Molecular engineering of coupled polynuclear systems: Orbital mechanism of the interaction between metallic centers

摘要: Abstract The aim of this work was to propose a strategy allowing the synthesis polynuclear complexes with expected magnetic properties. First, we recall broad outlines an orbital model for describing exchange interaction in coupled systems. This is grounded on concepts orbitals and overlap density between orbitals. Then focus two problems, namely design ferromagnetically-coupled systems binuclear exhibiting very large antiferromagnetic metal ions far away from each other. When zero, contribution also zero coupling purely ferromagnetic. Two strategies may be used obtain result, either strict orthogonality or accidental orthogonality. realized CuVO(fsa)(in2)en, CH(in3)OH [CuCr(fsa)(in2)en(H2O)2]Cl, 3H2O heterobinuclear complexes, where (fsa)2)en4− denotes bichelating ligand derived Schiff base N,N′(1-hydroxy, 2-carboxxy benzilidene) ethylene diamine. magnitude stabilization ground spin triplet regard excited singlet former complex explained topological way map density. predicted planar di-μ-hydroxo copper(II) dimers bridging angles around 92°, di-μ-azido azide bound end-on 103°. A latter type obtained, are contained inside cryptate cavity. actually Concerning binucleating ligands particularly able propagate electronic effects other, examples presented: derivatives dithioxamide which separated by more than 5.6 strongly interact through C2S2N2 network cryptate, occurs azido groups bridged end-to-end. In both cases mechanism specified.