Azido and 2,2'-Bipyrimidine Ligands as Useful Tools in Designing Two- and Three-Dimensional Manganese(II) Networks

摘要

Magneto-structural studies on azido-bridged dinuclear copper(n) complexes have shown that the end-to-end and end-on azido bridging ligands are able to mediate large antiferromagnetic and ferromagnetic interactions, respectively. The concept of accidental orthogonalitv and the theon of spin polarization have been applied by Kahn et al. to account for these magnetic interactions. Calculations have revealed that the interaction between the in-plane π_g HOMOs of the azido ligand and the d_(xy) metal orbitals containing the unpaired electron favors either the singlet (end-to-end azido bridge) or the triplet (end-on azido bridge) as ground state. The extension of these magneto-structural studies to other complexes with transition metal ions such as nickeldil cation afforded azido-bndged dinuclear, square and cubane tetranudear. and one-and two-dimensional compounds.