Syntheses, structures, and magnetic properties of acetate-bridged lanthanide complexes based on a tripodal oxygen ligand

Four homodinuclear lanthanide complexes, Dy 2 (L OEt ) 2 (OAc) 4 ( 1 ), Tb 2 (L OEt ) 2 (OAc) 4 ( 2 ), Ho 2 (L OEt ) 2 (OAc) 4 ( 3 ), and Gd 2 (L OEt ) 2 (OAc) 4 ( 4 ), have been synthesized and characterized based on a tripodal oxygen ligand Na [(η 5 -C 5 H 5 )Co(P(O)(OC 2 H 5 ) 2 ) 3 ] (NaL OEt ). Structural analyses show that the acetate anions bridge two symmetry-related Ln 3+ ions in the μ 2 :η 1 :η 1 and μ 2 :η 1 :η 2 coordination patterns, and each lanthanide (III) ion owns a twisted square antiprism (SAPR) conformation. Static magnetic measurements reveal the weak intramolecular ferromagnetic interaction between dysprosium (III) ions in 1 and antiferromagnetic Ln 3+ ···Ln 3+ couplings in the other three complexes. Through the analysis of the ligand-field effect and magnetic anisotropy axis orientation, the reasons for the lack of dynamic magnetic behavior in 1 were identified.