1,3-Diethyl-1,3-diphenyl­urea

Richard Betz; Thomas Gerber; Henk Schalekamp

doi:10.1107/S1600536811008294

. 2011 Mar 9;67(Pt 4):o827. doi: 10.1107/S1600536811008294

1,3-Diethyl-1,3-diphenylurea

Richard Betz ^a,^*, Thomas Gerber ^a, Henk Schalekamp ^a

PMCID: PMC3100078 PMID: 21754111

Abstract

The molecule of the title compound, C₁₇H₂₀N₂O, a symmetrical derivative of urea, shows non-crystallographic C ₂ symmetry. Interaction with the aromatic system of the phenyl substituents as well as amide-type resonance is responsible for the marked planarization of the coordination environments of the N atoms. C—H⋯O contacts give rise to the formation of centrosymmetric dimers in the crystal structure. The closest distance between the centroids of two adjacent rings is 3.8938 (11) Å.

Related literature

For the crystal structure of a uranium coordination compound with the title compound as a ligand, see: Zhu et al. (2008 ▶). For graph-set analysis of hydrogen bonds, see: Etter et al. (1990 ▶); Bernstein et al. (1995 ▶).

Experimental

Crystal data

C₁₇H₂₀N₂O
M _r = 268.35
Monoclinic,
a = 9.6990 (5) Å
b = 16.7622 (10) Å
c = 10.6011 (5) Å
β = 118.854 (4)°
V = 1509.52 (14) Å³
Z = 4
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 200 K
0.44 × 0.27 × 0.20 mm

Data collection

Bruker APEXII CCD diffractometer
14247 measured reflections
3723 independent reflections
2926 reflections with I > 2σ(I)
R _int = 0.030

Refinement

R[F ² > 2σ(F ²)] = 0.049
wR(F ²) = 0.141
S = 1.04
3723 reflections
183 parameters
H-atom parameters constrained
Δρ_max = 0.20 e Å⁻³
Δρ_min = −0.22 e Å⁻³

Data collection: APEX2 (Bruker, 2010 ▶); cell refinement: SAINT (Bruker, 2010 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and Mercury (Macrae et al., 2006 ▶); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811008294/ez2237sup1.cif

e-67-0o827-sup1.cif^{(17.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811008294/ez2237Isup2.hkl

e-67-0o827-Isup2.hkl^{(182.6KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C13—H13⋯O1ⁱ	0.95	2.68	3.326 (2)	126

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors thank Mr Matthew Mackay for helpful discussions.

supplementary crystallographic information

Comment

Chelate ligands are an important class of molecules in coordination chemistry due to the increased thermodynamic stability of coordination compounds obtainable in comparison to those derived from monodentate ligands only. Derivatives of urea are of particular interest in this aspect due to a number of reasons: firstly, urea itself can act as a neutral or – upon deprotonation – anionic ligand. Secondly, apart from exclusive N-donor action, the carbonyl O-atom may serve as donor as well. Thirdly, the possible derivatization of the N-atoms allows for the fine-tuning of the nucleophilicity of these atoms, such that a vast series of different symmetric, as well as asymmetric, derivatives is at hand. A crystal structure of a uranium coordination compound utilising the title compound as ligand has been published (Zhu et al., 2008). At the beginning of a bigger study to elucidate the rules guiding the formation of urea-derivative-supported coordination compounds we determined the structure of the title compound to allow for comparisons with the ligand in such compounds.

In the molecule (Fig. 1), the coordination environment around both nitrogen atoms is almost planar due to the interaction of the free electron pair not only in terms of amide-type resonance but also with the phenyl-moiety. The N-atoms are displaced by only 0.183 (1) Å and -0.180 (1) Å from the planes defined by the atoms bonded to them.

The least-squares planes defined by the carbon atoms of the phenyl rings enclose an angle of 40.31 (4) °.

In the crystal structure, C–H···O contacts are present whose range falls sightly below the sum of van-der-Waals radii of the atoms involved. They involve one of the phenyl hydrogen atoms which is meta to the nitrogen atom and connect the molecules into centrosymmetric dimers (Fig. 2). In terms of graph-set analysis, the descriptor for these contacts on the unitary level is R²₂(14) (Etter et al., 1990; Bernstein et al., 1995). The closest distance between two centers of gravity was measured at 3.8938 (11) Å.

The packing of the title compound is shown in Fig. 3.

Experimental

The compound was obtained commercially (Aldrich). Crystals suitable for the X-ray diffraction study were taken directly from the provided compound.