Summary: | 博士 === 淡江大學 === 化學學系博士班 === 96 === The molecular structure properties, the optical properties, and the molecular orbital transition of the organic light-emitting materials were calculated by using the density-functional theory (DFT), CIS and the time-dependent density-functional theory (TD-DFT) methods. In the part I, for N-substituted maleimides, the substituent gives only a slight influence on the maleimide chromophone. For 3,4-substituted maleimide, the steric repulsion between substituent and maleimide chromophone influences the extent of π-delocalization and the molecular conformation. The calculated maximum absorption wavelength and emission wavelength of maleimide derivatives are in good agreement with the experimental data. In the gas phase, both absorption and emission peaks are red-shift as compared to the non-substituted maleimide. For the 3,4-substituted maleimdies, the effect of substitution produces the most significant spectral red-shift as compared to other maleimdies. In the part Ⅱ, for Alq3 derivatives, the election-donation groups influence the HOMO energy significantly, and the election-withdrawing groups influence both the HOMO and LUMO energy. The maximum absorption wavelength of Alq3 derivatives are red-shift by substituents which connect at different bonding site. The significant molecular orbital energy difference can be produced by extent of the π-conjugation length between substituent and Alq3 chromophone.
|