可溶性钒氧酞菁在不同介质中的吸收光谱研究

研究了四丙基取代钒氧酞菁（Ｐｒ４ＶＯＰｃ）在不同介质中的吸收光谱。Ｐｒ４ＶＯＰｃ分子在不同介质中的吸收光谱差别很大：在稀溶液中以分子的单体吸收为主（λｍａｘ＝７０７ｎｍ），在浓溶液和ＰＭＭＡ薄膜中由于形成平行排列结构的二聚体而使分子单体的吸收峰发生蓝移（λｍａｘ＝６６０ｎｍ），在蒸发膜中则由于形成斜交结构的二聚体使得分子单体的吸收峰发生分裂形成红移和蓝移峰（λｍａｘ＝７２０ｎｍ，６６０ｎｍ），在溶液沉积的固态薄膜中由于形成结晶相Ｉ而表现出强烈的近红外吸收（λｍａｘ＝８２６．９ｎｍ）。造成这种差别的原因是四个丙基的引入加大了ＶＯＰｃ分子的空间位阻效应。通过热处理或溶剂蒸汽处理，可以使Ｐｒ４ＶＯＰｃ蒸发膜转变成具有强近红外吸收的结晶相Ｉ；而只有通过溶剂蒸汽处理才能使ＰＭＭＡ介质中的Ｐｒ４ＶＯＰｃ转变成结晶相ＩＩ。

Absorption Spectra of Soluble Vanadyl Phthalocyanine

Absorption spectra of soluble vanadyl phthaloeyanine Pr4VOPc (vanadyl phthaloeyanine with four propyl groups) in different medium were studied. Absorption due to the Pr4VOPc molecular monomers (λmax=706.0 nm) is dominant in dilute Pr4VOPe-chloroform solution. Absorption peak of the sublimed Pr4VOPc film is at 720.0 nm; whereas Pr4VOPc in solution east solid film shows a strong diffused absorption band ranging from 650.0 nm to 850.0 nm. In PMMA， absorption due to the molecular dimers is dominant (λmax=660.0 nm). This difference is caused by the great sterie effect between Pr4VOPc molecules. Pr4VOPc with strong near-IR absorption can be made by heating sublimed Pr4VOPc film or exposing it to organic solvent vapor. While only organic solvent treatment can make Pr4VOPc non-crystalline phase I in PMMA matrix change into crystalline phase II.