Synthesis and magneto-structural correlation of a new maleato bridged copper(II) coordination polymer

A one-dimensional (1-D) copper(II) coordination polymer [Cu(maleate)(2,2′-bipyridyl)]n·2H2O has been synthesised. Single crystal X-ray diffraction study reveals that maleate ion bridges two adjacent copper(II) centres along the chain in a syn–anti fashion. A complete cryomagnetic investigation of the title complex correlates well with the distorted square pyramidal geometry of the central copper(II) ion and bridging nature of the maleate. A τ value of 0.26 indicates the distortion towards tbp coordination allowing the magnetic orbital to acquire some character leading to a weak antiferromagnetic interaction having J = −0.26 cm−1. The complex has also been firmly established from several other instrumental techniques like Fourier transform infrared (FT-IR) and EPR spectroscopies.