%0 Generic
%A Mochizuki, Toshihide
%A Nogami, Takashi
%A Ishida, Takayuki
%D 2009
%T Ferromagnetic Superexchange Coupling through a Diamagnetic Iron(II) Ion in a Mixed-Valent Iron(III, II, III) meso-Helicate
%U https://acs.figshare.com/articles/dataset/Ferromagnetic_Superexchange_Coupling_through_a_Diamagnetic_Iron_II_Ion_in_a_Mixed_Valent_Iron_III_II_III_i_meso_i_Helicate/2874961
%R 10.1021/ic8020589.s001
%2 https://ndownloader.figshare.com/files/4572796
%K Ferromagnetic Superexchange
%K ground state
%K III
%K terminal S
%K II
%K ion
%K superexchange mechanism
%X meso-Helicates [Ni3(pzNTR)6]·4CH3CN and [Fe3(pzNTR)6](ClO4)2·CH3OH were prepared (HpzNTR stands for N-tert-butyl-α-3-pyrazolylnitrone). The former showed antiferromagnetic coupling between neighboring ions with J/kB = −28.2(2) K, which can be reasonably interpreted in terms of the superexchange mechanism. On the other hand, the latter exhibited ferromagnetic coupling with J/kB = +0.292(8) K between the two terminal S = 5/2 Fe3+ ions through the intervening diamagnetic Fe2+ ion. The admixture of low-lying excited states with the ground state stabilizes the ferromagnetically coupled state, like the Prussian blue magnet.
%I ACS Publications