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

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(−) < N(3)(−) < F(−)). Furthermore, a linear relationship was found between the spin density of the bridging ligand and J(calc).