Synchrotron powder diffraction characterization of the zeolite-based (p-N,N-dimethylnitroaniline-mordenite) guest-host phase

The crystal structure of a new phase consisting of the inclusion of the hyperpolarizable molecule p‐N,N‐dimethylnitroaniline (dimethyl‐para‐nitroaniline or dmpNA) in the large‐pore zeolite mordenite (MOR) has been determined from high‐resolution synchrotron powder diffraction at 300 and 90 K. The unit‐cell parameters and space group at 300 K are similar to those of as‐synthesized mordenite. The crystallographic study indicates that the MOR straight channels are almost fully loaded with molecules that are disordered over eight symmetry‐related sites. As expected, the molecules are located in the large 12‐membered ring channel, at the intersection with the secondary eight‐membered channel with which they might form hydrogen bonds. The elongation axes (and then the dipole moments) of the molecules are slightly tilted (28.57°) from [001]. The configuration found suggests an interaction of dmpNA with framework O atoms through its methyl groups.