Impact of metal linking ions on the structure and energy transfer dynamics in molecular bilayers on metal oxide films

Abstract Metal ion linked molecular multilayers have emerged as a simple, modular means to generate multimolecular assemblies for a range of applications from solar energy conversion to sensing. These applications primarily rely on efficient interlayer energy and electron transfer, which are determined by the distance and orientation between the metal ion linked molecules. Here, we investigate the impact of the metal ion on the structure and energy transfer dynamics in bilayer assemblies composed of an anthracene first layer ( A ) and porphyrin second layer ( P ) linked by Zn ^II , Zr ^IV , and La ^III ions. Using time-resolved spectroscopy, we find that A* to P energy transfer is similar in Zn and Zr bilayers but is slower in La-linked assemblies. A combination of UV–Vis polarized attenuated total reflectance spectroscopy and geometric calculations indicate that the differences in energy transfer rate/efficiency can be attributed to structural differences between the La-linked and other bilayers. These results demonstrate that the selection of metal ion impacts the structure of the bilayer and could provide a means of tuning the multilayer structure in future applications.