TỔNG HỢP, NGHIÊN CỨU PHỔ KHỐI LƯỢNG VÀ KHẢ NĂNG PHÁT QUANG CỦA PHỨC CHẤT HỖN HỢP PHỐI TỬ SALIXYLIC VÀ 2,2′-DIPYRIDYL N,N′-DIOXIT CỦA MỘT SỐ NGUYÊN TỐ ĐÁT HIẾM

Tóm tắt

Some complexes of Ln (III) (Ln:Nd, Sm, Eu, Tb, Dy, Er, Yb) with mixed ligands salicylate and 2,2’-
dipyridyl N,N′-dioxide have been synthesised. They have general formula are Ln(Sal)3(DipyO2) (Ln:Nd,Sm, Eu; Sal-: Salicylate, DipyO2: 2,2’-dipyridyl N,N′-dioxide) and [Ln(Sal)3(DipyO2)].2H2O (Ln: Tb,Dy, Er, Yb). The ion fragments and luminescence properties of complexes in solid state were
investigated by measuring the mass, emission spectra, the intramolecular ligand-to-rare earth energy transfer mechanisms were discussed. The mass spectra of complexes displayed complexes are monomes and there are three ion fragments in vapour.
The emission spectra of Sm(Sal)3(DipyO2) consist of the 4G5/2 → 6H7/2 and 4G5/2 → 6H9/2 dominant transitions located at 598 nm and 643 nm, the weaker 4G5/2 → 6H5/2 transition located at 561 nm, the weakest 4G5/2 → 6H11/2 transition located at 702 nm. The emission spectra of the Nd(III) complex displayed only one narrow band arising from 4F3/2 → 4I9/2. The emission spectrum of the Eu (III) complex displayed five bands arising from 5D0 → 7F1, 5D0 → 7F2, 5D0 → 7F3, 5D0 → 7F4, 5D0 → 7F5 transitions. The emission spectra of [Dy(Sal)3(DipyO2)].2H2O show one peak at 448 nm, which belongs to the 4F9/2 → 6H15/2 transition of Dy3+. The emission spectra of [Er(Sal)3(DipyO2)].2H2O consist of the 2H9/2→4I15/2 transition located at 440 nm. The emission spectra of the [Tb(Sal)3(DipyO2)].2H2O displayed five bands arising from 5D4 → 7F5 dominant transition located at 547 nm, the weaker 5D4 → 7F6, 5D4 → 7F4, 5D4 → 7F3, 5D4 → 7F2 transitions located at 489, 585, 620, 648 nm respectively. The emission spectra of the [Yb(Sal)3(DipyO2)].2H2O displayed one band at 456 nm, i.e. 2F5/2→2 I7/2 energy level of Yb3+ was observed. These complexes showed room-temperature photoluminescence.