Acta Crystallographica Section B

Structural Science

Volume 56, Part 6 (December 2000)

research papers

Acta Cryst. (2000). B56, 1080-1084 [ doi:10.1107/S0108768100011551 ]

Halogen trimer synthons in crystal engineering: low-temperature X-ray and neutron diffraction study of the 1:1 complex of 2,4,6-tris(4-chlorophenoxy)-1,3,5-triazine with tribromobenzene

C. K. Broder, J. A. K. Howard, D. A. Keen, C. C. Wilson, F. H. Allen, R. K. R. Jetti, A. Nangia and G. R. Desiraju

Abstract: The title complex has been studied using low-temperature X-ray (150 K) and neutron (100 K) diffraction. Molecules of the triazine host form a two-dimensional hexagonal network mediated by trigonally symmetric Cl₃ synthons having ClCl interactions of 3.441 (3) Å, a C-ClCl angle of 165° and a ClCl-C angle of 105°, close to the ideal values of 180 and 90°, respectively. The guest molecules are of an appropriate size to fit the hexagonal networks and interact with the host via C-H [pi] (phenyl) and C-Br [pi] (phenyl) interactions which stabilize the overall structure. Both C-donor bond vectors are directed more closely towards the mid-point (X) of an individual aromatic bond, rather than the ring centroid, with HX 2.817 (9) Å and C-HX 174.0 (9)°, and BrX 3.353 (4) Å and C-BrX 158.1 (2)°.

Keywords: Synthon; Low-temperature diffraction; Triazine host.