A variety of new tri- and tetranuclear Mn-Ln and Fe-Ln (Ln = lanthanide) complexes

作者：Mukherjee Shreya; Daniels Matthew R; Bagai Rashmi; Abboud Khalil A; Christou George; Lampropoulos Christos^*

来源：Polyhedron, 2010, 29(1): 54-65.

DOI：10.1016/j.poly.2009.06.003

• Crystal structures
• Manganese(III) clusters
• Iron(III) clusters
• Heterometallic clusters
• Magnetochemisrry

The use of carboxylates in the synthesis of 3d/4f clusters, with or without a second organic ligand, has afforded a series of tetranuclear M(2)Gd(2) complexes (M = Fe or Mn), and two new trinuclear M(2)Gd (M = Fe or Mn) molecular compounds. Only one of these, [Mn(2)Gd(2)O(2)(O(2)CBu')(8)(HO(2)CBu')(4)] (1), does not contain a multidentate chelate ligand. Two other similar tetranuclear clusters were synthesized from the use of triethanolamine (teaH(3)) and 1,1,1-tris(hydroxymethyl)ethane (thmeH(3)). [Mn(2)Gd(2)(OH)(2)(O(2)CPh)(4)(NO(3))(2)(teaH)(2)] (2) has very similar structure with 1, bearing a defective incomplete double-cubane core bridged by mu(3)-O atoms, whereas in the core of [NHEt(3)](2)[Fe(2)Gd(2)(O(2)CPh)(4)(thme)(2) (NO(3))(4)] (3) the thme(3-) ligand caps the two incomplete cubane units, providing the triply-bridging alkoxides needed for bridging. Two new oxide-centered triangular clusters were synthesized bearing the Schiff-based chelate 2-([2-(dimethylamino)ethyl]methylamino)ethanol (dmemH), namely [Fe(2)GdO(O(2)CBu')(2)(dmem)(2)(NO(3))(3)] (4). and [Mn(2)GdO(O(2)CBu')(2)(dmem)(2)(NO(3))(3)] (5). Magnetic susceptibility measurements and/or reduced magnetization studies established that complexes 1 and 3 have an S=5 ground state, complex 2 has S = 4, and complexes 4 and 5 are S = 7/2 in their ground states. These complexes portray the feasibility of obtaining products bearing metal cores commonly found in homometallic clusters, even when these include metals with completely different coordination chemistry and electronic structure, such as lanthanides.

• 出版日期2010-1-13