Magneto-structural maps and bridged-ligand effect for dichloro-bridged dinuclear copper(ii) complexes: a theoretical perspective.

Abstract

Theoretical understanding of magneto-structural correlations in dichloro-bridged dicopper(ii) complexes can guide the design of magnetic materials having broad-scale applications. However, previous reports suggest these correlations are complicated and unclear. To clarify possible correlations, magnetic coupling constants (J calc) of variants of a representative {Cu-(μ-Cl)2-Cu} complex A were calculated through BS-DFT. The variation of the Cu-(μ-Cl)-Cu angle (α), Cu⋯Cu distance (R 0), and Cu-Cl-Cu-Cl dihedral angle (τ) followed by structural optimization and calculation of the magnetic coupling constant (J calc) revealed several trends. J calc increased linearly with R 0 and τ, and initially increased and then decreased with α. Further, bridging ligand effects on J calc for dicopper(ii) complexes were evaluated through BS-DFT; the results revealed that J calc increased with increasing ligand field strength (I- < Br- < Cl- < N3 - < F-). Furthermore, a linear relationship was found between the spin density of the bridging ligand and J calc.