title: Localization of p-nitroaniline chains inside zeolite ZSM-5 with second-harmonic generation microscopy.
abstract: For the first time, second-harmonic generation microscopy (SHGM) has been employed to study zeolites. Large ZSM-5 crystals filled with p-nitroaniline (PNA) dipoles have been visualized. It is shown that SHGM can discriminate between the straight b-pores and the sinusoidal a-pores of this zeolite, thus revealing the intergrown structure of these crystals. Moreover, it is shown that dipole chains are formed not only in the b-pores but also in the a-pores. PNA only assembles into dipole chains of parallel orientation in those pores that are directly accessible from the outer surface. The area in which this PNA ordering prevails is limited to a strip near the outer surface of the zeolite crystal. A rationalization for these two observations is offered.
authors.affiliation: Department of Microbial and Molecular Systems, Centre for Surface Chemistry and Catalysis, Kasteelpark Arenberg 23, Belgium.
authors.forename: Monique A
authors.initials: MA
authors.lastname: van der Veen
authors.forename: Bert F
authors.initials: BF
authors.lastname: Sels
authors.forename: Dirk E
authors.initials: DE
authors.lastname: De Vos
authors.forename: Thierry
authors.initials: T
authors.lastname: Verbiest
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry*; D008027:Light; D008853:Microscopy; D017641:Zeolites / Q000737:chemistry*
chemical_list: D000814:Aniline Compounds; D017641:Zeolites; C008625:nitroaniline