1. Materials and Methods ......................................................................................................................................... 3 1.1 Steady-state (absorption, fluorescence and quantum yield) experiments ................................................. 3 1.2 Time-resolved fluorescence and transient absorption experiments ........................................................... 4 1.3 Density Functional Theory (DFT) Calculations .............................................................................................. 4 2. Synthesis and product characterization ................................................................................................................ 5 Results .......................................................................................................................................................................... 16 3. Optical properties ................................................................................................................................................ 16 4. Theoretical calculations ....................................................................................................................................... 23 5. NMR titration experiments ................................................................................................................................. 28 5.1 Titration of compound 3 with Ca(ClO4)2•4H2O ........................................................................................... 28 5.2 Titration of compound 3 with Zn(ClO4)2•6H2O ........................................................................................... 30 5.3 Titration of compound 6 with Zn(ClO4)2•6H2O ........................................................................................... 32 5.4 Titration of compounds 2 and 4 with Zn(ClO4)2•6H2O and Ca(ClO4)2•4H2O .............................................. 34