The standard redox potentials of the Fe^(3+)/Fe^(2+)(+0.77 V)and H_(3)AsO_(4)/H_(3)AsO_(3)(+0.56 V)stabilize the easy crystallization of ferric arsenates.However,activating solvothermal reactions with a reducing agent...The standard redox potentials of the Fe^(3+)/Fe^(2+)(+0.77 V)and H_(3)AsO_(4)/H_(3)AsO_(3)(+0.56 V)stabilize the easy crystallization of ferric arsenates.However,activating solvothermal reactions with a reducing agent such as hydrazine or ethanol may destabilize the solid compounds towards ferric,ferrous or mixed Fe^(2+/3+)arsenites.Few of them have been reported and in this work we have prepared four new members with various counter cations(Ba^(2+))or anions(OH^(−),Cl^(−))and various iron valence.The versatile condensation of ortho-arsenites(AsO_(3)^(2−))into pyro–(As_(2)O_(5)^(4−)),rings or meta-arsenites favours the creation of effcient spacers,able to tune the magnetic dimensionality of the iron-based framework.These four new members cover from 0D(paramagnetic Ba_(2)Fe^(Ⅱ)(As_(3)^(3+)O_(6))_(2)·H_(2)O),1D(S=5/2 ladders in BaFe_(2)^(Ⅱ)(As_(2)O_(5))(AsO_(3))(OH)),2D(layers of S=5/2 dimers in Ba_(2)Fe_(2)^(Ⅲ)(As_(2)O_(5))_(2),up to 3D(T_(N)=97 K in Fe_(3)^(2.66+)(As_(2)O_(5))(AsO_(3))Cl with charge ordering)topologies.Their magnetic properties are analysed by means of combined structural,experimental results and ab initio calculations.展开更多
基金supported by the ANR(Grant ANR ANR-16-CE08-0023).
文摘The standard redox potentials of the Fe^(3+)/Fe^(2+)(+0.77 V)and H_(3)AsO_(4)/H_(3)AsO_(3)(+0.56 V)stabilize the easy crystallization of ferric arsenates.However,activating solvothermal reactions with a reducing agent such as hydrazine or ethanol may destabilize the solid compounds towards ferric,ferrous or mixed Fe^(2+/3+)arsenites.Few of them have been reported and in this work we have prepared four new members with various counter cations(Ba^(2+))or anions(OH^(−),Cl^(−))and various iron valence.The versatile condensation of ortho-arsenites(AsO_(3)^(2−))into pyro–(As_(2)O_(5)^(4−)),rings or meta-arsenites favours the creation of effcient spacers,able to tune the magnetic dimensionality of the iron-based framework.These four new members cover from 0D(paramagnetic Ba_(2)Fe^(Ⅱ)(As_(3)^(3+)O_(6))_(2)·H_(2)O),1D(S=5/2 ladders in BaFe_(2)^(Ⅱ)(As_(2)O_(5))(AsO_(3))(OH)),2D(layers of S=5/2 dimers in Ba_(2)Fe_(2)^(Ⅲ)(As_(2)O_(5))_(2),up to 3D(T_(N)=97 K in Fe_(3)^(2.66+)(As_(2)O_(5))(AsO_(3))Cl with charge ordering)topologies.Their magnetic properties are analysed by means of combined structural,experimental results and ab initio calculations.
