Synthesis, crystal structures and triboluminescence of a pair of Eu(III)-based enantiomers

Using the chiral ligands LSS (+)-4,5-pinene bipyridine and LRR (−)-4,5-pinene bipyridine (Scheme 1), two novel Eu(III)-based complexes with the formula [Eu(DBM)3L] (LSS in 1, LRR in 2, DBM = dibenzoylmethanate) have been successfully synthesized and characterized by X-ray single crystal determination and spectroscopic methods. The crystal structure analysis of 1 and 2 reveal that they crystallize in the chiral space group P21 of the monoclinic system. The central Eu(III) ion is eight-coordinated in a geometrical environment intermediate between a square antiprism and a dodecahedron. The CD spectra reflect that complexes 1 and 2 are enantiomers. When ground in daylight, complexes 1 and 2 exhibit brilliant triboluminescence at room temperature.

Graphical abstractUsing the chiral ligands LSS (+)-4,5-pinene bipyridine and LRR (−)-4,5-pinene bipyridine, two novel lanthanide enantiomers [Eu(DBM)3L] (LSS in 1, LRR in 2, DBM = dibenzoylmethanate) have been successfully synthesized and characterized by X-ray single crystal determination and spectroscopic methods. They crystallize in the chiral space group P21 of the monoclinic system. Both of them exhibit brilliant triboluminescence in daylight.Figure optionsDownload full-size imageDownload as PowerPoint slide