Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536803010560/lh6060sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536803010560/lh6060Isup2.hkl |
CCDC reference: 214847
Colorless single crystals of (I) were grown as transparent needles, from a saturated aqueous solution containing DL-valine and fumaric acid, in 1:1 stoichiometric ratio.
The H atoms were placed at calculated positions and were allowed to ride on their respective parent atoms with HFIX instructions using SHELXL97 (Sheldrick, 1997) defaults.
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, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (spek, 1999); software used to prepare material for publication: SHELXL97.
C5H11NO2·0.5C4H4O4 | F(000) = 752 |
Mr = 175.18 | Dx = 1.332 Mg m−3 Dm = 1.34 (2) Mg m−3 Dm measured by flotation in xylene–bromoform |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2yc | Cell parameters from 25 reflections |
a = 24.417 (4) Å | θ = 7–13° |
b = 7.5713 (10) Å | µ = 0.11 mm−1 |
c = 10.013 (2) Å | T = 293 K |
β = 109.268 (10)° | Needle, colourless |
V = 1747.4 (5) Å3 | 0.28 × 0.22 × 0.14 mm |
Z = 8 |
Enraf-Nonius CAD-4 diffractometer | 1356 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.10 |
Graphite monochromator | θmax = 25.0°, θmin = 2.8° |
ω–2θ scans | h = 0→28 |
Absorption correction: ψ scan (North et al., 1968) | k = −8→8 |
Tmin = 0.88, Tmax = 0.98 | l = −11→11 |
2600 measured reflections | 2 standard reflections every 100 reflections |
1524 independent reflections | intensity decay: <1% |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.058 | H-atom parameters constrained |
wR(F2) = 0.154 | w = 1/[σ2(Fo2) + (0.0869P)2 + 1.3337P] where P = (Fo2 + 2Fc2)/3 |
S = 1.07 | (Δ/σ)max < 0.001 |
1524 reflections | Δρmax = 0.32 e Å−3 |
111 parameters | Δρmin = −0.28 e Å−3 |
0 restraints | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.007 (2) |
C5H11NO2·0.5C4H4O4 | V = 1747.4 (5) Å3 |
Mr = 175.18 | Z = 8 |
Monoclinic, C2/c | Mo Kα radiation |
a = 24.417 (4) Å | µ = 0.11 mm−1 |
b = 7.5713 (10) Å | T = 293 K |
c = 10.013 (2) Å | 0.28 × 0.22 × 0.14 mm |
β = 109.268 (10)° |
Enraf-Nonius CAD-4 diffractometer | 1356 reflections with I > 2σ(I) |
Absorption correction: ψ scan (North et al., 1968) | Rint = 0.10 |
Tmin = 0.88, Tmax = 0.98 | 2 standard reflections every 100 reflections |
2600 measured reflections | intensity decay: <1% |
1524 independent reflections |
R[F2 > 2σ(F2)] = 0.058 | 0 restraints |
wR(F2) = 0.154 | H-atom parameters constrained |
S = 1.07 | Δρmax = 0.32 e Å−3 |
1524 reflections | Δρmin = −0.28 e Å−3 |
111 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
O1 | 0.27658 (5) | 0.5467 (2) | 0.38149 (14) | 0.0333 (4) | |
O2 | 0.24030 (5) | 0.4490 (2) | 0.15951 (14) | 0.0351 (4) | |
O3 | 0.12567 (5) | −0.0296 (2) | 0.12750 (15) | 0.0371 (4) | |
H3A | 0.1555 | 0.0033 | 0.1147 | 0.056* | |
O4 | 0.08326 (5) | 0.1308 (2) | −0.06608 (15) | 0.0431 (5) | |
N1 | 0.17990 (5) | 0.7020 (2) | 0.38135 (14) | 0.0240 (4) | |
H1A | 0.1447 | 0.7406 | 0.3754 | 0.036* | |
H1B | 0.2029 | 0.7937 | 0.3831 | 0.036* | |
H1C | 0.1946 | 0.6390 | 0.4602 | 0.036* | |
C1 | 0.23603 (7) | 0.5223 (2) | 0.26606 (18) | 0.0230 (4) | |
C2 | 0.17563 (7) | 0.5892 (2) | 0.25650 (17) | 0.0230 (4) | |
H2 | 0.1617 | 0.6641 | 0.1722 | 0.028* | |
C3 | 0.13226 (8) | 0.4356 (3) | 0.2373 (2) | 0.0332 (5) | |
H3 | 0.1350 | 0.3647 | 0.1578 | 0.040* | |
C4 | 0.14757 (14) | 0.3151 (4) | 0.3640 (3) | 0.0630 (8) | |
H4A | 0.1870 | 0.2760 | 0.3863 | 0.094* | |
H4B | 0.1221 | 0.2147 | 0.3432 | 0.094* | |
H4C | 0.1434 | 0.3778 | 0.4434 | 0.094* | |
C5 | 0.06993 (10) | 0.5041 (4) | 0.1948 (4) | 0.0689 (9) | |
H5A | 0.0622 | 0.5788 | 0.1133 | 0.103* | |
H5B | 0.0649 | 0.5703 | 0.2717 | 0.103* | |
H5C | 0.0435 | 0.4060 | 0.1729 | 0.103* | |
C6 | 0.08116 (7) | 0.0364 (2) | 0.0300 (2) | 0.0277 (5) | |
C7 | 0.02520 (7) | −0.0165 (3) | 0.0492 (2) | 0.0317 (5) | |
H7 | 0.0259 | −0.0738 | 0.1319 | 0.038* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0259 (7) | 0.0428 (9) | 0.0285 (8) | 0.0043 (5) | 0.0053 (5) | −0.0091 (6) |
O2 | 0.0365 (7) | 0.0389 (9) | 0.0297 (8) | 0.0075 (6) | 0.0107 (6) | −0.0098 (6) |
O3 | 0.0263 (7) | 0.0401 (9) | 0.0437 (8) | −0.0014 (6) | 0.0101 (6) | 0.0121 (7) |
O4 | 0.0314 (7) | 0.0500 (10) | 0.0471 (9) | −0.0044 (6) | 0.0119 (6) | 0.0192 (8) |
N1 | 0.0253 (7) | 0.0219 (8) | 0.0249 (8) | 0.0007 (5) | 0.0084 (6) | −0.0034 (6) |
C1 | 0.0287 (9) | 0.0179 (8) | 0.0237 (9) | 0.0011 (6) | 0.0102 (7) | −0.0007 (7) |
C2 | 0.0268 (8) | 0.0212 (9) | 0.0197 (8) | 0.0016 (7) | 0.0059 (6) | −0.0022 (7) |
C3 | 0.0351 (10) | 0.0323 (11) | 0.0331 (10) | −0.0100 (8) | 0.0128 (8) | −0.0127 (8) |
C4 | 0.097 (2) | 0.0484 (16) | 0.0454 (13) | −0.0372 (14) | 0.0264 (13) | −0.0037 (12) |
C5 | 0.0340 (12) | 0.0668 (18) | 0.104 (2) | −0.0138 (12) | 0.0200 (13) | −0.0308 (18) |
C6 | 0.0279 (9) | 0.0236 (10) | 0.0325 (10) | −0.0022 (7) | 0.0113 (7) | 0.0004 (8) |
C7 | 0.0300 (9) | 0.0295 (10) | 0.0376 (11) | −0.0019 (7) | 0.0138 (7) | 0.0075 (8) |
O1—C1 | 1.263 (2) | C3—C4 | 1.507 (3) |
O2—C1 | 1.237 (2) | C3—C5 | 1.529 (3) |
O3—C6 | 1.297 (2) | C3—H3 | 0.9800 |
O3—H3A | 0.8200 | C4—H4A | 0.9600 |
O4—C6 | 1.214 (2) | C4—H4B | 0.9600 |
N1—C2 | 1.489 (2) | C4—H4C | 0.9600 |
N1—H1A | 0.8900 | C5—H5A | 0.9600 |
N1—H1B | 0.8900 | C5—H5B | 0.9600 |
N1—H1C | 0.8900 | C5—H5C | 0.9600 |
C1—C2 | 1.532 (2) | C6—C7 | 1.496 (2) |
C2—C3 | 1.541 (3) | C7—C7i | 1.322 (4) |
C2—H2 | 0.9800 | C7—H7 | 0.9300 |
C6—O3—H3A | 109.5 | C5—C3—H3 | 106.7 |
C2—N1—H1A | 109.5 | C2—C3—H3 | 106.7 |
C2—N1—H1B | 109.5 | C3—C4—H4A | 109.5 |
H1A—N1—H1B | 109.5 | C3—C4—H4B | 109.5 |
C2—N1—H1C | 109.5 | H4A—C4—H4B | 109.5 |
H1A—N1—H1C | 109.5 | C3—C4—H4C | 109.5 |
H1B—N1—H1C | 109.5 | H4A—C4—H4C | 109.5 |
O2—C1—O1 | 126.24 (16) | H4B—C4—H4C | 109.5 |
O2—C1—C2 | 116.59 (14) | C3—C5—H5A | 109.5 |
O1—C1—C2 | 117.17 (15) | C3—C5—H5B | 109.5 |
N1—C2—C1 | 109.74 (12) | H5A—C5—H5B | 109.5 |
N1—C2—C3 | 113.11 (14) | C3—C5—H5C | 109.5 |
C1—C2—C3 | 111.48 (15) | H5A—C5—H5C | 109.5 |
N1—C2—H2 | 107.4 | H5B—C5—H5C | 109.5 |
C1—C2—H2 | 107.4 | O4—C6—O3 | 125.38 (16) |
C3—C2—H2 | 107.4 | O4—C6—C7 | 122.61 (16) |
C4—C3—C5 | 112.7 (2) | O3—C6—C7 | 112.01 (16) |
C4—C3—C2 | 112.48 (16) | C7i—C7—C6 | 121.3 (2) |
C5—C3—C2 | 111.04 (19) | C7i—C7—H7 | 119.4 |
C4—C3—H3 | 106.7 | C6—C7—H7 | 119.4 |
O2—C1—C2—N1 | −169.55 (15) | C1—C2—C3—C4 | 65.3 (2) |
O1—C1—C2—N1 | 10.6 (2) | N1—C2—C3—C5 | 68.5 (2) |
O2—C1—C2—C3 | 64.3 (2) | C1—C2—C3—C5 | −167.25 (18) |
O1—C1—C2—C3 | −115.49 (17) | O4—C6—C7—C7i | 9.7 (4) |
N1—C2—C3—C4 | −58.9 (2) | O3—C6—C7—C7i | −170.6 (2) |
Symmetry code: (i) −x, −y, −z. |
D—H···A | D—H | H···A | D···A | D—H···A |
O3—H3A···O1ii | 0.82 | 1.68 | 2.4860 (18) | 168 |
N1—H1A···O4iii | 0.89 | 2.03 | 2.8755 (19) | 158 |
N1—H1B···O2iv | 0.89 | 1.97 | 2.826 (2) | 161 |
N1—H1C···O2iii | 0.89 | 2.05 | 2.9201 (19) | 166 |
C2—H2···O3v | 0.98 | 2.47 | 3.233 (2) | 135 |
Symmetry codes: (ii) −x+1/2, y−1/2, −z+1/2; (iii) x, −y+1, z+1/2; (iv) −x+1/2, y+1/2, −z+1/2; (v) x, y+1, z. |
Experimental details
Crystal data | |
Chemical formula | C5H11NO2·0.5C4H4O4 |
Mr | 175.18 |
Crystal system, space group | Monoclinic, C2/c |
Temperature (K) | 293 |
a, b, c (Å) | 24.417 (4), 7.5713 (10), 10.013 (2) |
β (°) | 109.268 (10) |
V (Å3) | 1747.4 (5) |
Z | 8 |
Radiation type | Mo Kα |
µ (mm−1) | 0.11 |
Crystal size (mm) | 0.28 × 0.22 × 0.14 |
Data collection | |
Diffractometer | Enraf-Nonius CAD-4 diffractometer |
Absorption correction | ψ scan (North et al., 1968) |
Tmin, Tmax | 0.88, 0.98 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2600, 1524, 1356 |
Rint | 0.10 |
(sin θ/λ)max (Å−1) | 0.595 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.058, 0.154, 1.07 |
No. of reflections | 1524 |
No. of parameters | 111 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.32, −0.28 |
Computer programs: CAD-4 Software (Enraf-Nonius, 1989), CAD-4 Software, SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), PLATON (spek, 1999), SHELXL97.
O1—C1 | 1.263 (2) | C2—C3 | 1.541 (3) |
O2—C1 | 1.237 (2) | C3—C4 | 1.507 (3) |
O3—C6 | 1.297 (2) | C3—C5 | 1.529 (3) |
O4—C6 | 1.214 (2) | C6—C7 | 1.496 (2) |
N1—C2 | 1.489 (2) | C7—C7i | 1.322 (4) |
C1—C2 | 1.532 (2) | ||
O2—C1—O1 | 126.24 (16) | C4—C3—C2 | 112.48 (16) |
O2—C1—C2 | 116.59 (14) | C5—C3—C2 | 111.04 (19) |
O1—C1—C2 | 117.17 (15) | O4—C6—O3 | 125.38 (16) |
N1—C2—C1 | 109.74 (12) | O4—C6—C7 | 122.61 (16) |
N1—C2—C3 | 113.11 (14) | O3—C6—C7 | 112.01 (16) |
C1—C2—C3 | 111.48 (15) | C7i—C7—C6 | 121.3 (2) |
C4—C3—C5 | 112.7 (2) | ||
O2—C1—C2—N1 | −169.55 (15) | N1—C2—C3—C4 | −58.9 (2) |
O1—C1—C2—N1 | 10.6 (2) | C1—C2—C3—C4 | 65.3 (2) |
O2—C1—C2—C3 | 64.3 (2) | N1—C2—C3—C5 | 68.5 (2) |
O1—C1—C2—C3 | −115.49 (17) | C1—C2—C3—C5 | −167.25 (18) |
Symmetry code: (i) −x, −y, −z. |
D—H···A | D—H | H···A | D···A | D—H···A |
O3—H3A···O1ii | 0.82 | 1.68 | 2.4860 (18) | 168 |
N1—H1A···O4iii | 0.89 | 2.03 | 2.8755 (19) | 158 |
N1—H1B···O2iv | 0.89 | 1.97 | 2.826 (2) | 161 |
N1—H1C···O2iii | 0.89 | 2.05 | 2.9201 (19) | 166 |
C2—H2···O3v | 0.98 | 2.47 | 3.233 (2) | 135 |
Symmetry codes: (ii) −x+1/2, y−1/2, −z+1/2; (iii) x, −y+1, z+1/2; (iv) −x+1/2, y+1/2, −z+1/2; (v) x, y+1, z. |
Fumaric acid, a key intermediate in the organic acid biosynthesis, is known to readily form adducts/complexes with other organic molecules. Valine, an essential amino acid, is hydrophobic with a non-polar hydrocarbon chain and plays a vital role in the stabilization of protein molecules. A determination of the present crystal structure, (I), was carried out to examine the stoichiometry and ionization states and it appears to be the first of its kind involving fumaric acid and an amino acid. Moreover, the aggregation and the interaction patterns observed in amino acid–carboxylic acid complexes might possibly contribute to the understanding of the self-assembly processes that might have led to the emergence of the primitive multimolecular systems. Recently, the crystal structures of complexes of DL-valine with maleic acid (Alagar et al., 2001) and trichloroacetic acid (Rajagopal et al., 2002) were reported from our laboratory.
Fig. 1 shows the molecular structure of (I) with the adopted atom-numbering scheme. The valine molecule exists as a zwitterion, and the fumaric acid molecule in the unionized state forming an adduct involving the two distinct species, a feature uncommon in similar crystal structures. Usually in the crystals of amino acid–carboxylic acid complexes, the amino acid molecule is expected to exist in the cationic state (with a neutral carboyxlic acid group and a positively charged amino group) and the dicarboxylic acid in the anionic state (with a neutral carboxylic acid group and a negatively charged carboxylate group) facilitated by a proton transfer. The observed zwitterionic form of DL-valine and the unionized state of fumaric acid in the present structure is due to a `break down' in the otherwise routine proton transfer observed in such complexes. The coformation of the valine molecule determined by χ11 [−58.9 (2)°] and χ12 [68.5 (2)°] differs significantly from the values observed for the monoclinic form of DL-valine (Mallikarjunan & Rao, 1969) and for the triclinic form of DL-valine (Dalhus & Görbitz, 1996). However, the values agree well with those observed in DL-valinium maleate (Alagar et al., 2001), in spite of the difference in the ionization states of the amino acid molecules. The fumaric acid molecule has a centre of symmetry and is planar with a trans conformation about the central C═C bond.
The adduct formed by DL-valine and fumaric acid are held together by hydrogen bonded interactions (Fig. 2). DL-valine molecules aggregate into layers parallel to the bc plane in which glide and screw related head-to-tail hydrogen bonds between the amino acids are present. The fumaric acid molecules have no hydrogen-bonded interactions among them. They only mediate interactions between DL-valine layers through hydrogen bonds leading to a three-dimensional network of molecules. The aggregation pattern of individual molecules is distinctly different from those observed in the complexes of DL-alanine with maleic acid and trichloroacetic acid.