A computational study of structural and magnetic properties of bi- and trinuclear Cu(II) complexes with extremely long Cu-Cu distances

作者：Baryshnikov Gleb V^*; Minaev Boris F; Baryshnikova Alina T; Agren Hans

来源：Chemical Physics, 2017, 491: 48-55.

DOI：10.1016/j.chemphys.2017.04.014

• Cu(II) complexes
• Spin-spin exchange
• Ferromagnetic coupling
• " broken symmetry" approximation
• DFT calculations
• Bader analysis
• Open-shell singlet

Three recently synthesized copper(II) complexes with aroylhydrazones of trifluoroacetic and benzenecarboxylic acids (Dalton Trans., 2013, 42, 16878) have been computationally investigated by density functional theory within the broken symmetry approximation accounting for empirical dispersion corrections. A topological analysis of electron density distributions has been carried out using Bader's "quantum theory of atoms in molecules" formalism. The calculated values of spin-spin exchange for the studied dinuclear complexes indicate a very weak ferromagnetic coupling of the unpaired electrons in good agreement with experimental data. At the same time, the trinuclear copper(II) complex possesses a low-spin doublet ground state with one ferromagnetic and two antiferromagnetic spin projections between the triangular-positioned Cu2+ ions. The estimated values of the coupling constants for the spin-spin exchange in this trinuclear complex are in a good agreement with experimental observations. The calculations support a mechanism of exchange coupling through the aromatic links in these strongly spin-separated systems.

• 出版日期2017-7-10