Ln(iii) complexes (Ln = Eu, Gd, Tb, Dy) with a chiral ligand containing 1,10-phenanthroline and (-)-menthol fragments: synthesis, structure, magnetic properties and photoluminescence

• Published in: Dalton transactions : an international journal of inorganic chemistry 2017-08, Vol.46 (34), p.11440-11450
• Main Authors: Larionov, Stanislav V, Bryleva, Yuliya A, Glinskaya, Ludmila A, Plyusnin, Victor F, Kupryakov, Arkady S, Agafontsev, Alexander M, Tkachev, Alexey V, Bogomyakov, Artem S, Piryazev, Dmitry A, Korolkov, Ilya V
• Format: Article
• Language: English
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c7dt01536d

A series of lanthanide(iii) complexes based on the new chiral ligand L, which contains 1,10-phenanthroline and (-)-menthol fragments, namely [LnL (NO ) ] (Ln = Eu (1), Gd (2), Tb (3), Dy (4)), have been synthesized and structurally characterized. Complexes 1-4 are isostructural and crystallize in the non-centrosymmetric space group P4 2 2. The mononuclear complexes comprise a 10-coordinate Ln ion with two bidentate N,N-donor ligands (L) and three bidentate chelating nitrate groups. The magnetic properties of complexes 1-4 are determined mainly by the Ln ions. In the case of complexes 3 and 4, significant anisotropy results in nonlinear field dependences of magnetization at low temperature. Complexes 1, 3 and 4 exhibit metal-centered red (Eu ), green (Tb ) and yellow (Dy ) luminescence, respectively, whereas complex 2 displays blue ligand-based luminescence in the solid state at room temperature. The luminescence quantum yield for the solid samples increases in the order 4 < 2 ≈ 3 < 1. The europium(iii) complex shows long luminescence lifetimes (up to 1750 μs) and a very high quantum yield (φ = 0.87); these make this compound promising for application in sensing and optoelectronics.