Fluorescence Resonance Energy Transfer of Fluorescent Molecules in Joint‐Linker Type Organic‐Inorganic Hybrid Gels

Abstract

Fluorescence resonance energy transfer (FRET) sensitized emission of perylene by pyrene in a joint‐linker type gel is observed for the first time. The joint‐linker type organic‐inorganic hybrid gels containing pyrene and perylene synthesized from multi‐functional cyclic siloxane, 1,3,5,7‐tetramethylcyclotetrasiloxane (TMCTS), or cubic silsesquioxane, 1,3,5,7,9,11,13,15‐octakis(dimethylsilyloxy)pentacyclo‐[9,5,1,1,1,1]octasilsesquioxane (POSS), as joint molecules, and α,ω‐nonconjugated dienes, 1,5‐hexadiene (HD), or 1,9‐decadiene (DD), as linker molecules, are involved in a photo hydrosilylation reaction with a bis(acetylacetonato)platinum catalyst in a toluene solution of pyrene and perylene. FRET from pyrene (donor) to perylene (acceptor) in the gels is studied quantitatively. The FRET efficiencies (E) of gels containing 300 or 30 x 10–6 m of pyrene and perylene are about 0.6–0.8 or 0.5, respectively, independent of the monomer concentration. Sensitized acceptor emission is observed in the gels, especially in the gels containing 300 x 10–6 m of pyrene and perylene molecules. The ratio of the increase of the sensitized acceptor emission to the loss of donor fluorescence, the G factor, is determined to evaluate the efficiency of the sensitized emission of the acceptor in the gels. The G factors of the gels containing 300 or 30 x 10–6 m of pyrene and perylene molecules are 0.4–0.75 or 0.07‐0.1, repectively, and the gels with TMCTS or DD have a slightly higher G factor than gels with POSS or HD.

Alginate/Cucurbit[7]uril/Dequalinium-Based Supramolecular Carbohydrates: Modulation of FRET Signals by Temperature Control

“…Over the past years, the number of publications on FRET-based supramolecular architectures for harvesting light energy has substantially increased. − ,,,− These publications describe derivatives of several parent fluorophores such as pyrene, , benzothiadiazole, aminonaphthalene, , phenylenevinylene, , tetraphenylethene, ,, Nile Red, , stilbazolium, porphyrin, , eosin Y, , salicylaldehyde azine, , rhodamines, boron dipyrromethene, ,,− , diphenylanthracene, and perylene as donors and/or acceptors. The employed macrocycles include cucurbituril, ,,, cyclodextrin, ,,, calixarenes, pillararenes, ,,,,, and heterorotaxane .…”

“…The employed macrocycles include cucurbituril, ,,, cyclodextrin, ,,, calixarenes, pillararenes, ,,,,, and heterorotaxane . The emission color has been tuned in the range of violet to red for excitation in the UV (335–383) ,,,− ,, and visible (470–490) , regions. In most cases, reversible responsiveness was modulated by chemical stimuli, , and the fabricated materials were applied in fluorescent inks, , optical switches, , biological probes, solar cells, organic–inorganic hybrid gels, optoelectronics, protein assembly, enzymatic assays, cancer cell diagnosis, color tuning, ,, photosynthesis mimicking, ,, artificial light harvesting, ,− and security encryption .…”

“…The emission color has been tuned in the range of violet to red for excitation in the UV (335–383) ,,,− ,, and visible (470–490) , regions. In most cases, reversible responsiveness was modulated by chemical stimuli, , and the fabricated materials were applied in fluorescent inks, , optical switches, , biological probes, solar cells, organic–inorganic hybrid gels, optoelectronics, protein assembly, enzymatic assays, cancer cell diagnosis, color tuning, ,, photosynthesis mimicking, ,, artificial light harvesting, ,− and security encryption . However, compared to all previously reported artificial light-harvesting systems, the distinct feature of the materials prepared herein is their responsiveness to temperature based on the shuttling of CB7 along the DCH stalk (Figure ), which obviates the need to change the ratio of donor to acceptor components. , Moreover, our supramolecular architecture can be simply fabricated by one-step formation of amide linkages between the amino groups of DCH and the carboxylic groups of ALG.…”

Synthesis and properties of multifunctional thiol crosslinked gels containing disulfide bond in the network structure

“…The joint‐liker type gels formed homogeneous network structure, and their mesh size could be controlled by the length of the linker molecules . The mesh of the network structure was usable for isolate incorporation of small molecules . We came to an idea to introduce reversible covalent disulfide bonds in the network to extend the applications of the type of gels.…”