Solvent effects on infrared spectra of 2-Methyl-4,5-dimethoxy-3-oxo-2H-pyridizine: Part 2. Binary solvent systems

This research on the solvent effects of 2-methyl-4,5-dimethoxy-3-oxo-2H-pyridizine (MDOP) in binary solvent systems on the infrared spectra for MDOP in n-hexane/CHCl₃ mixture solvents showed that there were three forms of carbonyl stretching vibration band ν(C=O)] of MPOP as the mole fraction of CHCl₃ in the binary solvents changes. In pure n-hexane solvent, the ν(C=O) of MDOP appeared at a relatively high wavenumber. With CHCl₃ added, the ν(C=O) shifted to lower wavenumbers. Two new bands were observed over a certain range of mixture solvent compositions. The origin of the bands was discussed in the terms of two kinds of hydrogen bond together with their individual dependence on mixture composition. Comparisons were drawn for the solvent sensitivities of ν(C=O) for propanone. Project supported by the Analysis and Measurement Foundation of Zhejiang Province, China.