The chemistry of vitamin B12. Part 20. Diaquocobinamide: pK values and evidence for conformational isomers

David A. Baldwin, Eric A. Betterton, John M. Pratt

Research output: Contribution to journalArticle

33 Scopus citations

Abstract

An improved method for preparing aqueous solutions of diaquocobinamide without hydrolysis products is described. The pKa values have been determined in 0.2 mol dm-3 NaClO4 at 25 °C as pK1 = 5.9 ± 0.1 and pK2 = 10.3 ± 0.2 and are shown to involve one proton each. Evidence is presented that diaquo-, aquohydroxo-, and dihydroxo-cobinamide exist in solution as isomers depending on hydrogen bonding between the axial ligands and different amide side-chains.

Original languageEnglish (US)
Pages (from-to)217-223
Number of pages7
JournalJournal of the Chemical Society, Dalton Transactions
Issue number2
DOIs
StatePublished - Jan 1 1983
Externally publishedYes

ASJC Scopus subject areas

  • Chemistry(all)

Fingerprint Dive into the research topics of 'The chemistry of vitamin B<sub>12</sub>. Part 20. Diaquocobinamide: pK values and evidence for conformational isomers'. Together they form a unique fingerprint.

  • Cite this