Role of the coordination of the azido bridge in the magnetic coupling of copper(II) binuclear complexes.
It is well-known that the azido bridge gives rise antiferromagnetic (AF) or ferromagnetic (F) coupling depending on its coordination mode, namely end-to-end or end-on, respectively. The aim of the present work is to analyse the factors contributing to this different magnetic behaviour. The difference dedicated configuration interaction (DDCI) method is applied to several binuclear Cu(II) azido-bridged models with both types of coordination. In end-on complexes, the direct exchange and the spin polarisation contributions are found to be responsible for the ferromagnetic coupling. In end-to-end complexes, both the direct exchange and the spin polarisation are small and the leading term is the antiferromagnetic dynamical polarisation contribution. The most relevant physical effects are included in the DDCI calculations so that good quantitative agreement is reached for the coupling constant as well as the spin densities.
Cabrero
Jesús
J
Departament de Química Física i Inorgànica and Institut d'Estudis Avançats, Universitat Rovira i Virgili Pl Imperial Tarraco, 1, 43005 Tarragona, Spain.
de Graaf
Coen
C
Bordas
Esther
E
Caballol
Rosa
R
Malrieu
Jean-Paul
JP