Abstract
Vacuum ultraviolet absorption spectra of six simple amides were measured. It was found that the positions of the firstπ→π * transition bands shift appreciably by the substitutions of methyl groups for hydrogen atoms of the NH2 and\(\begin{gathered} | \hfill \\ H - C = O \hfill \\ \end{gathered} \) groups. A general tendency is that the substitution in the NH2 group shifts the band toward longer wavelengths, in the\(\begin{gathered} | \hfill \\ H - C = O \hfill \\ \end{gathered} \) group however towards shorter wavelengths. This was explained satisfactorily by considering the nature of the band (intramolecular charge-transfer band) and the hyperconjugation effect of the methyl group.
Zusammenfassung
Vakuum-UV-Absorptions-Spektren von sechs einfachen Amiden wurden vermessen. Substitution von H durch Methyl am C-Atom des Formamids verschiebt den erstenπ→π *-Übergang zu kürzeren, am N-Atom zu längeren Wellenlängen. Dies kann durch die Natur der Bande (intramolekularer ‘charge transfer’) sowie durch Methylhyperkonjugation erklärt werden.
Résumé
Les spectres d'apsorption U.V. dans le vide ont été mesurés pour 6 amides simples. Le remplacement de H par CH3 sur l'atome de carbone de la formamide provoque un effet hypsochrome de la première transitionπ→π *; l'effet est batochrome pour la même substitution sur l'atome d'azote. Ceci peut être expliqué par la nature de la bande (transfert de charge intramoléculaire) et par l'hyperconjugaison du méthyle.
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References
Berger, A., A. Loewenstein, andS. Meiboom: J. Amer. chem. Soc.81, 62 (1959).
Sunners, R., L. H. Piette, andW. G. Shneider: Canad. J. Chem.38, 681 (1960).
Saika, A.: J. Amer. chem. Soc.82, 3540 (1960).
Brown, A. J. R., andE. W. Randall: J. molecular Spectroscopy13, 29 (1964).
Mizushima, S., T. Shimanouchi, S. Nagakura, K. Kuratani, M. Tsuboi, H. Baba, andO. Fujioka: J. Amer. chem. Soc.72, 3490 (1950).
Tsuboi, M.: Bull. chem. Soc. Japan22, 215, 255 (1949);24, 75 (1950).
Hunt, H. D., andW. T. Simpson: J. Amer. chem. Soc.75, 4540 (1953).
Peterson, D. L., andW. T. Simpson: J. Amer. chem. Soc.79, 2375 (1957).
Nagakura, S.: Molecular Physics3, 105 (1960).
Tsubomura, H., K. Kimura, K. Kaya, J. Tanaka, andS. Nagakura: Bull. chem. Soc. Japan37, 418 (1964).
Kon, H.: Bull. chem. Soc. Japan28, 275 (1955).
Walsh, A. D.: Trans. Faraday Soc.42, 66 (1946).
Watanabe, K., andT. Nakayama: J. Quant. Spectr. Radiant. Transfer2, 369 (1964).
Pariser, R., andR. G. Parr: J. chem. Physics22, 466, 767 (1953).
Kimura, M., andM. Aoki: Bull. chem. Soc. Japan26, 429 (1953).
Senti, F., andD. Harker: J. Amer. chem. Soc.62, 2008 (1940).
Pople, J. A.: Trans. Faraday Soc.49, 1375 (1953).
—: Proc. physic. Soc. LondonA68, 81 (1955).
Longuet-Higgins, H. C., andJ. N. Murrell: Proc. physic. Soc. LondonA68, 601 (1955).
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Kaya, K., Nagakura, S. Vacuum ultraviolet absorption spectra of simple amides. Theoret. Chim. Acta 7, 117–123 (1967). https://doi.org/10.1007/BF01151913
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DOI: https://doi.org/10.1007/BF01151913