Growth and X-ray structure of single crystals of 1,3,5-tris[(6,7-dimethyl-3-phenyl)quinoxaline-2-yl] benzene

Single crystals of 1,3,5-tris[(6,7-dimethyl-3-phenyl)quinoxaline-2-yl] benz ene (Me-TPQ) have been grown from the vapour phase under high-vacuum condit ions. Me-TPQ belongs to the class of star-shaped tris(phenylquinoxalines) w hich form usually amorphous glasses. Thermal analysis indicated however, th at the title compound possesses a crystal phase. The structure of Me-TPQ cr ystals has been determined by single crystal X-ray diffraction measurements . Two unit cells have been detected, monoclinic and orthorhombic. We report , here, the crystal structure of the latter, which might be of interest for non-linear optics applications. (C) 2001 Elsevier Science B.V. All rights reserved.