The syntheses of 3d–3d mixed heterometallic coordination polymers with magnetic properties

Novel 3d–3d heterometallic metal-organic frameworks, [M(ox)(bipy)] (1, M = Co and Zn; 2, M = Co and Cd; ox = oxalate, bipy = 4,4-bipyridine), have been synthesized by using two bidentate ligands under hydrothermal conditions. The Co(II) and Zn(II) ions in 1, and Co(II) and Cd(II) in 2 are location disordered, with a molar ratio of 0.72:0.28, and 0.96:0.04, respectively. The co-existence of the two metal ions in the structures makes them more thermally stable than previously reported homometallic polymers of Co(II) or Zn(II) ions. Compound 1 exhibits weaker antiferromagnetism than the pure Co(II) complex owing to the incorporation of Zn(II).