Magnetic Interactions in Dimeric Transition Metal Complexes:  Basic erythro-Chromium(III)

Abstract

First principles density functional theory is utilized to describe electronic structure and magnetic interactions between Cr(III) ions in linear and bent geometry of [cis-[hydroxotetramminechromium-μ-hydroxopentamminechromium]4+. The effective exchange parameter J is extracted and compared with empirical values fitted to experimental data. The calculated value J = 48 K for bent geometry compares well with the 30 K experimental value; the magnetic interaction is an order of magnitude larger in the linear configuration. Low-lying optical transitions are analyzed, making use of the transition state scheme, and are in semiquantitative agreement with experimental absorption.

Preparation and Structure of (Cu(pc))3(ReO4)2 and Theoretical Investigation of Cu(pc)(ReO4), Cu(pc)(ReO4)2, and (Cu(pc))3(ReO4)2

“…To display the extent of spin polarization over the entire molecule, we show in Figure a projection of spin density onto spherically symmetric functions about each center. To estimate the magnetic coupling energy between the Cu spins, we performed Magnetic Transition State (MTS) calculations on the molecule. , Here we report the simplest result, that of a spin-flip on the central Cu atom, for which the AF configuration is found to be more stable, with an energy difference of 0.11 eV. This may be taken as a first approximation to the energy difference between S = 3 / 2 and 1 / 2 states of the system.…”

Optical, Magnetic, and Electronic Properties of Peripherally Fused Macrocycles: Molybdocene Porphyrazines

“…These effects are all present in the complexes treated here; a detailed accounting of the effective magnetic coupling strengths and resulting Heisenberg-Hamiltonian parameters would best be treated in terms of a magnetic transition state analysis. 31 C. Partial Densities of States. Partial densities of states (PDOS) were calculated by weighting individual energy levels according to the Mulliken atomic orbital populations of the desired species.…”

“…The strength of the coupling has been qualitatively discussed in terms of distortions from planar symmetry and symmetry-breaking by ligand attachment. These effects are all present in the complexes treated here; a detailed accounting of the effective magnetic coupling strengths and resulting Heisenberg−Hamiltonian parameters would best be treated in terms of a magnetic transition state analysis …”