Ionization Ac curves

Figure 4. Ionization Ac curves. Solvents ethanol and O.IN in ethanol-water> 1 1.

After the reaction product at the Rf value of 0.40 was eluted with water from the chromatogram, its spectrum in neutral solvent and its ionization Ac curve were recorded. The neutral spectrum and the ionization Ac curve of bis-4-hydroxy-3,5-dimethoxyphenylmethane in 47.5% ethanol were also recorded the wavelengths of the ultraviolet absorption maxima of the two compounds—eluted product and reference compound—are given in Table II. The spectra of the compounds possess maxima at nearly identical wavelengths. Thus, paper chromatography and ultraviolet spectroscopy indicate positively that bis-4-hydroxy-3,5-dimethoxyphenylmethane is a product of the reaction of syringyl alcohol with alkali in aqueous solution. 

Bis-4-hydroxy-3y5-dimethoxyphenylmethane Neutral Solvent Ionization Ac Curve, ... 

Table V also shows that the spectra of the unknowns in neutral solvent possess peaks in the 273 m/z region, similar to the location of the peaks of the spectra representing the syringyl nucleus (Table II). The presence of the syringyl nucleus is also suggested by the maxima at 225, 256, and 292 m/z for the ionization Ac curves as shown in the same tables.

The maxima of the spectra of the eluted reference compound, diguaiacylmethane, and of the reaction product are located at almost identical wavelengths for both the neutral solvent and ionization Ac curve, as shown in Table VII. Furthermore, in both cases, the locations of the maxima of the ionization Ac curves agree well with the locations of the maxima of the ionization Ac curve of an ethanolic diguaiacylmethane solution (Table VII). Thus, paper chromatography and spectral analyses indicate that diguaiacylmethane is a product of the reaction of vanillyl alcohol with sodium hydroxide under aqueous reaction conditions. 

The ionization —Ac (Aa) curve for stilbene III (O.liVNaOH) showed a maximum at 378 m/z, Ac = 24300 (Figure 4). In alkaline solution the stilbene was extremely sensitive to light, and the UV absorption was therefore recorded within 1 minute after NaOH was added. The cause of the photochemical reaction, which also occurs in the absence of air, has not been elucidated. 

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