取代基对稀土夹心双酞菁铥荧光特性的影响

利用稳态荧光和时间分辨荧光方法研究了三明治型酞菁铥的荧光特性及其浓度、激发波长和取代基对荧光特性的影响。实验发现:3种双酞菁铥的氯仿溶液在700 nm处具有较强的荧光发射,给电子基-OC₈H₁₇的加入使得酞菁大环上π电子的离域性增强,降低了π分子轨道的能级差;同时,烷氧基上非成键电子能够和共轭体系中的π电子相互作用,形成p-π共轭,进一步降低了π-π^*之间的能级差,从而使荧光谱中发射峰的峰位发生红移,峰的强度也有变化。3种酞菁铥化合物在700 nm左右的荧光具有两个寿命,分别为单体和聚集体产生的,随着浓度的降低,单体成分逐渐增多。

Influence of Substituents on Photoluminescence Properties of Thulium Bisphthalocyanine Derivatives

The fluorescence properties of three thulium bisphthalovanine compounds were studied using the steady-state fluorescence and time-resolved fluorescence spectra. Meanwhile, the effect of the concentration, excitation wavelength and substituents on the fluorescence properties was discussed. A strong fluorescence emission at about 700 nm was found in the thulium bisphthalocyanine chloroform solution. The π-electron delocalizability of phthalocyanine macrocyle was strengthened, and the energy gap between π and π^* molecular orbital decreased with the alkoxyl substitutent -OC₈H₁₇ being added. Meanwhile, there formed the p-π conjugation system resulting from the interaction between non-bonding electron of -OC₈H₁₇ and π electron of phthalocyanine rings, which reduced the energy gap between π and π^* molecular orbits further, and made both the emission peak red shift and the emission intensity change. The fluorescence at about 700 nm exhibited two lifetimes, originated from the monomer and aggregates of phthalocyanines respectively. With the concentration decreasing, the components of monomer increased gradually.