Host–Guest Antenna Materials

Abstract

The focus of this review is on host-guest composites with photonic antenna properties. The material generally consists of cylindrical zeolite L crystals the channels of which are filled with dye molecules. The synthesis is based on the fact that molecules can diffuse into individual channels. This means that, under the appropriate conditions, they can also leave the zeolite by the same way. In some cases, however, it is desirable to block their way out by adding a closure molecule. Functionalization of the closure molecules allows tuning of, for example, wettability, refractive index, and chemical reactivity. The supramolecular organization of the dyes inside the channels is a first stage of organization. It allows light harvesting within a certain volume of a dye-loaded nanocrystalline zeolite and radiationless transport to both ends of the cylinder or from the ends to the center. The second stage of organization is the coupling to an external acceptor or donor stopcock fluorophore at the ends of the channels, which can trap or inject electronic excitation energy. The third stage of organization is the coupling to an external device through a stopcock molecule. The wide-ranging tunability of these highly organized materials offers fascinating new possibilities for exploring excitation-energy-transfer phenomena, and challenges for developing new photonic devices.

The high thermal stability of the synthetic zeolite K–L: Dehydration mechanism by in situ SR-XRPD experiments

“…The inclusion of guest molecules into ordered one-dimensional channel systems is particularly intriguing, as the resulting host-guest compounds may exhibit peculiar new properties. These hybrid materials can be exploited in several research fields, as devices for solar energy harvesting, processing/storing of information, and advanced sensing technology for analytics and diagnostics on the nanoscale [6,7,8].…”

“…As a result, very high concentrations of well oriented molecules can be obtained [6,7,8]. In view of the well-known affinity of zeolites for water, stability of the hybrid materials upon hydration is particularly critical.…”

Fluorescent nanopigments: Quantitative assessment of their quantum yield

“…2 ZL nanoparticles with an aspect ratio of 1:1 and a narrow size distribution around 200 nm were synthesized using a hydrothermal process. 59 Details on the synthesis procedure and parameters can be found in Ref.…”

“…[1][2][3][4][5][6][7][8] Moreover, functionalizing the external surface of the these fluorescent nanoparticles and embedding them into a dielectric ͑e.g., polymer͒ matrix has enabled the realization of a large variety of novel optophotonic devices. [9][10][11][12][13][14] Recently, due to the wealth of existing organic fluorescent dyes, their encapsulation into either an inorganic or an organic host has been demonstrated to be a very promising and versatile approach to synthesize a large palette of new fluorescent pigments.…”

“…In this article, we present an optical technique that allows the direct measurement of the absolute quantum yield of fluorescent nanoparticles such as zeolite L ͑ZL͒ nanocrystals 2,[20][21][22][28][29][30][31] and poly͑methyl methacrylate͒ ͑PMMA͒ nanospheres 5,17,19,[23][24][25]53,54 both loaded with fluorescent perylene molecules, which are well known for their chemical and photochemical stabilities as well as for their high quantum yield. 5,55 Our experimental method is based on the measurement of the diffuse reflectance ͑DR͒ spectra of fluorescent nanopigments adsorbed on microcrystalline cellulose substrates.…”