Crystal and molecular structure of 2,6-bis(4 fluorobenzylidene)cyclohexanone

Abstract

The title compound, C_20H_1_6F_2O, crystallizes in triclinic system with P1 space group and the unit cell parameters are: a = 9.700(5), b = 11.834(6), c = 14.315(7) $A^o$, \alpha = 78.464(9), \beta = 74.394(8), \gamma = 86.186(9)°, V = 1551.0(1) $A^o$ 3 and Z = 4. The final R-factor is 4.8%. The cyclohexanone ring adopts a sofa conformation. The different ways of adjusting to steric repulsion results in significant differences between molecule A and B with respect to torsion angles. The steric repulsion between the aromatic groups and hydrogen atoms on the cyclohexanone ring causes increase of the values of bond angles at the C atoms joining the rings and rotation of the corresponding bond, at the expense of conjugation energy of the system. In addition to the van der Waals interactions, C-H...O, C-H...F and C-H...\pi interactions stabilize the molecular packing