叶绿素C的光学性质

OPTICAL PROPERTIES OF CHLOROPHYLLO C(CHL C)

本文采用H(?)ckel分子轨道(HMO)近似方法,定量计算了叶绿素C(Chlc)分子的能级、π-键级及π-电荷密度。分析了Chlc的电子光谱及Chlc与氧之间的敏化荧光。

The absorption and luminescence spectia of Chl C in solusion have been analyzed.The energy levels of molecular orbital, charge density and heteroplar bond of n-electrons have been calculated quantitatively for Chl C by approximate method of Huckel molecular orbital (HMO).The sensitized fluorescence between Chl C and O2 has been analyzed qualitatively.Since the absorption of biomolecules arises from electronic transition of co-jugated n-election, only n-electrons at the porphyrin frame are considered in the calculation of the energies of molecular orbits. With this consideration and Huckel approximation the calculated eneigies are listed as follows: where a and B are Coloumb and exchange integrals respectively. The luminescence of 632nm is the transition from E6-E7.No fluorescence of O2 was observed as the oxygen solved in water was excited with 488nm line of an Argon laser. After Chl C had been added into the solusion, however, fluorescence from 1O2 appeared at 760nm and 870nm. This is the evidence of the existence of 1O2 and the energy transfer between Chl C and O2.As we known that 1O2 is a strong oxydizer. So cancer cells might be killed by oxydization of 1O2, when they are exposed under laser alight after Chl C is injected into vein.