Electron spin resonance study of the formation of two dimeric species in bis(1-phenylbutane-1,3-dionato)- and bis(ethylacetoacetato)-copper(II)

From the e.s r. spectra of the title complexes in frozen toluene solutions, it has been found that both form two dimeric species. The spin-exchange interaction energies of the dimers have been determined by measuring the temperature variation of the spectral intensity of the ΔM= 2 transitions over the range 1.6–4.2 K. The drmeric structures have been examined by computer simulation of the dimer e.s.r. spectra and are discussed in relation to two well known types of molecular packing in crystals of planar metal complexes and to the polymorphism drsplayed by many metal complexes.