Effect of Heavy‐Atom (Br) at the Phenyl Rings of Schiff‐Base Ligands on the NIR Luminescence of their Bimetallic Zn‐Nd Complexes

Abstract

Abstract Two heterobimetallic Zn‐Nd phenylene‐bridged Schiff‐base ligands complexes [ZnNd L 1 (Py)(NO 3 ) 3 ] ( 1 ) and [Zn L 2 Nd(Py)(NO 3 ) 3 ]·MeCN ( 2 ) (Py = pyridine, H 2 L 1 = N,N′ ‐bis‐ (3‐methoxy‐salicylidene)phenylene‐1,2‐diamine, H 2 L 2 = N,N′ ‐bis‐5‐bromo‐3‐methoxy‐salicylidene)phenylene‐1,2‐diamine) were obtained. Both 1 and 2 were structurally characterized by X‐ray crystallography, and their near‐infrared (NIR) luminescent properties were determined. For the two complexes, the occupation of pyridine at the axial position of 3d Zn 2+ ions could effectively prevent luminescent quenching arising from OH‐, NH‐ or CH oscillators of the solvates around the 4f Nd 3+ ions, and the heavy‐atom (Br) effect of the Schiff‐base ligands on their NIR luminescent properties is also discussed.