Synthesis, spectral and single crystal X-ray characterization of 5-(2-(2,3-dimethyl-5-oxo-1-phenyl-2,5-dihydro-1H-pyrazol-4-yl)hydrazono)pyrimidine-2,4,6(1H,3H,5H)-trione and its copper(II) complexes
Keywords: Barbituric acid; Azo-hydrazone tautomerism; Crystal structure; ESR spectrum;