The application of chiroptical spectroscopy (circular dichroism) in quantifying binding events in lanthanide directed synthesis of chiral luminescent self-assembly structures.

The binding of asymmetrical and optically pure tridentate ligands ( = and ) containing one carboxylic group and 2-naphthyl as an antenna to lanthanide ions ( = La(iii) and Eu(iii)) was studied in CHCN, showing the successive formation of , and stoichiometric species in solution. The europium complexes were also synthesised, structurally characterised and their photophysical properties probed in CHOH and CHCN. The changes in the chiroptical properties of both and were used (by circular dichroism (CD) spectroscopy) to monitor the formation of these chiral self-assemblies in solution. While circularly polarised luminescence (CPL) showed the formation of and as enantiomers, with high luminescence dissymmetry factors (), fitting the CD changes allowed for binding constants to be determined that were comparable to those seen in the analyses of absorbance and luminescence changes.