A Spin‐Admixed Ruthenium Complex

Abstract

The unusual magnetic behavior of [Ru2(μ‐O2CMe)(μ‐DPhF)3(H2O)]BF4⋅0.5 CH2Cl2 (1; DPhF=N,N′‐diphenylformamidinate), which is intermediate between that of compounds with spin states S=1/2 and S=3/2, is attributed to a quantum mechanical spin admixture. This phenomenon results from a multiple bond between the metal atoms which permits an appropriate disposition of molecular orbitals.

The First Open‐Paddlewheel Structures in Diruthenium Chemistry: Examples of Intermediate Magnetic Behaviour between Low and High Spin in Ru25+ Species

“…[3,4] Surely, the use of carboxylic acids with more acidic character than acetic acid would promote the replacement of the acetate group by other carboxylate ligands. Thus, the strongly acidic character of aqueous HCl is sufficient, even at low concentrations, to drive the substitution of the carboxylate by a chloride ligand to form [Ru 2 [7] with aqueous HBr and HI, respectively.…”

“…These values correspond to an intermediate situation between one and three unpaired electrons, which confirms the complexity of the magnetic behaviour in Ru 2 5 + compounds with formamidinate ligands. [3,4,[6][7][8][9] The plot of m eff versus temperature of complexes 1-4 and 6 is depicted in the Figure 2. The corresponding curves of the compounds [4] (1), Br (2), I (3)), the room-temperature magnetic moments increase from Cl to I, but in all cases they are intermediate between one and three unpaired electrons in all temperature ranges.…”

“…As a consequence, it is possible to find different magnetic behaviour, low and high spin, and even intermediate situations which must be associated with changes in the electronic spectra of the compounds. Complexes with the framework [Ru 2 A C H T U N G T R E N N U N G (DPhF) 3 ] 2 + present a rich variety of magnetic properties depending on the axial or equatorial ligands, [3,4,6,7] the counterion in the ionic species, [8] or even the solvent of crystallisation. [8] An analysis of the electronic transitions of this type of complex in the visible-near-infrared region allows us to perceive a relationship between the electronic spectra and their magnetic behaviour.…”

Pressure-driven high-to-low spin transition in the bimetallic quantum magnet[Ru2(O2CMe)4]3O’Neal1, Liu2, Miller3 et al. 2014Phys. Rev. B15030View full textAdd to dashboardCite

“…On the other hand, the mixed-valence Ru 2 (II/III) complex can undergo a high → low spin transition or exhibit intermediate admixed spin behavior [50][51][52][53][54][55] . This is because the presence of spin-orbit coupling causes the π ⋆ and δ ⋆ orbital energies to be quite close [50][51][52][53][54][55] , a situation that amplifies the effect of small perturbations.…”

“…This is because the presence of spin-orbit coupling causes the π ⋆ and δ ⋆ orbital energies to be quite close [50][51][52][53][54][55] , a situation that amplifies the effect of small perturbations. Consequently, spin-admixed ruthenium compounds occur 52 . Here, we recall that the valence configuration for the 11 electrons in the S = 3/2 state of the Ru dimer is generally accepted to be σ 2 π 4 δ 2 π * 2 δ * 150 .…”