Construction of a Novel 2D Polymer [Co(dmpzm)(dca)2]∞ from Reaction of a Mononuclear Complex [Co(dmpzm)Cl2] with Sodium Dicyanamide (dca) [dmpzm=bis(3,5-dimethylpyrazolyl)methane]

Reaction of CoCl2·6H2O with equimolar bis(3,5-dimethylpyrazolyl)methane (dmpzm) produced a mononuclear adduct [Co(dmpzm)Cl2] (1). Treatment of 1 with sodium dicyanamide (dca) afforded a polymeric complex [Co(dmpzm)(μ-dca)2]∞ (2). 1 and 2 were characterized by elemental analysis, IR spectra, thermogravimetric analysis and single-crystal X-ray diffraction. The cobalt atom in 1 adopts a distorted tetrahedral coordination geometry, bound to two N atoms of one dmpzm and two Cl atoms. Complex 2 has a 2D brick-wall network (extended along the bc plane) in which the {[Co(dmpzm)(μ-dca)]2}2n+n chains are interconnected by pairs of μ-dca anions along the c axis. The magnetic properties of 1 and 2 were also investigated.