Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.


Issue 21, 2017
Previous Article Next Article

Ultrafast IR spectroscopy of photo-induced electron transfer in self-assembled donor–acceptor coordination cages

Author affiliations

Abstract

Photo-induced processes in self-assembled coordination cages were studied by femtosecond infrared pump–probe spectroscopy. Densely packed, interpenetrated double cages were constructed from eight bis-monodentate redoxactive ligands bound to four Pd(II) nodes. Two types of ligands consisting of electron rich phenothiazine (PTZ) or electron deficient anthraquinone (ANQ) chromophores were used to assemble either homo-octameric or mixed-ligand cages. Upon photoexcitation the homo-octameric acceptor cage undergoes intersystem crossing to a long-lived triplet state, similar to the free acceptor ligand. Excitation of the free donor ligand leads to a fluorescent state with intramolecular charge transfer character. This fluorescence is completely quenched in the homo-octameric donor double cage due to a ligand-to-metal charge transfer followed by back electron transfer on a ps timescale. Only for the mixed-ligand cage irradiation produces a charge separated state with an oxidized PTZ radical cation and a reduced ANQ radical anion as proven by their vibrational fingerprints in the transient IR spectra. In dichloromethane the lifetime of this charge separated state extends from tens of ps to >1.5 ns which is attributed to the broad distribution of mixed-ligand cages with different stoichiometry and/or stereo configurations.

Graphical abstract: Ultrafast IR spectroscopy of photo-induced electron transfer in self-assembled donor–acceptor coordination cages

Back to tab navigation

Supplementary files

Article information


Submitted
07 Apr 2017
Accepted
11 May 2017
First published
12 May 2017

Phys. Chem. Chem. Phys., 2017,19, 13596-13603
Article type
Paper

Ultrafast IR spectroscopy of photo-induced electron transfer in self-assembled donor–acceptor coordination cages

J. Ahrens, M. Frank, G. H. Clever and D. Schwarzer, Phys. Chem. Chem. Phys., 2017, 19, 13596
DOI: 10.1039/C7CP02253K

Social activity

Search articles by author

Spotlight

Advertisements