Synthesis, crystal structures and photoluminescence properties of Sm-based enantiomeric pair

Novel Sm-based enantiomeric pair, generally formulated Sm(DBM)3L (LR,R in 1, LS,S in 2, DBM = dibenzoylmethanate) have been successfully prepared via the reaction of Sm(DBM)3·2H2O with chiral ligands LR,R (−)-4,5-pinene bipyridine and LS,S (+)-4,5-pinene bipyridine (Scheme 1), respectively. The crystal structure analysis of 1 and 2 reveal that they crystallize in chiral space group P21 of monoclinic system. The central Sm(III) ion is octacoordinate with six β-diketonate oxygen atoms and two chiral pinene bipyridine nitrogen atoms, forming a coordination polyhedron best described as the distorted square antiprism (SA). The CD spectra (Fig. S1) further confirm that 1 and 2 are enantiomers. The photoluminescence investigations of 1 and 2 demonstrate that they display deep-red luminescence characteristic of the Sm3+.