Crystal Structure, and Magnetic and Fluorescence Properties of a New Terbium(III) Complex, [Tb(L)<sub>3</sub>(2,2′-bipy)(DMF)]·(2,2′-bipy)

¹Key Laboratory of Functional Organometallic Materials of Hunan Province College, Department of Chemistry and Materials Science, Hengyang Normal University, Hengyang City, Hunan 421008, P. R. China

A new Tb(III) complex, [Tb(L)₃(2,2′-bipy)(DMF)]·(2,2′-bipy) (1), has been synthesized with 2-benzoylbenzoic acid (HL) and 2,2′-bipyridine (2,2′-bipy) as ligands. In 1, the Tb(III) ion is coordinated by nine atoms to give a distorted tri-capped trigonal-prismatic geometry. The magnetic and fluorescence properties of 1 are discussed. Compound 1 is paramagnetic in the temperature range of 300–24 K, and when the temperature decreases from 22 to 2 K, it exhibits weak ferromagnetism. The compound shows four intense fluorescence emission bands arising from the transitions of Tb³⁺: ⁵D₄ →⁷F₆ (492 nm), ⁵D₄ →⁷F₅ (546 nm), ⁵D₄ →⁷F₄ (590 nm) and ⁵D₄ →⁷F₃ (622 nm) with an excitation wavelength of 315 nm.