Argentivorous molecules with chromophores: dependence of their fluorescence intensities on the distance between a donor and an acceptor

We have prepared new argentivorous molecules (L-2 and L-3) having different linker lengths between cyclen and anthracene units. The structures of Ag+ complexes with the new ligands were investigated in solution and solid states. The silver(i) ion-induced H-1 NMR and UV-vis spectral changes of L-2 and L-3 showed the presence of 1: 1 complexes. The solid-state structures of the Ag+ complexes with L-2 and L-3 are stable 1: 1 complexes because four aromatic side-arms wrap the Ag+ incorporated in the cyclen unit. A photoinduced electron transfer (PET) effect that depends on the length of the linker connecting the nitrogen atoms of cyclen to the chromophore is also investigated. The result indicates a linear (log) correlation between the donor-chromophore average distances of the optimized structures calculated by DFT calculations and fluorescence intensities (log I), and the PET effect becomes ineffective at about 12 A in this system.

Automated summary

In this study, new argentivorous molecules with different linker lengths were synthesized and their complexes with Ag+ were investigated. The experiments showed that stable 1:1 complexes were formed between the new ligands and Ag+, and the strength of the photoinduced electron transfer effect had a linear correlation with the linker length.