Synthesis and luminescent properties of novel red-emitting Eu(III) complexes based on alanine aliphatic derivatives with different optical rotation

A series of novel luminescent amino acid-rare earth complexes (denoted as Eu(L/D-SA)3-Phen) have been successfully synthesized. Using stearoyl alanine (denoted as SA) with different optical rotations as the first ligand and 1,10-phenanthroline (Phen) as the second ligand, the products were prepared by solution chemical reaction. Fourier transform infrared spectrometer (FT-IR), nuclear magnetic resonance spectroscopy (1H NMR), X-ray diffraction (XRD), scanning electron microscope (SEM), ultraviolet and visible spectrum (UV) and photoluminescence spectroscopy were used to characterize the properties of Eu(L/D-SA)3-Phen. FT-IR, 1H NMR and XRD indicate that ligand SA and Phen were prepared and successfully combined with Eu3+ ions. SEM analysis shows relatively uniform morphological structure. Eu(L/D-SA)3-Phen exhibit a typical luminescence emission peak at 614 nm. In addition, the lifetimes of Eu(L/D-SA)3-Phen are in scale of millisecond. The relationship between fluorescence intensity of Eu(L/D-SA)3-Phen and the optical rotation of ligand SA has been studied and discussed. Based on the results, Eu(L/D-SA)3-Phen have excellent luminescent performance and possess potential application as luminescent materials.