Enhancing SIM behaviour in a mononuclear tetrahedral [Co(N,N′-2-iminopyrrolyl)2] complex.

A new homoleptic Co(II) complex bearing two highly sterically congested 2-formiminopyrrolyl N,N′-chelating ligands is reported, displaying slow relaxation of the magnetisation at zero static (DC) field. This compound shows a large value for the zero-field splitting (ZFS) parameter D of −42.6(4) cm⁻¹ leading to a spin-reversal energy barrier U_eff of 85 cm⁻¹. [ABSTRACT FROM AUTHOR]