【摘要】 本文对双荧光团化合物2-(ω-联苯基取代多亚甲基)-5-联苯基恶二唑—1、3、4,及其对应的模型化合物2-甲基-5-联基恶二唑,通过测定荧光光谱的方法,对分子内给体与受体之间的能量转移进行了研究,从实验结果初步得到了双荧光团化合物比相应的单荧光团化合物混合体系的能量转移速率高,荧光强度有明显的提高。并从化合物的结构上对给体与受体之间的距离对能量转移速率常数的影响作了初步探讨。更多还原

【Abstract】 Several bischromophore compounds 2-(ω-biphenylyl polymethylene)-5-biphenylyl oxadiazole-l,3,4(F1-(CH2) n-F2), compounds 1,2,3,4 respectively n = l,2,3,4, and the corresponding model compound 2-methyl-5-bi-phenylyl oxadiazole-1,3,4 (compound 5) have been synthesized. The intramc lecular energy transfer has been studied by fluorescence emission spectra.The fluorescence spectra of biphenyl, compound 5, the 1:1 mixture of compound 5 with biphenyl as well as compounds 1 to 4 have been determined. The spectrum data are listed in the table.TableFrom the table, it is that the bischromophore compounds 1 to 4 are excited at 245 nm, their range of fluorescence peak are broader than the mixtures’. The intensity of fluorescence spectra is increased. These phenomena are obviousty the results of intermolecular energy transfer.According to Forster’s viewpoint, the rate constant for dipole dipole energy transfer between a donor D and an acceptor A, i.e. kD→A is given by where R0 is the critical distance between the donor and the acceptor.From eq. ( 1 ), the rate constant of energy transfer is connected with the distance R. The less the value of R the larger the rate constant of energy transfer will be. Because of a negative sixth-power dependence of kD→A on R, a change in. R by just a few angstorms makes a large change in kD→A.According to the molecular structures of the compounds the distance between the donor and the acceptor in compounds 1 to 4 may differ from each other in order of:R1<R3<R4<R2From eq. (1), the rate constant of energy transfer kD-Amay differ from each ether in order of:This result has been shown in the table.更多还原