Resolution of Ultrafast Pyrene Excimer Emission Rise Times in Zeolites X and Y†

Abstract

Pyrene has been a favorite photophysical probe molecule for zeolite research because of its ability to exhibit both monomer and excimer emission upon excitation. This study combines the use of ultrafast time-resolved fluorescence spectroscopy with steady-state fluorescence spectroscopy to study the excimer emission of pyrene incorporated within zeolites LiY, NaY, KY and NaX. The effects of sealing technique and coincorporated solvents are also explored. Pyrene excimer emission is resolvable with the use of an ultrafast streak camera under all conditions examined in this study with a rise-time range of 6.8 to 16.0 picoseconds. For each zeolite sample the addition of cosolvents decreases the rise time, with a greater decrease for polar solvents than for a nonpolar solvent. The presence of a detectable rise time for excimer emission indicates that pyrene excimer formation is a dynamic process when pyrene is embedded within the cavities of zeolite host materials.

The Fluorescent Properties of pH‐Independent Cypridina Oxyluciferin Derivatives

“…[18][19][20][21] Reactive oxygen species have been found to be associated with the pathology of many diseases. [22][23][24][25] As we known, the most widely applied substrates which can reaction with molecular oxygen are firefly luciferin and coelenterazine, unfortunately, firefly luciferin requires the addition of magnesium ion and ATP to trigger light emission, [26][27][28][29][30][31][32][33] the process leading the light emission of coelenterazine requires the presence of calcium ion as cofactors, [34][35][36][37] which potentially leads to complex protocols in bioanalysis. For this reason, the co-factors independent cypridina bioluminescence has attracted considerable attention from biologists and chemists.…”

Theoretical Simulation of the Vibrationally Resolved UV Absorption Spectrum of Acryloyl Fluoride

“…[54] Moreover, by definition, the two physical quantities do not correspond with each other and can be very different in some cases. [10] Therefore, it is critical to simulate the spectrum for comparison with the experimental data.…”

“…In our previous work, we verified that the spectral simulation performs well for firefly luciferin, where the simulated spectra have band maxima that match the experimental data. [10] Numerous studies have provided the basis for developing a program for accurately simulating the vibrationally resolved spectrum since the 1990s or even before. [11][12][13] Many programs for simulating vibrationally resolved spectra have emerged and continue to be developed with the progress of quantum chemistry.…”

Direct observation of single plasmonic metal nanoparticle reaction in microcolumn with chromatic‐aberration‐free LASER light‐sheet scattering imaging

“…People have witnessed broad applications of MNPs in material [2], chemistry [3], and biomedical implements [4][5][6]. In particular, the study of MNPs at the single particle level has attracted much attention for researchers in multiple fields such as optoelectronics [7], catalysis [8,9], biosensors [10], drug delivery [11], and optical imaging [12,13]. Since the successful utilization of MNPs relies on the availability of synthetic methods to produce the desired morphology and surface functionalities [1,14,15], it is important to investigate chemical reactions [11,12,[16][17][18] and specific adsorptions of surfaceactive molecules on selective crystal planes of MNPs for their controlled growth.…”