“…), transition metal ions (such as Pt 2+/4+ , Cr 3+ , Mn 2+ , Ti 3+ , Fe 3+ , Ni 2+ , Cu 2+ or their combinations) or lanthanides (such as Yb 3+ , Nd 3+ , Er 3+ , Ce 3+ , Eu 3+ , Sm 3+ or Pr 3+ ) usually situated in the core of CLMSs not only ensures the assembly of the whole architecture but also brings functional physical and chemical properties. 5 Among those, CLMSs have been widely investigated as molecule-based models for catalysis 6 or as a particular family of molecule-based magnets. 7 Unexpectedly, the optical properties of CLMSs have been investigated only scarcely.…”