Syntheses and Ferroelectric Properties of a Couple of Chiral Europium(III) Complexes

A couple of pinene-containing europium(Ⅲ) complexes, Eu(TTA) 3 L 1a ( 1a ) and Eu(TTA) 3 L 1b ( 1b ) (TTA=thenoyltrifluoroacetonate, L 1a =(+)-4, 5-bis(pinene)-2, 2'-bipyridine, L 1b =(-)-4, 5-bis(pinene)-2, 2'-bipyridine), were prepared and characterized. The chiral characterization was confirmed by single crystal X-ray diffraction and distinct electronic circular dichroism (CD) signals. Complex 1a crystallizes in the polar space group P 1, and a strongly distorted square-antiprism environment around the Eu(Ⅲ) ion is exhibited. Due to the non-centrosymmetric structure, distinct ferroelectric behavior of complex 1a was observed as expected.