Chiral Dinuclear Ln(III) Complexes Derived from S- and R-2-(6-methoxy-2-naphthyl)propionate. Optical and Magnetic Properties.

Abstract

The reaction of LnCl3·6H2O with (S)-(+)-2-(6-methoxy-2-naphthyl)propionic acid (S-HL), best known as naproxen, and 1,10-phenanthroline (phen) in EtOH allows the isolation of dinuclear chiral compounds S-1-4 of the formula [Ln2(S-L)6(phen)2]·3DMF·H2O [Ln(III) = Eu (1), Gd (2), Tb (3) and Dy (4)]. The use of the R-enantiomeric species of the HL ligand led to complexes R-1-4 with the formula [Ln2(R-L)6(phen)2]·3DMF·H2O. Compounds R- and S-1, 3 and 4 show strong sensitized metal-centred luminescence in the visible region. Moreover, Dy(III) complexes R- and S-4 display field-induced singlemolecule magnet (SMM) behaviour. For chiral and emissive compounds circularly polarized luminescence (CPL) measurements have also been performed.