research communications\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 72| Part 5| May 2016| Pages 635-638

Crystal structure of L-leucyl-L-isoleucine 2,2,2-tri­fluoro­ethanol monosolvate

CROSSMARK_Color_square_no_text.svg

aDepartment of Chemistry, University of Oslo, PO Box 1033 Blindern, N-0315 Oslo, Norway
*Correspondence e-mail: c.h.gorbitz@kjemi.uio.no

Edited by W. T. A. Harrison, University of Aberdeen, Scotland (Received 2 March 2016; accepted 29 March 2016; online 5 April 2016)

Hydro­phobic dipeptides with either L-Leu or L-Phe constitute a rather heterogeneous group of crystal structures. Some form materials with large water-filled channels, but there is also a pronounced tendency to incorporate organic solvent mol­ecules, which then act as acceptors for one of the three H atoms of the charged N-terminal amino group. L-Leu-L-Ile has uniquely been obtained as two distinct hydrates, but has so far failed to co-crystallize with a simple alcohol. The present structure of C12H24N2O3·CF3CH2OH, which crystallizes with two dipeptide and two solvent mol­ecules in the asymmetric unit, demonstrates that when 2,2,2-tri­fluoro­ethanol is used as a solvent, its high capacity as a hydrogen-bond donor leads to formation of an alcohol solvate.

1. Chemical context

Dipeptides with at least one hydro­phobic residue (i.e. lacking a functional group) such as Val, Leu, Ile and Phe have a high propensity to form crystal structures that are divided into hydro­phobic and hydro­philic layers (Görbitz, 2010[Görbitz, C. H. (2010). Acta Cryst. B66, 84-93.]). The latter include two C(8) head-to-tail chains with two of the three N-terminal amino H atoms acting as donors and the C-terminal carboxyl­ate group as acceptor, and also a C(4) or C(5) chain using the peptide >N—H group as donor and, respectively, the peptide carbonyl group or the carboxyl­ate group as acceptor. The third amino H atom finds an acceptor in a polar side chain or, when both residues are hydro­phobic, in a co-crystallized solvent mol­ecule. L-Leu-L-Val has thus been obtained as a series of alcohol solvates (Görbitz & Torgersen, 1999[Görbitz, C. H. & Torgersen, E. (1999). Acta Cryst. B55, 104-113.]), but also as a non-layered hydrate (Görbitz & Gundersen, 1996[Görbitz, C. H. & Gundersen, E. (1996). Acta Chem. Scand. 50, 537-543.]). The same is true for L-Leu-L-Leu (Görbitz, 1998[Görbitz, C. H. (1998). Acta Chem. Scand. 52, 1343-1349.], 2001[Görbitz, C. H. (2001). Chem. Eur. J. 7, 2153-2159.]). L-Leu-L-Ile (LI) has, on the other hand, been obtained as two distinct hydrates; a 0.75 hydrate (Görbitz, 2004[Görbitz, C. H. (2004). Acta Cryst. E60, o647-o650.]; CSD refcode ETIWIN) that is isostructural to the Leu-Val analogue (Görbitz & Gundersen, 1996[Görbitz, C. H. & Gundersen, E. (1996). Acta Chem. Scand. 50, 537-543.]), and a 2.5 hydrate with extensive water channels (Görbitz & Rise, 2008[Görbitz, C. H. & Rise, F. (2008). J. Pept. Sci. 14, 210-216.]; CSD refcode HIZCOJ). Crystallization using methanol, ethanol or 2-propanol as precipitating agents did not result in formations of alcohol solvates.

[Scheme 1]

Recently we have become inter­ested in the use of fluorinated alcohols like 2,2,2-tri­fluoro­ethanol (TFE) and 1,1,1,3,3,3-hexa­fluoro-2-propanol during crystallization, not only due to their superior abilities to dissolve a large range of organic mol­ecules (abandoning the use of water if that is desirable), but also as crystal engineering tools to manipulate hydrogen-bonding patterns in solid-state structures by being incorporated into the crystal lattice by virtue of their strong hydrogen-bond-donating capacity. The crystal structure of the LI TFE solvate (I)[link] presented here provides an example of how this can take place.

2. Structural commentary

The four mol­ecules (two dipeptides and two solvent species) in the asymmetric unit are shown in Fig. 1[link]. The structure is well behaved with normal bond lengths and bond angles. Disorder for TFE mol­ecule D was easily resolved (see Refinement details). The mol­ecular conformations of the two peptide mol­ecules are quite different in terms of the side-chain conformations, Table 1[link]. The overall mol­ecular conformation of mol­ecule B is very close to that of mol­ecule B in the 2.5 hydrate (Görbitz & Rise, 2008[Görbitz, C. H. & Rise, F. (2008). J. Pept. Sci. 14, 210-216.]). A substantial 24.5° deviation from the idealized trans orientation at 180° for χ22 of mol­ecule B is needed to relieve a short contact between H91B and F2C, Fig. 2[link].

Table 1
Selected torsion angles (°)

Torsion angle Name Mol­ecule A/Mol­ecule B Conformation A/B
N1—C1—C6—N2 ψ1 162.6 (3)/117.8 (3) –/–
C1—C6—N2—C7 ω1 168.6 (3)/173.1 (3) –/–
C6—N2—C7—C12 φ2 −99.6 (4)/−65.5 (4) –/–
N2—C7—C12—O2 ψT −52.8 (4)/−41.1 (4) –/–
N1—C1—C2—C3 χ11 −69.5 (4)/177.8 (3) gauche−/trans
C1—C2—C3—C4 χ12,1 −68.2 (4)/−168.3 (3) gauche−/trans
C1—C2—C3—C5 χ12,2 170.1 (3)/69.1 (4) trans/gauche+
N2—C7—C8—C9 χ21,1 −60.9 (4)/−72.7 (3) gauche−/gauche
N2—C7—C8—C11 χ21,2 173.8 (3)/161.1 (3) trans/trans
C7—C8—C9—C10 χ22 −59.5 (4)/155.5 (3) gauche−/trans
[Figure 1]
Figure 1
The asymmetric unit of (I)[link], solvent mol­ecules being shown in different positions relative to the peptide mol­ecules than they have in the unit cell to avoid extensive overlap. The minor disorder orientation for TFE mol­ecule D is shown in wireframe representation. The amino group of mol­ecule A has an unusual eclipsed conformation (blue shade) resulting from formation of an intra­molecular hydrogen bond to O1A, while a normal staggered conformation (red shade) is observed for mol­ecule B. Thermal displacement ellipsoids are shown at the 50% probability level.
[Figure 2]
Figure 2
In the experimental crystal structure of (I)[link] (left) the ethyl group of the Ile residue of mol­ecule B is rotated to relieve a short distance between H91B and F2C. If the C7B—C8B—C9B—C10B torsion angle had been exactly 180°, this distance would have been too short (right). The terminal methyl group, with C10B as a sphere, is not involved in any short contacts.

3. Supra­molecular features

The unit cell and crystal-packing arrangement is illustrated in Fig. 3[link]a), hydrogen-bond parameters are listed in Table 2[link]. While the two mol­ecules in the asymmetric unit of structures like L-Met-L-Ala 2-propanol solvate (Görbitz, 2000[Görbitz, C. H. (2000). Acta Cryst. C56, e64-e65.]; CSD refcode CAQTOD) and L-Leu-L-Phe 2-propanol solvate (Görbitz, 1999[Görbitz, C. H. (1999). Acta Cryst. C55, 2171-2177.]; CSD refcode COCGOQ) are quite similar and related by pseudotranslational symmetry along a 10 Å long axis, the differences between the conformations (as discussed above) and relative positions of LI mol­ecules A and B are readily observed in Fig. 3[link]b). The C(5) hydrogen-bonded chain is part of an S5 hydrogen-bonded sheet, one out of four distinct types of sheets observed in layered dipeptide crystal structures (Görbitz, 2010[Görbitz, C. H. (2010). Acta Cryst. B66, 84-93.]).

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N1A—H1A⋯O3Ai 0.91 2.13 2.928 (4) 146
N1A—H2A⋯O1A 0.91 2.07 2.607 (4) 116
N1A—H3A⋯O2Bii 0.91 1.87 2.767 (4) 168
N2A—H4A⋯O3B 0.88 2.00 2.883 (4) 177
N1B—H1B⋯O2Aii 0.91 1.79 2.695 (4) 179
N1B—H2B⋯O3Bii 0.91 1.89 2.721 (4) 151
N1B—H3B⋯O1D 0.91 1.98 2.838 (5) 156
O1D—H1D⋯O1Aiii 0.86 (3) 1.87 (4) 2.695 (4) 159 (5)
O1C—H1C⋯O2Bii 0.86 (3) 1.85 (3) 2.693 (4) 167 (4)
Symmetry codes: (i) [-x, y+{\script{1\over 2}}, -z+1]; (ii) [-x+1, y+{\script{1\over 2}}, -z+1]; (iii) x+1, y, z.
[Figure 3]
Figure 3
Crystal packing of (I)[link] viewed (a) approximately along the x axis. (b) View approximately along the y axis showing a single hydrogen-bonded C(5) chain parallel to the x axis. Only H atoms involved in strong hydrogen bonds are included; peptide mol­ecule A and TFE mol­ecule C are shown with atoms in lighter colors.

This sheet is compared in Fig. 4[link] to the corresponding sheet of L-Leu-L-Val 2-propanol solvate (Görbitz & Torgersen, 1999[Görbitz, C. H. & Torgersen, E. (1999). Acta Cryst. B55, 104-113.]), where the third amino hydrogen atom is accepted by the co-crystallized alcohol mol­ecule (shaded blue in Fig. 4[link]b). At the same time, the hydroxyl group serves as a hydrogen-bond donor to the peptide carbonyl group, which is not involved in any other strong hydrogen bonds (in distinction to the related S4 pattern). Precisely the same function is taken by TFE mol­ecule D in Fig. 4[link]a), but solvent mol­ecule C is different; it seeks out and forms a hydrogen bond to the carboxyl­ate group of peptide mol­ecule B, uniquely abandoning its role as a hydrogen-bond acceptor (red shade in Fig. 4[link]b). The third amino H atom of mol­ecule A is then left to participate in only a bent intra­molecular inter­action that leads to the inherently less favorable eclipsed amino conformation shown in Fig. 1[link].

[Figure 4]
Figure 4
Hydrogen bonds in (a) the crystal structure of (I)[link] and (b) the crystal structure of L-Leu-L-Val 2-propanol solvate (Görbitz & Torgersen, 1999[Görbitz, C. H. & Torgersen, E. (1999). Acta Cryst. B55, 104-113.]; CSD refcode JUCSEF01). Peptide Cβ atoms and solvent C atoms carrying hydroxyl groups are shown as small spheres, other side-chain and solvent atoms have been omitted for clarity. The archetype S5 pattern in (b) is characterized by the presence of one syn and one anti head-to-tail C(8) chain with alternating mol­ecules being related by Screw symmetry (light grey shades), as well as a C(5) chain involving an amide >N—H donor and a carboxyl­ate acceptor. An S4 pattern has the same symmetry, but a C(4) chain to O=C< carbonyl acceptor, while consecutive mol­ecules in T5 and T4 sheets are related by Translation rather than by a screw operation (Görbitz, 2010[Görbitz, C. H. (2010). Acta Cryst. B66, 84-93.]). See text for details on the red and blue shades.

In summary, TFE has been shown to be co-crystallized with L-Leu-L-Ile, thus radically changing the hydrogen bonding pattern. Is is the first dipeptide alcohol solvate where an alcohol mol­ecule does not act as a hydrogen bond acceptor, but rather forms a strong hydrogen bond donor to a peptide carboxyl­ate acceptor.

4. Synthesis and crystallization

L-Leu-L-Val was purchased from Sigma–Aldrich and used as received. Colorless plates of the title compound were grown by vapor diffusion of aceto­nitrile into 30 µl of a saturated tri­fluoro­ethanol solution of the dipeptide.

5. Refinement details

Crystal data, data collection and structure refinement details are summarized in Table 3[link]. Solvent mol­ecule D is disordered over a major and a minor position with occupancies 0.825 (5) and 0.175 (5), respectively. The O1 and C1 atoms of the minor component were constrained to have the same set of anisotropic displacement parameters as the corresponding atoms of the major component, while C2 and the three F atoms were refined isotropically.

Table 3
Experimental details

Crystal data
Chemical formula C12H24N2O3·C2H3F3O
Mr 344.37
Crystal system, space group Monoclinic, P21
Temperature (K) 120
a, b, c (Å) 10.947 (3), 12.999 (4), 12.440 (4)
β (°) 101.833 (4)
V3) 1732.6 (9)
Z 4
Radiation type Mo Kα
μ (mm−1) 0.12
Crystal size (mm) 0.77 × 0.43 × 0.07
 
Data collection
Diffractometer Bruker D8 Advance single crystal CCD
Absorption correction Multi-scan (SADABS; Bruker, 2014[Bruker (2014). APEX2, SAINT-Plusus and SADABS. Bruker AXS, Inc., Madison, Wisconsin, USA.])
Tmin, Tmax 0.643, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections 10435, 5594, 4796
Rint 0.039
(sin θ/λ)max−1) 0.598
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.041, 0.095, 1.03
No. of reflections 5594
No. of parameters 454
No. of restraints 39
H-atom treatment H atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3) 0.27, −0.18
Computer programs: APEX2 and SAINT-Plus (Bruker, 2014[Bruker (2014). APEX2, SAINT-Plusus and SADABS. Bruker AXS, Inc., Madison, Wisconsin, USA.]), SHELXT (Sheldrick, 2015a[Sheldrick, G. M. (2015a). Acta Cryst. A71, 3-8.]), Mercury (Macrae et al., 2008[Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466-470.]) and SHELXL2014 (Sheldrick, 2015b[Sheldrick, G. M. (2015b). Acta Cryst. C71, 3-8.]).

Supporting information


Chemical context top

Dipeptides with at least one hydro­phobic residue (i.e. lacking a functional group) such as Val, Leu, Ile and Phe have a high propensity to form crystal structures that are divided into hydro­phobic and hydro­philic layers (Görbitz, 2010). The latter include two C(8) head-to-tail chains with two of the three N-terminal amino H atoms acting as donors and the C-terminal carboxyl­ate group as acceptor, and also a C(4) or C(5) chain using the peptide >N—H group as donor and, respectively, the peptide carbonyl group or the carboxyl­ate group as acceptor. The third amino H atom finds an acceptor in a polar side chain or, when both residues are hydro­phobic, in a co-crystallized solvent molecule. L-Leu-L-Val has thus been obtained as a series of alcohol solvates (Görbitz & Torgersen, 1999), but also as a non-layered hydrate (Görbitz & Gundersen, 1996). The same is true for L-Leu-L-Leu (Görbitz, 1998, 2001). L-Leu-L-Ile (LI) has uniquely been obtained as two distinct hydrates; a 0.75 hydrate (Görbitz, 2004; CSD refcode ETIWIN) that is isostructural to the Leu-Val analogue (Görbitz & Gundersen, 1996), and a 2.5 hydrate with extensive water channels (Görbitz & Rise, 2008; CSD refcode HIZCOJ). Crystallization using methanol, ethanol or 2-propanol as precipitating agents did not result in formations of alcohol solvates.

Recently we have become inter­ested in the use of fluorinated alcohols like 2,2,2-tri­fluoro­ethanol (TFE) and 1,1,1,3,3,3-hexa­fluoro-2-propanol during crystallization, not only due to their superior abilities to dissolve a large range of organic molecules (abandoning the use of water if that is desirable), but also as crystal engineering tools to manipulate hydrogen-bonding patterns in solid-state structures by being incorporated into the crystal lattice by virtue of their strong hydrogen-bond-donating capacity. The crystal structure of the LI TFE solvate (I) presented here provides an example of how this can take place.

Structural commentary top

The four molecules (two dipeptides and two solvent species) in the asymmetric unit are shown in Fig. 1. The structure is well behaved with normal bond lengths and bond angles. Disorder for TFE molecule D was easily resolved (see Refinement details). The molecular conformations of the two peptide molecules are quite different in terms of the side-chain conformations, Table 1. The overall molecular conformation of molecule B is very close to that of molecule B in the 2.5 hydrate (Görbitz & Rise, 2008). A substantial 24.5° deviation from the idealized trans orientation at 180° for χ22 of molecule B is needed to relieve a short contact between H91B and F2C, Fig. 2.

Supra­molecular features top

The unit cell and crystal-packing arrangement is illustrated in Fig. 3a), hydrogen-bond parameters are listed in Table 2. While the two molecules in the asymmetric unit of structures like L-Met-L-Ala 2-propanol solvate (Görbitz, 2000; CSD refcode CAQTOD) and L-Leu-L-Phe 2-propanol solvate (Görbitz, 2000; CSD refcode COCGOQ) are quite similar and related by pseudotranslational symmetry along a 10 Å long axis, the differences between the conformations (as discussed above) and relative positions of LI molecules A and B are readily observed in Fig. 3b). The C(5) hydrogen-bonded chain is part of an S5 hydrogen-bonded sheet, one out of four distinct types of sheets observed in layered dipeptide crystal structures (Görbitz, 2010).

This sheet is compared in Fig. 4 to the corresponding sheet of L-Leu-L-Val 2-propanol solvate (Görbitz & Torgersen, 1999), where the third amino hydrogen atom is accepted by the co-crystallized alcohol molecule (shaded blue in Figure 4b). At the same time, the hydroxyl group serves as a hydrogen-bond donor to the peptide carbonyl group, which is not involved in any other strong hydrogen bonds (in distinction to the related S4 pattern). Precisely the same function is taken by TFE molecule D in Fig. 4a), but solvent molecule C is different; it seeks out and forms a hydrogen bond to the carboxyl­ate group of peptide molecule B, uniquely abandoning its role as a hydrogen-bond acceptor (red shade in Fig. 4b). The third amino H atom of molecule A is then left to participate in only a bent intra­molecular inter­action that leads to the inherently less favorable eclipsed amino conformation shown in Fig. 1.

In summary, TFE has been shown to be co-crystallized with L-Leu-L-Ile, thus radically changing the hydrogen bonding pattern. Is is the first dipeptide alcohol solvate where an alcohol molecule does not act as a hydrogen bond acceptor, but rather forms a strong hydrogen bond donor to a peptide carboxyl­ate acceptor.

Synthesis and crystallization top

L-Leu-L-Val was purchased from Sigma–Aldrich and used as received. Colorless plates of the title compound were grown by vapor diffusion of aceto­nitrile into 30 µl of a saturated tri­fluoro­ethanol solution of the dipeptide.

Refinement details top

Crystal data, data collection and structure refinement details are summarized in Table 3. Solvent molecule D is disordered over a major and a minor position with occupancies 0.825 (5) and 0.175 (5), respectively. The O1 and C1 atoms of the minor component were constrained to have the same set of anisotropic displacement parameters as the corresponding atoms of the major component, while C2 and the three F atoms were refined isotropically.

Structure description top

Dipeptides with at least one hydro­phobic residue (i.e. lacking a functional group) such as Val, Leu, Ile and Phe have a high propensity to form crystal structures that are divided into hydro­phobic and hydro­philic layers (Görbitz, 2010). The latter include two C(8) head-to-tail chains with two of the three N-terminal amino H atoms acting as donors and the C-terminal carboxyl­ate group as acceptor, and also a C(4) or C(5) chain using the peptide >N—H group as donor and, respectively, the peptide carbonyl group or the carboxyl­ate group as acceptor. The third amino H atom finds an acceptor in a polar side chain or, when both residues are hydro­phobic, in a co-crystallized solvent molecule. L-Leu-L-Val has thus been obtained as a series of alcohol solvates (Görbitz & Torgersen, 1999), but also as a non-layered hydrate (Görbitz & Gundersen, 1996). The same is true for L-Leu-L-Leu (Görbitz, 1998, 2001). L-Leu-L-Ile (LI) has uniquely been obtained as two distinct hydrates; a 0.75 hydrate (Görbitz, 2004; CSD refcode ETIWIN) that is isostructural to the Leu-Val analogue (Görbitz & Gundersen, 1996), and a 2.5 hydrate with extensive water channels (Görbitz & Rise, 2008; CSD refcode HIZCOJ). Crystallization using methanol, ethanol or 2-propanol as precipitating agents did not result in formations of alcohol solvates.

Recently we have become inter­ested in the use of fluorinated alcohols like 2,2,2-tri­fluoro­ethanol (TFE) and 1,1,1,3,3,3-hexa­fluoro-2-propanol during crystallization, not only due to their superior abilities to dissolve a large range of organic molecules (abandoning the use of water if that is desirable), but also as crystal engineering tools to manipulate hydrogen-bonding patterns in solid-state structures by being incorporated into the crystal lattice by virtue of their strong hydrogen-bond-donating capacity. The crystal structure of the LI TFE solvate (I) presented here provides an example of how this can take place.

The four molecules (two dipeptides and two solvent species) in the asymmetric unit are shown in Fig. 1. The structure is well behaved with normal bond lengths and bond angles. Disorder for TFE molecule D was easily resolved (see Refinement details). The molecular conformations of the two peptide molecules are quite different in terms of the side-chain conformations, Table 1. The overall molecular conformation of molecule B is very close to that of molecule B in the 2.5 hydrate (Görbitz & Rise, 2008). A substantial 24.5° deviation from the idealized trans orientation at 180° for χ22 of molecule B is needed to relieve a short contact between H91B and F2C, Fig. 2.

The unit cell and crystal-packing arrangement is illustrated in Fig. 3a), hydrogen-bond parameters are listed in Table 2. While the two molecules in the asymmetric unit of structures like L-Met-L-Ala 2-propanol solvate (Görbitz, 2000; CSD refcode CAQTOD) and L-Leu-L-Phe 2-propanol solvate (Görbitz, 2000; CSD refcode COCGOQ) are quite similar and related by pseudotranslational symmetry along a 10 Å long axis, the differences between the conformations (as discussed above) and relative positions of LI molecules A and B are readily observed in Fig. 3b). The C(5) hydrogen-bonded chain is part of an S5 hydrogen-bonded sheet, one out of four distinct types of sheets observed in layered dipeptide crystal structures (Görbitz, 2010).

This sheet is compared in Fig. 4 to the corresponding sheet of L-Leu-L-Val 2-propanol solvate (Görbitz & Torgersen, 1999), where the third amino hydrogen atom is accepted by the co-crystallized alcohol molecule (shaded blue in Figure 4b). At the same time, the hydroxyl group serves as a hydrogen-bond donor to the peptide carbonyl group, which is not involved in any other strong hydrogen bonds (in distinction to the related S4 pattern). Precisely the same function is taken by TFE molecule D in Fig. 4a), but solvent molecule C is different; it seeks out and forms a hydrogen bond to the carboxyl­ate group of peptide molecule B, uniquely abandoning its role as a hydrogen-bond acceptor (red shade in Fig. 4b). The third amino H atom of molecule A is then left to participate in only a bent intra­molecular inter­action that leads to the inherently less favorable eclipsed amino conformation shown in Fig. 1.

In summary, TFE has been shown to be co-crystallized with L-Leu-L-Ile, thus radically changing the hydrogen bonding pattern. Is is the first dipeptide alcohol solvate where an alcohol molecule does not act as a hydrogen bond acceptor, but rather forms a strong hydrogen bond donor to a peptide carboxyl­ate acceptor.

Synthesis and crystallization top

L-Leu-L-Val was purchased from Sigma–Aldrich and used as received. Colorless plates of the title compound were grown by vapor diffusion of aceto­nitrile into 30 µl of a saturated tri­fluoro­ethanol solution of the dipeptide.

Refinement details top

Crystal data, data collection and structure refinement details are summarized in Table 3. Solvent molecule D is disordered over a major and a minor position with occupancies 0.825 (5) and 0.175 (5), respectively. The O1 and C1 atoms of the minor component were constrained to have the same set of anisotropic displacement parameters as the corresponding atoms of the major component, while C2 and the three F atoms were refined isotropically.

Computing details top

Data collection: APEX2 (Bruker, 2014); cell refinement: SAINT-Plus (Bruker, 2014); data reduction: SAINT-Plus (Bruker, 2014); program(s) used to solve structure: SHELXT (Sheldrick, 2015a); 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).

Figures top
[Figure 1] Fig. 1. The asymmetric unit of (I), solvent molecules being shown in different positions relative to the peptide molecules than they have in the unit cell to avoid extensive overlap. The minor disorder orientation for TFE molecule D is shown in wireframe representation. The amino group of molecule A has an unusual eclipsed conformation (blue shade) resulting from formation of an intramolecular hydrogen bond to O1A, while a normal staggered conformation (red shade) is observed for molecule B. Thermal displacement ellipsoids are shown at the 50% probability level.
[Figure 2] Fig. 2. In the experimental crystal structure of (I) (left) the ethyl group of the Ile residue of molecule B is rotated to relieve a short distance between H91B and F2C. If the C7B—C8B—C9B—C10B torsion angle had been exactly 180°, this distance would have been too short (right). The terminal methyl group, with C10B as a sphere, is not involved in any short contacts.
[Figure 3] Fig. 3. Crystal packing of (I) viewed (a) approximately along the x axis. (b) View approximately along the y axis showing a single hydrogen-bonded C(5) chain parallel to the x axis. Only H atoms involved in strong hydrogen bonds are included; peptide molecule A and TFE molecule C are shown with atoms in lighter colors.
[Figure 4] Fig. 4. Hydrogen bonds in (a) the crystal structure of (I) and (b) the crystal structure of L-Leu-L-Val 2-propanol solvate (Görbitz & Torgersen, 1999; CSD refcode JUCSEF01). Peptide Cβ atoms and solvent C atoms carrying hydroxyl groups are shown as small spheres, other side-chain and solvent atoms have been omitted for clarity. The archetype S5 pattern in (b) is characterized by the presence of one syn and one anti head-to-tail C(8) chain with alternating molecules being related by Screw symmetry (light grey shades), as well as a C(5) chain involving an amide >N—H donor and a carboxylate acceptor. An S4 pattern has the same symmetry, but a C(4) chain to OC< carbonyl acceptor, while consecutive molecules in T5 and T4 sheets are related by Translation rather than by a screw operation (Görbitz, 2010). See text for details on the red and blue shades.
L-Leucyl-L-isoleucine 2,2,2-trifluoroethanol monosolvate top
Crystal data top
C12H24N2O3·C2H3F3OF(000) = 736
Mr = 344.37Dx = 1.320 Mg m3
Monoclinic, P21Mo Kα radiation, λ = 0.71073 Å
a = 10.947 (3) ÅCell parameters from 4820 reflections
b = 12.999 (4) Åθ = 2.3–25.0°
c = 12.440 (4) ŵ = 0.12 mm1
β = 101.833 (4)°T = 120 K
V = 1732.6 (9) Å3Plate, colorless
Z = 40.77 × 0.43 × 0.07 mm
Data collection top
Bruker D8 Advance single crystal CCD
diffractometer
5594 independent reflections
Radiation source: fine-focus sealed tube4796 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.039
Detector resolution: 8.3 pixels mm-1θmax = 25.1°, θmin = 1.7°
Sets of exposures each taken over 0.5° ω rotation scansh = 1313
Absorption correction: multi-scan
(SADABS; Bruker, 2014)
k = 1512
Tmin = 0.643, Tmax = 1.000l = 1414
10435 measured reflections
Refinement top
Refinement on F239 restraints
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.041H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.095 w = 1/[σ2(Fo2) + (0.0401P)2 + 0.0691P]
where P = (Fo2 + 2Fc2)/3
S = 1.03(Δ/σ)max < 0.001
5594 reflectionsΔρmax = 0.27 e Å3
454 parametersΔρmin = 0.18 e Å3
Crystal data top
C12H24N2O3·C2H3F3OV = 1732.6 (9) Å3
Mr = 344.37Z = 4
Monoclinic, P21Mo Kα radiation
a = 10.947 (3) ŵ = 0.12 mm1
b = 12.999 (4) ÅT = 120 K
c = 12.440 (4) Å0.77 × 0.43 × 0.07 mm
β = 101.833 (4)°
Data collection top
Bruker D8 Advance single crystal CCD
diffractometer
5594 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2014)
4796 reflections with I > 2σ(I)
Tmin = 0.643, Tmax = 1.000Rint = 0.039
10435 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.04139 restraints
wR(F2) = 0.095H atoms treated by a mixture of independent and constrained refinement
S = 1.03Δρmax = 0.27 e Å3
5594 reflectionsΔρmin = 0.18 e Å3
454 parameters
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. One of the solvent molecules is disordered over two positions.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
O1A0.0423 (2)0.6609 (2)0.3719 (2)0.0280 (6)
O2A0.0083 (2)0.3213 (2)0.4273 (2)0.0325 (7)
O3A0.1629 (2)0.3989 (2)0.3414 (2)0.0305 (7)
N1A0.2285 (3)0.7482 (2)0.5048 (2)0.0199 (7)
H1A0.21650.77170.57080.030*
H2A0.16560.77110.45050.030*
H3A0.30280.77180.49290.030*
N2A0.1323 (2)0.5031 (2)0.3755 (2)0.0190 (7)
H4A0.20020.46710.40090.023*
C1A0.2293 (3)0.6338 (3)0.5053 (3)0.0183 (8)
H11A0.31230.60760.49600.022*
C2A0.1980 (3)0.5909 (3)0.6115 (3)0.0222 (8)
H21A0.11920.62290.62200.027*
H22A0.18260.51610.60180.027*
C3A0.2968 (3)0.6072 (3)0.7160 (3)0.0225 (8)
H31A0.32030.68160.72150.027*
C4A0.4133 (3)0.5437 (3)0.7136 (3)0.0307 (10)
H41A0.44650.56250.64890.046*
H42A0.39190.47040.71030.046*
H43A0.47640.55730.78020.046*
C5A0.2433 (4)0.5779 (4)0.8157 (3)0.0376 (11)
H51A0.16610.61640.81440.056*
H52A0.30400.59450.88300.056*
H53A0.22550.50400.81380.056*
C6A0.1269 (3)0.5994 (3)0.4086 (3)0.0192 (8)
C7A0.0299 (3)0.4538 (3)0.2983 (3)0.0180 (8)
H71A0.02580.50900.25920.022*
C8A0.0799 (3)0.3913 (3)0.2128 (3)0.0207 (8)
H81A0.14080.34030.25330.025*
C9A0.1501 (3)0.4587 (3)0.1444 (3)0.0270 (9)
H91A0.22330.48950.19410.032*
H92A0.18200.41410.09180.032*
C10A0.0738 (4)0.5449 (4)0.0804 (3)0.0442 (12)
H12A0.12260.57820.03240.066*
H13A0.05250.59570.13190.066*
H14A0.00300.51650.03580.066*
C11A0.0252 (3)0.3306 (4)0.1401 (3)0.0350 (10)
H15A0.06470.28540.18610.052*
H16A0.00930.28900.08770.052*
H17A0.08730.37850.10000.052*
C12A0.0472 (3)0.3866 (3)0.3615 (3)0.0215 (8)
O1B0.5502 (2)0.6220 (2)0.50128 (19)0.0238 (6)
O2B0.5573 (2)0.3479 (2)0.52421 (19)0.0215 (6)
O3B0.3600 (2)0.3917 (2)0.45792 (19)0.0216 (6)
N1B0.7727 (3)0.7368 (2)0.4733 (2)0.0226 (7)
H1B0.84610.76650.50660.034*
H2B0.70800.77150.49210.034*
H3B0.76550.73920.39910.034*
N2B0.6296 (2)0.5066 (2)0.3983 (2)0.0192 (7)
H4B0.69580.48770.37320.023*
C1B0.7706 (3)0.6274 (3)0.5093 (3)0.0193 (8)
H11B0.83200.58610.47790.023*
C2B0.8047 (3)0.6239 (3)0.6345 (3)0.0227 (8)
H21B0.88940.65300.65850.027*
H22B0.74620.66910.66360.027*
C3B0.8024 (3)0.5183 (3)0.6864 (3)0.0248 (9)
H31B0.72080.48480.65460.030*
C4B0.8116 (4)0.5314 (4)0.8093 (3)0.0371 (11)
H41B0.81150.46360.84380.056*
H42B0.74010.57150.82210.056*
H43B0.88910.56760.84110.056*
C5B0.9073 (4)0.4492 (3)0.6641 (3)0.0343 (10)
H51B0.90130.38150.69740.052*
H52B0.98810.48040.69600.052*
H53B0.89970.44140.58470.052*
C6B0.6391 (3)0.5850 (3)0.4685 (3)0.0189 (8)
C7B0.5130 (3)0.4513 (3)0.3620 (3)0.0184 (8)
H71B0.44630.50210.33160.022*
C8B0.5294 (3)0.3774 (3)0.2694 (3)0.0197 (8)
H81B0.61280.34390.29300.024*
C9B0.5323 (3)0.4366 (3)0.1635 (3)0.0261 (9)
H91B0.44560.45010.12430.031*
H92B0.57350.50380.18260.031*
C10B0.6011 (4)0.3791 (4)0.0867 (3)0.0393 (11)
H12B0.59680.41900.01920.059*
H13B0.56200.31180.06850.059*
H14B0.68860.36960.12310.059*
C11B0.4328 (3)0.2917 (3)0.2499 (3)0.0249 (9)
H15B0.44190.24890.31590.037*
H16B0.44530.24930.18790.037*
H17B0.34890.32170.23320.037*
C12B0.4741 (3)0.3938 (3)0.4562 (3)0.0175 (8)
O1C0.5265 (2)0.7674 (2)0.3049 (2)0.0299 (7)
H1C0.501 (4)0.784 (3)0.364 (3)0.045*
F1C0.2472 (2)0.77562 (19)0.09991 (19)0.0419 (6)
F2C0.3722 (2)0.64892 (18)0.1427 (2)0.0478 (7)
F3C0.2751 (2)0.7092 (2)0.26117 (19)0.0454 (7)
C1C0.4374 (3)0.8097 (3)0.2199 (3)0.0257 (9)
H11C0.47740.82810.15800.031*
H12C0.40320.87340.24590.031*
C2C0.3341 (3)0.7359 (3)0.1812 (3)0.0285 (9)
O1D0.8241 (3)0.7359 (3)0.2588 (3)0.0329 (10)0.825 (5)
H1D0.897 (4)0.710 (4)0.279 (4)0.049*0.825 (5)
F1D0.6835 (3)0.8066 (3)0.0612 (3)0.0441 (9)0.825 (5)
F2D0.8335 (3)0.7120 (3)0.0332 (3)0.0576 (12)0.825 (5)
F3D0.6481 (3)0.6516 (3)0.0016 (2)0.0572 (12)0.825 (5)
C1D0.7461 (4)0.6710 (4)0.1859 (3)0.0280 (13)0.825 (5)
H11D0.66400.66620.20720.034*0.825 (5)
H12D0.78290.60120.19010.034*0.825 (5)
C2D0.7286 (4)0.7099 (4)0.0713 (3)0.0353 (14)0.825 (5)
O11D0.8098 (19)0.6853 (16)0.2667 (12)0.0329 (10)0.175 (5)
H11E0.88670.69650.27460.049*0.175 (5)
F11D0.7114 (17)0.8328 (14)0.1014 (19)0.090 (11)*0.175 (5)
F12D0.8965 (12)0.7813 (13)0.1012 (14)0.077 (6)*0.175 (5)
F13D0.7446 (19)0.7253 (17)0.0213 (10)0.116 (10)*0.175 (5)
C11D0.760 (2)0.6624 (12)0.1569 (13)0.0280 (13)0.175 (5)
H13D0.66940.64800.14770.034*0.175 (5)
H14D0.80060.60000.13510.034*0.175 (5)
C12D0.7788 (13)0.7499 (11)0.0850 (10)0.038 (8)*0.175 (5)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O1A0.0237 (14)0.0214 (16)0.0342 (15)0.0061 (12)0.0051 (11)0.0037 (12)
O2A0.0238 (13)0.0317 (17)0.0442 (17)0.0035 (13)0.0125 (12)0.0137 (15)
O3A0.0144 (13)0.0460 (19)0.0315 (15)0.0020 (12)0.0056 (11)0.0025 (14)
N1A0.0179 (15)0.0213 (19)0.0198 (15)0.0020 (13)0.0025 (12)0.0007 (13)
N2A0.0143 (14)0.0186 (19)0.0224 (16)0.0012 (12)0.0003 (12)0.0011 (14)
C1A0.0182 (17)0.014 (2)0.0214 (19)0.0003 (14)0.0022 (14)0.0015 (15)
C2A0.0227 (18)0.021 (2)0.023 (2)0.0005 (16)0.0049 (15)0.0016 (17)
C3A0.030 (2)0.017 (2)0.0181 (18)0.0010 (16)0.0003 (15)0.0002 (16)
C4A0.026 (2)0.040 (3)0.024 (2)0.0019 (19)0.0003 (16)0.0031 (19)
C5A0.042 (2)0.046 (3)0.025 (2)0.008 (2)0.0083 (19)0.003 (2)
C6A0.0159 (17)0.020 (2)0.0212 (19)0.0007 (15)0.0033 (14)0.0014 (16)
C7A0.0162 (16)0.018 (2)0.0188 (18)0.0002 (15)0.0007 (13)0.0008 (15)
C8A0.0222 (17)0.021 (2)0.0206 (19)0.0013 (16)0.0073 (14)0.0026 (17)
C9A0.0266 (19)0.032 (3)0.023 (2)0.0011 (17)0.0055 (15)0.0006 (18)
C10A0.037 (2)0.058 (3)0.034 (3)0.003 (2)0.000 (2)0.018 (2)
C11A0.031 (2)0.038 (3)0.038 (2)0.0091 (19)0.0136 (19)0.014 (2)
C12A0.0215 (19)0.022 (2)0.0221 (19)0.0014 (17)0.0079 (14)0.0087 (18)
O1B0.0221 (13)0.0259 (16)0.0240 (14)0.0017 (11)0.0064 (11)0.0043 (12)
O2B0.0196 (12)0.0230 (16)0.0219 (13)0.0017 (10)0.0044 (11)0.0019 (11)
O3B0.0152 (12)0.0232 (15)0.0265 (13)0.0016 (11)0.0048 (10)0.0023 (12)
N1B0.0214 (15)0.0222 (19)0.0251 (17)0.0002 (13)0.0070 (13)0.0002 (14)
N2B0.0169 (14)0.0201 (18)0.0213 (16)0.0002 (12)0.0060 (12)0.0024 (14)
C1B0.0221 (18)0.014 (2)0.0229 (19)0.0009 (15)0.0075 (15)0.0016 (16)
C2B0.0206 (18)0.023 (2)0.0233 (19)0.0019 (15)0.0026 (15)0.0022 (17)
C3B0.0213 (18)0.029 (2)0.022 (2)0.0048 (16)0.0010 (15)0.0006 (17)
C4B0.042 (2)0.040 (3)0.027 (2)0.006 (2)0.0026 (19)0.001 (2)
C5B0.040 (2)0.025 (3)0.037 (2)0.000 (2)0.0062 (18)0.003 (2)
C6B0.0189 (17)0.020 (2)0.0174 (18)0.0003 (15)0.0037 (14)0.0050 (16)
C7B0.0146 (16)0.019 (2)0.0211 (19)0.0007 (15)0.0010 (14)0.0012 (16)
C8B0.0165 (17)0.022 (2)0.0202 (19)0.0003 (15)0.0024 (14)0.0034 (16)
C9B0.029 (2)0.029 (2)0.0203 (19)0.0030 (18)0.0060 (16)0.0003 (17)
C10B0.038 (2)0.059 (3)0.024 (2)0.004 (2)0.0127 (17)0.005 (2)
C11B0.0212 (18)0.028 (3)0.024 (2)0.0013 (17)0.0014 (15)0.0021 (17)
C12B0.0185 (18)0.013 (2)0.0196 (18)0.0022 (15)0.0011 (14)0.0045 (16)
O1C0.0289 (14)0.0399 (19)0.0208 (14)0.0083 (13)0.0045 (11)0.0017 (13)
F1C0.0378 (13)0.0410 (17)0.0400 (14)0.0028 (12)0.0079 (11)0.0016 (12)
F2C0.0526 (15)0.0330 (17)0.0551 (16)0.0018 (12)0.0048 (12)0.0159 (13)
F3C0.0418 (14)0.0557 (19)0.0410 (15)0.0157 (12)0.0140 (12)0.0048 (13)
C1C0.028 (2)0.026 (2)0.022 (2)0.0010 (17)0.0035 (16)0.0003 (17)
C2C0.035 (2)0.026 (3)0.024 (2)0.0008 (18)0.0042 (18)0.0010 (18)
O1D0.0277 (17)0.039 (3)0.0311 (17)0.003 (2)0.0032 (14)0.004 (2)
F1D0.054 (2)0.041 (2)0.035 (2)0.0164 (17)0.0036 (17)0.0132 (18)
F2D0.055 (2)0.084 (3)0.044 (2)0.0129 (19)0.0334 (17)0.0123 (19)
F3D0.073 (2)0.062 (3)0.0291 (17)0.0009 (19)0.0069 (16)0.0075 (16)
C1D0.026 (2)0.039 (3)0.020 (3)0.007 (2)0.007 (2)0.002 (2)
C2D0.034 (3)0.045 (4)0.028 (3)0.007 (3)0.007 (2)0.003 (3)
O11D0.0277 (17)0.039 (3)0.0311 (17)0.003 (2)0.0032 (14)0.004 (2)
C11D0.026 (2)0.039 (3)0.020 (3)0.007 (2)0.007 (2)0.002 (2)
Geometric parameters (Å, º) top
O1A—C6A1.238 (4)C1B—H11B1.0000
O2A—C12A1.247 (5)C2B—C3B1.519 (5)
O3A—C12A1.251 (4)C2B—H21B0.9900
N1A—C1A1.488 (5)C2B—H22B0.9900
N1A—H1A0.9100C3B—C4B1.520 (5)
N1A—H2A0.9100C3B—C5B1.526 (5)
N1A—H3A0.9100C3B—H31B1.0000
N2A—C6A1.323 (5)C4B—H41B0.9800
N2A—C7A1.466 (4)C4B—H42B0.9800
N2A—H4A0.8800C4B—H43B0.9800
C1A—C6A1.533 (5)C5B—H51B0.9800
C1A—C2A1.536 (5)C5B—H52B0.9800
C1A—H11A1.0000C5B—H53B0.9800
C2A—C3A1.525 (5)C7B—C12B1.523 (5)
C2A—H21A0.9900C7B—C8B1.538 (5)
C2A—H22A0.9900C7B—H71B1.0000
C3A—C4A1.525 (5)C8B—C11B1.521 (5)
C3A—C5A1.525 (5)C8B—C9B1.532 (5)
C3A—H31A1.0000C8B—H81B1.0000
C4A—H41A0.9800C9B—C10B1.527 (5)
C4A—H42A0.9800C9B—H91B0.9900
C4A—H43A0.9800C9B—H92B0.9900
C5A—H51A0.9800C10B—H12B0.9800
C5A—H52A0.9800C10B—H13B0.9800
C5A—H53A0.9800C10B—H14B0.9800
C7A—C8A1.526 (5)C11B—H15B0.9800
C7A—C12A1.538 (5)C11B—H16B0.9800
C7A—H71A1.0000C11B—H17B0.9800
C8A—C11A1.528 (5)O1C—C1C1.396 (4)
C8A—C9A1.534 (5)O1C—H1C0.86 (3)
C8A—H81A1.0000F1C—C2C1.342 (4)
C9A—C10A1.522 (6)F2C—C2C1.328 (4)
C9A—H91A0.9900F3C—C2C1.338 (4)
C9A—H92A0.9900C1C—C2C1.486 (5)
C10A—H12A0.9800C1C—H11C0.9900
C10A—H13A0.9800C1C—H12C0.9900
C10A—H14A0.9800O1D—C1D1.394 (4)
C11A—H15A0.9800O1D—H1D0.86 (3)
C11A—H16A0.9800F1D—C2D1.347 (4)
C11A—H17A0.9800F2D—C2D1.329 (4)
O1B—C6B1.228 (4)F3D—C2D1.338 (5)
O2B—C12B1.259 (4)C1D—C2D1.487 (5)
O3B—C12B1.254 (4)C1D—H11D0.9900
N1B—C1B1.493 (5)C1D—H12D0.9900
N1B—H1B0.9100O11D—C11D1.396 (6)
N1B—H2B0.9100O11D—H11E0.8400
N1B—H3B0.9100F11D—C12D1.345 (6)
N2B—C6B1.333 (5)F12D—C12D1.327 (6)
N2B—C7B1.453 (4)F13D—C12D1.337 (6)
N2B—H4B0.8800C11D—C12D1.488 (6)
C1B—C2B1.526 (5)C11D—H13D0.9900
C1B—C6B1.528 (5)C11D—H14D0.9900
C1A—N1A—H1A109.5H21B—C2B—H22B107.4
C1A—N1A—H2A109.5C2B—C3B—C4B108.8 (3)
H1A—N1A—H2A109.5C2B—C3B—C5B112.1 (3)
C1A—N1A—H3A109.5C4B—C3B—C5B110.6 (3)
H1A—N1A—H3A109.5C2B—C3B—H31B108.4
H2A—N1A—H3A109.5C4B—C3B—H31B108.4
C6A—N2A—C7A122.7 (3)C5B—C3B—H31B108.4
C6A—N2A—H4A118.7C3B—C4B—H41B109.5
C7A—N2A—H4A118.7C3B—C4B—H42B109.5
N1A—C1A—C6A106.6 (3)H41B—C4B—H42B109.5
N1A—C1A—C2A111.4 (3)C3B—C4B—H43B109.5
C6A—C1A—C2A108.2 (3)H41B—C4B—H43B109.5
N1A—C1A—H11A110.2H42B—C4B—H43B109.5
C6A—C1A—H11A110.2C3B—C5B—H51B109.5
C2A—C1A—H11A110.2C3B—C5B—H52B109.5
C3A—C2A—C1A116.0 (3)H51B—C5B—H52B109.5
C3A—C2A—H21A108.3C3B—C5B—H53B109.5
C1A—C2A—H21A108.3H51B—C5B—H53B109.5
C3A—C2A—H22A108.3H52B—C5B—H53B109.5
C1A—C2A—H22A108.3O1B—C6B—N2B123.9 (3)
H21A—C2A—H22A107.4O1B—C6B—C1B120.3 (3)
C4A—C3A—C5A110.0 (3)N2B—C6B—C1B115.8 (3)
C4A—C3A—C2A111.0 (3)N2B—C7B—C12B111.7 (3)
C5A—C3A—C2A109.6 (3)N2B—C7B—C8B108.2 (3)
C4A—C3A—H31A108.7C12B—C7B—C8B111.3 (3)
C5A—C3A—H31A108.7N2B—C7B—H71B108.5
C2A—C3A—H31A108.7C12B—C7B—H71B108.5
C3A—C4A—H41A109.5C8B—C7B—H71B108.5
C3A—C4A—H42A109.5C11B—C8B—C9B111.5 (3)
H41A—C4A—H42A109.5C11B—C8B—C7B113.2 (3)
C3A—C4A—H43A109.5C9B—C8B—C7B110.9 (3)
H41A—C4A—H43A109.5C11B—C8B—H81B107.0
H42A—C4A—H43A109.5C9B—C8B—H81B107.0
C3A—C5A—H51A109.5C7B—C8B—H81B107.0
C3A—C5A—H52A109.5C10B—C9B—C8B113.1 (3)
H51A—C5A—H52A109.5C10B—C9B—H91B109.0
C3A—C5A—H53A109.5C8B—C9B—H91B109.0
H51A—C5A—H53A109.5C10B—C9B—H92B109.0
H52A—C5A—H53A109.5C8B—C9B—H92B109.0
O1A—C6A—N2A125.0 (3)H91B—C9B—H92B107.8
O1A—C6A—C1A118.2 (3)C9B—C10B—H12B109.5
N2A—C6A—C1A116.6 (3)C9B—C10B—H13B109.5
N2A—C7A—C8A110.7 (3)H12B—C10B—H13B109.5
N2A—C7A—C12A109.8 (3)C9B—C10B—H14B109.5
C8A—C7A—C12A111.5 (3)H12B—C10B—H14B109.5
N2A—C7A—H71A108.3H13B—C10B—H14B109.5
C8A—C7A—H71A108.3C8B—C11B—H15B109.5
C12A—C7A—H71A108.3C8B—C11B—H16B109.5
C7A—C8A—C11A110.7 (3)H15B—C11B—H16B109.5
C7A—C8A—C9A112.0 (3)C8B—C11B—H17B109.5
C11A—C8A—C9A111.6 (3)H15B—C11B—H17B109.5
C7A—C8A—H81A107.4H16B—C11B—H17B109.5
C11A—C8A—H81A107.4O3B—C12B—O2B124.3 (3)
C9A—C8A—H81A107.4O3B—C12B—C7B117.4 (3)
C10A—C9A—C8A115.3 (3)O2B—C12B—C7B118.2 (3)
C10A—C9A—H91A108.5C1C—O1C—H1C104 (3)
C8A—C9A—H91A108.5O1C—C1C—C2C111.0 (3)
C10A—C9A—H92A108.5O1C—C1C—H11C109.4
C8A—C9A—H92A108.5C2C—C1C—H11C109.4
H91A—C9A—H92A107.5O1C—C1C—H12C109.4
C9A—C10A—H12A109.5C2C—C1C—H12C109.4
C9A—C10A—H13A109.5H11C—C1C—H12C108.0
H12A—C10A—H13A109.5F2C—C2C—F3C106.4 (3)
C9A—C10A—H14A109.5F2C—C2C—F1C106.4 (3)
H12A—C10A—H14A109.5F3C—C2C—F1C106.5 (3)
H13A—C10A—H14A109.5F2C—C2C—C1C113.1 (3)
C8A—C11A—H15A109.5F3C—C2C—C1C112.2 (3)
C8A—C11A—H16A109.5F1C—C2C—C1C111.7 (3)
H15A—C11A—H16A109.5C1D—O1D—H1D111 (4)
C8A—C11A—H17A109.5O1D—C1D—C2D111.0 (4)
H15A—C11A—H17A109.5O1D—C1D—H11D109.4
H16A—C11A—H17A109.5C2D—C1D—H11D109.4
O2A—C12A—O3A123.8 (3)O1D—C1D—H12D109.4
O2A—C12A—C7A118.6 (3)C2D—C1D—H12D109.4
O3A—C12A—C7A117.6 (3)H11D—C1D—H12D108.0
C1B—N1B—H1B109.5F2D—C2D—F3D106.4 (3)
C1B—N1B—H2B109.5F2D—C2D—F1D106.0 (4)
H1B—N1B—H2B109.5F3D—C2D—F1D106.7 (4)
C1B—N1B—H3B109.5F2D—C2D—C1D113.4 (4)
H1B—N1B—H3B109.5F3D—C2D—C1D111.5 (4)
H2B—N1B—H3B109.5F1D—C2D—C1D112.3 (3)
C6B—N2B—C7B121.8 (3)C11D—O11D—H11E109.5
C6B—N2B—H4B119.1O11D—C11D—C12D110.5 (7)
C7B—N2B—H4B119.1O11D—C11D—H13D109.6
N1B—C1B—C2B108.6 (3)C12D—C11D—H13D109.6
N1B—C1B—C6B108.4 (3)O11D—C11D—H14D109.6
C2B—C1B—C6B110.2 (3)C12D—C11D—H14D109.6
N1B—C1B—H11B109.9H13D—C11D—H14D108.1
C2B—C1B—H11B109.9F12D—C12D—F13D106.9 (7)
C6B—C1B—H11B109.9F12D—C12D—F11D106.0 (7)
C3B—C2B—C1B116.0 (3)F13D—C12D—F11D106.8 (7)
C3B—C2B—H21B108.3F12D—C12D—C11D113.3 (6)
C1B—C2B—H21B108.3F13D—C12D—C11D111.5 (7)
C3B—C2B—H22B108.3F11D—C12D—C11D111.9 (6)
C1B—C2B—H22B108.3
N1A—C1A—C2A—C3A69.5 (4)C7B—N2B—C6B—C1B173.1 (3)
C6A—C1A—C2A—C3A173.6 (3)N1B—C1B—C6B—O1B63.1 (4)
C1A—C2A—C3A—C4A68.2 (4)C2B—C1B—C6B—O1B55.6 (4)
C1A—C2A—C3A—C5A170.1 (3)N1B—C1B—C6B—N2B117.8 (3)
C7A—N2A—C6A—O1A6.9 (5)C2B—C1B—C6B—N2B123.5 (3)
C7A—N2A—C6A—C1A168.6 (3)C6B—N2B—C7B—C12B65.5 (4)
N1A—C1A—C6A—O1A21.6 (4)C6B—N2B—C7B—C8B171.7 (3)
C2A—C1A—C6A—O1A98.4 (4)N2B—C7B—C8B—C11B161.1 (3)
N1A—C1A—C6A—N2A162.6 (3)C12B—C7B—C8B—C11B38.0 (4)
C2A—C1A—C6A—N2A77.5 (4)N2B—C7B—C8B—C9B72.7 (3)
C6A—N2A—C7A—C8A136.9 (3)C12B—C7B—C8B—C9B164.2 (3)
C6A—N2A—C7A—C12A99.6 (4)C11B—C8B—C9B—C10B77.4 (4)
N2A—C7A—C8A—C11A173.8 (3)C7B—C8B—C9B—C10B155.5 (3)
C12A—C7A—C8A—C11A51.3 (4)N2B—C7B—C12B—O3B142.0 (3)
N2A—C7A—C8A—C9A60.9 (4)C8B—C7B—C12B—O3B97.0 (4)
C12A—C7A—C8A—C9A176.5 (3)N2B—C7B—C12B—O2B41.1 (4)
C7A—C8A—C9A—C10A59.5 (4)C8B—C7B—C12B—O2B80.0 (4)
C11A—C8A—C9A—C10A65.2 (4)O1C—C1C—C2C—F2C60.4 (4)
N2A—C7A—C12A—O2A52.8 (4)O1C—C1C—C2C—F3C60.0 (4)
C8A—C7A—C12A—O2A70.2 (4)O1C—C1C—C2C—F1C179.6 (3)
N2A—C7A—C12A—O3A129.1 (3)O1D—C1D—C2D—F2D63.6 (5)
C8A—C7A—C12A—O3A107.9 (4)O1D—C1D—C2D—F3D176.3 (4)
N1B—C1B—C2B—C3B177.8 (3)O1D—C1D—C2D—F1D56.6 (5)
C6B—C1B—C2B—C3B59.2 (4)O11D—C11D—C12D—F12D52.3 (19)
C1B—C2B—C3B—C4B168.3 (3)O11D—C11D—C12D—F13D172.9 (18)
C1B—C2B—C3B—C5B69.1 (4)O11D—C11D—C12D—F11D67.5 (19)
C7B—N2B—C6B—O1B5.9 (5)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1A—H1A···O3Ai0.912.132.928 (4)146
N1A—H2A···O1A0.912.072.607 (4)116
N1A—H3A···O2Bii0.911.872.767 (4)168
N2A—H4A···O3B0.882.002.883 (4)177
N1B—H1B···O2Aii0.911.792.695 (4)179
N1B—H2B···O3Bii0.911.892.721 (4)151
N1B—H3B···O1D0.911.982.838 (5)156
O1D—H1D···O1Aiii0.86 (3)1.87 (4)2.695 (4)159 (5)
O1C—H1C···O2Bii0.86 (3)1.85 (3)2.693 (4)167 (4)
Symmetry codes: (i) x, y+1/2, z+1; (ii) x+1, y+1/2, z+1; (iii) x+1, y, z.
Selected torsion angles (°) top
Torsion angleNameMolecule A/Molecule BConformation A/B
N1—C1—C6—N2ψ1162.6 (3)/117.8 (3)–/–
C1—C6—N2—C7ω1168.6 (3)/173.1 (3)–/–
C6—N2—C7—C12φ2-99.6 (4)/-65.5 (4)–/–
N2—C7—C12—O2ψT-52.8 (4)/-41.1 (4)–/–
N1—C1—C2—C3χ11-69.5 (4)/177.8 (3)gauche-/trans
C1—C2—C3—C4χ12,1-68.2 (4)/-168.3 (3)gauche-/trans
C1—C2—C3—C5χ12,2170.1 (3)/69.1 (4)trans/gauche+
N2—C7—C8—C9χ21,1-60.9 (4)/-72.7 (3)gauche-/gauche-
N2—C7—C8—C11χ21,2173.8 (3)/161.1 (3)trans/trans
C7—C8—C9—C10χ22-59.5 (4)/155.5 (3)gauche-/trans
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1A—H1A···O3Ai0.912.132.928 (4)146
N1A—H2A···O1A0.912.072.607 (4)116
N1A—H3A···O2Bii0.911.872.767 (4)168
N2A—H4A···O3B0.882.002.883 (4)177
N1B—H1B···O2Aii0.911.792.695 (4)179
N1B—H2B···O3Bii0.911.892.721 (4)151
N1B—H3B···O1D0.911.982.838 (5)156
O1D—H1D···O1Aiii0.86 (3)1.87 (4)2.695 (4)159 (5)
O1C—H1C···O2Bii0.86 (3)1.85 (3)2.693 (4)167 (4)
Symmetry codes: (i) x, y+1/2, z+1; (ii) x+1, y+1/2, z+1; (iii) x+1, y, z.

Experimental details

Crystal data
Chemical formulaC12H24N2O3·C2H3F3O
Mr344.37
Crystal system, space groupMonoclinic, P21
Temperature (K)120
a, b, c (Å)10.947 (3), 12.999 (4), 12.440 (4)
β (°) 101.833 (4)
V3)1732.6 (9)
Z4
Radiation typeMo Kα
µ (mm1)0.12
Crystal size (mm)0.77 × 0.43 × 0.07
Data collection
DiffractometerBruker D8 Advance single crystal CCD
Absorption correctionMulti-scan
(SADABS; Bruker, 2014)
Tmin, Tmax0.643, 1.000
No. of measured, independent and
observed [I > 2σ(I)] reflections
10435, 5594, 4796
Rint0.039
(sin θ/λ)max1)0.598
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.041, 0.095, 1.03
No. of reflections5594
No. of parameters454
No. of restraints39
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.27, 0.18

Computer programs: APEX2 (Bruker, 2014), SAINT-Plus (Bruker, 2014), SHELXT (Sheldrick, 2015a), Mercury (Macrae et al., 2008), SHELXL2014 (Sheldrick, 2015b).

 

References

First citationBruker (2014). APEX2, SAINT-Plusus and SADABS. Bruker AXS, Inc., Madison, Wisconsin, USA.  Google Scholar
First citationGörbitz, C. H. (1999). Acta Cryst. C55, 2171–2177.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationGörbitz, C. H. (2000). Acta Cryst. C56, e64–e65.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationGörbitz, C. H. (2001). Chem. Eur. J. 7, 2153–2159.  Google Scholar
First citationGörbitz, C. H. (2004). Acta Cryst. E60, o647–o650.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationGörbitz, C. H. (2010). Acta Cryst. B66, 84–93.  Web of Science CrossRef IUCr Journals Google Scholar
First citationGörbitz, C. H. (1998). Acta Chem. Scand. 52, 1343–1349.  Google Scholar
First citationGörbitz, C. H. & Gundersen, E. (1996). Acta Chem. Scand. 50, 537–543.  Google Scholar
First citationGörbitz, C. H. & Rise, F. (2008). J. Pept. Sci. 14, 210–216.  Web of Science PubMed Google Scholar
First citationGörbitz, C. H. & Torgersen, E. (1999). Acta Cryst. B55, 104–113.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationMacrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466–470.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
First citationSheldrick, G. M. (2015a). Acta Cryst. A71, 3–8.  Web of Science CrossRef IUCr Journals Google Scholar
First citationSheldrick, G. M. (2015b). Acta Cryst. C71, 3–8.  Web of Science CrossRef IUCr Journals Google Scholar

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Volume 72| Part 5| May 2016| Pages 635-638
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