Aqueous Basicity and Proton Affinity of Zwitterionc omega-(N-Methylpiperidine)-alkanocarboxylates and omega-(N-Piperidine)-alkanocarboxylic Acids

P Barczynski, Z Dega-Szafran, E Dulewicz…

Index: Barczynski; Dega-Szafran; Dulewicz; Petryna; Szafran Polish Journal of Chemistry, 2000 , vol. 74, # 8 p. 1149 - 1161

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Citation Number: 29

Abstract

The pKa values of 5 w-(N-methylpiperidine)-alkanocarboxylates (N-methylpiperidine betaines) and 5 w-(N-piperidine)-alkanocarboxylic acid were determined by potentiometric titration of their hydrohalides with KOH. Semiempirical geometry optimizations were performed for gaseous betaines. Four conformers were characterized and their PA values estimated. The PA values fulfilled the linear correlation with the aqueous pKa values ...