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

We have prepared new argentivorous molecules (L2 and L3) 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 1 H NMR and UV-vis spectral changes of L2 and L3 showed the presence of 1 : 1 complexes. The solid-state structures of the Ag + complexes with L2 and L3 are stable 1 : 1 complexes because four aromatic side-arms wrap the Ag + incorporated in the cyclen unit. A photo-induced 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 Å in this system.