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Crystal Research and Technology |
Cryst. Res. Technol. 38,
822 (2003) - Abstract -
Crystal and molecular structure of 2,6-bis(4-fluorobenzylidene)cyclohexanone
G. Ompraba, Z. A. Rafi, M. Yogavel*, D. Velmurugan*, K. Sekar**, E. Karthikeyan***, S. Perumal***, A. R. Choudhury****, T. N. Guru Row****
Bioinformatics Centre, Madurai Kamaraj University, Madurai -625 021, India
*Deparment of Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai –600 025, India
**Bioinformatics Centre and Supercomputer Education and Research Centre, Indian Institute of Science, Bangalore -560 012, India
***School of Chemistry, Madurai Kamaraj University, Madurai –625 021, India
****Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore -560 012, India
| Keywords | cyclohexanone, benzylidine, second harmonic generation, crystal structure |
| PACS | 61.10.Ng |
| DOI | 10.1002/crat.200310101 |
The title compound, C20H16F2O, crystallizes in triclinic system with P-1 space group and the unit cell parameters are: a = 9.700(5), b = 11.834(6), c = 14.315(7) Å, α = 78.464(9), β = 74.394(8), γ = 86.186(9)º, V = 1551.0(1) Å3 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... π interactions stabilize the molecular packing.
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