TY  - JOUR
A1  - Verma, Pramod Kumar
A1  - Steinbacher, Andreas
A1  - Schmiedel, Alexander
A1  - Nuernberger, Patrick
A1  - Brixner, Tobias
T1  - Excited-state intramolecular proton transfer of 2-acetylindan-1,3-dione studied by ultrafast absorption and fluorescence spectroscopy
JF  - Structural Dynamics
N2  - We employ transient absorption from the deep-UV to the visible region and fluorescence upconversion to investigate the photoinduced excited-state intramolecular proton-transfer dynamics in a biologically relevant drug molecule, 2-acetylindan-1,3-dione. The molecule is a ß-diketone which in the electronic ground state exists as exocyclic enol with an intramolecular H-bond. Upon electronic excitation at 300 nm, the first excited state of the exocyclic enol is initially populated, followed by ultrafast proton transfer (≈160 fs) to form the vibrationally hot endocyclic enol. Subsequently, solvent-induced vibrational relaxation takes place (≈10 ps) followed by decay (≈390 ps) to the corresponding ground state.
KW  - time resolved spectroscopy
KW  - ground states
KW  - fluorescence spectra
KW  - absorption spectra
KW  - ultraviolet light
KW  - hydrogen bonding
KW  - excited states
KW  - reaction mechanisms
KW  - fluorescence
KW  - solvents
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-181301
VL  - 3
ER  - 
TY  - JOUR
A1  - Wächtler, Maria
A1  - Kübel, Joachim
A1  - Barthelmes, Kevin
A1  - Winter, Andreas
A1  - Schmiedel, Alexander
A1  - Pascher, Torbjörn
A1  - Lambert, Christoph
A1  - Schubert, Ulrich S.
A1  - Dietzek, Benjamin
T1  - Energy transfer and formation of long-lived \(^3\)MLCT states in multimetallic complexes with extended highly conjugated bis-terpyridyl ligands
JF  - Physical Chemistry Chemical Physics
N2  - Multimetallic complexes with extended and highly conjugated bis-2,2':6',2''-terpyridyl bridging ligands, which present building blocks for coordination polymers, are investigated with respect to their ability to act as light-harvesting antennae. The investigated species combine Ru(II)- with Os(II)- and Fe(II)-terpyridyl chromophores, the latter acting as energy sinks. Due to the extended conjugated system the ligands are able to prolong the lifetime of the \(^3\)MLCT states compared to unsubstituted terpyridyl species by delocalization and energetic stabilization of the \(^3\)MLCT states. This concept is applied for the first time to Fe(II) terpyridyl species and results in an exceptionally long lifetime of 23 ps for the Fe(II) \(^3\)MLCT state. While partial energy (>80%) transfer is observed between the Ru(II) and Fe(II) centers with a time-constant of 15 ps, excitation energy is transferred completely from the Ru(II) to the Os(II) center within the first 200 fs after excitation.
KW  - polypyridyl complexes
KW  - bis-terpyridyl ligands
KW  - multimetallic complexes
KW  - metal-to-ligand charge transfer (MLCT)
KW  - RU-(II) complexes
KW  - Ru(II)–Fe(II)–Ru(II) complex
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-191041
VL  - 18
IS  - 4
ER  -