Controlling the intercomponent energy-transfer pattern in light-harvesting trimetallic complexes of Fe(ii), Ru(ii), and Os(ii)

Abstract

Polypyridine complexes of d⁶ metals are found to be very useful in designing photochemical molecular devices because of their exceptional thermodynamic stability and kinetic inertness, as well as outstanding photo-redox behaviours. This feature article will summarize the design strategies of a wide variety of homo- and hetero-trimetallic complexes incorporating Fe(II), Ru(II), and Os(II) metals and review their photophysical, electrochemical and intercomponent energy transfer behaviours. The direction of intercomponent energy transfer is controlled by the appropriate positioning of the metals in the trimetallic arrays. Finally, modulation of the photo-redox properties in the triads is feasible via exploitation of their secondary coordination sphere.