Related Experiment Video
Updated: Aug 23, 2025

Spatiotemporally Controlled Nuclear Translocation of Guests in Living Cells Using Caged Molecular Glues as Photoactivatable Tags
Published on: January 17, 2019
Photoinduced host-to-guest electron transfer in a self-assembled coordination cage
Sudhakar Ganta1, Jan-Hendrik Borter2, Christoph Drechsler1
1Department of Chemistry and Chemical Biology, TU Dortmund University Otto-Hahn Straße 6 44227 Dortmund Germany guido.clever@tu-dortmund.de.
Abstract:
A [Pd2L4] coordination cage, assembled from electron-rich phenothiazine-based ligands and encapsulating an electron-deficient anthraquinone-based disulfonate guest, is reported. Upon excitation at 400 nm, transient absorption spectroscopy unveils photoinduced electron transfer from the host's chromophores to the guest, as indicated by characteristic spectral features assigned to the oxidized donor and reduced acceptor. The structure of the host-guest complex was characterized by NMR spectroscopy, mass spectrometry and single-crystal X-ray analysis. Spectroelectrochemical experiments and DFT calculations both agree with the proposed light-induced charge separation. A kinetic analysis of the involved charge transfer channels reveals, besides a guest-independent LMCT path, 44% efficiency for the host-guest charge transfer (HGCT).
Related Concept Videos
Photochemical Electrocyclic Reactions: Stereochemistry
Selection Rules: Photochemical Activation
Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
Valence Bond Theory
[3,3] Sigmatropic Rearrangement of 1,5-Dienes: Cope Rearrangement
Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
Thermal and Photochemical Electrocyclic Reactions: Overview

