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

摘要

Novel Sm-based enantiomeric pair, generally formulated Sm(DBM)3L (L_(R,R) in 1, L_(s,s) in 2, DBM = dibenzoyl-methanate) have been successfully prepared via the reaction of Sm(DBM)3-2H2O with chiral ligands L_(R,R) (-)-4,5-pinene bipyridine and L_(S,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 (5-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. SI) 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 Sm~(3+).