Synthesis, Structures, and Luminescent Properties of Lanthanide Complexes with Triphenylphospine Oxide

Abstract

Seven lanthanide complexes [ Ln (OPPh 3 ) 3 (NO 3 ) 3 ] ( 1 – 3 ) (OPPh 3 = triphenylphosphine oxide, Ln = Nd, Sm, Gd), [Dy(OPPh 3 ) 4 (NO 3 ) 2 ](NO 3 ) ( 4 ), [ Ln (OPPh 3 ) 3 (NO 3 ) 3 ] 2 ( 5 – 7 ) ( Ln = Pr, Eu, Gd) were synthesized by the reactions of different lanthanide salts and OPPh 3 ligand in the air. These complexes were characterized by single‐crystal X‐ray diffraction analysis, elemental analysis, IR and fluorescence spectra. Structure analysis shows that complexes 1 – 4 are mononuclear complexes formed by OPPh 3 ligands and nitrates. The asymmetric units of complexes 5 – 7 consist of two crystallographic‐separate molecules. Complex 1 is self‐assembled to construct a 2D layer‐structure of (4,4) net topology by hydrogen bond interactions. The other complexes show a 1D chain‐like structure that was assembled by OPPh 3 ligands and nitrate ions through C–H ··· O interactions. Solid emission spectra of compounds 4 and 6 are assigned to the characteristic fluorescence of Tb 3+ ( λ em = 480, 574 nm) and Eu 3+ ( λ em = 552, 593, 619, 668 nm).