Nachweis innermolekularer beweglichkeit durch NMR-spektroskopie XVI. Lösungsmitteleinflüsse auf die stickstoffinversion in guanidinen-rotationen um CN-einfach- und CN-doppelbindungen in guanidiniumsalzen

The inversion rate of double bounded nitrogen in guanidines is influenced by protic solvents. A dependence on the polarity of the solvent has not been observed. The protonation of the guanidines occurs on the imino nitrogen forming salts in which there are up to four rotation barriers. The ΔG^† and log k values of intermolecular rotation perform a linear Hammett-correlation in N″-aryl-guanidinium salts as well as in guanidines. The steric effect on the rotations has been studed in o,o′-disubstitued N″-aryl-guanidinium salts.