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

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-dime nsional hexagonal network mediated by trigonally symmetric Cl-3 synthons ha ving Cl . . . Cl interactions of 3.441 (3) Angstrom, a C-Cl . . . Cl angle of 165 degrees and a Cl . . . Cl-C angle of 105 degrees, close to the ideal values of 180 and 90 degrees, respectively. The guest molecules are of an appropriate size to rt the hexagonal networks and interact with the host vi a C-H . . . pi (phenyl) and C-Br . . . pi (phenyl) interactions which stabi lize the overall structure. Both C-donor bond vectors are directed more clo sely towards the mid-point (X) of an individual aromatic bond, rather than the ring centroid, with H . . .X 2.817 (9) Angstrom and C-H . . .X 174.0 (9 )degrees, and Br . . .X 3.353 (4) Angstrom and C-Br . .X 158.1 (2)degrees.