A high-resolution synchrotron X-ray powder diffraction study of trans-stilbene in zeolite ZSM-5

Abstract

Upon adsorption of two molecules of stilbene per unit cell, the apparent symmetry of ZSM-5 changes to tetragonal, but the true symmetry is orthorhombic with a very small difference between aand b, which becomes progressively more pronounced with b > aas the sample is cooled to 25 K; the stilbene molecule is located in the straight channels, with one phenyl ring on the mirror plane, at the intersection of the straight and sinusoidal channels.