Wyniki wyszukiwania - BazTech

Ograniczanie wyników

1 Polish Journal of Chemistry

1 2002

Powiadomienia systemowe

Sesja wygasła!

Znaleziono wyników: 1

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: 2-nitroterephthalato-bridge

Sortuj według:

Ogranicz wyniki do:

Synthesis, Characterization and magnetic Properties of mi-2-Nitroterephthalato Binuclear Iron(II) Complexes

Li Y., Yan C. -W.

Polish Journal of Chemistry

2002

Vol. 76 / nr 6

765-771

Four new binuclear iron(II) complexes bridged by 2-nitroterephthalato groups (NTPHA) and ended with 4,4_-dimethyl-2,2_-bipyridine (Me2-bpy), 2,9-dimethyl-1,10-phenanthroline (Me2-phen), 5-chloro-1,10-phenanthroline (Cl-phen) or 5-bromo-1,10-phenanthroline (Br-phen), namely [Fe2(NTPHA)L4](ClO4)2 (L=Me2-bpy,Me2-phen, Cl-phen, Br-phen), have been synthesized and characterized. Based on elemental analyses, magnetic moments (at room temperature), molar conductance measurements, and spectroscopic studies, extended NTPHA-bridged structures consisting of two iron(II) ions, each in a distorted octahedral environment are proposed for these complexes. The variable temperature magnetic susceptibilities of complexes [Fe2(NTPHA)(Me2-bpy)4](ClO4)2 (1) and [Fe2(NTPHA)(Me2-phen)4](ClO4)2 (2) were measured over the range 4.2~300 K and the observed data were successfully simulated by the equation based on the spin Hamiltonian operator, _ _ _ H JS S _ _ _ 2 1 2, giving the exchange integrals J = -1.02 cm-1 for (1) and J = -1.96 cm-1 for (2). These results indicate the presence of a very weakly antiferromagnetic spin-exchange interaction between the iron(II) ions within each molecule. The influence of nitro substituent in the bridging ligand on magnetic interaction between the metal ions of this kind of complexes is also discussed.