Mono- and di-pyridine adducts of bis(3-substituted 2,4-pentanedionato)copper(II) complexes

Abstract

Adduct formation constants, K₁, for equilibria of the type, CuL₂+ py ⇌ CuL₂(py), where L =(MeCO·CR·COMe; R = Me, H, Cl, Ac, CO₂Et, CN, and NO₂) and py = pyridine, have been determined in benzene, acetone, and acetonitrile solution at 22 °C. The values of K₁ are correlated with the electronic nature of the substitutent, R, and the dielectric constant of the solvent. In two cases, R = CN and NO₂, further equilibria of type CuL₂py + py ⇌ CuL₂(py)₂ have been observed at high pyridine concentrations and diadduct formation constants, K₂ have been determined.