Effect of Substituents on the ESR Hyperfine Splittings in Copper Acetylacetonates

The ESR hyperfine splittings and g values for several substituted copper acetylacetonates have been measured in chloroform solution, and the values for copper acetylacetonate have been determined in various solvents. The hyperfine splittings are found to decrease with the substitution of more electronegative groups on the ligand and also decrease for a given ligand on going to a more basic solvent. The results have been discussed in terms of the electronic structures of the complexes.

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