Na2Ni(phenobarbiturato)4.3H2O, Na2Ni3(phenobarbiturato)2(OH)6.4H2O, and NaZn(phenobarbiturato)2(OH).H2O derivatives were prepared from Ni(II) and Zn(II) and phenobarbital. The Na2Ni(phenobarbiturato)4.3H2O complex is diamagnetic and isostructural with the complex previously reported, Na2Cu(phenobarbiturato)4, suggesting a square-planar environment around the Ni(II) ion. The DMF solutions of this complex show the existence of two species. The EPR spectra of the Cu(II) doped complex show the hyperfine and superhyperfine structures. The covalence parameters Alpha2, Beta2, and Delta2 show a strong bonding in the equatorial plane and suggests the formation of a [CuN4] chromophore. The anticonvulsant properties of the K2Cu(N-methylphenobarbiturato)4.8H2O are reported.