Buy article online - an online subscription or single-article purchase is required to access this article.
Download citation
Download citation
link to html
The title compound, rac-(R,R)-N,N'-bis(1-hydroxy-3-methyl-2-butyl)oxalamide, C12H24N2O4, crystallizes as a non-merohedral twin in the triclinic space group P\overline1. The twin is generated by a twofold rotation about c*. The terminal hydroxy groups of molecules related by an inversion center form hydrogen-bonded dimers. This hydrogen-bonding pattern is further extended into a one-dimensional chain by N-H...O hydrogen bonds.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270104020141/sx1143sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270104020141/sx1143Isup2.hkl
Contains datablock I

CCDC reference: 254948

Comment top

The present structure determination forms part of a systematic study related to hydrogen bonding and gelation properties of bis(amino acid) (Makarević et al., 2001; Perić et al., 2001) and bis(amino alcohol) oxalamide derivatives (Makarević et al., 2003). Fig. 1 shows the molecule of (I), with the atom-numbering scheme. The two iso-butyl residues are located on the same side of the oxalamide bridge and have similar geometries (Table 1). Atoms O1 and O11 of the central oxalamide unit are in a trans conformation and are almost coplanar, with an O1—C1—C11—O11 torsion angle of 177.1 (3)°. The terminal hydroxy groups form a hydrogen-bonded dimer (O21—H21O···O2) related by inversion symmetry (Table 2 and Fig. 2). Consequently, the two molecules of the dimer have opposite chirality. These dimers are further interconnected by N1—H1N···O1 and N11—H11N···O11 hydrogen bonds involving the oxalamide units. The molecules linked by the latter motif have the same chirality and form a one-dimensional ladder pattern (Fig. 3) typical of that found in the crystal structures of many retropeptides (Makarević et al., 2001, 2003). This ladder pattern involves intra- and intermolecular interactions, which form bifurcated (three-centred) hydrogen bonds; oxalamide atoms O11 and O1 act as double acceptors, while atoms N11 and N1 are double donors (Fig. 3 and Table 2). In addition to the ladder pattern involving the oxalamide groups there is an intermolecular hydrogen bond between the oxalamide group and the terminal hydroxy O atom (O2—H2O···O1; Table 2 and Fig. 3), and thus oxalamide atom O1 acts as a triple acceptor. The hydrogen-bonding pattern is an one-dimensional or α-network (Coe et al., 1997), composed of tunnels running along the crystallographic a axis. The inside of the tunnel is hydrophilic, featuring hydroxy and amide groups. The outside of the tunnel is dominated by iso-butyl groups and is thus hydrophobic (Fig. 2). The triclinic crystal is non-merohedrally twinned with a twofold rotation about c* (see Experimental). The corresponding twin supercell is approximately monoclinic (a=5.070 Å, b=40.991 Å, c=12.290 Å, α=90.74°, β=93.71° and γ=89.93°), with three times the volume of the triclinic cell. The twofold axis of the pseudo-monoclinic cell is coaxial to the c* axis of the triclinic cell (Fig. 4). A preliminary study with a Nonius CAD-4 point detector found the monoclinic cell. Only reflections with h+k=3n for any l were present, and scan profiles were split, indicating a possible twin supercell (Fig. 4). After transformation to the triclinic subcell, the twin relation was revealed using ROTAX (Cooper et al., 2002). However, since the data processing with EVALCCD (see Experimental) is much more appropriate than the treatment with ROTAX, we have chosen to use the EVALCCD data. EVALCCD uses physically relevant parameters, such as detector setup and crystal dimensions, to predict reflection shapes and consequently treats overlapping reflections correctly. This physical information is not available in the ROTAX approach.

Experimental top

The synthesis of (I) was described by Makarević et al. (2003).

Refinement top

Reflections for indexing were obtained by a locally written peaksearch program on the first 40 frames. These reflections were indexed using DIRAX (Duisenberg, 1992), resulting in two triclinic lattices related by a twofold rotation about hkl (001). Cell parameters and orientation were refined with PEAKREF (Schreurs, 2003). Reflection intensitities for both domains were integrated using the EVALCCD program suite (Duisenberg et al., 2003). Single reflections of the first domain and overlapping reflections of both domains were merged with MERGEHKLF5 (Schreurs, 2003). The twin refinement was performed with SHELXL97 (Sheldrick, 1997) using the data in HKLF5 format and refinement of batch scale factors (Herbst-Irmer & Sheldrick, 1998). The refinement resulted in a ratio of 80.6 (2):19.4 (2) for the two twin domains. H-atom coordinates were calculated geometrically and refined using a riding model. PLATON (Spek, 2003) was used in the preparation of material for publication.

Computing details top

Figures top
[Figure 1] Fig. 1. The molecular structure of (I), showing the S,S-enantiomer, with displacement ellipsoids at the 50% probability level.
[Figure 2] Fig. 2. The crystal packing of (I), viewed along the crystallographic a axis. The terminal hydroxy groups connect molecules of opposite chirality via O—H···O interactions into a centrosymmetric ring dimer. These ring dimers are connected by N—H···O hydrogen bonds, forming meso bilayers [in the online version, red molecules are of (R,R) and blue molecules are of (S,S) chirality].
[Figure 3] Fig. 3. The intra- and intermolecular N—H···O hydrogen bonds that form the ladder motif running along a. Intermolecular hydrogen bonds between the oxalamide O atoms and the terminal hydroxy groups (O2—H2O···O1) are shown.
[Figure 4] Fig. 4. The relation between the monoclinic supercell and triclinic cell: the twinning twofold axis coincides with the monoclinic b axis. [In the online version, the two triclinic domains are shown in red and blue.]
(I) top
Crystal data top
C12H24N2O4Z = 2
Mr = 260.33F(000) = 284
Triclinic, P1Dx = 1.247 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 5.0475 (9) ÅCell parameters from 212 reflections
b = 10.0957 (9) Åθ = 4.1–20.5°
c = 13.735 (3) ŵ = 0.09 mm1
α = 88.674 (12)°T = 150 K
β = 83.414 (19)°Prism, colorless
γ = 85.922 (10)°0.1 × 0.05 × 0.01 mm
V = 693.5 (2) Å3
Data collection top
Nonius KappaCCD
diffractometer
Rint = 0.097
CCD rotation images, thick slices scansθmax = 27.5°, θmin = 1.0°
3065 measured reflectionsh = 66
3065 independent reflectionsk = 1313
2017 reflections with I > 2σ(I)l = 1617
Refinement top
Refinement on F20 restraints
Least-squares matrix: fullH-atom parameters constrained
R[F2 > 2σ(F2)] = 0.063 w = 1/[σ2(Fo2) + (0.0193P)2 + 0.8157P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.126(Δ/σ)max < 0.001
S = 1.21Δρmax = 0.24 e Å3
1690 reflectionsΔρmin = 0.23 e Å3
164 parameters
Crystal data top
C12H24N2O4γ = 85.922 (10)°
Mr = 260.33V = 693.5 (2) Å3
Triclinic, P1Z = 2
a = 5.0475 (9) ÅMo Kα radiation
b = 10.0957 (9) ŵ = 0.09 mm1
c = 13.735 (3) ÅT = 150 K
α = 88.674 (12)°0.1 × 0.05 × 0.01 mm
β = 83.414 (19)°
Data collection top
Nonius KappaCCD
diffractometer
2017 reflections with I > 2σ(I)
3065 measured reflectionsRint = 0.097
3065 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0630 restraints
wR(F2) = 0.126H-atom parameters constrained
S = 1.21Δρmax = 0.24 e Å3
1690 reflectionsΔρmin = 0.23 e Å3
164 parameters
Special details top

Experimental. Intensity data were measured on a Nonius KappaCCD with a detector distance of 30.0 mm, a rotation increment of 1.8° per frame and a total integration time of 630.22 s per frame.

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
C10.6144 (9)0.2053 (4)0.0692 (3)0.0147 (11)
C110.6506 (8)0.2012 (4)0.1782 (3)0.0138 (11)
C20.8588 (8)0.2284 (4)0.0968 (3)0.0166 (11)
C210.4105 (8)0.1679 (4)0.3438 (3)0.0170 (11)
C30.9904 (8)0.0991 (5)0.1379 (3)0.0205 (12)
C310.2920 (9)0.0363 (5)0.3703 (4)0.0264 (12)
C40.9874 (9)0.3544 (4)0.1374 (3)0.0199 (12)
C410.2546 (9)0.2896 (5)0.3936 (3)0.0238 (12)
C50.8116 (9)0.4791 (5)0.1059 (4)0.0273 (12)
C510.4197 (10)0.4096 (5)0.3767 (4)0.0326 (13)
C61.0449 (9)0.3500 (5)0.2487 (3)0.0283 (13)
C610.1825 (11)0.2667 (5)0.5043 (4)0.0409 (15)
N10.8352 (7)0.2262 (4)0.0106 (3)0.0170 (9)
N110.4278 (7)0.1852 (4)0.2367 (2)0.0160 (9)
O10.3944 (5)0.1899 (3)0.0409 (2)0.0201 (8)
O110.8739 (5)0.2114 (3)0.2053 (2)0.0196 (8)
O21.2716 (5)0.0830 (3)0.1318 (2)0.0210 (8)
O210.4542 (7)0.0740 (3)0.3275 (2)0.0338 (9)
H11N0.28180.18480.210.019*
H1N0.97610.23950.03770.02*
H20.6760.23480.11490.02*
H210.59240.1630.36270.02*
H21O0.51920.05940.26630.051*
H2O1.30280.10520.07740.032*
H31A0.1160.03760.34820.032*
H31B0.27080.0250.4410.032*
H3A0.95950.09390.2060.025*
H3B0.90570.0260.10270.025*
H41.1580.35840.11030.024*
H410.08870.30770.36340.029*
H51A0.58460.39270.40490.049*
H51B0.45740.42620.30760.049*
H51C0.32170.48570.4070.049*
H5A0.89990.55640.130.041*
H5B0.64380.47790.13240.041*
H5C0.78060.48110.03570.041*
H61A0.08260.3440.5320.061*
H61B0.34340.25060.53510.061*
H61C0.07660.19130.51480.061*
H6A0.87990.34740.27690.042*
H6B1.13270.42770.27230.042*
H6C1.15840.27210.2670.042*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.015 (3)0.008 (3)0.020 (3)0.006 (2)0.002 (2)0.001 (2)
C110.012 (3)0.008 (3)0.021 (3)0.000 (2)0.001 (2)0.002 (2)
C20.012 (2)0.024 (3)0.015 (3)0.004 (2)0.004 (2)0.003 (2)
C210.016 (2)0.023 (3)0.011 (3)0.005 (2)0.002 (2)0.002 (2)
C30.015 (2)0.025 (3)0.021 (3)0.003 (2)0.002 (2)0.002 (2)
C310.026 (3)0.029 (3)0.023 (3)0.002 (2)0.004 (2)0.005 (2)
C40.022 (3)0.016 (3)0.021 (3)0.001 (2)0.001 (2)0.003 (2)
C410.021 (2)0.026 (3)0.023 (3)0.008 (2)0.002 (2)0.003 (2)
C50.032 (3)0.018 (3)0.031 (3)0.001 (2)0.002 (2)0.002 (2)
C510.041 (3)0.026 (3)0.030 (3)0.006 (3)0.007 (2)0.007 (3)
C60.035 (3)0.025 (3)0.024 (3)0.005 (2)0.002 (2)0.005 (2)
C610.052 (4)0.043 (4)0.023 (3)0.013 (3)0.011 (3)0.008 (3)
N10.012 (2)0.022 (2)0.017 (2)0.0012 (17)0.0008 (18)0.0028 (18)
N110.0086 (19)0.025 (2)0.014 (2)0.0022 (17)0.0009 (17)0.0008 (18)
O10.0116 (17)0.031 (2)0.0181 (17)0.0004 (14)0.0007 (14)0.0042 (15)
O110.0122 (18)0.030 (2)0.0165 (18)0.0006 (15)0.0037 (14)0.0024 (15)
O20.0191 (17)0.0239 (19)0.0205 (18)0.0014 (14)0.0046 (14)0.0059 (15)
O210.047 (2)0.023 (2)0.028 (2)0.0097 (17)0.0029 (17)0.0040 (16)
Geometric parameters (Å, º) top
O1—C11.239 (5)C4—C61.524 (6)
O11—C111.239 (5)C4—C51.528 (6)
O2—C31.429 (5)C4—H40.98
O2—H2O0.82C31—H31B0.97
C1—N11.325 (5)C31—H31A0.97
C1—C111.529 (6)C41—C511.517 (7)
N1—C21.466 (5)C41—C611.538 (6)
N1—H1N0.86C41—H410.98
O21—C311.430 (5)C5—H5C0.96
O21—H21O0.8804C5—H5B0.96
C2—C31.513 (6)C5—H5A0.96
C2—C41.533 (6)C51—H51C0.96
C2—H20.98C51—H51B0.96
C3—H3B0.97C51—H51A0.96
C3—H3A0.97C6—H6C0.96
C11—N111.322 (5)C6—H6B0.96
N11—C211.472 (5)C6—H6A0.96
N11—H11N0.86C61—H61C0.96
C21—C311.515 (6)C61—H61A0.96
C21—C411.540 (6)C61—H61B0.96
C21—H210.98
C3—O2—H2O109.5C2—C4—H4108
O1—C1—N1124.6 (4)O21—C31—C21112.5 (3)
O1—C1—C11121.2 (4)O21—C31—H31B109.1
N1—C1—C11114.2 (4)C21—C31—H31B109.1
C1—N1—C2125.3 (4)O21—C31—H31A109.1
C1—N1—H1N117.4C21—C31—H31A109.1
C2—N1—H1N117.4H31B—C31—H31A107.8
C31—O21—H21O113.4C51—C41—C61109.6 (4)
N1—C2—C3111.0 (4)C51—C41—C21109.4 (4)
N1—C2—C4110.3 (3)C61—C41—C21112.2 (4)
C3—C2—C4115.6 (4)C51—C41—H41108.5
N1—C2—H2106.5C61—C41—H41108.5
C3—C2—H2106.5C21—C41—H41108.5
C4—C2—H2106.5C4—C5—H5C109.5
O2—C3—C2114.1 (3)C4—C5—H5B109.5
O2—C3—H3B108.7H5C—C5—H5B109.5
C2—C3—H3B108.7C4—C5—H5A109.5
O2—C3—H3A108.7H5C—C5—H5A109.5
C2—C3—H3A108.7H5B—C5—H5A109.5
H3B—C3—H3A107.6C41—C51—H51C109.5
O11—C11—N11125.5 (4)C41—C51—H51B109.5
O11—C11—C1120.5 (4)H51C—C51—H51B109.5
N11—C11—C1114.0 (4)C41—C51—H51A109.5
C11—N11—C21125.0 (4)H51C—C51—H51A109.5
C11—N11—H11N117.5H51B—C51—H51A109.5
C21—N11—H11N117.5C4—C6—H6C109.5
N11—C21—C31107.8 (4)C4—C6—H6B109.5
N11—C21—C41109.6 (3)H6C—C6—H6B109.5
C31—C21—C41114.9 (3)C4—C6—H6A109.5
N11—C21—H21108.1H6C—C6—H6A109.5
C31—C21—H21108.1H6B—C6—H6A109.5
C41—C21—H21108.1C41—C61—H61C109.5
C6—C4—C5110.6 (4)C41—C61—H61A109.5
C6—C4—C2110.8 (4)H61C—C61—H61A109.5
C5—C4—C2111.2 (4)C41—C61—H61B109.5
C6—C4—H4108H61C—C61—H61B109.5
C5—C4—H4108H61A—C61—H61B109.5
O1—C1—N1—C23.0 (7)C11—N11—C21—C31121.3 (4)
C11—C1—N1—C2177.0 (4)C11—N11—C21—C41112.9 (4)
C1—N1—C2—C3101.3 (5)N1—C2—C4—C6172.9 (4)
C1—N1—C2—C4129.4 (4)C3—C2—C4—C646.1 (5)
N1—C2—C3—O273.9 (5)N1—C2—C4—C563.6 (5)
C4—C2—C3—O252.6 (5)C3—C2—C4—C5169.6 (4)
O1—C1—C11—O11177.1 (4)N11—C21—C31—O2161.5 (5)
N1—C1—C11—O112.9 (6)C41—C21—C31—O21175.9 (4)
O1—C1—C11—N112.3 (6)N11—C21—C41—C5169.1 (5)
N1—C1—C11—N11177.7 (4)C31—C21—C41—C51169.3 (4)
O11—C11—N11—C214.2 (7)N11—C21—C41—C61169.0 (4)
C1—C11—N11—C21175.1 (4)C31—C21—C41—C6147.5 (5)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2—H2O···O1i0.821.972.780 (4)169
N1—H1N···O1i0.862.142.896 (5)147
O21—H21O···O2ii0.882.032.880 (4)161.9
N11—H11N···O11iii0.862.072.870 (4)156
N1—H1N···O110.862.322.704 (5)108
N11—H11N···O10.862.332.713 (5)108
Symmetry codes: (i) x+1, y, z; (ii) x+2, y, z; (iii) x1, y, z.

Experimental details

Crystal data
Chemical formulaC12H24N2O4
Mr260.33
Crystal system, space groupTriclinic, P1
Temperature (K)150
a, b, c (Å)5.0475 (9), 10.0957 (9), 13.735 (3)
α, β, γ (°)88.674 (12), 83.414 (19), 85.922 (10)
V3)693.5 (2)
Z2
Radiation typeMo Kα
µ (mm1)0.09
Crystal size (mm)0.1 × 0.05 × 0.01
Data collection
DiffractometerNonius KappaCCD
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
3065, 3065, 2017
Rint0.097
(sin θ/λ)max1)0.650
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.063, 0.126, 1.21
No. of reflections1690
No. of parameters164
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.24, 0.23

Selected torsion angles (º) top
C11—C1—N1—C2177.0 (4)C1—C11—N11—C21175.1 (4)
C1—N1—C2—C3101.3 (5)C11—N11—C21—C31121.3 (4)
C1—N1—C2—C4129.4 (4)C11—N11—C21—C41112.9 (4)
N1—C2—C3—O273.9 (5)N11—C21—C31—O2161.5 (5)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2—H2O···O1i0.821.972.780 (4)169.3
N1—H1N···O1i0.862.142.896 (5)146.5
O21—H21O···O2ii0.882.032.880 (4)161.9
N11—H11N···O11iii0.862.072.870 (4)155.5
N1—H1N···O110.862.322.704 (5)107.7
N11—H11N···O10.862.332.713 (5)107.5
Symmetry codes: (i) x+1, y, z; (ii) x+2, y, z; (iii) x1, y, z.
 

Subscribe to Acta Crystallographica Section C: Structural Chemistry

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.

Buy online

You may purchase this article in PDF and/or HTML formats. For purchasers in the European Community who do not have a VAT number, VAT will be added at the local rate. Payments to the IUCr are handled by WorldPay, who will accept payment by credit card in several currencies. To purchase the article, please complete the form below (fields marked * are required), and then click on `Continue'.
E-mail address* 
Repeat e-mail address* 
(for error checking) 

Format*   PDF (US $40)
   HTML (US $40)
   PDF+HTML (US $50)
In order for VAT to be shown for your country javascript needs to be enabled.

VAT number 
(non-UK EC countries only) 
Country* 
 

Terms and conditions of use
Contact us

Follow Acta Cryst. C
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds