Fred Stitt

Spectrophotometric studies of the 2:4-dinitrophenylhydrazones of n-alka-2-enals and n-alka-2:4-dienals

Abstract Wavelength maxima and molar absorption coefficients in the ultraviolet-visible region are reported for chloroform solutions and for alkaline ethanol solutions of the 2:4-dinitrophenylhydrazones of the n-alka-2-enals containing from three to eleven carbon atoms and of the n-alka-2:4-dienals containing from five to twelve carbon atoms. Infrared spectra from 2 to 15 μ are reported for these compounds dispersed in potassium bromide disks. Correlations of u.v. and i.r. spectral features with degree of conjugated unsaturation are discussed. Although the infrared spectra of the individual members of each homologous series are similar, those examined can be differentiated. Characteristic spectral differences between the stable and unstable polymorphic forms of the 2-enal derivatives are reported.