(R)-2,2′-Bis[N′-(3,5-dichlorophenyl)ureido]-1,1′-binaphthalene chloroform disolvate

The title compound, C34H22Cl4N4O2·2CHCl3, is a new urea based on the 1,1′-binaphthalene skeleton, which crystallizes with two molecules of binaphthalene and four molecules of chloroform in the unit cell. The chloroform solvent molecules do not participate in non-covalent interactions and therefore, can be found in several positions. The binaphthalene molecules are connected via a system of N—H⋯O hydrogen bonds between the ureido units. C—H⋯O interactions also occur. In contrast to unsubstituted urea, where molecules form squares in crystals, the bulky substituents disturb this arrangement and three ureido groups form infinite chains, while the fourth interacts with a neighbouring binaphthalene ring via an N—H⋯π interaction. The solvent molecules are disordered with occupancy ratios of 0.60:0.40, 0.58:0.42, 0.50:0.50 and 0.77:0.23.

The title compound, C 34 H 22 Cl 4 N 4 O 2 Á2CHCl 3 , is a new urea based on the 1,1 0 -binaphthalene skeleton, which crystallizes with two molecules of binaphthalene and four molecules of chloroform in the unit cell. The chloroform solvent molecules do not participate in non-covalent interactions and therefore, can be found in several positions. The binaphthalene molecules are connected via a system of N-HÁ Á ÁO hydrogen bonds between the ureido units. C-HÁ Á ÁO interactions also occur. In contrast to unsubstituted urea, where molecules form squares in crystals, the bulky substituents disturb this arrangement and three ureido groups form infinite chains, while the fourth interacts with a neighbouring binaphthalene ring via an N-HÁ Á Á interaction. The solvent molecules are disordered with occupancy ratios of 0.60:0.40, 0.58:0.42, 0.50:0.50 and 0.77:0.23.  Table 1 Hydrogen-bond geometry (Å , ).

Experimental
(R)-1,1'-Binaphthyl-2,2'-diamine (150 mg, 0.53 mmol) in dry dichloromethane (45 ml) was treated with 3,5-dichlorophenyl isocyanate (800 mg, 4,26 mmol, 4 eq per amino group) at ambient temperature for 12 h. The reaction was quenched with methanol (10 ml) and stirred for another 12 h. The reaction mixture was evaporated in vacuo and purified by column chromatography (silica gel, dichloromethane) to give the title compound as a white solid (97% yield). Single crystals of the title compound suitable for X-ray diffraction were obtained by slow evaporation of CDCl 3 solution over a period of several days.

Refinement
Four molecules of chloroform are present in the asymmetric unit. Solvent can freely rotate in its cavity which leads to disorder of its position. Two possible positions were found and refined for each molecule. The position of atoms were found from maps of electron densities, disordered fragments were then placed in appropriate positions, and all distances between neighbouring atoms and angles were fixed. Site occupancies were refined for the different parts with the same thermal parameters for the same atoms in the various fragments. At the end of the refinement, site occupancies were fixed. Hydrogen atoms were placed in calculated positions with N-H = 0.86 Å and C-H = 0.93 Å. Thermal parameters were set to U iso (H) equal to 1.2 times U eq of the parent atom. Fig. 1. View of the one molecule of (R)-2,2'-bis[N-(3,5-dichlorophenyl)ureido]-1,1'-binaphthalene together with atom-labeling scheme. The hydrogen atoms which do not participate in hydrogen bonds and the solvents molecules were omitted for better clarity. Displacement ellipsoids are shown at the 50% probability level. Fig. 2. View of the other molecule of (R)-2,2'-bis[N-(3,5-dichlorophenyl)ureido]-1,1'-binaphthalene together with atom-labeling scheme. The hydrogen atoms which do not participate in hydrogen bonds and the solvents molecules were omitted for better clarity. Displacement ellipsoids are shown at the 50% probability level.

Special details
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 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 > σ(F 2 ) is used only for calculating Rfactors(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.