Five one-dimensional bimetallic WVMnIII complexes 1-5, consisting of [W(CN)6(bpy)]- anions and [Mn(Schiff base)]+ cations, were prepared. The central coordination geometry around each W atom is determined as a distorted dodecahedron (DD) for 1 and 2, and a distorted square antiprism (SAPR) for 3-5. Magnetic analyses demonstrate that compounds 1, 4, and 5 exhibit antiferromagnetic interactions between magnetic centers, which are different from the ferromagnetic couplings in 2 and 3. For the distorted DD geometry, the Mn-Nax (ax = axial) bond length increases when moving from 1 to 2, with the Mn-Nax-Cax angle remaining constant. The elongation of the bond length is responsible for the reduction in orbital overlap and consequent ferromagnetic coupling in 2. In comparison, for 3-5 with the distorted SAPR geometry, given that the Mn-N ax bond lengths are similar across all the samples, the increase in the Mn-Nax-Cax angles accounts for the enhanced magnetic strength. Notably, a correlation between structure and magnetic exchange coupling is established for the first time in WVMnIII bimetallic systems based on the [W(CN)6(bpy)]- precursor.
ASJC Scopus subject areas
- Inorganic Chemistry
- Physical and Theoretical Chemistry