Azapentalenes. XLIV. ¹H and ¹³C‐NMR study of mesoionic pyrazolo[1,2‐a]pyrazoles

Article type: Research Article

Authors: Claramunt, Rosa María | Trofimenko, Sviatoslav | Rozas, Isabel | Elguero, José

Affiliations: Departamento de Química Orgánica y Biología, UNED, Senda del Rey, s/n, E‐28040 Madrid, Spain | Du Pont Central Research and Development, Experimental Station, P.O. Box 80302, Wilmington, DE 19880‐0302, USA | Instituto de Química Médica, CSIC, Juan de la Cierva 3, E‐28006 Madrid, Spain

Abstract: The 1H and 13C chemical shifts as well as the 1H–1H and 1H–13C coupling constants of sixteen pyrazolo[1,2‐a]pyrazole derivatives have been measured. The most relevant features are discussed using resonance forms and simple additive models. AM1 semi‐empirical calculations have been carried out to provide a rationale for the NMR results.

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Journal: Spectroscopy, vol. 13, no. 2, pp. 113-123, 1997