Coordination compounds derived from R-phenylcyanamido ligands and cobalt (II)

Abstract

Five compounds have been synthesized in this work: [Co4(μ3-py2C(OH)O)4(4-Br-3-CF3-PhNCN)2 (PhCOO)2] (1), [Co4(μ2-py2C(OH)O)2(μ3-py2C(OCH3)O)2(μ2-4-Cl-PhNCN)2(4-Cl-PhNCN)2] (2), [Co(py2C(OH)O)(py2C(OCH2CH3)O)][NO3]·3H2O (3), [Zn2Tb(μ2-py2C(OCH2CH3)O)3(μ3-py2C(OCH2CH3)O) (NO3) (H2O)][Tb(NO3)5] (4) and [Dy5Co4(py2C(OH)O)4(μ3-py2CO2)4(μ4-py2CO2)2(O)2(H2O)6(NO3)2][NO3]5 (5). The metal ions of the five compounds are connected through oxo-bridges from the Di(2-pyridil) ketone derivatives formed after solvolysis and a posterior deprotonation. In addition the Co(II) atoms of compound 2 are connected by two R-phenylcyanamides in the end-on coordination mode. The magnetic susceptibility measurements were performed for compounds 1, 2, 4 and 5. Compound 1 and 2 exhibit a ferromagnetic coupling between the Co(II) metal ions. Compound 4 shows paramagnetic behaviour and 5 exhibit weak antiferromagnetic coupling between the Dy(II) ions. Compounds 1, 2 and 5 show SMM (Single Molecular Magnet) behaviour. The relaxation time of magnetization hasn’t been calculated.