the calculated equilibrium constant temperature dependences for compounds 1 and 2 in acetone-de. The assignment of the 16.2 ppm signal in compound 2 is further substantiated by the fact that the experimental data in Table 1 are in general agreement with the work of Bekarek, et al.,Vi who used 16N-H coupling constants to evaluate tautomer ratios for the parent phenylazo-2naphthol. Thermodynamic parameters derived from the equilibrium constant (Keq = [b]/[a]) temperature dependence data allow, for the first time, a quantitative comparison of the phenylazo-1-and -2-naphthol systems (see Table II).prepared from the corresponding substituted aniline by diazotiza-' tion and coupling with 2-and 1-naphthol, respectively. Spectroscopic Characterization.-A JEOL C-60-H nuclear magnetic resonance spectrometer equipped with a JES-VT-3 variable-temperature controller was employed for equilibrium constant determinations in acetone-d8; the solutions were ca. 10% (w/v). The nmr probe temperature control was calibrated, with an estimated accuracy of ±1°, using anhydrous methanol and ethylene glycol solutions. The probe temperature accuracy was periodically checked by using a 5-mm probe thermometer supplied by JEOL.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.