四氨基钴酞菁紫外-可见光谱量子化学研究

Quantum Chemical Study of Ultraviolet and Visible Spectra of Four Amino Cobalt Phthalocyanin

四氨基钴酞菁是一种很有前途的可见光催化剂,为丰富和完整该物质结构性质及反应活性的理论体系,尤其是其光谱性质的量子化学研究,利用量子化学计算模拟和实验研究相结合的方式对四氨基钴酞菁的紫外-可见光谱进行了比对研究。通过实验证明,四氨基钴酞菁的二甲基甲酰胺(DMF)溶液在324.98和709.94nm处出现两个明显的吸收峰。在密度泛函法的B3LYP/3-21G*水平上,采用含时密度泛函(timedependent density functional theory,TD-DFT)方法模拟四氨基钴酞菁的紫外-可见吸收光谱显示,得到了两个吸收谱带分别在321.41和709.92nm处,与实验值基本吻合,证明密度泛函理论在四氨基钴酞菁的量子化学理论研究是有效可靠的。通过量子计算还确定了每个吸收峰中各个电子跃迁的贡献率:在326.22nm处的吸收主要是电子从轨道152到163LUMO的跃迁;在314.42nm处的吸收主要是电子从轨道149到164LUMO+1的跃迁;在747.57nm处的吸收主要是电子从轨道162 HOMO到163LUMO的跃迁;在676.01nm处的吸收主要是电子从轨道162HOMO到164LUMO+1的跃迁。这些模拟数据对实验研究提供了极大的理论补充,四氨基钴酞菁的紫外-可见光谱量子化学研究对后续实验指导及应用有十分重要的理论意义。

Four amino cobalt phthalocyanine is well known as a promising photosensitizer. In order to enrich and complete the theoretical system of structural properties and reactivity, four amino cobalt phthalocyanine was synthesized and its ultraviolet- visible spectrum was obtained by experimental research. Then the experimental spectrum was compared with that obtained from theoretical calculation by quantum chemistry. The experimental results show that there are two obvious absorption peaks at 324.98 and 709.94 nm respectively in the ultraviolet-visible spectrum of four amino cobalt phthalocyanine. The density function- al B,3LYP/3-21G ＊ method was used in simulating ultraviolet-visible absorption spectra of four amino cobalt phthaloeyanine. The calculation results show that there should be two absorption peaks at 321.41 and 709.92 nm respectively. The simulation results agree well with the experimental values, which demonstrates that the density functional theory is valid and reliable in the theoret- ical research on four amino cobalt phthalocyanine. The contribution rate of various electron transitions in every absorption peak was determined by quantum computation. The contribution rate of various electron transition in every absorption peak was deter- mined by quantum computation. The absorption peak at 326.22 nm is mainly resulted from electronic transition from 152 to 163 LUMO orbit, the absorption peak at 314.42 nm is due to electronic transition from 149 to 164 LUMO＋I orbit, the absorption peak at 747.57 nm is mainly caused by electronic transition from 162 to 163 LUMO orbit, and the absorption peak at 676.01 ran is mainly caused by electronic transition from 162 to 164 LUMO＋ 1 orbit. These data provide great theoretical complement to experimental study. The quantum chemical study for four amino cobalt phthalocyanine ultraviolet-visible spectrum has very im- portant theoretical significance for experimental research in the future.