secondary ammonium ion piperidine piperidinium C5H12N chebi_ontology piperidinium cation Gmelin:239816 hexahydropyridinium 86.156 The conjugate acid of piperidine; major species at pH 7.3. piperidinium(1+) 86.09643 CHEBI:589779 piperidinium NQRYJNQNLNOLGT-UHFFFAOYSA-O InChI=1S/C5H11N/c1-2-4-6-5-3-1/h6H,1-5H2/p+1 MetaCyc:PIPERIDINE +1 C1CCCC[NH2+]1 piperidine