Potential photosensitizers for photodynamic therapy. III. Photophysical properties of a lipophilic chlorin and its zinc and tin chelates.
Photophysical properties of a lipophilic chlorin derivative and its zinc and tin chelates were investigated in chloroform. The quantum yields of the fluorescence phi F, of the S1----T1 intersystem crossing phi T and of singlet oxygen (1 delta g) formation phi delta, as well as the Stern-Volmer constants for the quenching of the S1 states by oxygen and the rate constants of quenching of O2(1 delta g) by the chlorins were measured. In comparison to the metal-free chlorin an increase of phi T and a decrease of phi F have been observed for the metal-containing derivatives, whereas the phi delta values remain constant.
Grewer
C
C
Institut für Physikalische und Theoretische Chemie, Universität Frankfurt, F.R.G.
Schermann
G
G
Schmidt
R
R
Völcker
A
A
Brauer
H D
HD
Meier
A
A
Montforts
F P
FP
D002614:Chelating Agents / Q000737:chemistry*; D005069:Evaluation Studies as Topic; D005453:Fluorescence; D008163:Luminescent Measurements; D010789:Phototherapy / Q000379:methods*; D011166:Porphyrins / Q000737:chemistry*; D011838:Radiation-Sensitizing Agents / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D014001:Tin / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry*
D002614:Chelating Agents; D011166:Porphyrins; D011838:Radiation-Sensitizing Agents; C006969:chlorin; D014001:Tin; D015032:Zinc