The two three-dimensional oxo-bfidged lanthanides {[Ln2(C4H2O4)3(H20)4]· 3H2O}3, with Ln=Ho3+ (1); Gd3+ (2), are isomorphous. They have layer-type structures built up from non-centrosymrnetric dinuclear...The two three-dimensional oxo-bfidged lanthanides {[Ln2(C4H2O4)3(H20)4]· 3H2O}3, with Ln=Ho3+ (1); Gd3+ (2), are isomorphous. They have layer-type structures built up from non-centrosymrnetric dinuclear unit Ln2O12(H2O)4, beside three lattice H20 molecules stabilizing the 3D open-frmnework. The building entities are linked through one classical syn-anti g2-carboxylato-K1O:K^1O' bridge. Within the bi-polyhedra, two double μ2-O'; K2O,O' bridges and a syn-syn classical one, support the magnetic measurements carried out on holmium compound indicating relatively weak anti-ferromagnetic interactions. The compari- son with magnetic studies on the almost similar reported Gd(III) compound, suggested that concomitant antiferromagnetic and ferro- magnetic properties could not be excluded. The two distinct thermal behaviors evidenced the higher metal-water bond strength with the smaller cation, and revealed the great supramolecular effects generated by hydrogen-bonding patterns.展开更多
基金Project supported by MESRS-Algeria and MDU-France(project CMEP-Programme Tassili)
文摘The two three-dimensional oxo-bfidged lanthanides {[Ln2(C4H2O4)3(H20)4]· 3H2O}3, with Ln=Ho3+ (1); Gd3+ (2), are isomorphous. They have layer-type structures built up from non-centrosymrnetric dinuclear unit Ln2O12(H2O)4, beside three lattice H20 molecules stabilizing the 3D open-frmnework. The building entities are linked through one classical syn-anti g2-carboxylato-K1O:K^1O' bridge. Within the bi-polyhedra, two double μ2-O'; K2O,O' bridges and a syn-syn classical one, support the magnetic measurements carried out on holmium compound indicating relatively weak anti-ferromagnetic interactions. The compari- son with magnetic studies on the almost similar reported Gd(III) compound, suggested that concomitant antiferromagnetic and ferro- magnetic properties could not be excluded. The two distinct thermal behaviors evidenced the higher metal-water bond strength with the smaller cation, and revealed the great supramolecular effects generated by hydrogen-bonding patterns.