1,2-Diphenylethane-1,2-diyl diisonicotinate monohydrate1

In the novel title compound, C26H20N2O4·H2O, the two phenyl rings make a dihedral angle of 45.3 (1)° with each other, and the dihedral angle between the two pyridyl planes is 69.8 (1)°.

In the novel title compound, C 26 H 20 N 2 O 4 ÁH 2 O, the two phenyl rings make a dihedral angle of 45.3 (1) with each other, and the dihedral angle between the two pyridyl planes is 69.8 (1) .
We thank the Natural Science Foundation of China (No. 20272019)  Synthesis of chiral molecules containing pyridine rings has attracted considerable attention in recent years (Aspinall, et al., 2003;Takenaka, et al., 2006;MacMahon, et al., 2001;Schuster, et al., 2005). In the title compound, (I), C 26 H 20 NO 2 , all bond lengths and angles show normal values (Shi, et al., 2006). The chiral molecule ( Figure 1) consists of two benzene rings and two pyridine rings. The dihedral angle between the two benzene ring is 45.28°. The torsion angle C2-C1-C7-O2 is -44.2 (2)°; the torsional angle The packing arrangement in a unit cell of the title molecule is shown in Figure 2.

S2. Experimental
The title compound, was synthesized by the reaction of trans-1,2-stilbene with nicotinic acid in dichloromethane. The single crystals of (I) suitable for X-ray diffraction were obtained from an ethanol solution by slow evaporation.

S3. Refinement
The H atoms bonded to N atom were located from difference density maps and refined isotropically. The H atoms bonded to C atoms were located geometrically and treated as riding, with C-H distances of 0.95-1.00 Å and with U iso (H) = 1.5Ueq(C) for methyl H atoms and 1.2Ueq(C) for others. Due to the absence of heavy atoms corresponding to Si, it was impossible to determine the absolute configuration in this case. At this stage, the Friedel pairs were merged.    The molecular packing diagram in the crystal for (I).
where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.13 e Å −3 Δρ min = −0.11 e Å −3 Special details 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. 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 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.