π‐Extended Salphen Scaffolds Enable CO2 Electroreduction and Singlet Oxygen Generation
- 1Department of Chemical Sciences, University of Naples Federico II University Campus of Monte S. Angelo Naples Italy
- 2Institute of Inorganic Chemistry University of Bonn Bonn Germany
- 3Department of Chemistry–Ångström Laboratory Uppsala University Uppsala Sweden
Abstract
π‐Extended conjugation offers the opportunity to unveil new frontiers in materials, coupling redox activity with tunable photophysical properties. Here, we report a new family of π‐conjugated salen ligands bearing phenylene bridges and tunable substituents, together with their corresponding boron difluoride complexes. Owing to the extended π‐delocalization, these new compounds show promising results in electrochemical CO2 reduction to CO, achieving a remarkable Faradaic efficiency for an organocatalyst (up to 56%). Electrochemical, spectroscopic, and computational analyses support a ligand‐centered mechanism in which single‐electron reduction activates the framework for CO2 binding at the imine nitrogen, forming an N‐bound CO2H intermediate. Beyond electrocatalysis, coordination to boron rigidifies the π‐framework, producing emissive boron‐salphen complexes with large Stokes shifts (>7000 cm− 1). These complexes function as efficient photosensitizers for singlet‐oxygen generation, enabling mild oxidative cleavage of alkenes under blue‐light irradiation. This work demonstrates that π‐extension transforms the traditional salphen framework into a redox‐active engine for small‐molecule activation, bypassing the need for transition metals in CO2 electroreduction while simultaneously unlocking good photosensitizing capabilities.
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BibTeX
@article{langellotti2026πextended,
title = {{π‐Extended Salphen Scaffolds Enable CO2 Electroreduction and Singlet Oxygen Generation}},
author = {Vincenzo Langellotti and André Korzun and Morgan J. McKee and Massimo Melchiorre and Taegeun Jo and J. Felipe Estrada‐Ruiz and Gregor Schnakenburg and Stefano Crespi and Francesco Ruffo and Nikolay Kornienko and Alessandro Bismuto},
journal = {Chemistry (Weinheim an Der Bergstrasse, Germany)},
year = {2026},
month = jul,
doi = {10.1002/chem.71385},
url = {https://doi.org/10.1002/chem.71385},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - π‐Extended Salphen Scaffolds Enable CO2 Electroreduction and Singlet Oxygen Generation
AU - Vincenzo Langellotti
AU - André Korzun
AU - Morgan J. McKee
AU - Massimo Melchiorre
AU - Taegeun Jo
AU - J. Felipe Estrada‐Ruiz
AU - Gregor Schnakenburg
AU - Stefano Crespi
AU - Francesco Ruffo
AU - Nikolay Kornienko
AU - Alessandro Bismuto
PY - 2026
DA - 2026/07/12
JO - Chemistry (Weinheim an Der Bergstrasse, Germany)
DO - 10.1002/chem.71385
UR - https://doi.org/10.1002/chem.71385
AB - π‐Extended conjugation offers the opportunity to unveil new frontiers in materials, coupling redox activity with tunable photophysical properties. Here, we report a new family of π‐conjugated salen ligands bearing phenylene bridges and tunable substituents, together with their corresponding boron difluoride complexes. Owing to the extended π‐delocalization, these new compounds show promising results in electrochemical CO2 reduction to CO, achieving a remarkable Faradaic efficiency for an organocatalyst (up to 56%). Electrochemical, spectroscopic, and computational analyses support a ligand‐centered mechanism in which single‐electron reduction activates the framework for CO2 binding at the imine nitrogen, forming an N‐bound CO2H intermediate. Beyond electrocatalysis, coordination to boron rigidifies the π‐framework, producing emissive boron‐salphen complexes with large Stokes shifts (>7000 cm− 1). These complexes function as efficient photosensitizers for singlet‐oxygen generation, enabling mild oxidative cleavage of alkenes under blue‐light irradiation. This work demonstrates that π‐extension transforms the traditional salphen framework into a redox‐active engine for small‐molecule activation, bypassing the need for transition metals in CO2 electroreduction while simultaneously unlocking good photosensitizing capabilities.
SN - 0947-6539
SN - 1521-3765
ER -