取代基对双酞菁铥LB膜及光谱特性的影响

采用紫外-可见吸收光谱的方法研究了三种稀土夹心双酞菁铥化合物在溶液和LB膜中的聚集性和光谱特性。实验结果表明三种稀土双酞菁化合物在氯仿溶液中形成了H-聚集体，但当浓度比较低时，溶液中表现出单体的吸收。取代基OC₈H₁₇的加入使氯仿溶液中双酞菁铥化合物的聚集性减弱，而且使得吸收峰发生红移，对吸收峰的强度也有较大的影响，造成了Soret吸收带的分裂。另外，取代基OC₈H₁₇对LB膜中双酞菁分子的存在状态有较大的影响，在LB膜中，TmPc₂和TmPcPc*分子以H-聚集体的形式存在，而TmPc*₂分子以T-聚集体的形式存在。形成LB膜后，由于双酞菁分子之间排列紧密，相互作用加强，使得薄膜中分子聚集体的吸收峰相对于溶液中聚集体的吸收峰发生了一定的红移，薄膜中分子排列方向的不同对吸收光谱也有一定的影响。

Influence of Substituents on Langmuir-Blodgett Films and Spectral Properties of Thulium Bisphthalocyanine Derivatives

The aggregation and spectral properties of three sandwich thulium bisphthalocyanine compounds in chloroform solution and LB films were investigated by using UV-Vis absorption spectra. The experimental results indicated that the three sandwich thulium bisphthalocyanine molecules formed H-aggregates in the chloroform solution, but the absorption spectra of the three sandwich thulium bisphthalocyanine compounds display strong absorption peaks of monomer when the concentration of the sandwich thulium bisphthalocyanine solutions was 10-7mol·L-1. The addition of substitutent —OC₈H₁₇ not only decreased the aggregation behaviors of the sandwich thulium bisphthalocyanine, but also leaded to red-shift of the absorption peaks, and it had a biggish influence on the intensity of absorption spectra. The absorption Soret bands were splitting when the substitutent —OC₈H₁₇ was added. The substitutent —OC₈H₁₇ had a strong effect on the existence state of bisphthalocyaines in LB films, while the TmPc2 and TmPcPc* molecules formed H-aggregates in LB films, however TmPc*₂ molecule formed T-aggregates. In the LB films, the distance between sandwich thulium bisphthalocyanine molecule was shortened, and the interaction of molecules was enhanced, therefore the absorption peaks were red-shifted compared with those in the solution, and the arranging state of sandwich thulium bisphthalocyanine molecule has biggish influence on the peaks of absorption spectra.