The nitrogen heterocyclic dithione rare earth complexes as a multi-response high-efficiency detection sensor for the detection of Cu2+, Co2+, Cr3+, Fe3+, Bi3+ cations and its magnetic study

•Eight rare earth complexes were successfully synthesized.•2 and 3 can recognize Cu2+, Fe3+, Co2+, Cr3+, Bi3+ in DMF solution.•In 2, the LOD are 2.33 × 10–5, 1.10 × 10–5, 2.14 × 10–5, 2.15 × 10–5 for Cu(II), Fe(III), Co(II), Cr(III), respectively,.•In 3, the LOD is 7.98 × 10–6 M for Bi(III).•3, 5 displays dominant antiferromagnetic interactions. In this paper, eight novel rare earth complexes Ln(H3L2)(DMA)3(H2O), (Ln = Sm (1), Tb(2), Dy(3), Gd(4), Ho(5), Tm(6), Er(H3L2)(DMA)2(H2O)2 (7), [(μ3-OH)(μ2OH2)3Eu3(H4/3L1)3]n (8)), have been successfully synthesized by solvothermal method. Herein, H4L1 is 1,4,1′,4′-Tetrahydro-[3,3′]bi[[1,2,4] triazolyl]-5,5′-dithione, H6L2 is 5-((5-thioxo-4,5-dihydro-1H,4′H-[3,3′-bi(1,2,4-triazol)]-5′-yl)thio)-1′,4′- dihydro-1H,5′H-[3,3′-bi(1,2,4-triazole)]-5′-thione which was synthesized through in situ condensation reaction of two H4L1. The complexes 1–7 are mononuclear zero-dimensional structures of SmIII, TbIII, DyIII, GdIII, HoIII, TmIII, and ErIII, respectively, and complex 8 is a trinuclear EuIII coordinational polymer. Complexes 1–8 were characterized by the single-crystal X-ray diffraction, powder XRD, infrared spectroscopy and elemental analysis. The luminescence sensing and basic magnetic properties will be studied further. It was found that complexes 2 and 3 could specifically recognize Cu2+, Fe3+, Co2+, Cr3+, and Bi3+ in DMF solution. In 2, the limit of detection (LOD) are 2.33 × 10–5 M, 1.10 × 10–5 M, 2.14 × 10–5 M, 2.15 × 10–5 M for Cu2+, Fe3+, Co2+, Cr3+, respectively, while in 3, the LOD is 7.98 × 10–6 M for Bi3+. Magnetic studies revealed that 3 and 5 exhibit dominant antiferromagnetic interactions. Eight rare earth complexes were successfully synthesized. 2 and 3 can recognize Cu2+, Fe3+, Co2+, Cr3+, Bi3+ in DMF solution. In 2, the LOD are 2.33 × 10–5 M, 1.10 × 10–5 M, 2.14 × 10–5 M, 2.15 × 10–5 M for Cu2+, Fe3+, Co2+, Cr3+, respectively, while in 3, the LOD is 7.98 × 10–6 M for Bi3+. [Display omitted]