In the title compound, C
5H
12NO
2+·ClO
4−·C
5H
11NO
2·H
2O, the valine as a zwitterion and valinium are bonded through a strong O—H
O hydrogen bond. Their ammonium groups and the perchlorate ion are held together by hydrogen bonds. Both valine and valinium show
gauche-II forms.
Supporting information
CCDC reference: 165673
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (C-C) = 0.006 Å
- Disorder in solvent or counterion
- R factor = 0.037
- wR factor = 0.110
- Data-to-parameter ratio = 7.3
checkCIF results
No syntax errors found
ADDSYM reports no extra symmetry
Alert Level C:
PLAT_302 Alert C Anion/Solvent Disorder ....................... 8.00 Perc.
General Notes
REFLT_03
From the CIF: _diffrn_reflns_theta_max 24.98
From the CIF: _reflns_number_total 1665
Count of symmetry unique reflns 1668
Completeness (_total/calc) 99.82%
TEST3: Check Friedels for noncentro structure
Estimate of Friedel pairs measured 0
Fraction of Friedel pairs measured 0.000
Are heavy atom types Z>Si present yes
WARNING: Large fraction of Friedel related reflns may
be needed to determine absolute structure
0 Alert Level A = Potentially serious problem
0 Alert Level B = Potential problem
1 Alert Level C = Please check
Colorless needle-shaped crystals of (I) were obtained by the slow evaporation of
an aqueous solution of L-valine and perchloric acid in a stoichiometric
ratio of 2:1.
There is a positional disorder of the perchlorate O atoms. The site-occupation
factors of O2 and O4 are 0.65 (5), and those of O2' and O4' 0.35 (5). The
disorder is possibly due to the onset of rotational disorder of the
perchlorate ion. The H atoms of the water molecule were located from the
difference Fourier maps and refined, while all the other H atoms were fixed by
geometric constraints using HFIX.
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, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 1999); software used to prepare material for publication: SHELXL97.
L-Valine
L-Valinium Perchlorate monohydrate
top
Crystal data top
C5H11NO2+·ClO4−·C5H12NO2·H2O | F(000) = 376 |
Mr = 352.77 | Dx = 1.366 Mg m−3 Dm = 1.369 Mg m−3 Dm measured by flotation in a mixture of carbon tetrachloride and xylene |
Monoclinic, P21 | Mo Kα radiation, λ = 0.71073 Å |
a = 11.235 (3) Å | Cell parameters from 25 reflections |
b = 5.8312 (14) Å | θ = 8.1–13.7° |
c = 13.0948 (19) Å | µ = 0.27 mm−1 |
β = 91.282 (16)° | T = 293 K |
V = 857.7 (3) Å3 | Needles, colorless |
Z = 2 | 0.25 × 0.23 × 0.13 mm |
Data collection top
Enraf-Nonius sealed tube diffractometer | Rint = 0.011 |
Radiation source: fine-focus sealed tube | θmax = 25.0°, θmin = 2.4° |
Graphite monochromator | h = 0→13 |
ω–2θ scans | k = 0→6 |
1751 measured reflections | l = −15→15 |
1665 independent reflections | 3 standard reflections every 60 min |
1481 reflections with I > 2σ(I) | intensity decay: none |
Refinement top
Refinement on F2 | Hydrogen site location: inferred from neighbouring sites |
Least-squares matrix: full | H atoms treated by a mixture of independent and constrained refinement |
R[F2 > 2σ(F2)] = 0.037 | w = 1/[σ2(Fo2) + (0.0658P)2 + 0.132P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.110 | (Δ/σ)max = 0.002 |
S = 1.17 | Δρmax = 0.21 e Å−3 |
1665 reflections | Δρmin = −0.26 e Å−3 |
228 parameters | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
1 restraint | Extinction coefficient: 0.030 (6) |
Primary atom site location: structure-invariant direct methods | Absolute structure: Flack (1983) |
Secondary atom site location: difference Fourier map | Absolute structure parameter: 0.06 (11) |
Crystal data top
C5H11NO2+·ClO4−·C5H12NO2·H2O | V = 857.7 (3) Å3 |
Mr = 352.77 | Z = 2 |
Monoclinic, P21 | Mo Kα radiation |
a = 11.235 (3) Å | µ = 0.27 mm−1 |
b = 5.8312 (14) Å | T = 293 K |
c = 13.0948 (19) Å | 0.25 × 0.23 × 0.13 mm |
β = 91.282 (16)° | |
Data collection top
Enraf-Nonius sealed tube diffractometer | Rint = 0.011 |
1751 measured reflections | 3 standard reflections every 60 min |
1665 independent reflections | intensity decay: none |
1481 reflections with I > 2σ(I) | |
Refinement top
R[F2 > 2σ(F2)] = 0.037 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.110 | Δρmax = 0.21 e Å−3 |
S = 1.17 | Δρmin = −0.26 e Å−3 |
1665 reflections | Absolute structure: Flack (1983) |
228 parameters | Absolute structure parameter: 0.06 (11) |
1 restraint | |
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 | x | y | z | Uiso*/Ueq | Occ. (<1) |
Cl1 | 0.32517 (7) | 0.02913 (19) | 0.09205 (6) | 0.0528 (3) | |
O1 | 0.2394 (3) | −0.0572 (11) | 0.0241 (3) | 0.1091 (18) | |
O3 | 0.2751 (5) | 0.0918 (11) | 0.1838 (3) | 0.1308 (19) | |
O2 | 0.3962 (13) | 0.197 (4) | 0.0469 (13) | 0.112 (6) | 0.65 (5) |
O4 | 0.4124 (9) | −0.132 (3) | 0.133 (2) | 0.124 (6) | 0.65 (5) |
O2' | 0.368 (5) | 0.231 (7) | 0.055 (3) | 0.178 (16) | 0.35 (5) |
O4' | 0.4038 (19) | −0.147 (4) | 0.084 (3) | 0.112 (7) | 0.35 (5) |
O1A | 0.4708 (3) | 0.4853 (5) | 0.3769 (2) | 0.0628 (8) | |
O1B | 0.3434 (3) | 0.3121 (4) | 0.4765 (2) | 0.0605 (8) | |
C11 | 0.3832 (3) | 0.4873 (6) | 0.4311 (2) | 0.0385 (8) | |
C12 | 0.3191 (3) | 0.7135 (6) | 0.4498 (3) | 0.0335 (7) | |
H12 | 0.3297 | 0.7530 | 0.5222 | 0.040* | |
N11 | 0.3775 (2) | 0.8941 (5) | 0.3884 (2) | 0.0380 (6) | |
H11A | 0.3410 | 1.0276 | 0.3980 | 0.057* | |
H11B | 0.3728 | 0.8567 | 0.3225 | 0.057* | |
H11C | 0.4536 | 0.9061 | 0.4079 | 0.057* | |
C13 | 0.1852 (3) | 0.6948 (7) | 0.4259 (3) | 0.0516 (9) | |
H13 | 0.1543 | 0.5767 | 0.4715 | 0.062* | |
C14 | 0.1204 (4) | 0.9175 (10) | 0.4518 (5) | 0.0815 (16) | |
H14A | 0.1406 | 0.9619 | 0.5206 | 0.122* | |
H14B | 0.0359 | 0.8940 | 0.4454 | 0.122* | |
H14C | 0.1439 | 1.0362 | 0.4056 | 0.122* | |
C15 | 0.1584 (4) | 0.6139 (10) | 0.3180 (4) | 0.0811 (15) | |
H15A | 0.0738 | 0.6049 | 0.3069 | 0.122* | |
H15B | 0.1930 | 0.4651 | 0.3082 | 0.122* | |
H15C | 0.1914 | 0.7202 | 0.2704 | 0.122* | |
O2A | 0.3947 (2) | 0.5095 (6) | 0.69524 (19) | 0.0576 (7) | |
O2B | 0.2391 (3) | 0.2967 (6) | 0.6483 (2) | 0.0647 (8) | |
H2B | 0.2688 | 0.3051 | 0.5918 | 0.097* | |
C21 | 0.3045 (3) | 0.4107 (7) | 0.7145 (3) | 0.0437 (8) | |
C22 | 0.2528 (3) | 0.4105 (7) | 0.8206 (3) | 0.0421 (8) | |
H22 | 0.2531 | 0.2517 | 0.8452 | 0.050* | |
N21 | 0.3369 (2) | 0.5432 (7) | 0.88663 (19) | 0.0498 (7) | |
H21A | 0.3103 | 0.5470 | 0.9501 | 0.075* | |
H21B | 0.3428 | 0.6856 | 0.8628 | 0.075* | |
H21C | 0.4082 | 0.4766 | 0.8866 | 0.075* | |
C23 | 0.1250 (3) | 0.4973 (9) | 0.8235 (3) | 0.0602 (10) | |
H23 | 0.0779 | 0.4046 | 0.7749 | 0.072* | |
C24 | 0.0737 (4) | 0.4601 (13) | 0.9282 (5) | 0.097 (2) | |
H24A | 0.0825 | 0.3019 | 0.9472 | 0.145* | |
H24B | −0.0092 | 0.5001 | 0.9265 | 0.145* | |
H24C | 0.1153 | 0.5548 | 0.9772 | 0.145* | |
C25 | 0.1139 (5) | 0.7465 (11) | 0.7894 (5) | 0.0901 (17) | |
H25A | 0.0322 | 0.7935 | 0.7922 | 0.135* | |
H25B | 0.1410 | 0.7612 | 0.7207 | 0.135* | |
H25C | 0.1616 | 0.8418 | 0.8340 | 0.135* | |
OW1 | 0.5770 (3) | 0.4660 (5) | 0.1852 (2) | 0.0578 (8) | |
HW1 | 0.519 (4) | 0.503 (12) | 0.153 (4) | 0.083 (17)* | |
HW2 | 0.543 (4) | 0.449 (10) | 0.245 (4) | 0.068 (14)* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Cl1 | 0.0524 (5) | 0.0638 (6) | 0.0419 (4) | −0.0023 (5) | −0.0037 (3) | 0.0025 (5) |
O1 | 0.0665 (18) | 0.177 (5) | 0.083 (2) | −0.021 (3) | −0.0084 (16) | −0.043 (3) |
O3 | 0.189 (4) | 0.139 (5) | 0.066 (2) | 0.002 (4) | 0.039 (2) | −0.020 (3) |
O2 | 0.102 (7) | 0.150 (14) | 0.084 (7) | −0.070 (7) | −0.020 (5) | 0.042 (7) |
O4 | 0.080 (4) | 0.120 (8) | 0.170 (13) | −0.019 (6) | −0.060 (6) | 0.065 (8) |
O2' | 0.29 (4) | 0.113 (17) | 0.13 (2) | −0.04 (2) | −0.08 (2) | 0.096 (17) |
O4' | 0.095 (10) | 0.111 (11) | 0.127 (17) | 0.067 (11) | −0.059 (10) | −0.042 (12) |
O1A | 0.0708 (16) | 0.0456 (17) | 0.0731 (17) | 0.0148 (14) | 0.0253 (14) | −0.0042 (14) |
O1B | 0.107 (2) | 0.0256 (13) | 0.0498 (15) | 0.0036 (15) | 0.0198 (15) | 0.0005 (12) |
C11 | 0.0523 (17) | 0.0316 (18) | 0.0315 (14) | 0.0059 (15) | −0.0015 (13) | −0.0056 (14) |
C12 | 0.0405 (16) | 0.0248 (15) | 0.0353 (16) | 0.0001 (14) | 0.0034 (13) | −0.0006 (13) |
N11 | 0.0407 (13) | 0.0269 (13) | 0.0466 (15) | −0.0021 (12) | 0.0059 (11) | −0.0032 (11) |
C13 | 0.0384 (17) | 0.0375 (19) | 0.079 (3) | −0.0039 (16) | 0.0071 (17) | 0.0009 (18) |
C14 | 0.046 (2) | 0.068 (3) | 0.131 (4) | 0.016 (2) | 0.009 (2) | −0.015 (3) |
C15 | 0.070 (3) | 0.075 (3) | 0.097 (3) | −0.010 (3) | −0.032 (2) | −0.015 (3) |
O2A | 0.0586 (14) | 0.0598 (16) | 0.0550 (13) | −0.0118 (16) | 0.0198 (11) | −0.0046 (15) |
O2B | 0.0749 (18) | 0.071 (2) | 0.0489 (14) | −0.0180 (17) | 0.0104 (12) | −0.0075 (16) |
C21 | 0.0466 (17) | 0.0368 (17) | 0.0480 (18) | 0.0015 (16) | 0.0106 (15) | 0.0026 (16) |
C22 | 0.0404 (16) | 0.0381 (17) | 0.0481 (18) | 0.0022 (16) | 0.0085 (13) | 0.0084 (16) |
N21 | 0.0476 (14) | 0.060 (2) | 0.0420 (13) | 0.0017 (17) | 0.0038 (11) | 0.0070 (16) |
C23 | 0.0392 (16) | 0.067 (3) | 0.075 (2) | 0.004 (2) | 0.0068 (15) | −0.007 (3) |
C24 | 0.063 (3) | 0.105 (5) | 0.125 (4) | −0.003 (3) | 0.053 (3) | −0.006 (4) |
C25 | 0.075 (3) | 0.079 (4) | 0.116 (4) | 0.038 (3) | −0.015 (3) | 0.008 (3) |
OW1 | 0.0605 (16) | 0.058 (2) | 0.0550 (15) | −0.0017 (14) | 0.0053 (13) | 0.0006 (14) |
Geometric parameters (Å, º) top
Cl1—O4' | 1.360 (17) | C15—H15C | 0.9600 |
Cl1—O2' | 1.37 (3) | O2A—C21 | 1.197 (4) |
Cl1—O3 | 1.387 (4) | O2B—C21 | 1.305 (5) |
Cl1—O1 | 1.391 (4) | O2B—H2B | 0.8200 |
Cl1—O2 | 1.402 (12) | C21—C22 | 1.519 (5) |
Cl1—O4 | 1.456 (11) | C22—N21 | 1.485 (5) |
O1A—C11 | 1.225 (4) | C22—C23 | 1.523 (5) |
O1B—C11 | 1.268 (4) | C22—H22 | 0.9800 |
C11—C12 | 1.525 (5) | N21—H21A | 0.8900 |
C12—N11 | 1.486 (4) | N21—H21B | 0.8900 |
C12—C13 | 1.534 (5) | N21—H21C | 0.8900 |
C12—H12 | 0.9800 | C23—C24 | 1.515 (7) |
N11—H11A | 0.8900 | C23—C25 | 1.524 (8) |
N11—H11B | 0.8900 | C23—H23 | 0.9800 |
N11—H11C | 0.8900 | C24—H24A | 0.9600 |
C13—C15 | 1.513 (6) | C24—H24B | 0.9600 |
C13—C14 | 1.531 (6) | C24—H24C | 0.9600 |
C13—H13 | 0.9800 | C25—H25A | 0.9600 |
C14—H14A | 0.9600 | C25—H25B | 0.9600 |
C14—H14B | 0.9600 | C25—H25C | 0.9600 |
C14—H14C | 0.9600 | OW1—HW1 | 0.80 (5) |
C15—H15A | 0.9600 | OW1—HW2 | 0.89 (5) |
C15—H15B | 0.9600 | | |
| | | |
O4'—Cl1—O2' | 113 (2) | C13—C15—H15A | 109.5 |
O4'—Cl1—O3 | 122.7 (16) | C13—C15—H15B | 109.5 |
O2'—Cl1—O3 | 104 (2) | H15A—C15—H15B | 109.5 |
O4'—Cl1—O1 | 96.9 (11) | C13—C15—H15C | 109.5 |
O2'—Cl1—O1 | 109.2 (16) | H15A—C15—H15C | 109.5 |
O3—Cl1—O1 | 111.2 (3) | H15B—C15—H15C | 109.5 |
O4'—Cl1—O2 | 96.8 (13) | C21—O2B—H2B | 109.5 |
O2'—Cl1—O2 | 16 (3) | O2A—C21—O2B | 124.9 (3) |
O3—Cl1—O2 | 115.3 (9) | O2A—C21—C22 | 122.4 (3) |
O1—Cl1—O2 | 112.1 (7) | O2B—C21—C22 | 112.7 (3) |
O4'—Cl1—O4 | 26.6 (9) | N21—C22—C21 | 106.3 (3) |
O2'—Cl1—O4 | 117 (2) | N21—C22—C23 | 113.6 (3) |
O3—Cl1—O4 | 97.5 (12) | C21—C22—C23 | 113.7 (3) |
O1—Cl1—O4 | 117.0 (10) | N21—C22—H22 | 107.6 |
O2—Cl1—O4 | 103.0 (9) | C21—C22—H22 | 107.6 |
O1A—C11—O1B | 124.0 (3) | C23—C22—H22 | 107.6 |
O1A—C11—C12 | 119.3 (3) | C22—N21—H21A | 109.5 |
O1B—C11—C12 | 116.7 (3) | C22—N21—H21B | 109.5 |
N11—C12—C11 | 108.1 (2) | H21A—N21—H21B | 109.5 |
N11—C12—C13 | 112.5 (3) | C22—N21—H21C | 109.5 |
C11—C12—C13 | 111.7 (3) | H21A—N21—H21C | 109.5 |
N11—C12—H12 | 108.1 | H21B—N21—H21C | 109.5 |
C11—C12—H12 | 108.1 | C24—C23—C22 | 110.6 (4) |
C13—C12—H12 | 108.1 | C24—C23—C25 | 111.8 (5) |
C12—N11—H11A | 109.5 | C22—C23—C25 | 112.4 (4) |
C12—N11—H11B | 109.5 | C24—C23—H23 | 107.3 |
H11A—N11—H11B | 109.5 | C22—C23—H23 | 107.3 |
C12—N11—H11C | 109.5 | C25—C23—H23 | 107.3 |
H11A—N11—H11C | 109.5 | C23—C24—H24A | 109.5 |
H11B—N11—H11C | 109.5 | C23—C24—H24B | 109.5 |
C15—C13—C14 | 112.7 (4) | H24A—C24—H24B | 109.5 |
C15—C13—C12 | 112.7 (3) | C23—C24—H24C | 109.5 |
C14—C13—C12 | 111.3 (3) | H24A—C24—H24C | 109.5 |
C15—C13—H13 | 106.5 | H24B—C24—H24C | 109.5 |
C14—C13—H13 | 106.5 | C23—C25—H25A | 109.5 |
C12—C13—H13 | 106.5 | C23—C25—H25B | 109.5 |
C13—C14—H14A | 109.5 | H25A—C25—H25B | 109.5 |
C13—C14—H14B | 109.5 | C23—C25—H25C | 109.5 |
H14A—C14—H14B | 109.5 | H25A—C25—H25C | 109.5 |
C13—C14—H14C | 109.5 | H25B—C25—H25C | 109.5 |
H14A—C14—H14C | 109.5 | HW1—OW1—HW2 | 98 (4) |
H14B—C14—H14C | 109.5 | | |
| | | |
O1A—C11—C12—N11 | 3.5 (4) | O2A—C21—C22—N21 | −1.8 (5) |
O1B—C11—C12—N11 | −178.7 (3) | O2B—C21—C22—N21 | 179.4 (3) |
O1A—C11—C12—C13 | 127.7 (3) | O2A—C21—C22—C23 | 124.0 (4) |
O1B—C11—C12—C13 | −54.4 (4) | O2B—C21—C22—C23 | −54.8 (5) |
N11—C12—C13—C15 | 65.7 (4) | N21—C22—C23—C24 | −66.4 (5) |
C11—C12—C13—C15 | −56.1 (5) | C21—C22—C23—C24 | 171.8 (4) |
N11—C12—C13—C14 | −62.1 (4) | N21—C22—C23—C25 | 59.3 (5) |
C11—C12—C13—C14 | 176.1 (4) | C21—C22—C23—C25 | −62.5 (5) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N11—H11A···O1Bi | 0.89 | 1.95 | 2.727 (4) | 145 |
N11—H11B···O3i | 0.89 | 2.51 | 3.113 (6) | 126 |
N11—H11B···O4i | 0.89 | 2.53 | 3.37 (3) | 159 |
N11—H11C···O2Aii | 0.89 | 2.28 | 2.886 (4) | 125 |
O2B—H2B···O1B | 0.82 | 1.74 | 2.562 (4) | 175 |
N21—H21A···O2′iii | 0.89 | 2.38 | 2.87 (3) | 115 |
N21—H21A···O1iv | 0.89 | 2.63 | 3.156 (6) | 118 |
N21—H21B···OW1ii | 0.89 | 1.98 | 2.818 (5) | 157 |
N21—H21C···O4ii | 0.89 | 2.13 | 3.013 (11) | 169 |
N21—H21C···O4′ii | 0.89 | 2.26 | 3.13 (2) | 168 |
OW1—HW1···O4i | 0.80 (5) | 2.45 (7) | 3.050 (12) | 133 (6) |
OW1—HW1···O4′i | 0.80 (5) | 2.57 (7) | 3.24 (3) | 143 (6) |
OW1—HW1···O2 | 0.80 (5) | 2.63 (6) | 3.115 (15) | 120 (6) |
OW1—HW1···O2′ | 0.80 (5) | 2.63 (7) | 3.18 (4) | 127 (6) |
OW1—HW2···O1A | 0.89 (5) | 1.93 (5) | 2.806 (4) | 167 (5) |
Symmetry codes: (i) x, y+1, z; (ii) −x+1, y+1/2, −z+1; (iii) x, y, z+1; (iv) x, y+1, z+1. |
Experimental details
Crystal data |
Chemical formula | C5H11NO2+·ClO4−·C5H12NO2·H2O |
Mr | 352.77 |
Crystal system, space group | Monoclinic, P21 |
Temperature (K) | 293 |
a, b, c (Å) | 11.235 (3), 5.8312 (14), 13.0948 (19) |
β (°) | 91.282 (16) |
V (Å3) | 857.7 (3) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.27 |
Crystal size (mm) | 0.25 × 0.23 × 0.13 |
|
Data collection |
Diffractometer | Enraf-Nonius sealed tube diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 1751, 1665, 1481 |
Rint | 0.011 |
(sin θ/λ)max (Å−1) | 0.594 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.037, 0.110, 1.17 |
No. of reflections | 1665 |
No. of parameters | 228 |
No. of restraints | 1 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.21, −0.26 |
Absolute structure | Flack (1983) |
Absolute structure parameter | 0.06 (11) |
Selected geometric parameters (Å, º) topO1A—C11 | 1.225 (4) | O2A—C21 | 1.197 (4) |
O1B—C11 | 1.268 (4) | O2B—C21 | 1.305 (5) |
| | | |
O1A—C11—C12—N11 | 3.5 (4) | O2A—C21—C22—N21 | −1.8 (5) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N11—H11A···O1Bi | 0.89 | 1.95 | 2.727 (4) | 144.8 |
N11—H11B···O3i | 0.89 | 2.51 | 3.113 (6) | 125.7 |
N11—H11B···O4i | 0.89 | 2.53 | 3.37 (3) | 159.3 |
N11—H11C···O2Aii | 0.89 | 2.28 | 2.886 (4) | 125.3 |
O2B—H2B···O1B | 0.82 | 1.74 | 2.562 (4) | 175.0 |
N21—H21A···O2'iii | 0.89 | 2.38 | 2.87 (3) | 115.2 |
N21—H21A···O1iv | 0.89 | 2.63 | 3.156 (6) | 118.4 |
N21—H21B···OW1ii | 0.89 | 1.98 | 2.818 (5) | 157.1 |
N21—H21C···O4ii | 0.89 | 2.13 | 3.013 (11) | 169.1 |
N21—H21C···O4'ii | 0.89 | 2.26 | 3.13 (2) | 168.0 |
OW1—HW1···O4i | 0.80 (5) | 2.45 (7) | 3.050 (12) | 133 (6) |
OW1—HW1···O4'i | 0.80 (5) | 2.57 (7) | 3.24 (3) | 143 (6) |
OW1—HW1···O2 | 0.80 (5) | 2.63 (6) | 3.115 (15) | 120 (6) |
OW1—HW1···O2' | 0.80 (5) | 2.63 (7) | 3.18 (4) | 127 (6) |
OW1—HW2···O1A | 0.89 (5) | 1.93 (5) | 2.806 (4) | 167 (5) |
Symmetry codes: (i) x, y+1, z; (ii) −x+1, y+1/2, −z+1; (iii) x, y, z+1; (iv) x, y+1, z+1. |
Valine is an essential amino acid. The crystal structures of L-valine (Torri et al., 1970), DL-valine (Mallikarjunan & Rao, 1969), L-valine hydrochloride monohydrate (Rao, 1969), L-valine hydrochloride (Parathasarathy, 1966; Ando et al., 1967), DL-valine hydrochloride (Di Blasio et al., 1977) and L-valine nitrate (Srinivasan & Rajaram, 1997) have been reported. In the present study, (I), the structure of valine with perchloric acid was undertaken.
All three possible rotational isomers of the valine molecule, viz. trans, gauche-I, gauche-II have been found in the crystalline state (Torri & Iitaka, 1970). In (I), both valine and valinium molecules are in gauche-II form. The amino N atom deviates from the carboxyl plane by 0.050 (6) Å in the valine molecule and 0.024 (7) Å in the valinium molecule, which corresponds to the twisting of the C—N bond out of the plane of the carboxyl group by 3.5 (4)° in valine and -1.8 (5)° in the valinium molecule. This tendency of twisting of the C—N bonds are found in various amino acids (Lakshminarayanan et al., 1967).
The valine and valinium molecules are bonded through a strong O—H···O hydrogen bond [O2B···O1B distance 2.562 (4) Å]. The perchlorate ion plays a vital role in forming hydrogen bonds with valine and valinium molecules, and stabilizing the structure. The water molecule links the ammonium group of the valinium molecule with perchlorate. A bifurcated hydrogen bond is observed in the case of the water molecule with perchlorate O atoms (Jeffrey & Saenger, 1991). The valine molecule is engaged in a head-to-tail straight (S2) sequence since the N11—H11A···O1B(x, y + 1, z) hydrogen bond connects two amino acids separated by a unit cell along the b axis, and a zigzag (Z1) sequence since N11—H11C···O2A(1 - x, y + 1/2, 1 - z) connects two 21-related amino acids (Vijayan, 1988).