Buy article online - an online subscription or single-article purchase is required to access this article.
Download citation
Download citation
link to html
The title bis­(glycyl-L-aspartic acid) oxalate complex {systematic name: bis­[2-(2-ammonio­acetamido)butane­dioic acid] oxalate 0.4-hydrate}, 2C6H11N2O5+·C2O42−·4H2O, crystallizes in a triclinic space group with the planar peptide unit in a trans conformation. The asymmetric unit consists of two glycyl-L-aspartic acid mol­ecules with positively charged amino groups and neutral carboxyl groups, and an oxalate dianion. The twist around the C—Cα bond indicates that both the peptide mol­ecules adopt extended conformations, while the twist around the N—Cα bond shows that one has a folded and the other a semi-extended state. The present complex can be described as an inclusion compound with the dipeptide mol­ecule as the host and the oxalate anion as the guest. The usual head-to-tail sequence of aggregation is not observed in this complex, as is also the case with the glycyl-L-aspartic acid dihydrate mol­ecule. The study of aggregation and inter­action patterns in binary systems is the first step towards understanding more complex phenomena. This further leads to results that are of general interest in bimolecular aggregation.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270106048566/hj3023sup1.cif
Contains datablocks I, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270106048566/hj3023Isup2.hkl
Contains datablock I

CCDC reference: 634884

Comment top

X-ray analysis of complexes of amino acids and peptides among themselves as well as with relevant molecules helps in understanding the geometrical features of elementary patterns of these complexes (Vijayan, 1988). The aggregation pattern of biological molecules largely depends on the non-covalent interactions. In these complexes there is always an extensive network of hydrogen bonds. The aggregation pattern can divulge information relating to chemical evolution and the origin of life. In addition, structural and conformational studies of peptides that contain acidic residues have shown that these compounds are implicated in the binding of calcium and similar metals to proteins (Wasserman et al., 1977). It has been observed that these residues are involved in the complexation of calcium in all calcium proteins of known structure (Kretsinger & Nelson, 1976). Most of the calcium-specific site sequences contain glycine adjacent to one or more of the coordinating acid peptide residues (Potter et al., 1977). The acidic side chain of these peptides offers unique possibilities of hydrogen bonding, which may result in unusual conformational properties. The crystal structure of the peptide glycyl-L-aspartic acid has been determined using single-crystal X-ray diffraction (Eggleston & Hodgson, 1982: Pichon-Pesme et al., 2000). Oxalic acid is the simplest dicarboxylic acid and it can, in principle, exist in three ionization states, viz. singly charged (semi-oxalate), doubly charged (oxalate) and neutral (oxalic acid). Oxalic acid has also been complexed with the peptides glycyl glycine (Ejsmont et al., 2003), glycyl-L-histidine and L-histidyl-L-alanine (Manoj & Vijayan, 2000). We present here the crystal structure of a bis(glycyl-L-aspartic acid) oxalate complex, (I), solved using single-crystal X-ray diffraction. Using the Cambridge Structural Database (CSD; update 5.26 of November 2004; Allen, 2002) an analysis of geometry in the salts of the peptide and oxalic acid has been carried out.

A displacement ellipsoid representation of the complex is given in Fig. 1. The asymmetric unit consists of two glycyl-L-aspartic acid molecules with positively charged amino groups and neutral carboxyl groups, and an oxalate ion, which is doubly negatively charged. A comparison of the bond parameters of the peptide unit in the complex and in the pure structure showed that only the bond parameters involving the main chain COOH group differ, as a result of the zwitterionic nature of the pure glycyl-L-aspartic acid. The peptide plane is defined by atoms C1, C2, O1, N2 and H6 for the first molecule and C7, C8, O6, N4 and H17 for the second molecule of peptide. The maximum deviations from the least-squares plane through these atoms occur for C3 [−0.023 (3) Å] and C7 [0.022 (4) Å].

The torsion angles of the two molecules of (I) and that of glycyl-L-aspartic acid are compared in Table 3. The planarity of the peptide unit is defined by the torsion angle ω, which characterizes the rotation around the C—N peptide bond. An ω value of 180° corresponds to a planar peptide unit (trans conformation). In the present complex the deviation of ω (C1—C2—N2—C3 and C7—C8—N4—C9) for both the peptide residues is about 3°, and hence they adopt trans conformations. The full conformation of a peptide chain is described by two additional torsion angles, ψ and ϕ, which characterize the twist around the C—Cα and N—Cα bonds, respectively (Suresh & Vijayan, 1985; Vijayan, 1988). The ψ angle around C—Cα is also extended in the present structure, which is also true for pure glycyl-L-aspartic acid molecule. As a rough guide, the confirmation may be considered as extended if the magnitude of ϕ is between 60 and 180°; otherwise it may be considered folded. According to this guide, one of the peptide molecules (molecule 2) is in a folded state and the other (molecule 1) is in a semi-extended state in the complex, unlike the molecule of pure glycyl-L-aspartic acid, which is extended, having a value of −133.3°. The aspartic acid residue has ψ1 of around 60° with the side chain trans to the carboxyl group in both the peptide molecules, unlike the case in pure glycyl-L-aspartic acid, which has a side chain having a cis conformation to the carboxyl group.

Comparison of the oxalate bond parameters for the three above-mentioned peptide–oxalate complexes shows that in all cases, with the exception of glycyl-L-histidine oxalate, the oxalate unit exists as doubly ionized oxalate anion. The stochiometery in the case of the present complex and bis(glycyl glycinium) oxalate is 2:1. The other two have 1:1 stochiometery. In all the complexes the oxalate ion is essentially planar, the O—C—C—O torsion angle having deviation of around 6° from planarity. Table 2 gives the hydrogen-bonding parameters in the present complex. The peptide molecule has a number of potential H-atom donors and acceptors in the structures. As observed previously (Eggleston & Hodgson, 1982) and in the present complex, intramolecular hydrogen bonding is absent. An arrangement in which the terminal amino group and the carboxylate group are brought into periodic hydrogen-bonded proximity is called a head-to-tail sequence. In the present complex, the terminal amine groups (i.e. N3/H12 and N1/H3) are hydrogen bonded to atoms O4 and O9 respectively, which are the main-chain alpha carboxyl O atoms. However, the arrangement is not the usual head-to-tail arrangement. Rather the two molecules are related by a pseudo-inversion center. It is also seen that the amine N atoms of each peptide molecule (N3—H14 and N1—H1) are hydrogen bonded to atoms O3 and O8, respectively, which are the side-chain carboxyl O atoms. Amine atoms H2 and H13 also form bifurcated hydrogen bonds to the oxalate O atoms (O13/O12 and O14/O11, respectively). The O-bound H atoms of the carboxyl groups of the main chain and the side chain act as hydrogen-bond donors to the oxalate O atom. Each oxalate O atom, in turn, acts as an acceptor of two hydrogen bonds (one to the amino N atom and the other to the OH group of the carboxyl group). Another interesting observation is that the peptide N atom forms a hydrogen bond to the peptide carbonyl (i.e. N2—H6···O1iii and N4—H17···O6i; Table 2) of the same molecule but in different asymmetric unit resulting in an S5–4 (Vijayan, 1988) sequence. Adjacent molecules are parallel. A hydrogen bond between the peptide N atom and the peptide carbonyl group is also observed in the pure glycyl-L-aspartic acid, bis(glycyl-L-histidine) oxalate and glycyl-L-histidine–oxalic acid complexes, but the same is not true for the L-histidyl-L-alanine complex. Hence it can be said that this might be due to the fact that the glycyl residue occupying the amine terminal position does not cause steric hindrance to allow this type of hydrogen bond to be formed in these kind of complexes. Of course, a systematic study of complexes of oxalic acid with peptides involving a glycyl residue at the amine terminal position is required to prove this point. In terms of graph-set notation (Bernstein et al., 1995), the largest motif has the first-level graph set N1 = DDD, the binary level being R24 (22). The next level graph set is N1 = DD, the binary level being R21 (5) and C4. The dipeptide and oxalate molecules are arranged parallel to the ab plane. Fig. 2 shows the packing as viewed down the crystallographic a axis. It is observed that the dipeptide molecules are stacked in such a way that the oxalate molecules are enclosed in the voids created during stacking. The present complex can be described as an inclusion compound with the dipeptide molecule as the host and the oxalate as the guest.

Experimental top

Crystals of bis(glycyl-L-aspartic acid) oxalate were grown by slow evaporation from a saturated aqueous solution containing stoichiometric quantities of glycyl-L-aspartic acid and oxalic acid.

Refinement top

All H atoms were fixed using geometrical constraints and were considered as riding on the atoms to which they are attached, with C—H, N—H and O—H distances of 0.97–0.98, 0.86–0.89 and 0.82 Å, respectively. At this stage, the maximum difference density of 0.60 e Å−3 indicated the presence of a possible atom site. In addition, a check for solvent-accessible volume using PLATON (Spek, 2003) showed a void of 128 Å3. An attempt to refine this peak as a water atom with full occupancy resulted in a high Uiso value. An alternative strategy, the SQUEEZE function of PLATON (van der Sluis & Spek, 1990: Spek, 2003) was used to eliminate the contribution of the electron density in the solvent region form the intensity data. PLATON total Potential Solvent Area Vol 29.4 Å3 [please clarify meaning of this] estimated that the cavity contained four electrons, which is equivalent to one partially occupied solvent water molecule. The PLATON suite was used to generate the reflection file and the refinement was carried out using this file.

Computing details top

Data collection: SMART (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); 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. An ellipsoid plot of bis(glycyl-L-aspartic acid) oxalate with the atom-numbering scheme and 50% probability displacement ellipsoids.
[Figure 2] Fig. 2. Packing diagram for the title salt viewed down the a axis.
bis[2-(2-ammonioacetamido)butanedioic acid] oxalate 0.4-hydrate top
Crystal data top
2C6H11N2O5+·C2O42·0.4H2OZ = 1
Mr = 477.56F(000) = 246
Triclinic, P1Dx = 1.519 Mg m3
Hall symbol: P 1Mo Kα radiation, λ = 0.71073 Å
a = 4.8100 (8) ÅCell parameters from 2081 reflections
b = 10.7760 (18) Åθ = 2.0–26.4°
c = 10.8756 (18) ŵ = 0.14 mm1
α = 69.325 (3)°T = 300 K
β = 85.792 (3)°Irregular, colourless
γ = 81.946 (3)°0.24 × 0.19 × 0.13 mm
V = 522.03 (15) Å3
Data collection top
Bruker SMART CCD area-detector
diffractometer
1732 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.028
Graphite monochromatorθmax = 26.4°, θmin = 2.0°
ϕ and ω scansh = 65
5499 measured reflectionsk = 1313
2081 independent reflectionsl = 1313
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)] = 0.059Hydrogen site location: constr
wR(F2) = 0.133H-atom parameters constrained
S = 1.11 w = 1/[σ2(Fo2) + (0.0749P)2]
where P = (Fo2 + 2Fc2)/3
2081 reflections(Δ/σ)max < 0.001
297 parametersΔρmax = 0.28 e Å3
3 restraintsΔρmin = 0.19 e Å3
Crystal data top
2C6H11N2O5+·C2O42·0.4H2Oγ = 81.946 (3)°
Mr = 477.56V = 522.03 (15) Å3
Triclinic, P1Z = 1
a = 4.8100 (8) ÅMo Kα radiation
b = 10.7760 (18) ŵ = 0.14 mm1
c = 10.8756 (18) ÅT = 300 K
α = 69.325 (3)°0.24 × 0.19 × 0.13 mm
β = 85.792 (3)°
Data collection top
Bruker SMART CCD area-detector
diffractometer
1732 reflections with I > 2σ(I)
5499 measured reflectionsRint = 0.028
2081 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0593 restraints
wR(F2) = 0.133H-atom parameters constrained
S = 1.11Δρmax = 0.28 e Å3
2081 reflectionsΔρmin = 0.19 e Å3
297 parameters
Special details top

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All e.s.d.'s are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

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
O40.0104 (7)0.4777 (4)0.3705 (4)0.0488 (14)
O80.3237 (9)0.3465 (4)0.1545 (4)0.0510 (16)
O90.1254 (8)0.5107 (3)0.0168 (3)0.0446 (14)
O120.3319 (10)0.8424 (4)0.1311 (5)0.0655 (16)
O130.7000 (9)0.8660 (4)0.0103 (4)0.0596 (16)
N10.2079 (9)0.3927 (4)0.6125 (4)0.0378 (12)
N50.4292 (8)0.5234 (4)0.2696 (4)0.0316 (14)
C20.4128 (12)0.4195 (6)0.5026 (5)0.0431 (19)
C30.2647 (10)0.4768 (5)0.3739 (5)0.0299 (17)
C60.3133 (10)0.5768 (4)0.1387 (4)0.0268 (16)
C70.2577 (10)0.4624 (5)0.0941 (5)0.0297 (17)
C100.4976 (11)0.6692 (5)0.0415 (5)0.0343 (16)
C110.4956 (12)0.8009 (5)0.0618 (5)0.0389 (17)
O171.2525 (8)1.0291 (5)0.4262 (4)0.0607 (14)
O210.9577 (10)1.1712 (4)0.6203 (5)0.0697 (18)
O221.2008 (8)1.0048 (4)0.7744 (4)0.0521 (16)
O251.0426 (12)0.6538 (5)0.5892 (5)0.083 (2)
O260.7376 (8)0.6641 (4)0.7483 (4)0.0462 (12)
N141.0929 (9)1.1014 (4)0.1719 (4)0.0385 (16)
N180.8189 (8)0.9927 (4)0.5108 (4)0.0334 (14)
C150.8765 (13)1.0801 (8)0.2765 (6)0.056 (2)
C161.0034 (11)1.0304 (6)0.4127 (5)0.0421 (17)
C190.8926 (10)0.9466 (5)0.6496 (5)0.0345 (17)
C201.0259 (11)1.0540 (5)0.6792 (6)0.0389 (17)
C231.0769 (11)0.8122 (5)0.6907 (6)0.0427 (17)
C240.9524 (12)0.7022 (5)0.6697 (5)0.0407 (18)
O270.9036 (9)0.3279 (4)0.9456 (4)0.0545 (16)
O280.6271 (8)0.4250 (4)0.7740 (4)0.0453 (14)
O290.4371 (9)0.1874 (4)0.8223 (4)0.0577 (14)
O300.6904 (10)0.1015 (4)0.9994 (4)0.0590 (16)
C270.7228 (11)0.3286 (5)0.8712 (5)0.0337 (16)
C280.6043 (10)0.1932 (5)0.9011 (5)0.0320 (17)
H1A0.091970.338740.604220.0561*
H1B0.297500.353720.687900.0561*
H1C0.109810.469200.612200.0561*
H2A0.530170.337270.506960.0514*
H2B0.532910.482160.508880.0514*
H50.605580.522210.279020.0381*
H60.132030.629150.144140.0319*
H90.075790.449300.034460.0668*
H10A0.435720.686510.046600.0411*
H10B0.688760.624970.047920.0411*
H130.698840.936950.001810.0897*
H14A1.204421.157450.179490.0578*
H14B1.011851.135940.094110.0578*
H14C1.194161.023650.178520.0578*
H15A0.761791.015190.270900.0676*
H15B0.755761.163360.264210.0676*
H180.646900.995440.492280.0401*
H190.717160.933700.701720.0417*
H221.254661.065780.791210.0780*
H23A1.254170.823300.641800.0514*
H23B1.117040.785800.783160.0514*
H260.722580.586220.758440.0689*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O40.027 (2)0.075 (3)0.039 (2)0.0149 (19)0.0008 (17)0.010 (2)
O80.064 (3)0.032 (2)0.057 (3)0.0070 (19)0.025 (2)0.0103 (19)
O90.067 (3)0.0296 (19)0.041 (2)0.0147 (18)0.0257 (19)0.0088 (17)
O120.082 (3)0.044 (2)0.083 (3)0.024 (2)0.022 (3)0.036 (2)
O130.071 (3)0.044 (2)0.071 (3)0.034 (2)0.004 (2)0.020 (2)
N10.043 (2)0.037 (2)0.036 (2)0.0133 (19)0.005 (2)0.012 (2)
N50.019 (2)0.046 (3)0.033 (2)0.0090 (18)0.0089 (18)0.014 (2)
C20.036 (3)0.059 (4)0.030 (3)0.009 (3)0.005 (2)0.008 (3)
C30.026 (3)0.031 (3)0.031 (3)0.006 (2)0.005 (2)0.007 (2)
C60.028 (3)0.023 (2)0.029 (3)0.0042 (19)0.0081 (19)0.0066 (19)
C70.031 (3)0.025 (3)0.035 (3)0.013 (2)0.001 (2)0.009 (2)
C100.042 (3)0.032 (3)0.029 (2)0.010 (2)0.010 (2)0.007 (2)
C110.052 (3)0.030 (3)0.035 (3)0.014 (2)0.018 (3)0.005 (2)
O170.031 (2)0.092 (3)0.043 (2)0.027 (2)0.0127 (18)0.006 (2)
O210.087 (3)0.028 (2)0.096 (4)0.008 (2)0.046 (3)0.015 (2)
O220.059 (3)0.040 (2)0.065 (3)0.0190 (19)0.026 (2)0.018 (2)
O250.131 (5)0.050 (3)0.079 (3)0.036 (3)0.045 (3)0.035 (3)
O260.055 (2)0.038 (2)0.055 (2)0.0221 (19)0.001 (2)0.0221 (19)
N140.044 (3)0.033 (2)0.037 (3)0.0081 (19)0.016 (2)0.006 (2)
N180.023 (2)0.036 (2)0.036 (3)0.0096 (17)0.0092 (19)0.0023 (19)
C150.037 (3)0.078 (4)0.046 (4)0.017 (3)0.011 (3)0.007 (3)
C160.033 (3)0.049 (3)0.041 (3)0.014 (2)0.012 (3)0.006 (3)
C190.024 (3)0.035 (3)0.050 (3)0.009 (2)0.008 (2)0.018 (2)
C200.034 (3)0.041 (3)0.051 (3)0.010 (2)0.009 (2)0.024 (3)
C230.040 (3)0.035 (3)0.054 (3)0.011 (2)0.013 (2)0.012 (2)
C240.063 (4)0.016 (2)0.040 (3)0.004 (2)0.002 (3)0.007 (2)
O270.072 (3)0.036 (2)0.061 (3)0.025 (2)0.037 (2)0.010 (2)
O280.065 (3)0.035 (2)0.038 (2)0.0283 (19)0.0119 (19)0.0047 (19)
O290.081 (3)0.041 (2)0.054 (2)0.034 (2)0.028 (2)0.005 (2)
O300.087 (3)0.031 (2)0.056 (3)0.027 (2)0.037 (2)0.003 (2)
C270.043 (3)0.027 (2)0.036 (3)0.014 (2)0.003 (2)0.014 (2)
C280.041 (3)0.034 (3)0.029 (3)0.021 (2)0.009 (2)0.013 (2)
Geometric parameters (Å, º) top
O4—C31.225 (6)N18—C191.467 (7)
O8—C71.197 (7)N18—C161.322 (7)
O9—C71.307 (6)N14—H14A0.8899
O12—C111.200 (7)N14—H14C0.8903
O13—C111.329 (7)N14—H14B0.8897
O9—H90.8199N18—H180.8598
O13—H130.8196C2—C31.504 (7)
O17—C161.215 (7)C6—C101.504 (7)
O21—C201.207 (8)C6—C71.536 (7)
O22—C201.295 (7)C10—C111.510 (8)
O25—C241.196 (8)C2—H2A0.9697
O26—C241.307 (7)C2—H2B0.9706
O22—H220.8197C6—H60.9799
O26—H260.8199C10—H10A0.9703
O27—C271.228 (7)C10—H10B0.9698
O28—C271.253 (7)C15—C161.528 (8)
O29—C281.240 (7)C19—C231.525 (8)
O30—C281.223 (7)C19—C201.535 (8)
N1—C21.465 (7)C23—C241.492 (8)
N5—C61.455 (6)C15—H15A0.9698
N5—C31.320 (6)C15—H15B0.9700
N1—H1C0.8897C19—H190.9797
N1—H1A0.8901C23—H23A0.9702
N1—H1B0.8902C23—H23B0.9698
N5—H50.8598C27—C281.559 (8)
N14—C151.463 (8)
O4···N12.663 (6)N14···O30iv2.793 (6)
O4···N5i2.991 (5)N14···O8vi2.947 (6)
O4···C2i3.160 (7)N14···O12v3.035 (7)
O4···C73.201 (7)N14···O172.733 (6)
O8···N14ii2.947 (6)N14···O27iv2.882 (6)
O8···C33.146 (7)N18···O212.767 (6)
O8···O27iii3.224 (6)N18···O17i2.870 (6)
O8···N52.740 (6)C2···O283.220 (7)
O9···O26iii3.097 (5)C2···O4v3.160 (7)
O9···O27iii2.531 (6)C2···O25i3.257 (9)
O9···C24iii3.397 (6)C3···O83.146 (7)
O9···C10i3.388 (7)C7···O43.201 (7)
O12···N53.210 (7)C7···O27iii3.218 (7)
O12···N14i3.035 (7)C10···O9v3.388 (7)
O13···C28iv3.284 (7)C10···O26xii3.327 (7)
O13···O30iv2.571 (6)C11···O22iii3.396 (7)
O17···C233.146 (7)C11···O30iv3.322 (7)
O17···N142.733 (6)C15···O17i3.328 (7)
O17···C15v3.328 (7)C15···O30iv3.128 (8)
O17···O213.170 (7)C16···O213.115 (8)
O17···C202.972 (7)C20···O172.972 (7)
O17···N18v2.870 (6)C20···O29vi3.351 (7)
O21···N182.767 (6)C23···O26v3.347 (7)
O21···C163.115 (8)C23···O173.146 (7)
O21···N1vi2.793 (7)C24···O283.364 (7)
O21···O173.170 (7)C24···O9viii3.397 (6)
O21···O29vii3.235 (7)C27···O263.392 (7)
O22···C11viii3.396 (7)C28···O13x3.284 (7)
O22···O29vi2.622 (6)C7···H10Bi3.0079
O25···N1v2.741 (7)C11···H53.0997
O25···C2v3.257 (9)C16···H23A2.8989
O26···C23i3.347 (7)C20···H1Avi2.9409
O26···C10ix3.327 (7)C24···H1Cv2.7884
O26···C273.392 (7)C27···H9viii2.7284
O26···O282.618 (6)C27···H14Bx2.8727
O26···O9viii3.097 (5)C27···H1B2.8800
O27···N14x2.882 (6)C27···H262.6088
O27···O8viii3.224 (6)C28···H13x2.5724
O27···O302.636 (6)C28···H1B2.7388
O27···C7viii3.218 (7)C28···H22ii2.8710
O27···O9viii2.531 (6)C28···H14Bx2.8249
O28···C23.220 (7)H1A···O292.8511
O28···N12.902 (6)H1A···O21ii1.9479
O28···N1v3.233 (6)H1A···C20ii2.9409
O28···O262.618 (6)H1A···O42.4802
O28···O292.702 (6)H1B···C272.8800
O28···C243.364 (7)H1B···C282.7388
O29···N12.727 (6)H1B···O291.9382
O29···O282.702 (6)H1B···O282.2466
O29···O21xi3.235 (7)H1C···C24i2.7884
O29···O22ii2.622 (6)H1C···O25i1.8986
O29···C20ii3.351 (7)H1C···O28i2.7987
O30···O13x2.571 (6)H1C···O42.6737
O30···N14x2.793 (6)H2A···O21xi2.5950
O30···O272.636 (6)H2B···O282.7853
O30···C11x3.322 (7)H2B···O4v2.6561
O30···C15x3.128 (8)H2B···H52.3896
O4···H62.5071H5···H2B2.3896
O4···H1A2.4802H5···C113.0997
O4···H1C2.6737H5···H10B2.3905
O4···H2Bi2.6561H5···O4v2.1673
O4···H5i2.1673H6···H10Bi2.4557
O8···H14Aii2.1135H6···O122.5679
O8···H15Bxi2.6813H6···O42.5071
O9···H10Bi2.4684H9···O27iii1.7247
O9···H10A2.4920H9···C27iii2.7284
O12···H14Ci2.1950H10A···H23Biii2.3410
O12···H62.5679H10A···O92.4920
O17···H23A2.5966H10A···O26xii2.6361
O17···H15Av2.8887H10B···H6v2.4557
O17···H18v2.0174H10B···H52.3905
O17···H14A2.5586H10B···O9v2.4684
O17···H14C2.7505H10B···C7v3.0079
O21···H2Avii2.5950H13···C28iv2.5724
O21···H1Avi1.9479H13···O30iv1.7589
O22···H19v2.6433H13···O29iv2.8928
O22···H23A2.7870H14A···O8vi2.1135
O22···H23B2.4172H14A···O27iv2.9041
O25···H1Cv1.8986H14A···O172.5586
O26···H10Aix2.6361H14B···O30iv2.0625
O26···H23Ai2.7506H14B···O27iv2.1497
O26···H192.7558H14B···C28iv2.8249
O27···H14Ax2.9041H14B···C27iv2.8727
O27···H14Bx2.1497H14C···O12v2.1950
O27···H262.8688H14C···O172.7505
O27···H9viii1.7247H15A···H182.3713
O28···H261.8062H15A···O30iv2.7967
O28···H1B2.2466H15A···O17i2.8887
O28···H2B2.7853H15B···O8vii2.6813
O28···H1Cv2.7987H15B···H182.5703
O29···H1B1.9382H18···O17i2.0174
O29···H13x2.8928H18···H15A2.3713
O29···H1A2.8511H18···H15B2.5703
O29···H22ii1.8113H19···O22i2.6433
O30···H15Ax2.7967H19···O262.7558
O30···H14Bx2.0625H22···O29vi1.8113
O30···H13x1.7589H22···C28vi2.8710
N1···O21ii2.793 (7)H23A···O172.5966
N1···O42.663 (6)H23A···O222.7870
N1···O25i2.741 (7)H23A···O26v2.7506
N1···O28i3.233 (6)H23A···C162.8989
N1···O282.902 (6)H23B···O222.4172
N1···O292.727 (6)H23B···H10Aviii2.3410
N5···O4v2.991 (5)H26···O272.8688
N5···O82.740 (6)H26···O281.8062
N5···O123.210 (7)H26···C272.6088
C7—O9—H9109.48C7—C6—H6107.55
C11—O13—H13109.48N5—C6—H6107.52
C20—O22—H22109.49C10—C6—H6107.52
C24—O26—H26109.46C6—C10—H10B108.86
C3—N5—C6120.3 (4)C11—C10—H10A108.84
C2—N1—H1A109.44C11—C10—H10B108.87
C2—N1—H1B109.48H10A—C10—H10B107.69
C2—N1—H1C109.51C6—C10—H10A108.82
H1A—N1—H1B109.43N14—C15—C16111.9 (5)
H1A—N1—H1C109.49O17—C16—C15121.4 (5)
H1B—N1—H1C109.48O17—C16—N18124.5 (5)
C3—N5—H5119.89N18—C16—C15114.1 (5)
C6—N5—H5119.84N18—C19—C23111.9 (4)
C16—N18—C19123.3 (4)N18—C19—C20110.6 (4)
C15—N14—H14C109.44C20—C19—C23112.4 (4)
H14B—N14—H14C109.47O22—C20—C19113.1 (5)
H14A—N14—H14B109.51O21—C20—C19120.8 (5)
C15—N14—H14B109.47O21—C20—O22126.0 (6)
C15—N14—H14A109.48C19—C23—C24114.8 (5)
H14A—N14—H14C109.46O25—C24—O26123.8 (6)
C19—N18—H18118.35O25—C24—C23122.9 (6)
C16—N18—H18118.32O26—C24—C23113.3 (5)
N1—C2—C3110.3 (4)N14—C15—H15A109.26
N5—C3—C2114.9 (4)N14—C15—H15B109.23
O4—C3—C2120.6 (5)C16—C15—H15A109.22
O4—C3—N5124.5 (5)C16—C15—H15B109.20
N5—C6—C7110.3 (4)H15A—C15—H15B107.94
C7—C6—C10111.9 (4)N18—C19—H19107.21
N5—C6—C10111.8 (4)C20—C19—H19107.26
O9—C7—C6110.0 (4)C23—C19—H19107.21
O8—C7—O9125.9 (5)C19—C23—H23A108.57
O8—C7—C6124.1 (5)C19—C23—H23B108.57
C6—C10—C11113.6 (4)C24—C23—H23A108.55
O12—C11—C10125.4 (5)C24—C23—H23B108.60
O13—C11—C10110.0 (5)H23A—C23—H23B107.55
O12—C11—O13124.6 (5)O27—C27—O28127.3 (5)
N1—C2—H2A109.62O27—C27—C28115.7 (5)
C3—C2—H2B109.59O28—C27—C28117.1 (5)
N1—C2—H2B109.54O29—C28—O30126.1 (5)
C3—C2—H2A109.66O29—C28—C27117.4 (5)
H2A—C2—H2B108.11O30—C28—C27116.4 (5)
C6—N5—C3—C2177.6 (5)C6—C10—C11—O13168.3 (4)
C3—N5—C6—C10158.4 (5)C6—C10—C11—O1212.7 (8)
C3—N5—C6—C776.3 (6)N14—C15—C16—O179.8 (10)
C6—N5—C3—O42.1 (8)N14—C15—C16—N18171.4 (6)
C19—N18—C16—C15177.5 (6)N18—C19—C20—O22151.3 (5)
C19—N18—C16—O171.2 (10)C23—C19—C20—O21157.5 (5)
C16—N18—C19—C2057.7 (7)N18—C19—C20—O2131.6 (7)
C16—N18—C19—C2368.4 (7)N18—C19—C23—C2457.5 (6)
N1—C2—C3—O410.2 (8)C23—C19—C20—O2225.4 (7)
N1—C2—C3—N5170.1 (5)C20—C19—C23—C24177.4 (5)
C10—C6—C7—O961.8 (5)C19—C23—C24—O25111.2 (7)
C10—C6—C7—O8119.2 (6)C19—C23—C24—O2669.2 (6)
N5—C6—C7—O85.9 (7)O27—C27—C28—O29174.7 (5)
C7—C6—C10—C11164.7 (4)O27—C27—C28—O303.9 (7)
N5—C6—C7—O9173.0 (4)O28—C27—C28—O294.5 (7)
N5—C6—C10—C1171.0 (5)O28—C27—C28—O30177.0 (5)
Symmetry codes: (i) x1, y, z; (ii) x1, y1, z; (iii) x1, y, z1; (iv) x, y+1, z1; (v) x+1, y, z; (vi) x+1, y+1, z; (vii) x, y+1, z; (viii) x+1, y, z+1; (ix) x, y, z+1; (x) x, y1, z+1; (xi) x, y1, z; (xii) x, y, z1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···O21ii0.891.952.793 (7)158
N1—H1B···O280.892.252.902 (6)130
N1—H1B···O290.891.942.727 (6)147
N1—H1C···O25i0.891.902.741 (7)157
N5—H5···O4v0.862.1702.991 (5)160
O9—H9···O27iii0.821.722.531 (6)167
O13—H13···O30iv0.821.762.571 (6)170
N14—H14A···O8vi0.892.112.947 (6)156
N14—H14B···O27iv0.892.152.882 (6)139
N14—H14B···O30iv0.892.062.793 (6)139
N14—H14C···O12v0.892.203.035 (7)157
N18—H18···O17i0.862.022.870 (6)171
O22—H22···O29vi0.821.812.622 (6)170
O26—H26···O280.821.812.618 (6)170
C2—H2A···O21xi0.972.593.432 (8)145
C10—H10B···O9v0.972.473.388 (7)158
Symmetry codes: (i) x1, y, z; (ii) x1, y1, z; (iii) x1, y, z1; (iv) x, y+1, z1; (v) x+1, y, z; (vi) x+1, y+1, z; (xi) x, y1, z.

Experimental details

Crystal data
Chemical formula2C6H11N2O5+·C2O42·0.4H2O
Mr477.56
Crystal system, space groupTriclinic, P1
Temperature (K)300
a, b, c (Å)4.8100 (8), 10.7760 (18), 10.8756 (18)
α, β, γ (°)69.325 (3), 85.792 (3), 81.946 (3)
V3)522.03 (15)
Z1
Radiation typeMo Kα
µ (mm1)0.14
Crystal size (mm)0.24 × 0.19 × 0.13
Data collection
DiffractometerBruker SMART CCD area-detector
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
5499, 2081, 1732
Rint0.028
(sin θ/λ)max1)0.625
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.059, 0.133, 1.11
No. of reflections2081
No. of parameters297
No. of restraints3
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.28, 0.19

Computer programs: SMART (Bruker, 2004), SAINT (Bruker, 2004), SAINT, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEP-3 (Farrugia, 1997), SHELXL97.

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···O21i0.891.952.793 (7)158
N1—H1B···O280.892.252.902 (6)130
N1—H1B···O290.891.942.727 (6)147
N1—H1C···O25ii0.891.902.741 (7)157
N5—H5···O4iii0.862.1702.991 (5)160
O9—H9···O27iv0.821.722.531 (6)167
O13—H13···O30v0.821.762.571 (6)170
N14—H14A···O8vi0.892.112.947 (6)156
N14—H14B···O27v0.892.152.882 (6)139
N14—H14B···O30v0.892.062.793 (6)139
N14—H14C···O12iii0.892.203.035 (7)157
N18—H18···O17ii0.862.022.870 (6)171
O22—H22···O29vi0.821.812.622 (6)170
O26—H26···O280.821.812.618 (6)170
C2—H2A···O21vii0.972.593.432 (8)145
C10—H10B···O9iii0.972.473.388 (7)158
Symmetry codes: (i) x1, y1, z; (ii) x1, y, z; (iii) x+1, y, z; (iv) x1, y, z1; (v) x, y+1, z1; (vi) x+1, y+1, z; (vii) x, y1, z.
1. Comparision of the torsion angles between bis(glycyl-L aspartic acid) oxalate and glycyl-L-aspartic acid dihydrate top
Atomsbis (glycyl-L aspartic acid) oxalateGlycyl-L aspartic acid
Torsion angles (°)Torsion angles(°)
Molecule 1Molecule 2
N1-C2-C3-N5(ψ)170.1 (5)-171.4 (6)-164.40
C2-C3-N5-C6(ω)177.6 (5)-177.5 (6)-175.90
C3-N5-C6-C7 (ϕ)-76.3 (6)57.7 (7)-133.24
N5-C6-C10-C11(ψ1)-71.0 (5)-57.5 (6)56.43
'N5-C6-C7-O8(ψ2') '-5.9 (7)31.6 (7)1.04
'N5-C6-C7-O9(ψ2'') '173.0 (4)-151.3 (5)-179.46
C7-C6-C10-C11(ψ2)164.7 (4)177.4 (5)-68.02
 

Subscribe to Acta Crystallographica Section C: Structural Chemistry

The full text of this article is available to subscribers to the journal.

If you have already registered and are using a computer listed in your registration details, please email support@iucr.org for assistance.

Buy online

You may purchase this article in PDF and/or HTML formats. For purchasers in the European Community who do not have a VAT number, VAT will be added at the local rate. Payments to the IUCr are handled by WorldPay, who will accept payment by credit card in several currencies. To purchase the article, please complete the form below (fields marked * are required), and then click on `Continue'.
E-mail address* 
Repeat e-mail address* 
(for error checking) 

Format*   PDF (US $40)
   HTML (US $40)
   PDF+HTML (US $50)
In order for VAT to be shown for your country javascript needs to be enabled.

VAT number 
(non-UK EC countries only) 
Country* 
 

Terms and conditions of use
Contact us

Follow Acta Cryst. C
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds