Related Experiment Video
Updated: Sep 25, 2026

Determination of the Photoisomerization Quantum Yield of a Hydrazone Photoswitch
Published on: February 7, 2022
Photoswitchable Ambiphilicity: Light-Gated Frustrated Lewis Pair Reactivity and Z-Type Interaction
Lennart Stoess1, Emil L M Paulin1, Fabian Michel1
1Anorganisch-Chemisches Institut, Ruprechts-Karls Universität Heidelberg, Heidelberg, Germany.
Abstract:
Ambiphilic molecules, species containing both Lewis acidic and basic sites, enable a broad range of phenomena in chemistry, from frustrated Lewis pairs (FLPs) to supported Z-type interactions. However, the balance between their Lewis acidic and basic functions is normally fixed by molecular synthesis. Combining these features with photoswitchable architectures offers untapped potential for reversible substrate binding and control of transition metal properties. Here, we demonstrate that the incorporation of a photoswitchable Lewis acid into intramolecular phosphorus/boron Lewis pairs allows for stimuli-responsive modulation of ambiphilicity. In the context of FLP-type reactivity, both thermodynamic and kinetic control over substrate activation is achieved, culminating in the light-gated binding and release of CO2. Implementing these ambiphiles as ligands in transition metal chemistry enables control over metal-boron Z-type interactions. Photoswitchable ambiphilicity thus provides a common light-addressable handle for controlling substrate-binding thermodynamics, reaction kinetics, and transition-metal electronic structure.
Related Concept Videos
Photochemical Electrocyclic Reactions: Stereochemistry
Selection Rules: Photochemical Activation
Woodward–Hoffmann Selection Rules and Microscopic Reversibility
Cycloaddition Reactions: MO Requirements for Photochemical Activation
[3,3] Sigmatropic Rearrangement of 1,5-Dienes: Cope Rearrangement
SN2 Reaction: Stereochemistry
If the substrate is an achiral molecule at the α-carbon, the inversion of configuration is not observed.
Electrophiles
While a positive electrophile, like a proton, reacts due to its vacant, low-energy 1s orbital, the...
