Transfer of Electronic Excitation Energy between Dye Molecules in the Channels of Zeolite L

Abstract

We show that the intercalation of dye molecules, which penetrate the cylinders from the bottom and the top surface, into the linear channels of zeolite L can be observed with the help of a fluorescence microscope. By means of a polarizer, we have proved the alignment of the dye molecules in the channels, because maximum luminescence appears parallel to the longitudinal axis of the microcrystals and extinction perpendicular to it. A simple and elegant experiment for the visual proof of the energy transfer from pyronine to oxonine in zeolite is based on the observation that both dyes are intercalated from an aqueous solution within about the same time. This leads to high dye concentrations in the zeolite and therefore to short distances between the molecules, which enables energy transfer between them. This experiment also allows a simple determination of the shortest distances between neighboring dye molecules along linear channels.

Visual Observation of Contact‐Induced Intercrystalline Migration of Aromatic Species Adsorbed in Zeolites by Fluorescence Microscopy

“…[17,21] Fluorescence microscopy was previously applied by Calzaferri's group to the investigation of the intercalation, alignment, and energy transfer of dye molecules in the channel-type zeolite L crystals of 1-3 mm size. [22][23][24] However, the technique has not been applied to the study of interzeolite diffusion. In our study, the photophysical processes of guest species dependent on the specific charge-compensating cations were exploited as indicator reactions to yield a luminescence color characteristic of individual zeolite particles.…”

Hexagonal microlasers based on organic dyes in nanoporous crystals

“…Lattice constants and free pore diameter φ of molecular sieves with linear channels [13]. migration [9]. Nanoporous crystals were also studied as hosts for luminophores [10], pigments [11], optical switches [12] or dye lasers [5].…”

Self-organized patterns of microparticles in polymer films

“…To visualize the patterns, the ZL nanochannels were filled with the luminescent dye oxonine [18]. Dye-loaded ZL crystals were prepared by refluxing 70 mg of ZL (Lucidot DISC, Clariant) in an aqueous solution of oxonine (3,7-diaminophenoxazinylium) chloride (4.5 mL, 0.13 mM) for 16 h. The crystals were recovered by centrifugation, washed with methanol to remove oxonine molecules adsorbed on the external surface, and oven-dried at 60 °C.…”