| Abstract: | The ultraviolet absorption band of a complex between 9-ethyladenine and ∈-caprolactam has been observed at a wavelength longer than that of the absorption band for the 9-ethyladenine monomer. Absorbance values (at 277.5 mμ) of solutions that contained 9-ethyladenine and different concentrations of ∈-caprolactam in cyclohexane were determined at different temperatures. Linear plots were utilized to determine the apparent association constant (K′ ) of the 9-ethyladenine-caprolactam complex over the range of 25° to 60°. The K′ values for the complex of 4-aminopyrimidine and ∈-caprolactam were determined for the same temperature range from the absorbance of cyclohexane solutions at 282.5 mμ. The K' values of the two complexes are the same at 25°, but ∈-caprolactam is more strongly bonded to 9-ethyladenine than to 4-aminopyrimidine at elevated temperatures. The synthesis of 4-amino-1-ethylbenzimidazole hydro-chloride was performed. An attempt to detect a complex between ∈-caprolactam and 4-amino-1-ethylbenzimidazole in a cyclohexane solution was not successful. |
