Synthesis, crystal structure and photo-induced isomerization of [N,N′-bis(4-fluorobenzylidene)ethylenediamine]bromo(triphenylphosphine)copper(I)

The title Schiff base complex is a model compound for photoisomerization reactions which occur in photobiological processes such as vision. The Schiff base ligand and the complex have been prepared in a one-pot synthesis. In the crystal structure of the complex, copper has a distorted tetrahedral coordination. Photochemical investigations in solution reveal time-resolved spectroscopic changes that are interpreted in terms of a transformation from E to Z configuration of the CN bonds of the coordinated Schiff base ligand. Application of multivariate curve resolution and non-linear least squares curve fitting to the spectroscopic profiles provides a rate constant of 0.11 min−1 for the photoisomerization and a quantum yield of 0.246.

The distorted-tetrahedral title complex is obtained as an EE isomer, but is converted to the ZZ form on visible irradiation, for which the rate constant and quantum yield have been determined.Figure optionsDownload as PowerPoint slide