Easy assembly of visible light excited lanthanide containing edifices and structural origin

Reaction of quinolone type antibiotics (enrofloxacin, ciprofloxacin, norfloxacin and ofloxacin) with lanthanide ions (Eu 3+ and Tb 3+ ) afforded eight kinds of complexes that can be dissolved in water. These compounds possess not only the advantages of long excited state lifetimes, but also allow excitation in the visible light range depending on the concentration variation. Especially the excitation wavelength of the terbium complexes can be extended into 405 nm. Theoretical studies demonstrated that the calculated energy gaps between HOMO and LUMO+1 orbital could be reduced and a dimeric structure was formed during the concentration experiments. Moreover, uniform and long rod-like structures (diameter: 100 nm; length: 10 μm) were achieved and concentration dependence has been investigated. The strategy of combining lanthanide characteristic emission nature and longer wavelength excitations can be applicable to the development of luminescent devices with controllable shapes.