Darstellung von organischen Dikationen durch Protonierung von Iminiumsalzen. - NMR-spektroskopische Bestimmung der Topomerisierungsbarrieren im Bis(dimethylamino)-dimethylammonio-carbeniumion

Autor: Michael Hauber, Jean Sommer, Erwin Haug, Willi Kantlehner, Beate Schlagenhauf, Roland Jost
Rok vydání: 1993
Předmět:
Zdroj: Journal f�r Praktische Chemie/Chemiker-Zeitung. 335:55-60
ISSN: 1521-3897
0941-1216
DOI: 10.1002/prac.19933350109
Popis: Preparation of Organic Dications by Protonation of Iminium-Salts. – NMR-Spectroscopic Evaluation of the Topomerisation Barriers in the Bis(dimethylamino)-dimethylammonio-carbeniumion 1,3-Bis(dimethylamino)-2-aza-2-propenylium-chloride (4a) is protonated by inorganic acids as HCl, HBr, HI, H2SO4, HBF4 and HClO4 to give the corresponding 1,3-bis(dimethylamino)-2-azapropan-1,3-diylium-salts (7a–f) which are isolated and characterized by elemental analysis and their 1H-NMR-spectra. N, N, N′, N′, N″, N″-Hexamethylguanidinium-chloride (5a) can be protonated only by super acid systems e.g. HFSO3/SbF5. The dication thus formed presents 3 topomerisation barriers. Two of them are explained as restricted rotations, whereas the third is assumed to be a frozen torsional vibration.
Databáze: OpenAIRE
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