Photoswitching of Copper(I) Chromophores with Dithienylethene-Based Ligands.

Metal-containing dithienylethenes offer new opportunities for variations in photochromic behavior. This work reports a series of copper(I) complexes containing dithienylethene-based bidentate phosphine ligands displaying varying photochromic properties. A copper dimer is used as a common precursor, allowing diverse photochromic functionality to be achieved. Calculations show that ring closing of the peripheral dithienyl moiety leads to a slight expansion of the five-membered metallacycle. The photochromic properties and photoreaction quantum yields of these complexes are tunable by variation of the ancillary ligands. Photoswitchable catalysis of a hydroboration reaction with one of the copper complexes is demonstrated.