Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536802002751/ci6100sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536802002751/ci6100Isup2.hkl |
CCDC reference: 182619
Single crystals of (I) were grown from a saturated aqueous solution containing DL-valine and trichloroacetic acid in stoichiometric ratio.
All the H atoms were located from a difference Fourier map and were included in the refinement with isotropic displacement parameters. The range of C—H and N—H bond lengths are 0.96 (3)–0.98 (2) Å and 0.84 (2)–0.90 (2) Å, respectively, and the O—H distance is 0.89 (3) Å.
Data collection: SMART-NT (Bruker, 1999); cell refinement: SMART-NT; data reduction: SAINT-NT (Bruker, 1999); 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.
Fig. 1. The molecular structure of (I) with the atom-numbering scheme and 50% probability displacement ellipsoids. | |
Fig. 2. Packing of the molecules of (I) viewed down the a axis. |
C5H12NO2+·C2Cl3O2− | Z = 2 |
Mr = 280.53 | F(000) = 288 |
Triclinic, P1 | Dx = 1.578 Mg m−3 Dm = 1.60 Mg m−3 Dm measured by floatation in bromoform and xylene |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 7.2380 (14) Å | Cell parameters from 1024 reflections |
b = 8.4150 (17) Å | θ = 2.5–23.0° |
c = 10.303 (2) Å | µ = 0.77 mm−1 |
α = 106.50 (3)° | T = 123 K |
β = 97.50 (3)° | Prismatic, colourless |
γ = 95.80 (3)° | 0.50 × 0.40 × 0.15 mm |
V = 590.2 (2) Å3 |
Bruker SMART CCD diffractometer | 3537 independent reflections |
Radiation source: fine-focus sealed tube | 3204 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.019 |
Detector resolution: 8 pixels mm-1 | θmax = 30.7°, θmin = 2.6° |
ω scans | h = −9→10 |
Absorption correction: empirical (using intensity measurements) (SADABS; Bruker, 1998) | k = −11→12 |
Tmin = 0.68, Tmax = 0.89 | l = −14→14 |
7923 measured reflections |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.033 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.083 | All H-atom parameters refined |
S = 1.04 | w = 1/[σ2(Fo2) + (0.0346P)2 + 0.3602P] where P = (Fo2 + 2Fc2)/3 |
3537 reflections | (Δ/σ)max < 0.001 |
184 parameters | Δρmax = 0.61 e Å−3 |
0 restraints | Δρmin = −0.59 e Å−3 |
C5H12NO2+·C2Cl3O2− | γ = 95.80 (3)° |
Mr = 280.53 | V = 590.2 (2) Å3 |
Triclinic, P1 | Z = 2 |
a = 7.2380 (14) Å | Mo Kα radiation |
b = 8.4150 (17) Å | µ = 0.77 mm−1 |
c = 10.303 (2) Å | T = 123 K |
α = 106.50 (3)° | 0.50 × 0.40 × 0.15 mm |
β = 97.50 (3)° |
Bruker SMART CCD diffractometer | 3537 independent reflections |
Absorption correction: empirical (using intensity measurements) (SADABS; Bruker, 1998) | 3204 reflections with I > 2σ(I) |
Tmin = 0.68, Tmax = 0.89 | Rint = 0.019 |
7923 measured reflections |
R[F2 > 2σ(F2)] = 0.033 | 0 restraints |
wR(F2) = 0.083 | All H-atom parameters refined |
S = 1.04 | Δρmax = 0.61 e Å−3 |
3537 reflections | Δρmin = −0.59 e Å−3 |
184 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 | ||
Cl1 | 0.30543 (4) | 0.87106 (4) | 0.82868 (4) | 0.03004 (9) | |
Cl2 | 0.55245 (5) | 1.08232 (6) | 0.73112 (7) | 0.05368 (15) | |
Cl3 | 0.47752 (6) | 0.72657 (7) | 0.59258 (4) | 0.05099 (13) | |
O1 | 0.40290 (13) | 0.45980 (12) | 0.79978 (11) | 0.0270 (2) | |
O2 | 0.23758 (14) | 0.54991 (11) | 0.97001 (10) | 0.02560 (19) | |
O3 | 0.65035 (13) | 0.72929 (12) | 0.89273 (11) | 0.0263 (2) | |
O4 | 0.83858 (13) | 0.92835 (12) | 0.85109 (12) | 0.0294 (2) | |
N | 0.03102 (15) | 0.24810 (14) | 0.91265 (12) | 0.0222 (2) | |
C1 | 0.26405 (16) | 0.44550 (15) | 0.86814 (13) | 0.0207 (2) | |
C2 | 0.13296 (17) | 0.28081 (15) | 0.80351 (13) | 0.0214 (2) | |
C3 | −0.00515 (18) | 0.28336 (17) | 0.67831 (14) | 0.0261 (2) | |
C4 | 0.0915 (3) | 0.2638 (3) | 0.55220 (18) | 0.0449 (4) | |
C5 | −0.1044 (2) | 0.4382 (2) | 0.70797 (17) | 0.0352 (3) | |
C6 | 0.68459 (17) | 0.84578 (14) | 0.84195 (13) | 0.0202 (2) | |
C7 | 0.51198 (17) | 0.88333 (16) | 0.75411 (14) | 0.0241 (2) | |
H10 | 0.475 (4) | 0.559 (3) | 0.835 (3) | 0.056 (7)* | |
H1N | 0.116 (3) | 0.251 (2) | 0.984 (2) | 0.035 (5)* | |
H2N | −0.033 (3) | 0.153 (3) | 0.885 (2) | 0.032 (5)* | |
H3N | −0.042 (3) | 0.328 (2) | 0.9425 (19) | 0.030 (5)* | |
H2 | 0.206 (3) | 0.192 (2) | 0.7769 (18) | 0.023 (4)* | |
H3 | −0.101 (3) | 0.181 (2) | 0.659 (2) | 0.032 (5)* | |
H41 | 0.182 (4) | 0.360 (3) | 0.565 (3) | 0.057 (7)* | |
H42 | −0.002 (4) | 0.248 (3) | 0.470 (3) | 0.067 (8)* | |
H43 | 0.160 (3) | 0.169 (3) | 0.535 (2) | 0.045 (6)* | |
H51 | −0.195 (3) | 0.438 (3) | 0.631 (2) | 0.051 (6)* | |
H52 | −0.016 (3) | 0.537 (3) | 0.724 (2) | 0.047 (6)* | |
H53 | −0.169 (3) | 0.456 (3) | 0.788 (2) | 0.047 (6)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cl1 | 0.02090 (14) | 0.02902 (16) | 0.0465 (2) | 0.00414 (11) | 0.01287 (13) | 0.01786 (14) |
Cl2 | 0.02408 (17) | 0.0534 (3) | 0.1099 (4) | 0.00881 (16) | 0.0161 (2) | 0.0630 (3) |
Cl3 | 0.0367 (2) | 0.0797 (3) | 0.02576 (18) | 0.0071 (2) | −0.00067 (14) | 0.00196 (19) |
O1 | 0.0187 (4) | 0.0204 (4) | 0.0395 (5) | −0.0041 (3) | 0.0067 (4) | 0.0069 (4) |
O2 | 0.0247 (4) | 0.0199 (4) | 0.0297 (5) | −0.0032 (3) | 0.0026 (3) | 0.0067 (3) |
O3 | 0.0211 (4) | 0.0214 (4) | 0.0364 (5) | −0.0032 (3) | −0.0021 (4) | 0.0138 (4) |
O4 | 0.0190 (4) | 0.0226 (4) | 0.0448 (6) | −0.0060 (3) | −0.0015 (4) | 0.0132 (4) |
N | 0.0190 (5) | 0.0177 (5) | 0.0296 (5) | −0.0031 (4) | 0.0012 (4) | 0.0100 (4) |
C1 | 0.0159 (5) | 0.0169 (5) | 0.0294 (6) | −0.0006 (4) | 0.0001 (4) | 0.0098 (4) |
C2 | 0.0165 (5) | 0.0166 (5) | 0.0301 (6) | −0.0015 (4) | 0.0041 (4) | 0.0069 (4) |
C3 | 0.0211 (5) | 0.0283 (6) | 0.0245 (6) | −0.0049 (5) | 0.0019 (4) | 0.0049 (5) |
C4 | 0.0385 (9) | 0.0610 (12) | 0.0300 (8) | −0.0066 (8) | 0.0092 (6) | 0.0086 (7) |
C5 | 0.0322 (7) | 0.0387 (8) | 0.0327 (7) | 0.0059 (6) | −0.0069 (6) | 0.0127 (6) |
C6 | 0.0180 (5) | 0.0153 (5) | 0.0248 (5) | −0.0006 (4) | 0.0012 (4) | 0.0043 (4) |
C7 | 0.0173 (5) | 0.0262 (6) | 0.0324 (6) | 0.0014 (4) | 0.0050 (4) | 0.0146 (5) |
Cl1—C7 | 1.7747 (14) | C2—C3 | 1.5320 (19) |
Cl2—C7 | 1.7580 (14) | C2—H2 | 0.957 (18) |
Cl3—C7 | 1.7749 (17) | C3—C5 | 1.525 (2) |
O1—C1 | 1.3150 (16) | C3—C4 | 1.531 (2) |
O1—H10 | 0.89 (3) | C3—H3 | 1.00 (2) |
O2—C1 | 1.2136 (17) | C4—H41 | 0.96 (3) |
O3—C6 | 1.2538 (15) | C4—H42 | 0.98 (3) |
O4—C6 | 1.2300 (15) | C4—H43 | 0.97 (2) |
N—C2 | 1.4953 (17) | C5—H51 | 0.96 (2) |
N—H1N | 0.89 (2) | C5—H52 | 0.96 (2) |
N—H2N | 0.84 (2) | C5—H53 | 0.98 (2) |
N—H3N | 0.90 (2) | C6—C7 | 1.5578 (18) |
C1—C2 | 1.5197 (17) | ||
C1—O1—H10 | 111.8 (16) | C3—C4—H41 | 110.6 (15) |
C2—N—H1N | 108.5 (13) | C3—C4—H42 | 110.3 (17) |
C2—N—H2N | 110.6 (14) | H41—C4—H42 | 110 (2) |
H1N—N—H2N | 108.0 (18) | C3—C4—H43 | 112.7 (13) |
C2—N—H3N | 111.8 (12) | H41—C4—H43 | 106 (2) |
H1N—N—H3N | 106.9 (18) | H42—C4—H43 | 107 (2) |
H2N—N—H3N | 110.8 (18) | C3—C5—H51 | 112.5 (14) |
O2—C1—O1 | 125.57 (11) | C3—C5—H52 | 110.3 (14) |
O2—C1—C2 | 122.27 (11) | H51—C5—H52 | 104.8 (19) |
O1—C1—C2 | 112.15 (11) | C3—C5—H53 | 114.8 (13) |
N—C2—C1 | 107.11 (11) | H51—C5—H53 | 107.3 (19) |
N—C2—C3 | 111.25 (10) | H52—C5—H53 | 106.5 (19) |
C1—C2—C3 | 112.46 (10) | O4—C6—O3 | 127.11 (12) |
N—C2—H2 | 107.2 (11) | O4—C6—C7 | 117.64 (11) |
C1—C2—H2 | 109.2 (11) | O3—C6—C7 | 115.22 (11) |
C3—C2—H2 | 109.5 (11) | C6—C7—Cl2 | 112.03 (9) |
C5—C3—C4 | 111.94 (15) | C6—C7—Cl1 | 111.82 (9) |
C5—C3—C2 | 112.10 (11) | Cl2—C7—Cl1 | 108.40 (8) |
C4—C3—C2 | 111.28 (13) | C6—C7—Cl3 | 105.78 (9) |
C5—C3—H3 | 108.9 (11) | Cl2—C7—Cl3 | 109.62 (8) |
C4—C3—H3 | 107.7 (11) | Cl1—C7—Cl3 | 109.13 (8) |
C2—C3—H3 | 104.5 (11) | ||
O2—C1—C2—N | −22.42 (16) | C1—C2—C3—C4 | 76.93 (16) |
O1—C1—C2—N | 158.59 (10) | O4—C6—C7—Cl2 | −20.09 (16) |
O2—C1—C2—C3 | 100.10 (14) | O3—C6—C7—Cl2 | 161.92 (10) |
O1—C1—C2—C3 | −78.89 (13) | O4—C6—C7—Cl1 | −142.02 (11) |
N—C2—C3—C5 | 70.86 (14) | O3—C6—C7—Cl1 | 40.00 (14) |
C1—C2—C3—C5 | −49.30 (15) | O4—C6—C7—Cl3 | 99.30 (12) |
N—C2—C3—C4 | −162.91 (13) | O3—C6—C7—Cl3 | −78.68 (12) |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H10···O3 | 0.89 (3) | 1.72 (3) | 2.601 (2) | 169 (2) |
N—H2N···O4i | 0.84 (2) | 1.93 (2) | 2.761 (2) | 169.6 (19) |
N—H1N···O3ii | 0.89 (2) | 1.94 (2) | 2.804 (2) | 163.6 (19) |
N—H3N···O2iii | 0.90 (2) | 2.00 (2) | 2.871 (2) | 162.5 (17) |
Symmetry codes: (i) x−1, y−1, z; (ii) −x+1, −y+1, −z+2; (iii) −x, −y+1, −z+2. |
Experimental details
Crystal data | |
Chemical formula | C5H12NO2+·C2Cl3O2− |
Mr | 280.53 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 123 |
a, b, c (Å) | 7.2380 (14), 8.4150 (17), 10.303 (2) |
α, β, γ (°) | 106.50 (3), 97.50 (3), 95.80 (3) |
V (Å3) | 590.2 (2) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.77 |
Crystal size (mm) | 0.50 × 0.40 × 0.15 |
Data collection | |
Diffractometer | Bruker SMART CCD diffractometer |
Absorption correction | Empirical (using intensity measurements) (SADABS; Bruker, 1998) |
Tmin, Tmax | 0.68, 0.89 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 7923, 3537, 3204 |
Rint | 0.019 |
(sin θ/λ)max (Å−1) | 0.718 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.033, 0.083, 1.04 |
No. of reflections | 3537 |
No. of parameters | 184 |
H-atom treatment | All H-atom parameters refined |
Δρmax, Δρmin (e Å−3) | 0.61, −0.59 |
Computer programs: SMART-NT (Bruker, 1999), SMART-NT, SAINT-NT (Bruker, 1999), SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), PLATON (Spek, 1999), SHELXL97.
Cl1—C7 | 1.7747 (14) | N—C2 | 1.4953 (17) |
Cl2—C7 | 1.7580 (14) | C1—C2 | 1.5197 (17) |
Cl3—C7 | 1.7749 (17) | C2—C3 | 1.5320 (19) |
O1—C1 | 1.3150 (16) | C3—C5 | 1.525 (2) |
O2—C1 | 1.2136 (17) | C3—C4 | 1.531 (2) |
O3—C6 | 1.2538 (15) | C6—C7 | 1.5578 (18) |
O4—C6 | 1.2300 (15) | ||
O2—C1—O1 | 125.57 (11) | O4—C6—O3 | 127.11 (12) |
O2—C1—C2 | 122.27 (11) | O4—C6—C7 | 117.64 (11) |
O1—C1—C2 | 112.15 (11) | O3—C6—C7 | 115.22 (11) |
N—C2—C1 | 107.11 (11) | C6—C7—Cl2 | 112.03 (9) |
N—C2—C3 | 111.25 (10) | C6—C7—Cl1 | 111.82 (9) |
C1—C2—C3 | 112.46 (10) | Cl2—C7—Cl1 | 108.40 (8) |
C5—C3—C4 | 111.94 (15) | C6—C7—Cl3 | 105.78 (9) |
C5—C3—C2 | 112.10 (11) | Cl2—C7—Cl3 | 109.62 (8) |
C4—C3—C2 | 111.28 (13) | Cl1—C7—Cl3 | 109.13 (8) |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H10···O3 | 0.89 (3) | 1.72 (3) | 2.601 (2) | 169 (2) |
N—H2N···O4i | 0.84 (2) | 1.93 (2) | 2.761 (2) | 169.6 (19) |
N—H1N···O3ii | 0.89 (2) | 1.94 (2) | 2.804 (2) | 163.6 (19) |
N—H3N···O2iii | 0.90 (2) | 2.00 (2) | 2.871 (2) | 162.5 (17) |
Symmetry codes: (i) x−1, y−1, z; (ii) −x+1, −y+1, −z+2; (iii) −x, −y+1, −z+2. |
In our laboratory, we have been elucidating the crystal structures of proton-transfer complexes of the type A·B, where A is a amino acid and B is a carboxylic acid which is believed to have existed in the pre-biotic earth (Miller & Orgel, 1974; Kvenvolden et al., 1971). A brief survey on the Cambridge structural Database Database (Allen & Kennard, 1993) revealed scarcity of precise crystallographic data on amino acid–halogeno acetic acid complexes. We report here, the crystal structure of a complex of DL-valine with trichloroacetic acid, namely, DL-valinium trichloroacetate, (I). Systematic X-ray investigation, on such compounds are expected to throw light on the importance of halogen–halogen interactions on biomolecular aggregation patterns. The crystal structure of a complex of a dipeptide with trichloroacetic acid, L-phenylalanylglycine trichloroaceteate is already reported (Mitra & Subramanian, 1993). The crystal structure of trichloroacetic acid still remains unknown.
In (I), the valine molecule is in a cationic state with a positively charged amino group and an uncharged carboxylic acid group. The trichloroacetic acid exists in the anionic state with a negatively charged carboxylate group (Fig. 1). The carboxylate group of valine is planar and the amino nitrogen deviates from this plane by 0.528 (1) Å leading to the twisting of the C—N bond out of the plane of the carboxyl group by 21.9 (1)°. The conformation of the valine molecule determined by the internal rotation angles ψ2 [-22.4 (2)], χ11 [-162.9 (1)] and χ12 [70.9 (1)°] agree well with 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, in DL-valinium maleate (Alagar et al., 2001), χ11 [57.1 (2)°] deviates siginificantly from that observed in the present study. In the crystal, the valine and the trichloroacetic acid molecules are alteratively linked by O—H···O and N—H···O hydrogen bonds to form infinte one-dimensional chains along [110]. The inversion related chains are interlinked by N—H···O hydrogen bonds to form infinite two-dimensional network parallel to (001). In this network, the D and L isomers exist as centrosymmetrically hydrogen-bonded dimers (Table 2).