C_(60)-糖皮质激素荧光特性研究

Fluorescence Properties of C_(60)-Glucocorticoids

C60及其衍生物的荧光特性的研究是富勒烯科学领域的一个重要分支。研究了C60-糖皮质激素类衍生物的荧光性质,发现室温下用350nm波长的光激发,C60-糖皮质激素类衍生物在447nm处有荧光发射。由于C60分子中60个碳原子是等价的,属Ih群,呈高度对称性,因而同样条件下难以观测到荧光。而C60-糖皮质激素类衍生物在形成的过程中分子结构的对称性发生了改变,使得这类化合物可以在一定波长光的激发下发射荧光。此外,通过对系列浓度(10～130μmol·L-1)的C60-糖皮质激素氯仿溶液的荧光测定,发现这类化合物存在荧光浓度自猝灭现象,10～64μmol·L-1浓度范围内,荧光强度随浓度的增大而逐渐增大,大于64μmol·L-1时荧光强度随浓度的增大而逐渐降低。

C60 and its derivatives have become a research hotspot because of their unique structures, physical and chemical properties. The fluorescence properties of C60 and its derivatives are an important research embranchment of the fullerene science field. In the present paper the fluorescence properties of C60-glucocortlcoids were firstly investigated. When excited with the wavelength of 350 nm at room temperature, C60-glucocorticoids displayed the fluorescence emission in chloroform at 447 nm. The sixty carbon atoms of C60 molecule are equivalent, belonging to the Ih group, and presenting high symmetry. It is difficult to observe the fluorescence of C60 under the same condition because of the high symmetry of C60 molecule. The fluorescence emission of C60-glucocorticoids is probably due to the decrease in the high symmetry of C60 molecule. Moreover, the fluorescence emission at 447 nm of a series of concentrations （10-13 μmol·L^-1） of C60-glucocorticoids chloroform solutions excited at 350 nm was determined, and the result indicated that the C60-glucocorticoids in chloroform could quench itself＇s fluorescence intensity. Within the concentration range of 10-64 μmol·L^-1, the fluorescence intensity increased along with the accretion of the concentration. When the concentration of C60-glucocorticoids was greater than 64 μmol·L^-1 the fluorescence intensity decreased gradually.