Six heterometallic coordination polymers containing cobalt(II): Syntheses, crystal structures and magnetic properties

Abstract

Six new coordination polymers, [Co(NiL)(aipt)] (1), [Co2(ML)(hipt)2(CH3OH)(H2O)]·CH3OH (M=Cu (2), Ni (3)), [Co2(C2O4)2(CuL)2] (4), [Co4(NiL)4(ipt)4(H2O)2] (5) and [Co(CuL)(tpt)] (6) (H2L=2,3-dioxo-5,6,14,15-dibenzo-1,4,8,12-tetraazacyclo-pentadeca-7,13-dien; H2aipt=5-aminoisophthalic acid; H2hipt=5-hydroxyisophthalic acid; H2ipt=isophthalic acid; H2tpt=terephthalic acid), have been synthesized by a solvothermal method and characterized by single-crystal X-ray diffraction. Complexes 1, 4 and 5 exhibit different infinite chain structures formed by CoNi (1), Co2Cu2 (4), Co4Ni4 (5) units, respectively, via oxamide and diverse carboxylate bridges, while complexes 2, 3 and 6 exhibit different two-dimensional network structures formed by Co2M or Co2M2 units via oxamide and 5-hydroxyisophthalate or terephthalate bridges. The results of magnetic determination show weak antiferromagnetic interactions in 1–3 and 5–6, and the spin–orbit coupling interaction of Co(II) is a primary factor in the magnetic behaviors.