Density functional and post-Hartree-Fock studies on effective exchange interaction ofd-?-d conjugated systems involvingm-phenylene-type bridge

Spin-polarization in 1,3,5-trihydroxybenzene-bridged first-row transition metal complexes

“…The above given examples indicate that the concept of spin polarization, which almost always works in organic chemistry to predict ferromagnetic interactions and to rationally develop new high-spin compounds, cannot be applied in a straight-forward manner to transition metal complexes. Several theoretical investigations were performed to get insight into the question why the concept of spinpolarization cannot be applied that simply to transition metal complexes [63,67,92,93]. Karafiloglou already showed for organic diradicals that not only the spin polarization, but also exchange and superexchange interactions contribute to the overall coupling [56].…”

“…Takano et al investigated dinuclear Cu II and Mn II complexes with a bridging pyrimidine ligand using DFT and post-HartreeeFock methods [92]. They concluded that superexchange interactions leading to antiferromagnetic interactions are more important in meta-phenylene-bridged transition metal complexes as compared to meta-phenylene-bridged organic carbenes and radicals.…”

A Neutral Fe4tBuL4 All Ferric Grid Complex: Structural and Variable Temperature Magnetic Properties

“…A broken‐symmetry calculation was performed on the high‐spin state ( S = 10) using the “flipspin” key word (two Fe sites, 0 and 171 from the coordinate file, were spin flipped). The energies of the S = 10 and broken symmetry singlet states were calculated, and the magnetic exchange coupling parameter was estimated using the method of Yamaguchi . The program Chemissian was used to prepare the spin density plot.…”

Hybrid density functional study of ligand coordination effects on the magnetic couplings and the dioxygen binding of the models of hemocyanin

“…The energy gap by UDFT calculations between the highest spin (HS) and lowest spin (LS) states was utilized to estimate J ab values. UDFT solutions in the LS states usually exhibit the BS problem 48–52. Spin projection of the BS solutions should be carried out to eliminate the spin contaminations in UDFT.…”

“…Spin projection of the BS solutions should be carried out to eliminate the spin contaminations in UDFT. In this study, since these models can be regarded as two spin site systems, the J ab values were calculated using the combination of UDFT with the Heisenberg model 51, 52 as where Y E X and Y 〈 S 2 〉 X denote the total energy and total angular momentum of the spin state Y by UDFT, respectively. The scheme of J ab has been formulated by using our AP procedure 51, 52.…”