Field-induced slow magnetic relaxation in a hydrogen-bonding linked Co(II) 1D supramolecular coordination polymer

We have investigated the dynamic behaviour of the magnetization of a hydrogen-bonding linked Co(II) 1D supramolecular coordination polymer. In the structure, two different mononuclear Co(II) species are linked by O-H center dot center dot center dot N hydrogen bonding through coordinated H2O and [GRAPHICS] . Field-induced slow magnetic relaxation effect is observed and the anisotropy energy barrier is 33K. Ab initio calculations reveal that Co(II) ion in [Co(bpm)(2)(N-3)(2)] species is uniaxial anisotropic with a negative axial zero-field splitting parameter of D=-82.4cm(-1). The Co(II) ion in [Co(bpm)(2)(H2O)(2)](2+) species, however, is easy-plane anisotropic with a positive D and negative E value (D=46.3cm(-1), E=-7.8cm(-1)). This is an interesting complex in which slow magnetic relaxation stems from the combination contribution of uniaxial anisotropy and easy plane anisotropy.