Di- and tetranuclear heterometallic 3d-4f cobalt(II)-lanthanide(III) complexes derived from a hexadentate bisoxime: Syntheses, structures and magnetic properties

Five heterometallic Co(II)-Ln(III) complexes, a discrete heterodinuclear complex [CoLLa(Py) (NO3)(3)(CH3OH)] (1) (PY = pyridine), a heterotetranuclear dimer [CO2L2La2(4,4'-biPY)(NO3)(6)(CH3OH)(2)] (2) (4,4'-bipy = 4,4'-bipyridine) and three discrete heterodinuclear complexes [CoLLn(OAc)(NO3)(2)(CH3OH)] (Ln = Gd (3), Tb (4), Dy (5)), were synthesized with a hexadentate bisoxime ligand 1,2-bis(3-methoxysalicylideneaminooxy)ethane (H2L), and characterized by single crystal X-ray diffraction. The complexes 1, 3, 4 and 5 are discrete heterodinuclear structures, but the assembly of two dinuclear units [CoLLa (NO3)3(CH3OH)] and one 4,4'-bipyridine results in a discrete heterotetranuclear dimer 2. The Co(II) and La(III) atoms in the complexes 1 and 2 are penta- and decacoordinated, while the Co(II) and Ln(III) (Ln = Gd, Tb and Dy) atoms in the complexes 3, 4 and 5 are hexa- and nonacoordinated, respectively. Magnetic measurements were performed on the complexes 3, 4 and 5, where an intramolecular ferromagnetic interaction is found in the complex 3. (C) 2016 Elsevier Ltd. All rights reserved.