Nonlinear Optical Properties of Redox-Active Mono-, Bi-, and Trimetallic σ-Acetylide Complexes Connected through a Phenyl Ring in the Cp(dppe)Fe Series. An Example of Electro-switchable NLO Response

The first-order hyperpolarizabilities of a series of mono-, bi-, and trinuclear organometallic compounds were determined using Hyper-Rayleigh Scattering at 1.06 μm. The molecular nonlinear optical responses (NLO) were investigated for various combinations of iron(II) and iron(III), including mixed-valence iron(II)/iron(III) complexes. In the latter case, it is shown that the NLO activity can be controlled by one-electron redox processes.