Linked lanthanides shine light on field of crystal engineering

Rare earth metals, when linked, can act as a conduit for energy flow, and show promise for the development of novel materials.

Scientists have connected two soft crystals and observed the energy transfer between them—a finding that could lead to the development of sophisticated, responsive materials. The study, by scientists at Hokkaido University in Japan, was published in the journal Nature Communications.

Soft crystals are flexible molecular solids with highly ordered structures. When they are subjected to external stimuli, such as vapor or rubbing, their molecular structures are reordered and they respond by changing shape, color or luminescence.

“We wanted to know what would happen if we merged soft crystals at the molecular level to connect them,” says Yasuchika Hasegawa, a materials chemist at Hokkaido University and lead author of the study. Hasegawa and his team used rare earth metals called lanthanides, whose ions have similarly large radii and therefore form similar structures. Lanthanide compounds, of which there are 15, are interesting because they can luminesce.