1,3-Bis(alkylimino)isoindolinates of rare earth metals: Synthesis, molecular structure and photoluminescence

摘要

The rare earth metal isoindolinates Ln((PrL)-Pr-i)(3) (Ln = Sc (1), Y (2), Eu (3), Dy (4), Yb (5); (PrL)-Pr-i= 1,3-bis(isopropylimino)isoindolinate anion) and [(MeL)Ce](2)(mu-Mel)(4) (6) (MeL = 1,3-bis(methylimino)isoindolinate anion) were synthesized by reactions of the amides Ln[N(SiMe3)(2)](3) with 1,3-bis(isopropylimino)isoindoline ((PrLH)-Pr-i) or 1,3-bis(methylimino)isoindoline (MeLH), respectively. The X-ray diffraction study revealed that in monomeric molecules of the isopropyl-substituted compounds 2 and 4 the cations Ln(3+) are eta(2)-coordinated by three isoindolinate ligands. The methyl-substituted 6 exists in a crystal as a dinner containing two terminal eta(2)-coordinated ligands and four bridging isoindolinate ligands two of which are bonded to Ce atoms in eta(3) fashion (eta:eta:eta-N,N,N) but two others in eta(4) manner (eta:eta(2):eta-N,N,N). All the obtained complexes in solutions exhibited ligand-centered photoluminescence, the spectra of which consist of one broadened band with a maximum at 400-450 nm.