PT Journal
AU Schneider, K
   Chettri, A
   Cole, H
   Reglinski Dr., K
   Brückmann, J
   Roque III, J
   Stumper Dr., A
   Nauroozi Dr., D
   Schmid Dr., S
   Lagerholm Dr., C
   Rau Prof. Dr., S
   Bäuerle Prof. Dr., P
   Eggeling Prof. Dr., C
   Cameron Dr., C
   McFarland Prof. Dr., S
   Dietzek Prof. Dr., B
TI Intracellular photophysics of an osmium complex bearing an oligothiophene extended ligand
SO Chemistry – A European Journal
JI Chem. Eur. J.
PD November
PY 2020
BP 14844
EP 14851
VL 26, 2020
IS 65
PU Wiley-VCH
DI 10.1002/chem.202002667
WP https://www.db-thueringen.de/receive/dbt_mods_00049755
LA en
DE in vitro spectroscopy; oligothiophene; osmium polypyridyl; transient absorption; ultrafast spectroscopy
SN 0947-6539
AB This contribution describes the excited‐state properties of an Osmium‐complex when taken up into human cells. The complex 1 [Os(bpy) 2 (IP‐4T)](PF 6 ) 2 with bpy=2,2′‐bipyridine and IP‐4T=2‐{5′‐[3′,4′‐diethyl‐(2,2′‐bithien‐5‐yl)]‐3,4‐diethyl‐2,2′‐bithiophene}imidazo[4,5‐ f ][1,10]phenanthroline) can be discussed as a candidate for photodynamic therapy in the biological red/NIR window. The complex is taken up by MCF7 cells and localizes rather homogeneously within in the cytoplasm. To detail the sub‐ns photophysics of 1 , comparative transient absorption measurements were carried out in different solvents to derive a model of the photoinduced processes. Key to rationalize the excited‐state relaxation is a long‐lived 3 ILCT state associated with the oligothiophene chain. This model was then tested with the complex internalized into MCF7 cells, since the intracellular environment has long been suspected to take big influence on the excited state properties. In our study of 1 in cells, we were able to show that, though the overall model remained the same, the excited‐state dynamics are affected strongly by the intracellular environment. Our study represents the first in depth correlation towards ex‐vivo and in vivo ultrafast spectroscopy for a possible photodrug.
PI Weinheim
ER