Salen homonuclear and heteronuclear lanthanide(III) complexes with near-infrared (NIR) luminescence

•Salen homonuclear and heteronuclear lanthanide complexes were synthesized.•A convenient and viable synthetic route is achieved.•‘Dual emission’ and metal-centered NIR emission were determined, respectively.

Two lanthanide complexes are achieved by utilizing H2salen/acac ligands (H2salen = N,N′-ethylenebis(salicylideneimine), acac = acetylacetonate). They are homonuclear [Nd4(μ3-OH)2(salen)2(acac)6(CH3OH)2]·CH3OH (1) and heteronuclear [NdYb(salen)2(acac)2] (2). The structures of the two complexes were determined by X-ray crystallographic studies and their photophysical properties were investigated. The homonuclear Nd4 complex exhibits characteristic metal-centered NIR emission. The heteronuclear NdYb shows ‘dual emission’ from both neodymium(III) and ytterbium(III) ions.

Graphical abstractTwo homonuclear and heteronuclear lanthanide complexes were constructed from salen and β-diketonate ligands. The homonuclear complex exhibits characteristic metal-centered NIR emission, while the heteronuclear complex shows ‘dual emission’.Figure optionsDownload full-size imageDownload as PowerPoint slide