Pyrenyl excimers induced by the crystallization of POSS moieties: spectroscopic studies and sensing applications.
An ester (PBPOSS) of 1-pyrenebutyric acid (PBA) and 1-(2,3-propanediol)propoxy-3,5,7,9,11,13,15-isobutylpentacyclo-[9.5.1.1(3,9).1(5,15).1(7,13)]octasiloxane (a polyhedral oligomeric silsesquioxane, POSS) is synthesized by simple one-step esterification. Thin films of PBPOSS fabricated by the spin-coating technique exhibit strong excimer emissions of visible light. Upon exposure to the vapours of nitroaromatic compounds, including trinitro- toluene and dinitrotoluene, the films show fast fluorescence quenching. The high performance of these gas sensors is due to the high excimer contents and good vapour permeability of the PBPOSS films. Spectroscopic studies indicate that the crystallization of the POSS moieties in PBPOSS films induce the formation of pyrenyl excimers.
Bai
Hua
H
Department of Chemistry, Tsinghua University, Beijing 100084, P. R. China.
Li
Chun
C
Shi
Gaoquan
G