A Ni(Ⅱ)complex harnessed in a pentagonal bipyramidal environment by a rigid N_(5)-macrocyclic ligand(i.e.1,3,10,12-tetramethyl-1,2,11,12-tetraaza[3](2,6)-pyridino[3](2,9)-1,10-phenanthrolinophane-2,10-diene)is shown ...A Ni(Ⅱ)complex harnessed in a pentagonal bipyramidal environment by a rigid N_(5)-macrocyclic ligand(i.e.1,3,10,12-tetramethyl-1,2,11,12-tetraaza[3](2,6)-pyridino[3](2,9)-1,10-phenanthrolinophane-2,10-diene)is shown to exhibit axial anisotropy with a ZFS D parameter in the order of−10 to−15 cm^(-1),and this anisotropy is not significantly changed by apical ligand substitution.Using the latter complex as a building unit,a ferromagnetic 1-D CN-bridged Ni-Cr coordination polymer with SCM behavior characterized by a barrier of magnetization reversal U_(eff)/k_(B)=54 K(37 cm^(-1))withτ0=2.28×10^(−11)s was obtained.The Cr(Ⅲ)complex involved in the design was chosen to favor parallel organization of the anisotropy axes of the Ni units along the 1-D array,and thus maximize the magnetic anisotropy of the supramolecular system.A related chain compound prepared with diamagnetic[Ni(CN)_(4)]^(2−)units,and a trinuclear CN-bridged[NiCr_(2)]complex enabled assessing respectively the magnetic anisotropy of Ni(Ⅱ)in this coordination sphere and its exchange interaction with Cr(Ⅲ)found to be ferromagnetic and of the order of 10 cm^(-1).The crystal structures and magnetic behaviors of all compounds are reported.展开更多
文摘A Ni(Ⅱ)complex harnessed in a pentagonal bipyramidal environment by a rigid N_(5)-macrocyclic ligand(i.e.1,3,10,12-tetramethyl-1,2,11,12-tetraaza[3](2,6)-pyridino[3](2,9)-1,10-phenanthrolinophane-2,10-diene)is shown to exhibit axial anisotropy with a ZFS D parameter in the order of−10 to−15 cm^(-1),and this anisotropy is not significantly changed by apical ligand substitution.Using the latter complex as a building unit,a ferromagnetic 1-D CN-bridged Ni-Cr coordination polymer with SCM behavior characterized by a barrier of magnetization reversal U_(eff)/k_(B)=54 K(37 cm^(-1))withτ0=2.28×10^(−11)s was obtained.The Cr(Ⅲ)complex involved in the design was chosen to favor parallel organization of the anisotropy axes of the Ni units along the 1-D array,and thus maximize the magnetic anisotropy of the supramolecular system.A related chain compound prepared with diamagnetic[Ni(CN)_(4)]^(2−)units,and a trinuclear CN-bridged[NiCr_(2)]complex enabled assessing respectively the magnetic anisotropy of Ni(Ⅱ)in this coordination sphere and its exchange interaction with Cr(Ⅲ)found to be ferromagnetic and of the order of 10 cm^(-1).The crystal structures and magnetic behaviors of all compounds are reported.
