Buy article online - an online subscription or single-article purchase is required to access this article.
The crystal structure of L-valyl-L-leucine acetonitrile solvate presented here adds to 24 previously reported structures of dipeptides constructed from the five nonpolar amino acids L-alanine, L-valine, L-isoleucine, L-leucine and L-phenylalanine. It thus constitutes the final piece in the 5 × 5 puzzle of hydrophobic dipeptide structures. This opportunity is taken to review the crystal packing arrangements and hydrogen-bonding preferences of a rather unique group of substances, with updated information on the various hydrogen-bonding patterns and the associated peptide conformations.
Supporting information
CCDC reference: 1825080
Data collection: APEX2 (Bruker, 2014); cell refinement: APEX2 (Bruker, 2014); data reduction: APEX2 (Bruker, 2014); program(s) used to solve structure: APEX2 (Bruker, 2014); program(s) used to refine structure: SHELXT (Sheldrick, 2015a); molecular graphics: Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXL2014 (Sheldrick, 2015b).
(S)-2-((S)-2-Amino-3-methyl-butyrylamino)-4-methyl-pentanoic acid
acetonitrile solvate
top
Crystal data top
C11H22N2O3·C2H3N | Dx = 1.165 Mg m−3 |
Mr = 271.36 | Mo Kα radiation, λ = 0.71073 Å |
Orthorhombic, P212121 | Cell parameters from 858 reflections |
a = 5.341 (3) Å | θ = 2.5–20.7° |
b = 13.536 (6) Å | µ = 0.08 mm−1 |
c = 21.406 (8) Å | T = 100 K |
V = 1547.6 (12) Å3 | Plate, colorless |
Z = 4 | 0.42 × 0.15 × 0.01 mm |
F(000) = 592 | |
Data collection top
Bruker D8 Venture with Photon 100 CMOS detector diffractometer | 1572 independent reflections |
Radiation source: fine-focus sealed tube | 903 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.190 |
Detector resolution: 8.3 pixels mm-1 | θmax = 20.8°, θmin = 2.4° |
Sets of exposures each taken over 0.5° ω rotation scans | h = −5→4 |
Absorption correction: multi-scan SADABS (Bruker, 2014) | k = −13→12 |
Tmin = 0.612, Tmax = 1.000 | l = −21→19 |
6287 measured reflections | |
Refinement top
Refinement on F2 | Hydrogen site location: inferred from neighbouring sites |
Least-squares matrix: full | H-atom parameters constrained |
R[F2 > 2σ(F2)] = 0.082 | w = 1/[σ2(Fo2) + (0.0807P)2] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.184 | (Δ/σ)max < 0.001 |
S = 1.01 | Δρmax = 0.26 e Å−3 |
1572 reflections | Δρmin = −0.28 e Å−3 |
140 parameters | Extinction correction: SHELXL, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
72 restraints | Extinction coefficient: 0.093 (13) |
Special details top
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes)
are estimated using the full covariance matrix. The cell esds are taken
into account individually in the estimation of esds in distances, angles
and torsion angles; correlations between esds in cell parameters are only
used when they are defined by crystal symmetry. An approximate (isotropic)
treatment of cell esds is used for estimating esds involving l.s. planes. |
Refinement. Non-terminal C-atoms refined isotropically due to poor
reflection-to-parameter ratio.
All H atoms in theoretical positions. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
O1 | 0.0880 (14) | 0.6221 (6) | 0.2086 (3) | 0.029 (2) | |
O2 | 0.0294 (16) | 0.3336 (5) | 0.2523 (3) | 0.028 (2) | |
O3 | −0.3193 (14) | 0.3338 (5) | 0.1909 (3) | 0.023 (2) | |
N1 | 0.5574 (18) | 0.7039 (6) | 0.2281 (4) | 0.025 (3) | |
H1 | 0.5398 | 0.7151 | 0.1864 | 0.037* | |
H2 | 0.7148 | 0.7210 | 0.2402 | 0.037* | |
H3 | 0.4436 | 0.7408 | 0.2495 | 0.037* | |
N2 | 0.2677 (18) | 0.4746 (6) | 0.1816 (3) | 0.018 (3) | |
H4 | 0.4091 | 0.4414 | 0.1792 | 0.022* | |
C1 | 0.513 (2) | 0.5941 (7) | 0.2418 (5) | 0.022 (3)* | |
H11 | 0.6553 | 0.5547 | 0.2242 | 0.026* | |
C2 | 0.503 (2) | 0.5788 (7) | 0.3127 (5) | 0.024 (3)* | |
H2A | 0.3637 | 0.6196 | 0.3303 | 0.029* | |
C3 | 0.455 (2) | 0.4695 (8) | 0.3284 (5) | 0.031 (4) | |
H31 | 0.4490 | 0.4611 | 0.3738 | 0.046* | |
H32 | 0.2953 | 0.4487 | 0.3101 | 0.046* | |
H33 | 0.5907 | 0.4290 | 0.3111 | 0.046* | |
C4 | 0.756 (2) | 0.6102 (8) | 0.3446 (5) | 0.034 (4) | |
H41 | 0.7440 | 0.5997 | 0.3898 | 0.051* | |
H42 | 0.8932 | 0.5703 | 0.3277 | 0.051* | |
H43 | 0.7884 | 0.6802 | 0.3362 | 0.051* | |
C5 | 0.270 (3) | 0.5645 (9) | 0.2086 (5) | 0.026 (3)* | |
C6 | 0.037 (2) | 0.4292 (7) | 0.1560 (5) | 0.024 (3)* | |
H61 | −0.0846 | 0.4834 | 0.1469 | 0.028* | |
C7 | 0.094 (2) | 0.3760 (8) | 0.0945 (4) | 0.020 (3)* | |
H71 | −0.0575 | 0.3399 | 0.0811 | 0.025* | |
H72 | 0.2274 | 0.3266 | 0.1022 | 0.025* | |
C8 | 0.180 (2) | 0.4454 (8) | 0.0401 (5) | 0.022 (3)* | |
H81 | 0.3251 | 0.4851 | 0.0555 | 0.026* | |
C9 | −0.030 (2) | 0.5183 (8) | 0.0217 (5) | 0.037 (4) | |
H91 | −0.0821 | 0.5560 | 0.0586 | 0.056* | |
H92 | 0.0322 | 0.5637 | −0.0104 | 0.056* | |
H93 | −0.1734 | 0.4813 | 0.0052 | 0.056* | |
C10 | 0.269 (2) | 0.3846 (8) | −0.0147 (4) | 0.032 (4) | |
H101 | 0.4019 | 0.3396 | −0.0009 | 0.048* | |
H102 | 0.1292 | 0.3463 | −0.0315 | 0.048* | |
H103 | 0.3348 | 0.4286 | −0.0472 | 0.048* | |
C11 | −0.087 (3) | 0.3579 (8) | 0.2046 (5) | 0.024 (3)* | |
C13 | 0.032 (2) | 0.8103 (9) | 0.0897 (5) | 0.047 (4) | |
H131 | 0.0379 | 0.8689 | 0.0629 | 0.070* | |
H132 | 0.0140 | 0.8308 | 0.1334 | 0.070* | |
H133 | −0.1104 | 0.7689 | 0.0778 | 0.070* | |
C12 | 0.265 (3) | 0.7538 (10) | 0.0825 (6) | 0.038 (4) | |
N3 | 0.450 (2) | 0.7083 (8) | 0.0788 (5) | 0.043 (3) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
O1 | 0.012 (5) | 0.038 (5) | 0.038 (5) | 0.001 (4) | 0.000 (4) | −0.007 (4) |
O2 | 0.021 (6) | 0.040 (5) | 0.022 (4) | 0.003 (5) | −0.004 (4) | 0.008 (4) |
O3 | 0.007 (5) | 0.029 (5) | 0.033 (5) | 0.001 (4) | 0.003 (4) | −0.001 (4) |
N1 | 0.015 (7) | 0.040 (6) | 0.019 (5) | −0.005 (6) | 0.003 (5) | 0.000 (5) |
N2 | 0.010 (5) | 0.026 (4) | 0.019 (4) | 0.005 (4) | −0.002 (4) | −0.002 (4) |
C3 | 0.026 (9) | 0.048 (8) | 0.019 (7) | 0.006 (8) | −0.003 (7) | 0.000 (6) |
C4 | 0.027 (9) | 0.049 (8) | 0.025 (7) | 0.008 (9) | −0.010 (7) | −0.003 (6) |
C9 | 0.041 (10) | 0.041 (7) | 0.030 (7) | −0.010 (8) | −0.001 (7) | 0.001 (6) |
C10 | 0.027 (9) | 0.047 (8) | 0.022 (7) | 0.004 (8) | 0.004 (7) | −0.001 (6) |
C13 | 0.015 (9) | 0.064 (9) | 0.062 (9) | 0.008 (8) | −0.001 (8) | −0.004 (7) |
C12 | 0.031 (8) | 0.051 (8) | 0.032 (7) | −0.004 (7) | 0.001 (7) | −0.003 (6) |
N3 | 0.037 (9) | 0.048 (7) | 0.045 (7) | −0.005 (7) | −0.003 (7) | 0.002 (6) |
Geometric parameters (Å, º) top
O1—C5 | 1.246 (13) | C4—H43 | 0.9800 |
O2—C11 | 1.238 (12) | C6—C7 | 1.530 (13) |
O3—C11 | 1.317 (13) | C6—C11 | 1.566 (14) |
N1—C1 | 1.534 (12) | C6—H61 | 1.0000 |
N1—H1 | 0.9100 | C7—C8 | 1.565 (13) |
N1—H2 | 0.9100 | C7—H71 | 0.9900 |
N1—H3 | 0.9100 | C7—H72 | 0.9900 |
N2—C5 | 1.347 (12) | C8—C10 | 1.509 (13) |
N2—C6 | 1.482 (14) | C8—C9 | 1.544 (14) |
N2—H4 | 0.8800 | C8—H81 | 1.0000 |
C1—C2 | 1.533 (14) | C9—H91 | 0.9800 |
C1—C5 | 1.535 (17) | C9—H92 | 0.9800 |
C1—H11 | 1.0000 | C9—H93 | 0.9800 |
C2—C3 | 1.538 (13) | C10—H101 | 0.9800 |
C2—C4 | 1.573 (16) | C10—H102 | 0.9800 |
C2—H2A | 1.0000 | C10—H103 | 0.9800 |
C3—H31 | 0.9800 | C13—C12 | 1.468 (18) |
C3—H32 | 0.9800 | C13—H131 | 0.9800 |
C3—H33 | 0.9800 | C13—H132 | 0.9800 |
C4—H41 | 0.9800 | C13—H133 | 0.9800 |
C4—H42 | 0.9800 | C12—N3 | 1.165 (15) |
| | | |
C1—N1—H1 | 109.5 | C7—C6—C11 | 111.5 (8) |
C1—N1—H2 | 109.5 | N2—C6—H61 | 107.9 |
H1—N1—H2 | 109.5 | C7—C6—H61 | 107.9 |
C1—N1—H3 | 109.5 | C11—C6—H61 | 107.9 |
H1—N1—H3 | 109.5 | C6—C7—C8 | 114.7 (8) |
H2—N1—H3 | 109.5 | C6—C7—H71 | 108.6 |
C5—N2—C6 | 122.8 (11) | C8—C7—H71 | 108.6 |
C5—N2—H4 | 118.6 | C6—C7—H72 | 108.6 |
C6—N2—H4 | 118.6 | C8—C7—H72 | 108.6 |
C2—C1—N1 | 109.0 (8) | H71—C7—H72 | 107.6 |
C2—C1—C5 | 113.1 (10) | C10—C8—C9 | 112.3 (9) |
N1—C1—C5 | 107.1 (9) | C10—C8—C7 | 110.1 (9) |
C2—C1—H11 | 109.2 | C9—C8—C7 | 111.2 (10) |
N1—C1—H11 | 109.2 | C10—C8—H81 | 107.7 |
C5—C1—H11 | 109.2 | C9—C8—H81 | 107.7 |
C1—C2—C3 | 110.6 (8) | C7—C8—H81 | 107.7 |
C1—C2—C4 | 111.2 (10) | C8—C9—H91 | 109.5 |
C3—C2—C4 | 107.9 (10) | C8—C9—H92 | 109.5 |
C1—C2—H2A | 109.0 | H91—C9—H92 | 109.5 |
C3—C2—H2A | 109.0 | C8—C9—H93 | 109.5 |
C4—C2—H2A | 109.0 | H91—C9—H93 | 109.5 |
C2—C3—H31 | 109.5 | H92—C9—H93 | 109.5 |
C2—C3—H32 | 109.5 | C8—C10—H101 | 109.5 |
H31—C3—H32 | 109.5 | C8—C10—H102 | 109.5 |
C2—C3—H33 | 109.5 | H101—C10—H102 | 109.5 |
H31—C3—H33 | 109.5 | C8—C10—H103 | 109.5 |
H32—C3—H33 | 109.5 | H101—C10—H103 | 109.5 |
C2—C4—H41 | 109.5 | H102—C10—H103 | 109.5 |
C2—C4—H42 | 109.5 | O2—C11—O3 | 126.2 (11) |
H41—C4—H42 | 109.5 | O2—C11—C6 | 120.0 (12) |
C2—C4—H43 | 109.5 | O3—C11—C6 | 113.7 (11) |
H41—C4—H43 | 109.5 | C12—C13—H131 | 109.5 |
H42—C4—H43 | 109.5 | C12—C13—H132 | 109.5 |
O1—C5—N2 | 123.9 (12) | H131—C13—H132 | 109.5 |
O1—C5—C1 | 119.8 (11) | C12—C13—H133 | 109.5 |
N2—C5—C1 | 116.2 (12) | H131—C13—H133 | 109.5 |
N2—C6—C7 | 110.3 (10) | H132—C13—H133 | 109.5 |
N2—C6—C11 | 111.1 (9) | N3—C12—C13 | 177.7 (15) |
| | | |
N1—C1—C2—C3 | 179.2 (9) | C5—N2—C6—C7 | 139.9 (9) |
C5—C1—C2—C3 | 60.2 (14) | C5—N2—C6—C11 | −95.9 (11) |
N1—C1—C2—C4 | −60.9 (13) | N2—C6—C7—C8 | −65.0 (12) |
C5—C1—C2—C4 | −179.9 (9) | C11—C6—C7—C8 | 171.0 (10) |
C6—N2—C5—O1 | −8.0 (17) | C6—C7—C8—C10 | 171.2 (10) |
C6—N2—C5—C1 | 170.7 (9) | C6—C7—C8—C9 | −63.6 (13) |
C2—C1—C5—O1 | 79.9 (13) | N2—C6—C11—O2 | −11.7 (14) |
N1—C1—C5—O1 | −40.2 (14) | C7—C6—C11—O2 | 111.9 (12) |
C2—C1—C5—N2 | −98.9 (12) | N2—C6—C11—O3 | 164.8 (9) |
N1—C1—C5—N2 | 140.9 (9) | C7—C6—C11—O3 | −71.7 (12) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···N3 | 0.91 | 2.35 | 3.247 (12) | 167 |
N1—H2···O2i | 0.91 | 2.05 | 2.851 (13) | 146 |
N1—H2···O1ii | 0.91 | 2.50 | 3.071 (12) | 122 |
N1—H3···O3iii | 0.91 | 1.91 | 2.778 (11) | 158 |
N2—H4···O3ii | 0.88 | 2.07 | 2.922 (11) | 162 |
C1—H11···O1ii | 1.00 | 2.51 | 3.173 (15) | 124 |
C3—H32···O2 | 0.98 | 2.45 | 3.348 (14) | 153 |
C13—H132···O2iii | 0.98 | 2.46 | 3.413 (14) | 164 |
C13—H133···N3iv | 0.98 | 2.49 | 3.412 (17) | 157 |
Symmetry codes: (i) −x+1, y+1/2, −z+1/2; (ii) x+1, y, z; (iii) −x, y+1/2, −z+1/2; (iv) x−1, y, z. |
Subscribe to Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials
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.