Tmax0.958, 0.958
No. of measured, independent and
observed [I > 2σ(I)] reflections
1318, 1132, 1091
Rint0.085
(sin θ/λ)max1)0.594
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.061, 0.173, 1.06
No. of reflections1132
No. of parameters93
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.33, 0.54

Computer programs: CAD-4 Software (Enraf-Nonius, 1989), CAD-4 Software, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), PLATON (Spek, 1999), SHELXL97.

Selected geometric parameters (Å, º) top
O1—C11.240 (4)C4—O31.244 (4)
O2—C11.259 (4)C4—O41.322 (4)
O1—C1—O2126.2 (3)O2—C1—C2115.3 (3)
O1—C1—C2118.3 (3)
O1—C1—C2—N110.8 (4)N1—C2—C3—C471.9 (3)
O2—C1—C2—N1173.9 (3)C1—C2—C3—C452.8 (3)
O1—C1—C2—C3136.2 (3)C2—C3—C4—O32.9 (4)
O2—C1—C2—C348.5 (3)C2—C3—C4—O4177.0 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···O1i0.891.932.813 (4)171
N1—H1C···O3ii0.892.022.809 (4)147
O4—H4···O2iii0.822.152.933 (4)161
N1—H1B···O11iv0.892.222.854 (4)128
O11—H11···O2v0.782.062.837 (4)170
O11—H12···O2i0.802.052.817 (4)160
N1—H1B···O30.892.553.093 (4)120
Symmetry codes: (i) x1/2, y+1/2, z; (ii) x1, y, z; (iii) x+5/2, y, z+1/2; (iv) x+1, y1/2, z+1/2; (v) x1, y+1, z.
 

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