关键词: 光致发光, 密度泛函理论, d-p π键模型, 淬灭, 机制

Abstract: We investigated the electronic structure, photophysical properties, and thermal stability of N- (3-trimethoxysilylethyl)ethylenediamine (TMSEEDA). The optimized structural parameters in the ground state and first excited state were obtained from density functional theory calculations. The results showed that there was probably π electron delocalization within the Si－O skeleton, which induced the long wavelength absorption. A broad and intense blue emission with a maximum at 430 nm was observed for both the solution and the solid state with 270 nm excitation at room temperature. The absorption intensity for the solid state was five-times that of the pure TMSEEDA. For the ethanol solution, the photoluminescence intensity increased with increasing concentration of TMSEEDA and reached a maximum at a concentration of 100%. These results suggest there is no concentration quenching for TMSEEDA. An accepted model of electron delocalization and d-p π-bonding within the Si－O skeleton was applied to explain the long wavelength absorption and blue emission.

Key words: Photoluminescence, Density functional theory, d-p π-bonding model, Quenching, Mechanism