“…It has been shown that exchange interaction is affected by several structural parameters such as the identity of the bridging atoms (X), the Cu-Cu' distances, the bridging angles Cu-X-Cu' (α), the dihedral angles containing Cu ions and the coordination geometries around copper ions. 5,9,[45][46][47][48][49] For planar dihydroxo-bridged copper complexes, a simple, linear, correlation between the singlet-triplet separation 2J and the angle α was reported. [45][46][47] However, in the case of dihalo-bridged copper complexes, the wider variety of geometries available to such systems and the possibility for relatively low-lying halogens' d-orbitals to interact with copper orbitals make the overall picture more complicated.…”