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A Molecular Photosensitizer in a Porous Block Copolymer Matrix‐Implications for the Design of Photocatalytically Active Membranes
Author(s) -
Chettri Avinash,
Kruse JanHendrik,
Kumar Jha Keshav,
Dröge Lara,
Romanenko Iuliia,
Neumann Christof,
Kupfer Stephan,
Turchanin Andrey,
Rau Sven,
Schacher Felix H.,
Dietzek Benjamin
Publication year - 2021
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.202102377
Subject(s) - photosensitizer , copolymer , membrane , intermolecular force , materials science , photochemistry , polymer , chemistry , organic chemistry , molecule , composite material , biochemistry
Recently, porous photocatalytically active block copolymer membranes were introduced, based on heterogenized molecular catalysts. Here, we report the integration of the photosensitizer, i. e., the light absorbing unit in an intermolecular photocatalytic system into block copolymer membranes in a covalent manner. We study the resulting structure and evaluate the orientational mobility of the photosensitizer as integral part of the photocatalytic system in such membranes. To this end we utilize transient absorption anisotropy, highlighting the temporal reorientation of the transition dipole moment probed in a femtosecond pump‐probe experiment. Our findings indicate that the photosensitizer is rigidly bound to the polymer membrane and shows a large heterogeneity of absolute anisotropy values as a function of location probed within the matrix. This reflects the sample inhomogeneity arising from different protonation states of the photosensitizer and different intermolecular interactions of the photosensitizers within the block copolymer membrane scaffold.