organic papers
o1306
K. Rajagopalet al. C3H8NO2+C4H5O6ÿ DOI: 10.1107/S1600536802019414 Acta Cryst.(2002). E58, o1306±o1308 Acta Crystallographica Section EStructure Reports
Online ISSN 1600-5368
L
-Alaninium tartrate
K. Rajagopal,aM. Subha Nandhini,bR. V. Krishnakumarc and S. Natarajanb*
aDepartment of Physics, Saraswathi Narayanan
College, Madurai 625 022, India,bDepartment
of Physics, Madurai Kamaraj University, Madurai 625 021, India, andcDepartment of
Physics, Thiagarajar College, Madurai 625 009, India
Correspondence e-mail: [email protected]
Key indicators
Single-crystal X-ray study T= 293 K
Mean(C±C) = 0.005 AÊ Rfactor = 0.044 wRfactor = 0.114 Data-to-parameter ratio = 6.5
For details of how these key indicators were automatically derived from the article, see http://journals.iucr.org/e.
#2002 International Union of Crystallography Printed in Great Britain ± all rights reserved
In the title compound, C3H8NO2+C4H5O6ÿ, the l-alanine
molecule exists in the cationic form, with a positively charged amino group and an uncharged carboxylic acid group. The tartaric acid molecule exists in the mono-ionized state. The structure is stabilized by a three-dimensional network of OÐ H O and NÐH O hydrogen bonds. No head-to-tail hydrogen bond is observed among the amino acid molecules. The aggregation pattern observed in the structure has striking similarities to those observed in other related amino acid± tartaric acid complexes.
Comment
Precise X-ray crystallographic investigations of amino acid± carboxylic acid complexes are expected to throw much light on the nature of intermolecular interactions and biomolecular aggregation patterns that might well have occurred in prebiotic polymerization (Vijayan, 1988; Prasad & Vijayan, 1993). Recently, the crystal structures of sarcosinium tartrate (Krishnakumar et al., 2001) and l-prolinium tartrate (Subha Nandhiniet al., 2001) have been elucidated in our laboratory. The present study reports the crystal structure of the title compound, (I), a complex ofl-alanine with tartaric acid.
Fig. 1 shows the molecular structure of (I), with the atom-numbering scheme. Thel-alanine molecule in (I) exists in the cationic form, with a positively charged amino group and an uncharged carboxylic acid group. The tartaric acid molecule exists as a semi-tartrate ion, with a free carboxylic acid group and a negatively charged carboxylate ion. The C4ÐO3 and C4 O4 bond distances [1.279 (4) and 1.238 (4) AÊ, respec-tively] of the free carboxylic acid group are signi®cantly different from, but closely related to, those of sarcosinium tartrate [1.288 (3) and 1.222 (3) AÊ, respectively] and l-prolinium tartrate [1.294 (4) and 1.200 (4) AÊ, respectively]. The decrease in the CÐO and increase in the C O bond lengths may be attributed to a strong O3ÐH3 O8(x, y, z+ 1) hydrogen bond observed in the crystal structure, with an O O distance of 2.466 (3) AÊ. This observation is supported by the fact that strong OÐH X hydrogen bonds involving the carboxylic acid O atom as donor permit some double-bond character in the CÐO bond and some single-bond character in C O (Hahn, 1957). The angle between the planes of the two
halves of the semi-tartrate ion, O3/O4/C4/C5/O5 and O7/O8/ C6/C7/O6, is 53.0 (1), which agrees well with the value observed in tartaric acid [54.6 (4); Okaya et al., 1966], but deviates far from the values observed in sarcosinium tartrate [65.0 (1); Krishnakumaret al., 2001] andl-prolinium tartrate [71.4 (1); Subha Nandhiniet al., 2001]. The carbon skeleton of the semi-tartrate anion is essentially planar [torsion angle C4ÐC5ÐC6ÐC7ÿ175.1 (2)]. The CÐO double- and single-bond distances of the carboxylic acid group of the amino acid molecule are found to be as expected [1.185 (5) and 1.319 (5) AÊ, respectively].
Fig. 2 shows the packing of molecules of (I), viewed down the shortest axis (aaxis). The alaninium and semi-tartrate ions form alternate layers along the c axis. No head-to-tail hydrogen bond is observed among the amino acid molecules, as in the cases of sarcosinium tartrate (Krishnakumaret al., 2001) andl-prolinium tartrate (Subha Nandhiniet al., 2001). Alaninium and semi-tartrate ions aggregate into layers parallel to theacplane. These layers are interconnected by the translation-related OÐH O and NÐH O hydrogen bonds, leading to a characteristic three-dimensional aggrega-tion pattern. Semi-tartrate anions are held together by the translation-related OÐH O hydrogen bonds. A common feature observed among the crystal structures of (I),
sarcosi-nium tartrate andl-prolinium tartrate is that the shortest cell dimension in all of them is close to 5.0 AÊ. The aggregation pattern observed in (I) has striking similarities to those observed in the other two amino acid±tartaric acid complexes. Interestingly, in all the amino acid±tartaric acid complexes studied so far, no direct hydrogen-bonded links are observed among the amino acid molecules.
Experimental
Colorless plate-shaped single crystals of (I) were grown from a saturated aqueous solution containingl-alanine and tartaric acid in a 1:1 ratio.
Crystal data C3H8NO2+C4H5O6ÿ
Mr= 239.18
Monoclinic,P21
a= 5.1446 (8) AÊ
b= 13.721 (3) AÊ
c= 7.4751 (9) AÊ
= 98.09 (1)
V= 522.42 (14) AÊ3
Z= 2
Dx= 1.521 Mg mÿ3
Dm= 1.53 Mg mÿ3
Dmmeasured by ¯otation in a
mixture of xylene and carbon tetrachloride
MoKradiation Cell parameters from 25
re¯ections
= 2.8±25.0 = 0.14 mmÿ1
T= 293 (2) K Plate, colorless 0.350.300.15 mm Data collection
Enraf±Nonius CAD-4 diffractometer
!±2scans
Absorption correction: scan (Northet al., 1968)
Tmin= 0.952,Tmax= 0.979
1061 measured re¯ections 954 independent re¯ections 944 re¯ections withI> 2(I)
Rint= 0.018 max= 25.0
h= 0!6
k= 0!16
l=ÿ8!8 2 standard re¯ections
every 200 re¯ections intensity decay: <2%
Re®nement Re®nement onF2
R[F2> 2(F2)] = 0.044
wR(F2) = 0.114
S= 1.07 954 re¯ections 146 parameters
H-atom parameters constrained
w= 1/[2(F
o2) + (0.0848P)2
+ 0.196P]
whereP= (Fo2+ 2Fc2)/3
(/)max< 0.001
max= 0.40 e AÊÿ3
min=ÿ0.30 e AÊÿ3
Extinction correction:SHELXL97 Extinction coef®cient: 0.045 (14)
Table 1
Selected geometric parameters (AÊ,).
O1ÐC1 1.319 (5) O2ÐC1 1.185 (5) O4ÐC4 1.238 (4) O7ÐC7 1.247 (4)
O8ÐC7 1.256 (4) N1ÐC2 1.479 (5) C1ÐC2 1.533 (5) C2ÐC3 1.503 (6)
O2ÐC1ÐO1 125.4 (3) O2ÐC1ÐC2 124.5 (3) O1ÐC1ÐC2 110.1 (3) N1ÐC2ÐC3 111.9 (4)
N1ÐC2ÐC1 107.8 (3) C3ÐC2ÐC1 111.8 (4) O7ÐC7ÐO8 125.5 (3)
O2ÐC1ÐC2ÐN1 ÿ10.8 (5) O1ÐC1ÐC2ÐN1 167.7 (3) O2ÐC1ÐC2ÐC3 112.5 (5) O1ÐC1ÐC2ÐC3 ÿ69.0 (5)
O4ÐC4ÐC5ÐO5 0.4 (4) C4ÐC5ÐC6ÐC7 ÿ175.1 (2) O6ÐC6ÐC7ÐO8 ÿ19.5 (4)
Acta Cryst.(2002). E58, o1306±o1308 K. Rajagopalet al. C3H8NO2+C4H5O6ÿ
o1307
organic papers
Figure 2
The packing of molecules of (I), viewed down theaaxis. Figure 1
organic papers
o1308
K. Rajagopalet al. C3H8NO2+C4H5O6ÿ Acta Cryst.(2002). E58, o1306±o1308 Table 2Hydrogen-bonding geometry (AÊ,).
DÐH A DÐH H A D A DÐH A
O1ÐH1 O6i 0.82 1.84 2.651 (4) 169
O6ÐH6 O7ii 0.82 1.99 2.765 (4) 158
O5ÐH5 O4 0.82 2.15 2.639 (3) 119 O5ÐH5 O2ii 0.82 2.34 2.878 (4) 124
O3ÐH3 O8iii 0.82 1.66 2.466 (3) 170
N1ÐH1A O7 0.89 1.90 2.740 (4) 157 N1ÐH1C O5iv 0.89 2.49 2.958 (4) 114
N1ÐH1B O4v 0.89 2.01 2.815 (4) 149
Symmetry codes: (i)ÿx;yÿ1
2;2ÿz; (ii)xÿ1;y;z; (iii)x;y;1z; (iv) 1x;y;z; (v)
1x;y;zÿ1.
In the absence of signi®cant anomalous scattering effects and with no Friedel pairs, the absolute con®guration, assumed from the synthesis, could not be con®rmed crystallographically. The positions of H atoms, located from the ®nal difference Fourier map, were in disagreement with those favoured by the dimensions of the carboxyl and carboxylate groups of the tartrate anion. Hence, H atoms were generated geometrically and were allowed to ride on their respective parent atoms withSHELXL97 (Sheldrick, 1997) defaults for bond lengths and displacement parameters.
Data collection: CAD-4 Software (Enraf±Nonius, 1989); cell re®nement: CAD-4 Software; data reduction: CAD-4 Software; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to re®ne structure:SHELXL97 (Sheldrick, 1997);
molecular graphics:PLATON(Spek, 1999); software used to prepare material for publication:SHELXL97.
KR thanks the UGC for the FIP programme. SN thanks the Council of Scienti®c and Industrial Research (CSIR), India, for ®nancial assistance. The authors also thank the UGC for the DRS programme and the Bio-informatics Centre, Madurai Kamaraj University, for providing access to the the Cambridge Structural Database (Allen & Kennard, 1993).
References
Allen, F. H. & Kennard, O. (1993).Chem. Des. Autom. News,8, 1, 31±37. Enraf±Nonius (1989).CAD-4Software. Version 5.0. Enraf±Nonius, Delft, The
Netherlands.
Hahn, T. (1957).Z. Kristallogr.109, 438±466.
Krishnakumar, R. V., Subha Nandhini, M. & Natarajan, S. (2001).Acta Cryst.
C57, 165±166.
North, A. C. T., Phillips, D. C. & Mathews, F. S. (1968).Acta Cryst.A24, 351± 359.
Okaya, Y., Stemple, N. R. & Kay, M. I (1966).Acta Cryst.21, 237±243. Prasad, G. S. & Vijayan, M. (1993).Acta Cryst.B49, 348±356. Sheldrick, G. M. (1990).Acta Cryst.A46, 467±473.
Sheldrick, G. M. (1997).SHELXL97. University of GoÈttingen, Germany. Spek, A. L. (1999). PLATON for Windows. Utrecht University, The
Netherlands.
Subha Nandhini, M., Krishnakumar, R. V. & Natarjan, S. (2001).Acta Cryst.
C57, 423±424.
supporting information
sup-1 Acta Cryst. (2002). E58, o1306–o1308
supporting information
Acta Cryst. (2002). E58, o1306–o1308 [https://doi.org/10.1107/S1600536802019414]
L
-Alaninium tartrate
K. Rajagopal, M. Subha Nandhini, R. V. Krishnakumar and S. Natarajan
L-alaninium tartrate
Crystal data
C3H8NO2+·C4H5O6−
Mr = 239.18
Monoclinic, P21 Hall symbol: P 2yb
a = 5.1446 (8) Å
b = 13.721 (3) Å
c = 7.4751 (9) Å
β = 98.09 (1)°
V = 522.42 (14) Å3
Z = 2
F(000) = 252
Dx = 1.521 Mg m−3
Dm = 1.53 Mg m−3
Dm measured by flotation in a mixture of xylene and carbon tetrachloride
Mo Kα radiation, λ = 0.71073 Å Cell parameters from 25 reflections
θ = 2.8–25.0°
µ = 0.14 mm−1
T = 293 K Plates, colourless 0.35 × 0.30 × 0.15 mm
Data collection
Enraf-Nonius CAD-4 diffractometer
Radiation source: fine-focus sealed tube Graphite monochromator
ω–2θ scans
Absorption correction: ψ scan (North et al. 1968)
Tmin = 0.952, Tmax = 0.979 1061 measured reflections
954 independent reflections 944 reflections with I > 2σ(I)
Rint = 0.018
θmax = 25.0°, θmin = 2.8°
h = 0→6
k = 0→16
l = −8→8
2 standard reflections every 200 reflections intensity decay: <2%
Refinement
Refinement on F2 Least-squares matrix: full
R[F2 > 2σ(F2)] = 0.044
wR(F2) = 0.114
S = 1.07 954 reflections 146 parameters 1 restraint
Primary atom site location: structure-invariant direct methods
Secondary atom site location: difference Fourier map
Hydrogen site location: inferred from neighbouring sites
H-atom parameters constrained
w = 1/[σ2(F
o2) + (0.0848P)2 + 0.196P] where P = (Fo2 + 2Fc2)/3
(Δ/σ)max < 0.001 Δρmax = 0.40 e Å−3 Δρmin = −0.30 e Å−3
supporting information
sup-2 Acta Cryst. (2002). E58, o1306–o1308
Special details
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-factorsbased 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)
x y z Uiso*/Ueq
O1 0.1688 (6) 0.5120 (3) 0.7325 (4) 0.0490 (9)
H1 0.1520 0.4853 0.8283 0.074*
O2 0.5462 (5) 0.5643 (2) 0.8841 (4) 0.0434 (7)
O3 0.1891 (5) 0.8233 (2) 1.3666 (3) 0.0371 (7)
H3 0.1219 0.8269 1.4595 0.056*
O4 −0.1330 (6) 0.7148 (3) 1.2868 (3) 0.0459 (8)
O5 −0.0059 (5) 0.6910 (2) 0.9597 (3) 0.0355 (6)
H5 −0.1203 0.6687 1.0140 0.053*
O6 −0.1078 (5) 0.90422 (19) 0.9821 (3) 0.0306 (6)
H6 −0.2144 0.8816 0.9008 0.046*
O7 0.4473 (4) 0.8258 (2) 0.7834 (3) 0.0330 (6)
O8 0.0315 (4) 0.8467 (2) 0.6604 (3) 0.0329 (6)
N1 0.6550 (6) 0.6760 (2) 0.6067 (4) 0.0314 (7)
H1A 0.6216 0.7198 0.6883 0.047*
H1B 0.6782 0.7063 0.5048 0.047*
H1C 0.7998 0.6431 0.6488 0.047*
C1 0.3949 (7) 0.5587 (3) 0.7495 (5) 0.0305 (8)
C2 0.4315 (8) 0.6077 (3) 0.5704 (5) 0.0354 (8)
H2A 0.2729 0.6452 0.5277 0.042*
C3 0.4727 (13) 0.5341 (4) 0.4281 (7) 0.0680 (18)
H3A 0.4944 0.5673 0.3181 0.102*
H3B 0.3230 0.4918 0.4070 0.102*
H3C 0.6270 0.4964 0.4683 0.102*
C4 0.0555 (6) 0.7650 (3) 1.2559 (4) 0.0262 (7)
C5 0.1493 (6) 0.7578 (3) 1.0720 (4) 0.0256 (7)
H5A 0.3315 0.7349 1.0893 0.031*
C6 0.1387 (6) 0.8580 (2) 0.9813 (4) 0.0217 (7)
H6A 0.2735 0.8992 1.0496 0.026*
C7 0.2117 (6) 0.8436 (2) 0.7923 (4) 0.0215 (6)
Atomic displacement parameters (Å2)
U11 U22 U33 U12 U13 U23
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sup-3 Acta Cryst. (2002). E58, o1306–o1308
O3 0.0431 (13) 0.0515 (17) 0.0194 (11) −0.0106 (13) 0.0135 (10) −0.0046 (12) O4 0.0540 (16) 0.058 (2) 0.0300 (13) −0.0215 (15) 0.0212 (12) −0.0022 (12) O5 0.0498 (14) 0.0334 (13) 0.0255 (13) −0.0115 (12) 0.0129 (11) −0.0048 (11) O6 0.0291 (12) 0.0371 (14) 0.0274 (12) 0.0068 (10) 0.0105 (9) −0.0082 (11) O7 0.0269 (12) 0.0476 (16) 0.0269 (11) 0.0013 (11) 0.0127 (9) −0.0042 (11) O8 0.0300 (12) 0.0512 (16) 0.0191 (11) 0.0002 (12) 0.0085 (9) −0.0020 (11) N1 0.0354 (14) 0.0376 (16) 0.0244 (13) −0.0106 (13) 0.0154 (11) 0.0011 (12) C1 0.0336 (18) 0.0248 (16) 0.0356 (18) −0.0061 (14) 0.0137 (14) 0.0002 (15) C2 0.039 (2) 0.0349 (19) 0.0329 (18) −0.0091 (16) 0.0083 (14) 0.0035 (15) C3 0.110 (5) 0.056 (3) 0.045 (3) −0.043 (3) 0.037 (3) −0.020 (2) C4 0.0292 (15) 0.0302 (16) 0.0204 (15) 0.0014 (15) 0.0075 (12) 0.0054 (14) C5 0.0282 (15) 0.0313 (18) 0.0179 (14) 0.0009 (14) 0.0055 (11) −0.0005 (14) C6 0.0209 (14) 0.0261 (15) 0.0193 (14) −0.0006 (12) 0.0072 (11) −0.0040 (12) C7 0.0260 (15) 0.0202 (14) 0.0201 (14) −0.0028 (13) 0.0093 (11) −0.0013 (12)
Geometric parameters (Å, º)
O1—C1 1.319 (5) N1—H1B 0.8900
O1—H1 0.8200 N1—H1C 0.8900
O2—C1 1.185 (5) C1—C2 1.533 (5)
O3—C4 1.279 (4) C2—C3 1.503 (6)
O3—H3 0.8200 C2—H2A 0.9800
O4—C4 1.238 (4) C3—H3A 0.9600
O5—C5 1.412 (4) C3—H3B 0.9600
O5—H5 0.8200 C3—H3C 0.9600
O6—C6 1.418 (4) C4—C5 1.522 (4)
O6—H6 0.8200 C5—C6 1.530 (5)
O7—C7 1.247 (4) C5—H5A 0.9800
O8—C7 1.256 (4) C6—C7 1.525 (4)
N1—C2 1.479 (5) C6—H6A 0.9800
N1—H1A 0.8900
C1—O1—H1 109.5 C2—C3—H3C 109.5
C4—O3—H3 109.5 H3A—C3—H3C 109.5
C5—O5—H5 109.5 H3B—C3—H3C 109.5
C6—O6—H6 109.5 O4—C4—O3 126.2 (3)
C2—N1—H1A 109.5 O4—C4—C5 119.3 (3)
C2—N1—H1B 109.5 O3—C4—C5 114.5 (3)
H1A—N1—H1B 109.5 O5—C5—C4 110.8 (3)
C2—N1—H1C 109.5 O5—C5—C6 109.7 (2)
H1A—N1—H1C 109.5 C4—C5—C6 110.2 (3)
H1B—N1—H1C 109.5 O5—C5—H5A 108.7
O2—C1—O1 125.4 (3) C4—C5—H5A 108.7
O2—C1—C2 124.5 (3) C6—C5—H5A 108.7
O1—C1—C2 110.1 (3) O6—C6—C7 113.5 (2)
N1—C2—C3 111.9 (4) O6—C6—C5 112.1 (3)
N1—C2—C1 107.8 (3) C7—C6—C5 107.2 (3)
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sup-4 Acta Cryst. (2002). E58, o1306–o1308
N1—C2—H2A 108.4 C7—C6—H6A 107.9
C3—C2—H2A 108.4 C5—C6—H6A 107.9
C1—C2—H2A 108.4 O7—C7—O8 125.5 (3)
C2—C3—H3A 109.5 O7—C7—C6 116.3 (3)
C2—C3—H3B 109.5 O8—C7—C6 118.2 (3)
H3A—C3—H3B 109.5
O2—C1—C2—N1 −10.8 (5) O5—C5—C6—O6 72.3 (3)
O1—C1—C2—N1 167.7 (3) C4—C5—C6—O6 −49.9 (3)
O2—C1—C2—C3 112.5 (5) O5—C5—C6—C7 −52.9 (3)
O1—C1—C2—C3 −69.0 (5) C4—C5—C6—C7 −175.1 (2)
O4—C4—C5—O5 0.4 (4) O6—C6—C7—O7 163.2 (3)
O3—C4—C5—O5 179.0 (3) C5—C6—C7—O7 −72.5 (3)
O4—C4—C5—C6 122.0 (4) O6—C6—C7—O8 −19.5 (4)
O3—C4—C5—C6 −59.3 (4) C5—C6—C7—O8 104.8 (3)
Hydrogen-bond geometry (Å, º)
D—H···A D—H H···A D···A D—H···A
O1—H1···O6i 0.82 1.84 2.651 (4) 169
O6—H6···O7ii 0.82 1.99 2.765 (4) 158
O5—H5···O4 0.82 2.15 2.639 (3) 119
O5—H5···O2ii 0.82 2.34 2.878 (4) 124
O3—H3···O8iii 0.82 1.66 2.466 (3) 170
N1—H1A···O7 0.89 1.90 2.740 (4) 157
N1—H1C···O5iv 0.89 2.49 2.958 (4) 114
N1—H1B···O4v 0.89 2.01 2.815 (4) 149