A series of eight novel complexes of chloranilic acid (CA) with the first-row transition metals (M = Mn, Cr, Ni, Co) were prepared and characterised by single-crystal X-ray diffraction, IR spectroscopy and polycrystalline X-band electron spin resonance (ESR) spectroscopy.

The studied heterometallic [CuFe] compounds, based on an [Fe(C₂O₄)₃]³⁻ building block and containing a 3D network or 1D ladder-like chains, were synthesized depending on whether the test tube with the same reaction layers was exposed to daylight or not.

A series of complexes with [{M(phen) ₂ } ₂ (μ-C ₂ O ₄ )] ²⁺ cations (M = Mn, Co, Ni, Cu, and Zn) and bis(oxalate)chromium( iii ) anions is synthesised. Magnetic exchange interactions mediated through oxalate bridge in the homodinuclear cations have been discussed.