A dicarboxylate with asymmetric coordination ability: Characterization of a two dimensional coordination polymer of copper(II) exhibiting spin canting

A copper(II) coordination polymer {[Cu2(cpa)2]}n (1) (cpaH2 = 4-carboxyphenoxyacetic acid) has been synthesized by hydrothermal technique. The X-ray structure of the compound shows that it is a 2D coordination polymer where Cu(II) ions are pentacoordinated in a square pyramidal fashion. The magnetic measurement of 1 in different magnetic fields suggest a weak ferromagnetic ordering taking place below 20 K, arising from spin canting phenomenon due to the non-coplanar basal planes of copper ions.