Synthesis and characterization of lanthanide complexes containing a bulky tridentate [N,N,O] Schiff base ligand

Abstract

The lanthanide complexes containing a bulky tridentate [N,N,O] Schiff base ligand 3,5-Bu t 2-2-(OH)C 6H 2CH=N-8-C 9H 6N (HL) were synthesized and characterized. The reaction of anhydrous LnCl 3 with NaL formed in situ in a 1:1 molar ratio in THF at room temperature afforded the lanthanide Schiff base dichloride complexes LnLCl 2(DME) (Ln=Eu ( 1); Sm ( 2)). Complexes 1 and 2 can be used as precursors for the synthesis of the lanthanide cyclopentadienyl Schiff base derivatives. The reactions of complexes 1 and 2 with one equiv of NaCH 3C 5H 4 in THF provided the desired products LnL(CH 3C 5H 4)Cl(THF)·THF (Ln=Eu ( 3); Sm ( 4)) in good isolated yields. These complexes were characterized by elemental analysis, IR spectra, and X-ray structural determination, in the case of complexes 3 and 4. The crystal data of complex 3 are monoclinic, P2 1/c space group, a=1.3370(2) nm, b=1.5190(2) nm, c=1.8910(3) nm, β=109.846(4)°, V=3.6125(8) nm 3, Z=4, D c=1.416 mg/m 3, μ=1.847 mm −1, F(000)=1584, R=0.0707, w R=0.1350. The crystal data of complex 4 are monoclinic, P2 1/ c space group, a=1.3383(1) nm, b=1.5210(2) nm, c=1.8960(2) nm, β =109.878(3)°, V=3.6293(7) nm 3, Z=4, D c=1.407 mg/m 3, μ=1.728 mm −1, F(000)=1580, R=0.0670, w R=0.1385.