3,3′-Diphenyl-1,1′-[2,2′-oxybis(2,1-phenylene)]diurea N,N-dimethylformamide disolvate

In the structure of the title compound, C26H22N4O3·2C3H7NO, one of the DMF solvent molecules is disordered over two sets of positions in a 0.5:0.5 ratio. In the 1,1′-[2,2′-oxybis(2,1-phenylene)]bis(3-phenylurea) molecule, the two diphenylurea segments are linked via an ether O atom and are inclined at an angle of 53.80 (4)° to one another. In the crystal structure, classical N—H⋯O hydrogen bonds link each molecule to two DMF solvent molecules and these aggregates form columns down a through C—H⋯π interactions. Additional C—H⋯O interactions link the main molecule and the solvent molecules, forming columns of independent zigzag chains along b.

In the structure of the title compound, C 26 H 22 N 4 O 3 Á-2C 3 H 7 NO, one of the DMF solvent molecules is disordered over two sets of positions in a 0.5:0.5 ratio. In the 1,1 0 -[2,2 0oxybis(2,1-phenylene)]bis(3-phenylurea) molecule, the two diphenylurea segments are linked via an ether O atom and are inclined at an angle of 53.80 (4) to one another. In the crystal structure, classical N-HÁ Á ÁO hydrogen bonds link each molecule to two DMF solvent molecules and these aggregates form columns down a through C-HÁ Á Á interactions. Additional C-HÁ Á ÁO interactions link the main molecule and the solvent molecules, forming columns of independent zigzag chains along b.
Cg1 is the centroid of the C1-C6 ring.

Comment
While a large amount of work has been done on organic-metal cation complexes, there is much less known about analogous organic-anion complexes. We are interested in looking at diureas as potential anion binding agents. Ureas and thioureas have previously shown some promise in this area, and bind to anions such as fluoride and chloride through the hydrogen atoms attached to the urea N atoms (Gunnlaugsson et al., 2004;Kim & Kim, 2005).
The title diurea compound, (I), was synthesized by the reaction of phenyl isocyanate and an aromatic diamine. The crystal structure shows that the bis-2,2-oxyphenyl motif used here may not be optimal for anion binding, as the urea units are splayed away from each other, though some of this may be due to binding to the solvent in the solid state. Initial NMR studies showed some affinity for both fluoride and chloride anions in chloroform.
This variation is undoubtedly due to crystal packing effects.
In the crystal, classical N-H···O hydrogen bonds link each molecule to two DMF solvates (Table 1) and these aggregates form columns down a through an additional C31-H31A···Cg1 interaction, where Cg1 is the centroid of the C1···C6 ring.
Then, C-H···O interactions further link the molecule and solvates into zigzag chains along b. The combination of these interactions stacks the chains into independent but interleaving columns, down a, as shown in Fig. 2.

Experimental
To a solution of bis(2-aminophenyl)ether (1.00 g, 5.00 mmol) in dry distilled CH 2 Cl 2 (30 ml) was added phenyl isocyanate (1.20 g, 10.00 mmol) and the reaction stirred under nitrogen at room temperature for 24 h. In the absence of significant anomalous scattering effects, 2780 Friedel pairs were averaged for the refinement. One of the DMF solvate molecules is disordered over two sites and, in the final refinement cycles, the occupancy factors of the two disorder components were each fixed at 0.5. Common, isotropic temperature factors were applied to the non-H atoms of these components. In the final difference map, two peaks > 0.7 e Å −3 in the vicinity of the O5 and O5' atoms of the two components of the disordered dimethylformamide solvate were apparent.

Special details
Experimental. One of the DMF solvate molecules is disordered over two sites: common, isotropic temperature factors were applied to the non-H atoms of this moiety. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2sigma(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.