Synthesis, characterization and luminescence properties of LnIII (Ln = Eu, Tb, Ce, Sm, Dy) complexes containing a terpyridine ligand and a 3d–4f type conjugated terpyridine-alkyne bridging EuIII–Co0 carbonyl cluster complex

Seven new organic trivalent lanthanide complexes containing a terpyridine or terpyridine-alkyne ligand, [Ln(L1)(CH3OH)(NO3)3] (Ln = Eu 1, Tb 2, Ce 3, Sm 4, Dy 5; L1 = 4-(4-bromophenyl)-2,2′:6′,2″-terpyridine) and [Ln(L2)(NO3)3] (Ln = Eu 6, Tb 7; L2 = 4-(4-trimethylsilyl phenylacetylene)-2,2′:6′,2″-terpyridine), were synthesized by the reaction of Ln(NO3)3·6H2O (Ln = Eu, Tb, Ce, Sm, Dy) with L1 and L2, respectively. In addition, a new 3d–4f type conjugated EuIII–Co0 carbonyl cluster complex, [(NO3)3Eu(η3-L2-μ)(Co2(CO)6)] 8, was obtained by the reaction of complex 6 with Co2(CO)8 in THF. All of these complexes were characterized and X-ray single-crystal diffraction reveals that the CeIII ion is ten-coordinated and lies approximately in the center of a polyhedron with 16 faces in the structure of complex 3. The molecular conformation is stabilized by intra- and intermolecular hydrogen bonds, and intermolecular π–Br and π–π interactions. The luminescence properties of these complexes were also investigated in the solid state.

Graphical abstractSeven new lanthanide luminescent complexes containing terpyridine derivates and one new EuIII–Co0 conjugated luminescent carbonyl cluster complex have been prepared and characterized, including an X-ray crystal structure in the case of the CeIII complex, with intermolecular hydrogen bonds, π–Br and π–π interactions. The luminescence properties of these complexes have been investigated in the solid state.Figure optionsDownload full-size imageDownload as PowerPoint slide