Dinuclear (FeII, GdIII) Complexes Deriving from Hexadentate Schiff Bases: Synthesis, Structure, and Mössbauer and Magnetic Properties
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- 作者：Jean-Pierre Costes ; Juan Modesto Clemente-Juan ; Franç ; oise Dahan ; Fré ; dé ; ric Dumestre ; and Jean-Pierre Tuchagues
- 刊名：Inorganic Chemistry
- 出版年：2002
- 出版时间：June 3, 2002
- 年：2002
- 卷：41
- 期：11
- 页码：2886 - 2891
- 全文大小：100K
- 年卷期：v.41,no.11(June 3, 2002)
- ISSN：1520-510X
文摘
The dinuclear (FeII, GdIII) complexes studied in this report derive from hexadentate Schiff base ligands abbreviatedH2Li (i = 1, 2, 3). H2L1 = N,N'-bis(3-methoxysalicylidene)-1,3-diamino-2,2'-dimethyl-propane, H2L2 = N,N'-bis(3-methoxysalicylidene)-1,2-diamino-2-methylpropane, and H2L3 = N,N'-bis(3-methoxysalicylidene)-1,2-diaminoethane.The crystal and molecular structures of three complexes have been determined at 160 K. Depending on the solventused in the preparation, L1Fe(CH3OH)Gd(NO3)3(CH3OH)2, 1, or L1Fe((CH3)2CO)Gd(NO3)3, 1', is obtained from H2L1.A similar complex, L2Fe((CH3)2CO)Gd(NO3)3, 2, is obtained from H2L2. Complex 1 crystallizes in the orthorhombicspace group Pca21 (No. 29): a = 22.141(3) Å, b = 9.4159(16) Å, c = 15.2075(17) Å, V = 3170.4(7) Å3, Z =4. Complexes 1' and 2 crystallize in the monoclinic space group P21/c (No. 14): 1', a = 9.6264(17) Å, b =19.662(3) Å, c = 16.039(3) Å, 
= 95.15(2)
, V = 3023.6(9) Å3, Z = 4; 2, a = 9.7821(13) Å, b = 18.7725(17)Å, c = 16.100(2) Å, = 96.497(16), V = 2937.5(6) Å3, Z = 4. Complexes 1, 1', and 2 possess an Fe(Ophenoxo)2Gd core. The mononuclear L3Fe complex could be prepared from H2L3 but not the related dinuclear (Fe, Gd)species. Mössbauer spectroscopy evidences that the iron center is in the +2 oxidation state for the six complexes.The experimental magnetic susceptibility and magnetization data of complexes 1, 1', and 2 indicate the occurrenceof weak FeII-GdIII ferromagnetic interactions. Single ion zero-field splitting of the iron(II) must be taken into accountfor satisfactorily fitting the data by exact calculation of the energy levels associated to the spin Hamiltonian throughdiagonalization of the full matrix for axial symmetry (1, J = 0.50 cm-1, D = 2.06 cm-1; 1', J = 0.41 cm-1, D =3.22 cm-1; 2, J = 0.08 cm-1, D = 4.43 cm-1).
= 95.15(2), V = 3023.6(9) Å3, Z = 4; 2, a = 9.7821(13) Å, b = 18.7725(17)Å, c = 16.100(2) Å, = 96.497(16), V = 2937.5(6) Å3, Z = 4. Complexes 1, 1', and 2 possess an Fe(Ophenoxo)2Gd core. The mononuclear L3Fe complex could be prepared from H2L3 but not the related dinuclear (Fe, Gd)species. Mössbauer spectroscopy evidences that the iron center is in the +2 oxidation state for the six complexes.The experimental magnetic susceptibility and magnetization data of complexes 1, 1', and 2 indicate the occurrenceof weak FeII-GdIII ferromagnetic interactions. Single ion zero-field splitting of the iron(II) must be taken into accountfor satisfactorily fitting the data by exact calculation of the energy levels associated to the spin Hamiltonian throughdiagonalization of the full matrix for axial symmetry (1, J = 0.50 cm-1, D = 2.06 cm-1; 1', J = 0.41 cm-1, D =3.22 cm-1; 2, J = 0.08 cm-1, D = 4.43 cm-1).