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organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 68| Part 5| May 2012| Page o1565
doi:10.1107/S1600536812017527

N-(2,6-Diiso­propyl­phen­yl)formamide toluene 0.33-solvate

Matthias Berger,a Jan W. Batsb* and Norbert Aunera

aInstitut für Anorganische Chemie der Universität Frankfurt, Max-von-Laue-Strasse 7, D-60438 Frankfurt am Main, Germany, and bInstitut für Organische Chemie, Universität Frankfurt, Max-von-Laue-Strasse 7, D-60438 Frankfurt am Main, Germany
*Correspondence e-mail: bats@chemie.uni-frankfurt.de

(Received 11 April 2012; accepted 19 April 2012; online 28 April 2012)

The crystal packing of the title compound, C13H19NO·0.33C7H8, shows a channel at [001], which contains grossly disordered toluene solvent mol­ecules. The angle between the benzene ring and the mean plane of the formamide group is 71.1 (1)°. The amide groups of neighbouring mol­ecules are connected by N—H⋯O hydrogen bonds, forming 21 helical chains propagating along [001]. Mol­ecules are also connected by weak inter­molecular C—H⋯O hydrogen bonds, forming 61 helices.

Related literature

For the synthesis of the starting material, see: Krishnamurthy (1982[Krishnamurthy, S. (1982). Tetrahedron Lett. 23, 3315-3318.]); Hinter­mann (2007[Hintermann, L. (2007). Beilstein J. Org. Chem. 3, No. 22. doi:10.1186/1860-5397-3-22.]). For the crystal structures of related compounds, see: Stibrany & Potenza (2006[Stibrany, R. T. & Potenza, J. A. (2006). Private communication (refcode TEVJIO). CCDC, Cambridge, England.]); Chitanda et al. (2008[Chitanda, J. M., Quail, J. W. & Foley, S. R. (2008). Acta Cryst. E64, o1728.]); Omondi et al. (2008[Omondi, B., Fernandes, M. A., Layh, M. & Levendis, D. C. (2008). Acta Cryst. C64, o137-o138.]); Gowda et al. (2009[Gowda, B. T., Foro, S. & Fuess, H. (2009). Acta Cryst. E65, o1633.]). For the treatment of the disordered solvent, see: Spek (2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]).

[Scheme 1]

Experimental

Crystal data

  • C13H19NO·0.33C7H8

  • Mr = 236.00

  • Hexagonal, P 61

  • a = 16.9133 (6) Å

  • c = 8.4451 (4) Å

  • V = 2092.2 (2) Å3

  • Z = 6

  • Mo Kα radiation

  • μ = 0.07 mm−1

  • T = 185 K

  • 0.65 × 0.20 × 0.19 mm
Data collection

  • Siemens SMART 1K CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 2000[Sheldrick, G. M. (2000). SADABS. University of Göttingen, Germany.]) Tmin = 0.933, Tmax = 0.987

  • 23771 measured reflections

  • 1748 independent reflections

  • 1503 reflections with I > 2σ(I)

  • Rint = 0.057
Refinement

  • R[F2 > 2σ(F2)] = 0.058

  • wR(F2) = 0.125

  • S = 1.08

  • 1748 reflections

  • 144 parameters

  • 1 restraint

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.16 e Å−3

  • Δρmin = −0.16 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A D⋯A D—H⋯A
N1—H1A⋯O1i 0.80 (4) 2.05 (4) 2.826 (3) 164 (3)
C4—H4A⋯O1ii 0.95 2.56 3.418 (3) 150
C13—H13A⋯C3i 0.95 3.01 3.917 (4) 161
C13—H13A⋯C4i 0.95 3.03 3.973 (4) 173
Symmetry codes: (i) [-x, -y+1, z+{\script{1\over 2}}]; (ii) [y-1, -x+y, z-{\script{1\over 6}}].

Data collection: SMART (Siemens, 1995[Siemens (1995). SMART and SAINT. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Siemens, 1995[Siemens (1995). SMART and SAINT. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536812017527/su2409sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536812017527/su2409Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536812017527/su2409Isup3.cml

checkCIF report


Comment top

The title compound was obtained as a byproduct from the synthesis of the N-heterocyclic carbene precursor 1,3-bis-(2,6-diisopropylphenyl)imidazolium chloride (Hintermann, 2007). Crystallization from a solution in toluene provided single crystals of the title compound, whose crystal structure is reported herein.

The molecular structure of the title molecule is shown in Fig. 1. The angle between the benzene ring and the mean plane of the formamide group is 71.1 (1)°. It is slightly smaller than the value of 77.4 (1)° reported for the crystal structure of the solvent-free compound (Stibrany & Potenza, 2006; Chitanda et al., 2008). This non-planar geometry is required by steric repulsions between the formamide group and the isopropyl substituents. An almost planar molecule has been reported for non-substituted N-phenylformamide (Omondi et al., 2008; Gowda et al., 2009).

In the crystal, molecules are connected by intermolecular hydrogen bonding between the amide groups to form helical 21 chains in the c axis direction (Table1, Fig. 2). The molecules are also connected by a weak intermolecular formamide-benzene C—H···π interaction. The C—H vector of this contact does not point to the midpoint of the acceptor ring, but points more closely to the C3—C4 bond. Similar hydrogen bonded chains occur in the solvent-free compound mentioned above. Molecules in adjacent chains are connected by a very weak intermolecular benzene-formamide C—H···O interaction to form a helix about a 61 screw axis.

The crystal packing (Fig. 3) shows a channel along the c axis with an average radius of 3.71 Å and it is surrounded by isopropyl groups. Each channel contains two toluene solvate molecules per unit cell, as estimated by the SQUEEZE routine in PLATON (Spek, 2009).

Related literature top

For the synthesis of the starting material, see: Krishnamurthy (1982); Hintermann (2007). For the crystal structures of related compounds, see: Stibrany & Potenza (2006); Chitanda et al. (2008); Omondi et al. (2008); Gowda et al. (2009). For the treatment of the disordered solvent, see: Spek (2009).

Experimental top

N-(2,6-diisopropylphenyl)formamide was obtained as a byproduct from the synthesis of 1,3-bis-(2,6-diisopropylphenyl)imidazolium chloride (Hintermann, 2007). It can also be synthesized as reported by Krishnamurthy (1982). Crystallization from toluene resulted in the formation of colourless rod-shaped crystals of the title compound. To confirm the toluene contents of the sample, some single crystals were dissolved in CDCl3. 1H-NMR spectra of this solution showed the resonances of the major and minor rotamer of N-(2,6-diisopropylphenyl)formamide (Chitanda et al., 2008) and also the resonances of toluene.

Refinement top

Friedel opposites were merged. An arbitrary direction of the polar axis was choosen. The crystal packing shows a channel about [0 0 1] with a volume of 366 Å3. Thus the channel has an effective diameter of 7.43 Å. Only diffuse electron density with a maximum of 0.68 e.Å-3 was found in the channel. The SQUEEZE routine in PLATON (Spek, 2009) was used to subtract the solvent contribution from the observed reflection intensities. The solvent electron count in the channel was calculated as 100 electrons/cell. Assuming the solvent to be toluene, there would be two grossly disordered toluene molecules in the unit cell. The NH H atom was located in a difference electron-density map and freely refined. The C-bound H atoms were included in calculated positions and treated as riding atoms: C-H = 0.95, 0.98 and 1.00Å for CH(aromatic), CH3 and CH(methine) H atoms, respectively, with Uiso(H) = k × Ueq(parent C-atom), where k = 1.5 for CH3 H-atoms and = 1.2 for other H-atoms.

Computing details top

Data collection: SMART (Siemens, 1995); cell refinement: SAINT (Siemens, 1995); data reduction: SAINT (Siemens, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title molecule, showing the atom-labelling. Displacement ellipsoids are drawn at the 50% probability level.
[Figure 2] Fig. 2. A view of the hydrogen bonded helical 21 chain of title molecules lying parallel to the c axis. Displacement ellipsoids are drawn at the 50% probability level. The hydrogen bonds are shown as dotted lines [symmetry codes: (i) -x, -y + 1, z + 0.5; (ii) -x, -y + 1, z - 0.5].
[Figure 3] Fig. 3. A view along the c axis of the crystal packing of the title compound, showing the solvent accessible channel along [0 0 1]. H atoms on C atoms have been omitted for clarity. Displacement ellipsoids are drawn at the 50% probability level. Intermolecular N—H···O hydrogen bonds are shown as dotted lines.
N-(2,6-Diisopropylphenyl)formamide toluene 0.33-solvate top
Crystal data top
C13H19NO·0.33C7H8Dx = 1.124 Mg m−3
Mr = 236.00Mo Kα radiation, λ = 0.71073 Å
Hexagonal, P61Cell parameters from 8192 reflections
Hall symbol: P 61θ = 3–24°
a = 16.9133 (6) ŵ = 0.07 mm−1
c = 8.4451 (4) ÅT = 185 K
V = 2092.2 (2) Å3Rod, colourless
Z = 60.65 × 0.20 × 0.19 mm
F(000) = 772
Data collection top
Siemens SMART 1K CCD
diffractometer		1748 independent reflections
Radiation source: normal-focus sealed tube1503 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.057
ω scansθmax = 28.0°, θmin = 2.4°
Absorption correction: multi-scan
(SADABS; Sheldrick, 2000)		h = −21→21
Tmin = 0.933, Tmax = 0.987k = −22→21
23771 measured reflectionsl = −11→10
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.058Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.125H atoms treated by a mixture of independent and constrained refinement
S = 1.08 w = 1/[σ2(Fo2) + (0.06P)2 + 0.4P]
where P = (Fo2 + 2Fc2)/3
1748 reflections(Δ/σ)max < 0.001
144 parametersΔρmax = 0.16 e Å−3
1 restraintΔρmin = −0.16 e Å−3
Crystal data top
C13H19NO·0.33C7H8Z = 6
Mr = 236.00Mo Kα radiation
Hexagonal, P61µ = 0.07 mm−1
a = 16.9133 (6) ÅT = 185 K
c = 8.4451 (4) Å0.65 × 0.20 × 0.19 mm
V = 2092.2 (2) Å3
Data collection top
Siemens SMART 1K CCD
diffractometer		1748 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 2000)		1503 reflections with I > 2σ(I)
Tmin = 0.933, Tmax = 0.987Rint = 0.057
23771 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0581 restraint
wR(F2) = 0.125H atoms treated by a mixture of independent and constrained refinement
S = 1.08Δρmax = 0.16 e Å−3
1748 reflectionsΔρmin = −0.16 e Å−3
144 parameters
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
xyzUiso*/Ueq
O10.08661 (11)0.55915 (13)0.1114 (2)0.0375 (5)
N1−0.02094 (15)0.50925 (15)0.3050 (3)0.0315 (5)
H1A−0.0291 (19)0.496 (2)0.397 (4)0.034 (8)*
C1−0.09762 (16)0.49482 (18)0.2086 (3)0.0297 (6)
C2−0.16677 (16)0.40479 (18)0.1800 (3)0.0323 (6)
C3−0.24197 (17)0.3921 (2)0.0909 (3)0.0410 (7)
H3A−0.28990.33200.06890.049*
C4−0.24742 (19)0.4656 (2)0.0349 (4)0.0464 (8)
H4A−0.29950.4556−0.02380.056*
C5−0.17845 (19)0.5530 (2)0.0628 (4)0.0458 (7)
H5A−0.18300.60280.02120.055*
C6−0.10153 (17)0.57032 (19)0.1513 (3)0.0375 (6)
C7−0.15810 (18)0.32460 (18)0.2384 (3)0.0387 (6)
H7A−0.12710.34170.34380.046*
C8−0.2497 (2)0.2370 (2)0.2604 (4)0.0532 (8)
H8A−0.28930.24950.32810.080*
H8B−0.23980.19040.31030.080*
H8C−0.27890.21500.15700.080*
C9−0.0972 (2)0.3076 (2)0.1255 (4)0.0480 (8)
H9A−0.03780.36360.11550.072*
H9B−0.12630.29000.02120.072*
H9C−0.08840.25850.16760.072*
C10−0.02693 (19)0.6683 (2)0.1845 (4)0.0443 (7)
H10A0.02670.66600.22890.053*
C11−0.0572 (3)0.7136 (2)0.3082 (6)0.0721 (11)
H11A−0.07560.67680.40520.108*
H11B−0.10900.71810.26700.108*
H11C−0.00650.77480.33170.108*
C120.0049 (3)0.7257 (3)0.0336 (6)0.0755 (12)
H12A0.01590.6919−0.04940.113*
H12B0.06150.78300.05510.113*
H12C−0.04230.7392−0.00180.113*
C130.06249 (17)0.53788 (17)0.2494 (3)0.0319 (6)
H13A0.10720.54230.32240.038*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0290 (9)0.0517 (11)0.0258 (10)0.0156 (9)−0.0015 (8)−0.0027 (8)
N10.0328 (12)0.0378 (12)0.0192 (11)0.0141 (10)−0.0025 (9)−0.0013 (10)
C10.0236 (12)0.0416 (14)0.0241 (13)0.0166 (10)0.0014 (10)−0.0033 (11)
C20.0269 (12)0.0433 (14)0.0218 (12)0.0138 (11)0.0042 (10)−0.0044 (11)
C30.0291 (13)0.0561 (17)0.0313 (15)0.0163 (13)−0.0002 (12)−0.0094 (14)
C40.0287 (14)0.075 (2)0.0391 (16)0.0288 (15)−0.0051 (12)−0.0067 (15)
C50.0412 (16)0.0625 (18)0.0452 (18)0.0345 (15)0.0027 (14)0.0055 (15)
C60.0311 (13)0.0508 (16)0.0337 (15)0.0227 (12)0.0050 (11)0.0009 (13)
C70.0377 (14)0.0409 (15)0.0301 (14)0.0141 (12)−0.0028 (12)−0.0046 (12)
C80.0514 (18)0.0426 (16)0.0497 (18)0.0117 (14)0.0077 (16)−0.0040 (15)
C90.0461 (16)0.0455 (16)0.0511 (19)0.0219 (13)0.0010 (15)−0.0035 (15)
C100.0391 (15)0.0446 (16)0.0546 (19)0.0250 (13)0.0054 (14)0.0076 (15)
C110.064 (2)0.0493 (18)0.082 (3)0.0127 (16)0.012 (2)−0.016 (2)
C120.073 (2)0.066 (2)0.077 (3)0.026 (2)0.022 (2)0.023 (2)
C130.0275 (12)0.0368 (14)0.0280 (13)0.0134 (11)−0.0070 (10)−0.0054 (11)
Geometric parameters (Å, º) top
O1—C131.227 (3)C7—H7A1.0000
N1—C131.328 (4)C8—H8A0.9800
N1—C11.445 (3)C8—H8B0.9800
N1—H1A0.80 (4)C8—H8C0.9800
C1—C61.398 (4)C9—H9A0.9800
C1—C21.401 (4)C9—H9B0.9800
C2—C31.399 (4)C9—H9C0.9800
C2—C71.517 (4)C10—C111.527 (5)
C3—C41.375 (4)C10—C121.528 (5)
C3—H3A0.9500C10—H10A1.0000
C4—C51.371 (4)C11—H11A0.9800
C4—H4A0.9500C11—H11B0.9800
C5—C61.399 (4)C11—H11C0.9800
C5—H5A0.9500C12—H12A0.9800
C6—C101.525 (4)C12—H12B0.9800
C7—C81.528 (4)C12—H12C0.9800
C7—C91.532 (4)C13—H13A0.9500
C13—N1—C1124.2 (2)C7—C8—H8C109.5
C13—N1—H1A117 (2)H8A—C8—H8C109.5
C1—N1—H1A119 (2)H8B—C8—H8C109.5
C6—C1—C2122.6 (2)C7—C9—H9A109.5
C6—C1—N1119.3 (2)C7—C9—H9B109.5
C2—C1—N1118.1 (2)H9A—C9—H9B109.5
C3—C2—C1117.4 (2)C7—C9—H9C109.5
C3—C2—C7121.6 (2)H9A—C9—H9C109.5
C1—C2—C7120.9 (2)H9B—C9—H9C109.5
C4—C3—C2120.9 (3)C6—C10—C11111.6 (2)
C4—C3—H3A119.6C6—C10—C12112.0 (3)
C2—C3—H3A119.6C11—C10—C12110.6 (3)
C5—C4—C3120.7 (3)C6—C10—H10A107.5
C5—C4—H4A119.7C11—C10—H10A107.5
C3—C4—H4A119.7C12—C10—H10A107.5
C4—C5—C6121.2 (3)C10—C11—H11A109.5
C4—C5—H5A119.4C10—C11—H11B109.5
C6—C5—H5A119.4H11A—C11—H11B109.5
C1—C6—C5117.2 (3)C10—C11—H11C109.5
C1—C6—C10122.5 (2)H11A—C11—H11C109.5
C5—C6—C10120.2 (3)H11B—C11—H11C109.5
C2—C7—C8113.7 (2)C10—C12—H12A109.5
C2—C7—C9109.9 (2)C10—C12—H12B109.5
C8—C7—C9110.2 (2)H12A—C12—H12B109.5
C2—C7—H7A107.6C10—C12—H12C109.5
C8—C7—H7A107.6H12A—C12—H12C109.5
C9—C7—H7A107.6H12B—C12—H12C109.5
C7—C8—H8A109.5O1—C13—N1125.4 (2)
C7—C8—H8B109.5O1—C13—H13A117.3
H8A—C8—H8B109.5N1—C13—H13A117.3
C13—N1—C1—C6−73.6 (3)N1—C1—C6—C100.9 (4)
C13—N1—C1—C2108.2 (3)C4—C5—C6—C10.6 (4)
C6—C1—C2—C3−0.3 (4)C4—C5—C6—C10−178.3 (3)
N1—C1—C2—C3177.9 (2)C3—C2—C7—C8−26.6 (4)
C6—C1—C2—C7177.4 (2)C1—C2—C7—C8155.8 (2)
N1—C1—C2—C7−4.4 (3)C3—C2—C7—C997.4 (3)
C1—C2—C3—C4−0.3 (4)C1—C2—C7—C9−80.1 (3)
C7—C2—C3—C4−178.0 (3)C1—C6—C10—C11−105.1 (3)
C2—C3—C4—C51.1 (4)C5—C6—C10—C1173.8 (4)
C3—C4—C5—C6−1.2 (5)C1—C6—C10—C12130.3 (3)
C2—C1—C6—C50.2 (4)C5—C6—C10—C12−50.8 (4)
N1—C1—C6—C5−178.0 (2)C1—N1—C13—O13.0 (4)
C2—C1—C6—C10179.1 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···O1i0.80 (4)2.05 (4)2.826 (3)164 (3)
C4—H4A···O1ii0.952.563.418 (3)150
C13—H13A···C3i0.953.013.917 (4)161
C13—H13A···C4i0.953.033.973 (4)173
Symmetry codes: (i) −x, −y+1, z+1/2; (ii) y−1, −x+y, z−1/6.

Experimental details

Crystal data
Chemical formulaC13H19NO·0.33C7H8
Mr236.00
Crystal system, space groupHexagonal, P61
Temperature (K)185
a, c (Å)16.9133 (6), 8.4451 (4)
V (Å3)2092.2 (2)
Z6
Radiation typeMo Kα
µ (mm−1)0.07
Crystal size (mm)0.65 × 0.20 × 0.19
Data collection
DiffractometerSiemens SMART 1K CCD
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 2000)
Tmin, Tmax0.933, 0.987
No. of measured, independent and
observed [I > 2σ(I)] reflections		23771, 1748, 1503
Rint0.057
(sin θ/λ)max (Å−1)0.660
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.058, 0.125, 1.08
No. of reflections1748
No. of parameters144
No. of restraints1
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3)0.16, −0.16

Computer programs: SMART (Siemens, 1995), SAINT (Siemens, 1995), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···O1i0.80 (4)2.05 (4)2.826 (3)164 (3)
C4—H4A···O1ii0.952.563.418 (3)150
C13—H13A···C3i0.953.013.917 (4)161
C13—H13A···C4i0.953.033.973 (4)173
Symmetry codes: (i) −x, −y+1, z+1/2; (ii) y−1, −x+y, z−1/6.
 

References

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ISSN: 2056-9890
Volume 68| Part 5| May 2012| Page o1565
doi:10.1107/S1600536812017527
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