Photoswitchable N‐Heterocyclic Carbenes: Using Light to Modulate Electron‐Donating Properties

Abstract

Ligands in the limelight: Light was used to change the electron-donating properties of an N-heterocyclic carbene (NHC) moiety within chalcogen and metal adducts. Photoinduced electrocyclic ring closure of a photochromic 4,5-dithienylimidazolone increased its νCO frequency. Likewise, UV irradiation of an analogous photochromic [(NHC)Ir(CO)2Cl] complex decreased the carbene's electron-donating ability. Subsequent exposure to visible light reversed both photocyclization reactions. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.