Title of article :
Synthesis, crystal structures, electrochemical and magnetic properties of polynuclear {Fe4} and {Fe8Na4} carboxylate/picolinate clusters
Author/Authors :
Arizaga، نويسنده , , L. and Cerd?، نويسنده , , M.F. and Faccio، نويسنده , , R. and Mombr?، نويسنده , , A.W. and Novak، نويسنده , , M.A. and Gonz?lez، نويسنده , , R. and Kremer، نويسنده , , C. and Chiozzone، نويسنده , , R.، نويسنده ,
Abstract :
Reaction of sodium picolinate with FeIII oxo-centered carboxylate triangles in MeCN in the presence of PPh4Cl yields (PPh4)[Fe4O2(O2CR)7(pic)2] (R = Ph (1), But (2)). Omitting the phosphonium cation produces [Fe8Na4O4(O2CPh)16(pic)4(H2O)4] (3), which contains two Fe4Na2 units bridged by two picolinate ligands. X-ray crystal structures of 1 and 3 are reported.
metric profiles in MeCN show four one-electron reduction steps for complexes 1 and 2. Variable-temperature magnetic susceptibility measurements in polycrystalline samples of 1 and 3 reveal strong antiferromagnetic couplings leading to S = 0 ground states.
Keywords :
Iron(III) picolinate complexes , Electrochemical properties , Magnetic properties , Iron(III) carboxylate clusters
