A novel luminescent functionalized siloxane polymer

Abstract

The simple chemical reaction between acetone and tetrachlorosilane is found to yield a functionalized siloxane polymer that can emit light under normal conditions, if irradiated with a suitable wavelength. In situ multinuclear NMR spectra during various stages of the reaction show the formation of intermediates such as mesityl oxide (MeO), diacetone alcohol (DAA), phorone, isophorone, etc. Thus, the reaction is initiated via a type of self-condensation of acetone in the presence of tetrachlorosilane. The reaction provides a strongly acidic dehydrating atmosphere, which can be generated otherwise only in the presence of a specific catalyst and or at high temperatures. The reaction of the keto group with SiCl₄ is known to form siloxy-conjugated enes. On the other hand, the fast hydrolysis reaction leads to a siloxane network. Thus various condensation and dehydration reactions lead to a functionalized siloxane polymer with a lot of inherentπ -bonded carbon atoms. The gel obtained shows strong room-temperature photoluminescence (PL) with a maxima at 655 nm. The origin of PL is the presence of large amount of delocalized π-electrons in the system, which can enhance the radiative recombination of holes and electrons, which is further supported by the ESR spectra of the gel.