First μ3-oxalato-bridged cis and trans configurations nickel macrocyclic complex: Synthesis, structure and magnetic properties

A novel nickel macrocyclic complex {[Ni 2 (cyclam) 2 ( μ 3 -C 2 O 4 )]} n · (ClO 4 ) 2 · H 2 O has been synthesized and structural characterized by single-crystal X-ray diffraction. The complex forms a chain-like one-dimensional structure linked through a novel μ 3 -oxalato-bridging mode, which has never been reported for nickel. The complex adopts both trans -III configuration with the R , R , S , S arrangement of the four chiral nitrogen centers and cis -V conformation with the R , R , R , R nitrogen configuration. Variable-temperature magnetic susceptibility studies indicate the existence of weak antiferromagnetic ( zj = −1.07 cm −1 ) coupling.