2003 Fiscal Year Final Research Report Summary
Hemispherical Synthesis of L-Lysine dendrimers for Clustering of Functional Groups and developing new Functions.
| Project/Area Number |
13450380
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
高分子合成
|
|---|
| Research Institution | Kyushu Institute of Technology |
|---|
Principal Investigator |
NISHINO Norikazu Kyushu Institute Of Technology, Graduate School of Life Science and Systems Engineering, Professor, 大学院・生命体工学研究科, 教授 (40145165)
|
|---|
| Project Period (FY) |
2001 – 2003
|
| Keywords | Dendrimers / L-Lysine / Zn-Porphyrin / Free-base Porphyrin / Energy Transfer |
|---|
| Research Abstract |
Free -base porphyrins and Zn(II)-porphyrins were combined to a dendritic poly(L-lysine) in various fashions such as scramble, hemisphere, and double strata. Efficient quenching (90%) of emission at 610 nm was observed from 8 Zn(II)-porphyrins to 16 or 32 free base porphyrins in double strata fashion. Methyl viologen groups were also combined to the surface of the dendrimer to built a novel electron transfer system.
Clusters of Zn(II)-porphyrins and methyl viologen were introduced to dendritic poly(L-lysine)s in different manners. The synthesis of (Zn8/MV16)K14 and (Zn8/MV8)K14 were carried out according to previous reports. Both of the dendrimers showed about six times more efficient fluorescence quenching in comparison with the unbound porphyrin/methyl viologen system. Furthermore, the purple colored dendrimer solution turned brilliant blue on continuous irradiation of the Soret band of Zn(II)-porphyrin in (Zn8/MV16)K14 and (Zn8/MV8)K14 in the presence of triethanolamine indicating the generation of methyl viologen radical ion.
Free-base and Zn(II)-porphyrin centered dendritic poly(L-lysine)s (Fbl/Zn8)K4 and (Znl/Fb8)K4 were designed and synthesized using 6,10,16,20-tetrakis(4-amino-phenyl)porphyrin(TAP). The dendrimer (Fbl/Zn8)K4) was subjected to fluorescence measurements with reference to a mixture of (Fb1)K4 and eight equivalents of Zn(II)-porphyrin in DMF. Upon excitation at 660 nm for Q band of Zn(II)-porphyrin, the emission at 610 nm from Zn(II)-porphyrin was significantly quenched. Instead, emission from free-base porphyrin at 660 nm and 720 nm increased significantly. Most interestingly, extent.of decrease in the emission at 610 nm and the extent of increase in emission at 660 nm were almost same. This fact suggests that energy transfer occurred quantitatively. Fluorescence measurement for (Zn1/Fb8)K4 was also performed and compared with (Fb1/Zn8)K4.
|
Research Products
(10 results)
