Dinuclear lanthanide complexes supported by a hybrid salicylaldiminato/calix[4]arene-ligand: synthesis, structure, and magnetic and luminescence properties of (HNEt3)[Ln2(HL)(L)] (Ln = SmIII, EuIII, GdIII, TbIII)

Steve Ullmann; Peter Hahn; Laura Blömer; Anne Mehnert; Christian Laube; Bernd Abel; Berthold Kersting

doi:10.1039/c9dt00292h

Dinuclear lanthanide complexes supported by a hybrid salicylaldiminato/calix[4]arene-ligand: synthesis, structure, and magnetic and luminescence properties of (HNEt₃)[Ln₂(HL)(L)] (Ln = Sm^III, Eu^III, Gd^III, Tb^III)

Dalton Trans. 2019 Mar 19;48(12):3893-3905. doi: 10.1039/c9dt00292h.

Authors

Steve Ullmann¹, Peter Hahn, Laura Blömer, Anne Mehnert, Christian Laube, Bernd Abel, Berthold Kersting

Affiliation

¹ Institut für Anorganische Chemie, Universität Leipzig, Johannisallee 29, 04103 Leipzig, Germany. b.kersting@uni-leipzig.de.

PMID: 30815651
DOI: 10.1039/c9dt00292h

Abstract

The synthesis, structures, and properties of a new calix[4]arene ligand with an appended salicylaldimine unit (H4L = 25-[2-((2-methylphenol)imino)ethoxy]-26,27,28-trihydroxy-calix[4]arene) and four lanthanide complexes (HNEt3)[Ln2(HL)(L)] (Ln = SmIII (4), EuIII (5), GdIII (6), and TbIII (7)) are reported. X-ray crystallographic analysis (for 4 and 6) reveals an isostructural series of dimeric complexes with a triply-bridged NO3Ln(μ-O)2(OHO)LnO3N core and two seven coordinated lanthanide ions. According to UV-vis spectrometric titrations in MeCN and ESI-MS the dimeric nature is maintained in solution. The apparent stability constants range between log K = 5.8 and 6.3. The appended salicylaldimines sensitize EuIII and TbIII emission (λexc 311 nm) in the solid state or immersed in a polycarbonate glass at 77 K (for 5, 7) and at 295 K (for 7).