The alkoxysilane modified pyrene (Py-Si) was synthesized by modifying a reported procedure [24]. Firstly, 1-(4–hydroxyphe-
nyl)-4-pyrenyl-2,3-diaza-1,3-butadiene(Py-OH) was obtained as a starting material following the literature procedure [17].Then,1 mmol of Py-OH was mixed with 6.37 mmol of TESPIC,which was dissolved in 20 mL chloroform in
a round-bottom flask , and the mixture was stirred under N2 atmosphere at 60 1 C for 72 h. Then cold hexane was added dropwise into the flask to precipitate a yellow solid from the mixture. The final filtered-off precipitate was washed with several portions of cold hexane,