metal-organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoSTRUCTURAL
CHEMISTRY
ISSN: 2053-2296

A 1:1 adduct of DL-threonine and arsenic acid

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aDepartment of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland
*Correspondence e-mail: w.harrison@abdn.ac.uk

(Received 15 April 2005; accepted 19 April 2005; online 13 May 2005)

The title compound, DL-threonine–arsenic acid (1/1), C4H9NO3·H3AsO4, is an unusual adduct containing zwitterionic threonine and neutral arsenic acid mol­ecules. The component species inter­act by way of N—H⋯O and O—H⋯O hydrogen bonds, leading to parallel [001] chains of threonine and arsenic acid mol­ecules which are crosslinked by further O—H⋯O and N—H⋯O bonds, resulting in a three-dimensional network.

Comment

Only a handful of crystal structures conaining the neutral arsenic acid (H3AsO4) moiety have been determined, including N,N,N-trimethylglycine (beatine) arsenic acid (Schildkamp et al., 1984[Schildkamp, W., Schafer, G. & Spilker, J. (1984). Z. Kristallogr. 168, 187-195.]), tetra­phenyl­phospho­nium chloride arsenic acid (Ruhlandt-Senge et al., 1992[Ruhlandt-Senge, K., Bacher, A.-D. & Müller, U. (1992). Z. Naturforsch. Teil B, 47, 1677-1680.]) and L-histininium dihydrogen arsenate arsenic acid (Ratajczak et al., 2000[Ratajczak, H., Barycki, J., Pietraszko, A., Baran, J., Debrus, S., May, M. & Venturini, J. (2000). J. Mol. Struct. 526, 269-278.]). We present here the synthesis and structure of the title compound, C4H9NO3·H3AsO4, (I)[link] (Fig. 1[link]), an unusual 1:1 adduct of neutral DL-threonine (threo-α-amino-β-hydroxy-n-butyric acid) and arsenic acid moieties.

[Scheme 1]

The H3AsO4 arsenic acid mol­ecule in (I)[link] shows its normal tetra­hedral geometry about As [mean As—O = 1.680 (2) Å], with the unprotonated formal As1=O4 double bond showing its expected (Lee & Harrison, 2003a[Lee, C. & Harrison, W. T. A. (2003a). Acta Cryst. E59, m739-m741.]) shortening relative to the three As—OH vertices (Table 1[link]).

Each threonine mol­ecule is chiral (the arbitrarily chosen asymmetric unit mol­ecule has an S conformation at C2 and an R conformation at C3), but space-group symmetry generates a 50:50 mix of enantiomers, which is consistent with the racemic starting material. The DL-threonine entity is zwitterionic (i.e. nominal H-atom transfer from O1 or O2 to N1) and the C1—O1 and C1—O2 bond lengths of the delocalized carboxyl group are almost identical (Table 1[link]). It is perhaps surprising that the threonine is not protonated (overall positive charge) under the low pH reaction conditions.

For ease of comparison with other structures, we refer to atoms C2, C3 and C4 as Cα, Cβ and Cγ, respectively, and atom O3 as Oγ. In (I)[link], with respect to N1 and the Cα—Cβ bond, both Cγ and Oγ are gauche [torsion angles = −61.4 (3) and 61.5 (3)°, respectively], as are the two H atoms attached to Cα and Cβ (H—Cα—Cβ—H = −62.4°). A similar so-called gauche-I/gauche-II mol­ecular conformation was seen in DL-threoninium hydrogen phosphate (Ravikumar et al., 2002[Ravikumar, B., Sridhar, B. & Rajaram, R. K. (2002). Acta Cryst. E58, o1185-o1187.]), with equivalent torsion angles of N1—Cα—Cβ—Cγ = −64.1 (3)°, N1—Cα—Cβ—Oγ = 59.5 (2)° and H—Cα—Cβ—H = −64.4°. By way of contrast, L-threonine (Janczak et al., 1997[Janczak, J., Zobel, D. & Luger, P. (1997). Acta Cryst. C53, 1901-1904.]) has a quite different trans(Cγ)/gauche(Oγ) conformation about the Cα—Cβ bond, with equivalent angles of N1—Cα—Cβ—Cγ = −174.82 (9)°, N1—Cα—Cβ—Oγ = −54.6 (1)° and H—Cα—Cβ—H = −179.3°. The `backbone' O2—C1—Cα—N1 (ψ1) torsion angle in (I)[link] is −12.3 (3)°, which compares well with the value of −7.8 (3)° seen in DL-threoninium hydrogen phosphate (Ravikumar et al., 2002[Ravikumar, B., Sridhar, B. & Rajaram, R. K. (2002). Acta Cryst. E58, o1185-o1187.]). In L-threonine itself, the carboxyl group is somewhat more twisted about the Cα—C1 bond, yielding (using our atom-numbering scheme) a O2—C1—Cα—N1 torsion angle of −25.3 (2)°. The gauche/gauche threonine geometry in (I)[link] could be reinforced by the intra­molecular N1—H1B⋯O3 and N1—H1C⋯O2 hydrogen bonds (Fig. 1[link] and Table 2[link]).

As well as van der Waals forces, the component species in (I)[link] inter­act by means of a network of N—H⋯O and O—H⋯O hydrogen bonds (Table 2[link]). It is notable that atom H1B is involved in a bifurcated N—H⋯(O,O) hydrogen bond (angle sum about H1B = 360°) and atom H1C makes a trifurcated N—H⋯(O,O,O) link (average angle about H1C = 108°). The H3AsO4 units are linked into polymeric chains of single tetra­hedra propagating along [001] (Fig. 2[link]) by way of the O5—H5⋯O4vi bond (see Table 2[link] for symmetry code). Adjacent tetra­hedra in the chain are thus related by c-glide symmetry. The As⋯Asvi separation is 4.5516 (5) Å. The other two As—OH vertices (atoms O6 and O7) act as hydrogen-bond donors to carboxyl acceptor O atoms on nearby threonine mol­ecules. The organic species of (I)[link] also forms c-glide symmetry-generated chains, via N1—H1B⋯O1ii (Fig. 3[link]). Adjacent threonine mol­ecules in the [001] chain therefore have opposite chiralities. Finally, the other N—H moieties (N1—H1B and N1—H1C) and the O3—H3 hydroxyl group make hydrogen bonds to nearby arsenic acid mol­ecules (Table 2[link]), complementing the arsenic acid-to-threonine hydrogen bonds involving atoms H6 and H7 (Fig. 4[link]). All of the O atoms in the structure accept at least one hydrogen bond.

The structure of (I)[link] is quite distinct from those of salt-like ammonium hydrogenarsenates (Lee & Harrison, 2003a[Lee, C. & Harrison, W. T. A. (2003a). Acta Cryst. E59, m739-m741.],b[Lee, C. & Harrison, W. T. A. (2003b). Acta Cryst. E59, m959-m960.],c[Lee, C. & Harrison, W. T. A. (2003c). Acta Cryst. E59, m1151-m1153.]), where H-atom transfer from arsenic acid to amine occurs.

[Figure 1]
Figure 1
The asymmetric unit of (I)[link], showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii. Hydrogen bonds are indicated by dashed lines.
[Figure 2]
Figure 2
Detail of a hydrogen-bonded arsenic acid chain in (I)[link]. [Symmetry codes are as in Table 2[link], with the addition of (vii) x, [{1\over 2}] − y, z + [{1\over 2}]; (viii) x, y, 1 + z.]
[Figure 3]
Figure 3
Detail of a hydrogen-bonded DL-threonine chain in (I)[link]. Methyl H atoms have been omitted for clarity. [Symmetry codes are as in Table 2[link], with the addition of (ix) x, [{3\over 2}] − y, z − [{1\over 2}]; (x) x, y, z − 1.]
[Figure 4]
Figure 4
The unit-cell packing in (I)[link] projected down [001], showing the cross-linked stacks of DL-threonine and arsenic acid moieties.

Experimental

Aqueous DL-threonine solution (0.5 M, 10 ml) was added to an aqueous H3AsO4 solution (0.5 M, 10 ml), giving a clear solution. A mass of needles of (I)[link] grew as the water evaporated from the increasingly viscous liquor over the course of a few days.

Crystal data
  • C4H9NO3·H3AsO4

  • Mr = 261.07

  • Monoclinic, P 21 /c

  • a = 10.1195 (6) Å

  • b = 9.8062 (6) Å

  • c = 8.9643 (6) Å

  • β = 99.098 (1)°

  • V = 878.37 (10) Å3

  • Z = 4

  • Dx = 1.974 Mg m−3

  • Mo Kα radiation

  • Cell parameters from 2540 reflections

  • θ = 2.9–32.2°

  • μ = 3.88 mm−1

  • T = 293 (2) K

  • Needle, colourless

  • 0.45 × 0.03 × 0.01 mm

Data collection
  • Bruker SMART 1000 CCD area-detector diffractometer

  • ω scans

  • Absorption correction: multi-scan(SADABS; Bruker, 1999[Bruker (1999). SMART (Version 5.624), SAINT (Version 6.02a) and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.])Tmin = 0.274, Tmax = 0.962

  • 7588 measured reflections

  • 3122 independent reflections

  • 2165 reflections with I > 2σ(I)

  • Rint = 0.049

  • θmax = 32.5°

  • h = −14 → 15

  • k = −14 → 14

  • l = −9 → 13

Refinement
  • Refinement on F2

  • R[F2 > 2σ(F2)] = 0.037

  • wR(F2) = 0.087

  • S = 0.94

  • 3122 reflections

  • 120 parameters

  • H-atom parameters constrained

  • w = 1/[σ2(Fo2) + (0.0417P)2] where P = (Fo2 + 2Fc2)/3

  • (Δ/σ)max < 0.001

  • Δρmax = 0.80 e Å−3

  • Δρmin = −0.74 e Å−3

Table 1
Selected geometric parameters (Å, °)[link]

C1—O2 1.263 (3)
C1—O1 1.264 (3)
As1—O4 1.639 (2)
As1—O6 1.6769 (19)
As1—O7 1.699 (2)
As1—O5 1.704 (2)
O2—C1—C2—N1 −12.3 (3) 
O1—C1—C2—N1 165.4 (2)
O2—C1—C2—C3 109.0 (3)
O1—C1—C2—C3 −73.2 (3)
N1—C2—C3—O3 61.5 (3)
C1—C2—C3—O3 −59.3 (3)
N1—C2—C3—C4 −61.4 (3)
C1—C2—C3—C4 177.7 (2)
H2—C2—C3—H3A −62.4

Table 2
Hydrogen-bond geometry (Å, °)[link]

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1A⋯O4i 0.89 1.92 2.800 (3) 170
N1—H1B⋯O1ii 0.89 2.15 2.903 (3) 143
N1—H1B⋯O3 0.89 2.38 2.810 (3) 110
N1—H1C⋯O7iii 0.89 2.30 3.069 (3) 145
N1—H1C⋯O2 0.89 2.33 2.646 (3) 101
N1—H1C⋯O6iv 0.89 2.35 2.890 (3) 119
O3—H3⋯O5v 0.82 2.14 2.906 (3) 156
O5—H5⋯O4vi 0.79 1.79 2.580 (3) 179
O6—H6⋯O2vi 0.77 1.76 2.514 (3) 169
O7—H7⋯O1 0.84 1.73 2.569 (3) 179
Symmetry codes: (i) x, y+1, z; (ii) [x, -y+{\script{3\over 2}}, z+{\script{1\over 2}}]; (iii) [-x, y+{\script{1\over 2}}, -z+{\script{3\over 2}}]; (iv) -x, -y+1, -z+1; (v) [-x+1, y+{\script{1\over 2}}, -z+{\script{3\over 2}}]; (vi) [x, -y+{\script{1\over 2}}, z-{\script{1\over 2}}].

The hydroxy H atoms were found in difference maps and refined as riding on their parent O atoms in their as-found relative positions. H atoms bonded to C and N atoms were placed in idealized positions, with C—H = 0.96–0.98 Å and N—H = 0.89 Å, and refined as riding, with the rigid NH3 or CH3 groups allowed to rotate freely about the bond joining the atoms in question to C1. The constraint Uiso(H) = 1.2Ueq(carrier) or 1.5Ueq(methyl carrier) was applied as appropriate.

Data collection: SMART (Bruker, 1999[Bruker (1999). SMART (Version 5.624), SAINT (Version 6.02a) and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 1999[Bruker (1999). SMART (Version 5.624), SAINT (Version 6.02a) and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997[Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997[Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany.]); molecular graphics: ORTEP-3 (Farrugia, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]); software used to prepare material for publication: SHELXL97.

Supporting information


Comment top

Only a handful of crystal structures conaining the neutral arsenic acid (H3AsO4) moiety have been determined, including N,N,N-trimethyl glycine (beatine) arsenic acid (Schildkamp et al., 1984), tetraphenylphosphonium chloride arsenic acid (Ruhlandt-Senge et al., 1992) and L-histininium dihydrogen arsenate arsenic acid (Ratajczak et al., 2000). Here, we present the synthesis and structure of the title compound, C4H9NO3·H3AsO4, (I) (Fig. 1), an unusual 1:1 adduct of neutral DL-threonine (threo-α-amino-β-hydroxy-n-butyric acid) and arsenic acid moieties.

The H3AsO4 arsenic acid molecule in (I) shows its normal tetrahedral geometry about As [mean As—O 1.680 (2) Å], with the unprotonated formal double As1O4 bond showing its expected (Lee & Harrison, 2003a) shortening relative to the three As—OH vertices (Table 1).

Each threonine molecule is chiral (the arbitrarily chosen asymmetric unit molecule has an S conformation at C2 and an R conformation at C3) but space-group symmetry generates a 50:50 mix of enantiomers, which is consistent with the racemic starting material. The C4H9NO3 entitly is zwitterionic (i.e. nominal H-atom transfer from O1 or O2 to N1) and the C1—O1 and C1—O2 bond lengths of the delocalized carboxyl group are almost identical (Table 1). It is perhaps surprising that the threonine is not protonated (overall positive charge) under the low-pH reaction conditions.

For ease of comparison with other structures, we refer to atoms C2, C3 and C4 as Cα, Cβ and Cγ, respectively, and atom O3 as Oγ. In (I), with respect to N1 and the Cα—Cβ bond, both Cγ and Oγ are gauche [torsion angles −61.4 (3) and 61.5 (3)°, respectively], as are the two H atoms attached to Cα and Cβ (H—Cα—Cβ—H = −62.4°). A similar so-called gauche-I/gauche-II molecular conformation is seen in DL-threoninium hydrogen phosphate (Ravikumar et al., 2002), with equivalent torsion angles of N1—Cα—CβCg = −64.1 (3)°, N1—Cα—Cβ—Oγ = 59.5 (2)° and H—Cα—Cβ—H = −64.4°. By way of contrast, L-threonine (Janczak et al., 1997) has a quite different trans(Cγ)/gauche(Oγ) conformation about the Cα—Cβ bond, with equivalent angles of N1—Cα—CβCg = −174.82 (9)°, N1—Cα—Cβ—Oγ = −54.6 (1)° and H—Cα—Cβ—H = −179.3°. The `backbone' O2—C1—Cα—N1 ψ1 torsion angle in (I) is −12.3 (3)°, which compares well with the value of −7.8 (3)° seen in DL-threoninium hydrogen phosphate (Ravikumar et al., 2002). In L-threonine itself, the carboxyl group is somewhat more twisted about the Cα—C1 bond, yielding (using our atom-numbering scheme) O2—C1—Cα—N1 = −25.3 (2)°. The gauche/gauche threonine geometry in (I) could be reinforced by the intramolecular N1—H1B···O3 and N1—H1C···O2 hydrogen bonds (Fig.1 and Table 2).

As well as van der Waals' forces, the component species in (I) interact by means of a network of N—H···O and O—H···O hydrogen bonds (Table 2). It is notable that atom H1B is involved in a bifurcated N—H···(O,O) hydrogen bond (angle sum about H1B = 360°) and atom H1C makes a trifurcated N—H···(O,O,O) link (average angle about H1C = 108°). The H3AsO4 units are linked into polymeric chains of single tetrahedra propagating along [001] (Fig. 2) by way of the O5—H5···O4vi bond (see Table 2 for symmetry code). Adjacent tetrahedra in the chain are thus related by c-glide symmetry. The As···Asvi separation is 4.5516 (5) Å. The other two As—OH vertices (atoms O6 and O7) act as hydrogen-bond donors to carboxyl acceptor O atoms on nearby threonine molecules. The organic species of (I) also forms c-glide symmetry-generated chains, via N1—H1B···O1ii (Fig. 3). Adjacent threonine molecules in the [001] chain therefore have opposite chiralities. Finally, the other N—H moieties (N1—H1B and N1—H1C) and the O3—H3 hydroxyl group make hydrogen bonds to nearby arsenic acid molecules (Table 2), to complement the arsenic acid-to-threonine hydrogen bonds involving atoms H6 and H7 (Fig. 4). All of the O atoms in the structure accept at least one hydrogen bond.

The structure of (I) is quite distinct from those of salt-like ammonium hydrogenarsenates (Lee & Harrison, 2003a,b,c), where H-atom transfer from arsenic acid to amine occurs.

Experimental top

Aqueous DL-threonine solution (0.5 M, 10 ml) was added to an H3AsO4 solution (0.5 M, 10 ml), giving a clear solution. A mass of needles of (I) grew as the water evaporated from the increasingly viscous liquor over the course of a few days.

Refinement top

The hydroxy H atoms were found in difference maps and refined as riding on their parent O atoms in their as-found relative positions. H atoms bonded to C and N atoms were placed in idealized positions, with C—H = 0.96–0.98 Å and N—H = 0.89 Å, and refined as riding, with the rigid NH3 or CH3 groups allowed to rotate freely about the bond joining the atoms in question to C1. The constraint Uiso(H) = 1.2Ueq(carrier) or Uiso(H) = 1.5Ueq(methyl carrier) was applied, as appropriate.

Computing details top

Data collection: SMART (Bruker, 1999); cell refinement: SAINT (Bruker, 1999); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97.

Figures top
[Figure 1] Fig. 1. The asymmetric unit of (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii. Hydrogen bonds are indicated by dashed lines.
[Figure 2] Fig. 2. Detail of a hydrogen-bonded arsenic acid chain in (I). [Symmetry codes as in Table 2; additionally: (vii) x, 1/2 − y, z + 1/2; (viii) x, y, 1 + z.]
[Figure 3] Fig. 3. Detail of a hydrogen-bonded DL-threonine chain in (I). Methyl H atoms have been omitted for clarity. [Symmetry codes as in Table 2; additionally: (ix) x, 3/2 − y, z − 1/2; (x) x, y, z − 1.]
[Figure 4] Fig. 4. The unit-cell packing in (I) projected down [001], showing the cross-linked stacks of DL-threonine and arsenic acid moieties.
DL-threonine–arsenic acid (1/1) top
Crystal data top
C4H9NO3·H3AsO4F(000) = 528
Mr = 261.07Dx = 1.974 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 2540 reflections
a = 10.1195 (6) Åθ = 2.9–32.2°
b = 9.8062 (6) ŵ = 3.88 mm1
c = 8.9643 (6) ÅT = 293 K
β = 99.098 (1)°Needle, colourless
V = 878.37 (10) Å30.45 × 0.03 × 0.01 mm
Z = 4
Data collection top
Bruker SMART 1000 CCD area-detector
diffractometer
3122 independent reflections
Radiation source: fine-focus sealed tube2165 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.049
ω scansθmax = 32.5°, θmin = 2.9°
Absorption correction: multi-scan
(SADABS; Bruker, 1999)
h = 1415
Tmin = 0.274, Tmax = 0.962k = 1414
7588 measured reflectionsl = 913
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)] = 0.037Hydrogen site location: difmap (O-H) and geom (C-H, N-H)
wR(F2) = 0.087H-atom parameters constrained
S = 0.94 w = 1/[σ2(Fo2) + (0.0417P)2]
where P = (Fo2 + 2Fc2)/3
3122 reflections(Δ/σ)max < 0.001
120 parametersΔρmax = 0.80 e Å3
0 restraintsΔρmin = 0.74 e Å3
Crystal data top
C4H9NO3·H3AsO4V = 878.37 (10) Å3
Mr = 261.07Z = 4
Monoclinic, P21/cMo Kα radiation
a = 10.1195 (6) ŵ = 3.88 mm1
b = 9.8062 (6) ÅT = 293 K
c = 8.9643 (6) Å0.45 × 0.03 × 0.01 mm
β = 99.098 (1)°
Data collection top
Bruker SMART 1000 CCD area-detector
diffractometer
3122 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 1999)
2165 reflections with I > 2σ(I)
Tmin = 0.274, Tmax = 0.962Rint = 0.049
7588 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0370 restraints
wR(F2) = 0.087H-atom parameters constrained
S = 0.94Δρmax = 0.80 e Å3
3122 reflectionsΔρmin = 0.74 e Å3
120 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
C10.1951 (3)0.6430 (3)0.7378 (3)0.0194 (5)
C20.2502 (3)0.7846 (3)0.7235 (3)0.0202 (5)
H20.22990.81380.61780.024*
C30.4023 (3)0.7827 (3)0.7723 (3)0.0253 (5)
H3A0.44090.71580.71030.030*
C40.4678 (3)0.9195 (4)0.7561 (4)0.0404 (8)
H4A0.56320.90840.77040.061*
H4B0.44440.98140.83070.061*
H4C0.43740.95560.65710.061*
N10.1864 (2)0.8810 (2)0.8190 (3)0.0246 (5)
H1A0.18790.96490.78130.037*
H1B0.23120.87990.91280.037*
H1C0.10200.85590.81990.037*
O10.2186 (2)0.5576 (2)0.6395 (2)0.0280 (4)
O20.1269 (2)0.6198 (2)0.8414 (3)0.0315 (5)
O30.4228 (2)0.7367 (3)0.9236 (3)0.0386 (6)
H30.49950.71570.95890.046*
As10.15993 (3)0.20962 (3)0.52512 (3)0.01895 (8)
O40.2169 (2)0.1352 (2)0.6862 (2)0.0274 (4)
O50.2961 (2)0.2523 (2)0.4450 (2)0.0305 (5)
H50.27260.28770.36670.037*
O60.0552 (2)0.1168 (2)0.4012 (2)0.0266 (4)
H60.08530.04930.37870.032*
O70.0704 (2)0.35389 (19)0.5414 (3)0.0286 (5)
H70.11870.41970.57450.034*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0229 (13)0.0142 (11)0.0202 (12)0.0040 (10)0.0009 (10)0.0029 (9)
C20.0220 (12)0.0173 (11)0.0209 (11)0.0011 (11)0.0023 (9)0.0001 (11)
C30.0221 (13)0.0250 (13)0.0287 (13)0.0024 (12)0.0036 (10)0.0028 (12)
C40.0246 (17)0.0317 (16)0.064 (2)0.0073 (14)0.0039 (16)0.0012 (16)
N10.0235 (12)0.0214 (11)0.0286 (12)0.0002 (10)0.0028 (9)0.0018 (10)
O10.0302 (11)0.0207 (9)0.0330 (11)0.0036 (9)0.0043 (9)0.0066 (9)
O20.0401 (13)0.0206 (9)0.0364 (12)0.0053 (9)0.0142 (10)0.0026 (9)
O30.0244 (11)0.0606 (15)0.0287 (11)0.0050 (11)0.0023 (9)0.0101 (11)
As10.01933 (13)0.01707 (12)0.01934 (12)0.00126 (12)0.00037 (8)0.00114 (12)
O40.0362 (12)0.0231 (10)0.0206 (9)0.0023 (9)0.0029 (8)0.0041 (8)
O50.0210 (10)0.0467 (12)0.0229 (10)0.0013 (9)0.0003 (8)0.0072 (9)
O60.0275 (11)0.0215 (9)0.0275 (10)0.0002 (8)0.0056 (8)0.0069 (8)
O70.0246 (11)0.0163 (9)0.0443 (13)0.0015 (8)0.0038 (9)0.0025 (9)
Geometric parameters (Å, º) top
C1—O21.263 (3)N1—H1A0.89
C1—O11.264 (3)N1—H1B0.89
C1—C21.509 (4)N1—H1C0.89
C2—N11.489 (3)O3—H30.82
C2—C31.532 (4)As1—O41.639 (2)
C2—H20.98As1—O61.6769 (19)
C3—O31.414 (4)As1—O71.699 (2)
C3—C41.514 (4)As1—O51.704 (2)
C3—H3A0.98O5—H50.79
C4—H4A0.96O6—H60.77
C4—H4B0.96O7—H70.84
C4—H4C0.96
O2—C1—O1125.3 (3)H4A—C4—H4C109.5
O2—C1—C2118.7 (2)H4B—C4—H4C109.5
O1—C1—C2116.0 (2)C2—N1—H1A109.5
N1—C2—C1109.7 (2)C2—N1—H1B109.5
N1—C2—C3110.5 (2)H1A—N1—H1B109.5
C1—C2—C3109.4 (2)C2—N1—H1C109.5
N1—C2—H2109.1H1A—N1—H1C109.5
C1—C2—H2109.1H1B—N1—H1C109.5
C3—C2—H2109.1C3—O3—H3116.0
O3—C3—C4112.0 (3)O4—As1—O6116.04 (10)
O3—C3—C2105.4 (2)O4—As1—O7114.42 (11)
C4—C3—C2113.4 (3)O6—As1—O7102.63 (10)
O3—C3—H3A108.6O4—As1—O5106.60 (11)
C4—C3—H3A108.6O6—As1—O5108.81 (11)
C2—C3—H3A108.6O7—As1—O5108.05 (11)
C3—C4—H4A109.5As1—O5—H5109.5
C3—C4—H4B109.5As1—O6—H6114.0
H4A—C4—H4B109.5As1—O7—H7112.5
C3—C4—H4C109.5
O2—C1—C2—N112.3 (3)C1—C2—C3—O359.3 (3)
O1—C1—C2—N1165.4 (2)N1—C2—C3—C461.4 (3)
O2—C1—C2—C3109.0 (3)C1—C2—C3—C4177.7 (2)
O1—C1—C2—C373.2 (3)H2—C2—C3—H3A62.4
N1—C2—C3—O361.5 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···O4i0.891.922.800 (3)170
N1—H1B···O1ii0.892.152.903 (3)143
N1—H1B···O30.892.382.810 (3)110
N1—H1C···O7iii0.892.303.069 (3)145
N1—H1C···O20.892.332.646 (3)101
N1—H1C···O6iv0.892.352.890 (3)119
O3—H3···O5v0.822.142.906 (3)156
O5—H5···O4vi0.791.792.580 (3)179
O6—H6···O2vi0.771.762.514 (3)169
O7—H7···O10.841.732.569 (3)179
Symmetry codes: (i) x, y+1, z; (ii) x, y+3/2, z+1/2; (iii) x, y+1/2, z+3/2; (iv) x, y+1, z+1; (v) x+1, y+1/2, z+3/2; (vi) x, y+1/2, z1/2.

Experimental details

Crystal data
Chemical formulaC4H9NO3·H3AsO4
Mr261.07
Crystal system, space groupMonoclinic, P21/c
Temperature (K)293
a, b, c (Å)10.1195 (6), 9.8062 (6), 8.9643 (6)
β (°) 99.098 (1)
V3)878.37 (10)
Z4
Radiation typeMo Kα
µ (mm1)3.88
Crystal size (mm)0.45 × 0.03 × 0.01
Data collection
DiffractometerBruker SMART 1000 CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 1999)
Tmin, Tmax0.274, 0.962
No. of measured, independent and
observed [I > 2σ(I)] reflections
7588, 3122, 2165
Rint0.049
(sin θ/λ)max1)0.756
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.037, 0.087, 0.94
No. of reflections3122
No. of parameters120
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.80, 0.74

Computer programs: SMART (Bruker, 1999), SAINT (Bruker, 1999), SAINT, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEP-3 (Farrugia, 1997), SHELXL97.

Selected geometric parameters (Å, º) top
C1—O21.263 (3)As1—O61.6769 (19)
C1—O11.264 (3)As1—O71.699 (2)
As1—O41.639 (2)As1—O51.704 (2)
O2—C1—C2—N112.3 (3)C1—C2—C3—O359.3 (3)
O1—C1—C2—N1165.4 (2)N1—C2—C3—C461.4 (3)
O2—C1—C2—C3109.0 (3)C1—C2—C3—C4177.7 (2)
O1—C1—C2—C373.2 (3)H2—C2—C3—H3A62.4
N1—C2—C3—O361.5 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···O4i0.891.922.800 (3)170
N1—H1B···O1ii0.892.152.903 (3)143
N1—H1B···O30.892.382.810 (3)110
N1—H1C···O7iii0.892.303.069 (3)145
N1—H1C···O20.892.332.646 (3)101
N1—H1C···O6iv0.892.352.890 (3)119
O3—H3···O5v0.822.142.906 (3)156
O5—H5···O4vi0.791.792.580 (3)179
O6—H6···O2vi0.771.762.514 (3)169
O7—H7···O10.841.732.569 (3)179
Symmetry codes: (i) x, y+1, z; (ii) x, y+3/2, z+1/2; (iii) x, y+1/2, z+3/2; (iv) x, y+1, z+1; (v) x+1, y+1/2, z+3/2; (vi) x, y+1/2, z1/2.
 

Acknowledgements

HSW thanks the Carnegie Trust for the Universities of Scotland for an undergraduate vacation studentship.

References

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First citationRavikumar, B., Sridhar, B. & Rajaram, R. K. (2002). Acta Cryst. E58, o1185–o1187.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationRuhlandt-Senge, K., Bacher, A.-D. & Müller, U. (1992). Z. Naturforsch. Teil B, 47, 1677–1680.  CAS Google Scholar
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