Accessing Lanthanide‐to‐Lanthanide Energy Transfer in a Family of Site‐Resolved [LnIIILnIII′] Heterodimetallic Complexes.

The ligand H3L (6‐[3‐oxo‐3‐(2‐hydroxyphenyl)propionyl]pyridine‐2‐carboxylic acid), which exhibits two different coordination pockets, has been exploited to engender and study energy transfer (ET) in two dinuclear [LnIIILnIII′] analogues of interest, [EuYb] and [NdYb]. Their structural and physical properties have been compared with newly synthesised analogues featuring no possible ET ([EuLu], [NdLu], and [GdYb]) and with the corresponding homometallic [EuEu] and [NdNd] analogues, which have been previously reported. Photophysical data suggest that ET between EuIII and YbIII does not occur to a significant extent, whereas emission from YbIII originates from sensitisation of the ligand. In contrast, energy migration seems to be occurring between the two NdIII centres in [NdNd], as well as in [NdYb], in which YbIII luminescence is thus, in part, sensitised by ET from Nd. This study shows the versatility of this molecular platform to further the investigation of lanthanide‐to‐lanthanide ET phenomena in defined molecular systems. [ABSTRACT FROM AUTHOR]