Structure and EPR spectra of binuclear copper(II) complexes with acyldihydrazones of benzenedicarboxylic acids and trifluoroacetylacetone

Binuclear copper(II) complexes with acyldihydrazones of benzenedicarboxylic acid and trifluoroacetylacetone have been synthesized and studied. The structure of the copper(II) complex with diacylhydrazone of 1,3-benzenedicarboxylic acid (H 4 L) of composition [Cu 2 L · 2LPy] has been studied by X-ray diffraction. The crystals are triclinic: a = 9.2298(4) Å, b = 11.8510(6) Å, c = 13.8314(7) Å, α = 90.780(3)°, β = 96.124(3)°, γ = 99.264(3)°, space group , Z = 2. The number of symmetry-unrelated reflections with I > 2σ( I ) 5941; R = 0.0357, R w = 0.0589. The complex contains two equivalent copper atoms at a distance of 9.56 Å from each other in the square-planar coordination environment. The high-temperature EPR spectra of the complexes show a signal of seven HFS lines indicating the coupling of unpaired electrons to two equivalent copper nuclei ( g = 2.113−2.116, a Cu = 37.0−37.2 × 10 −4 cm −1 ).