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 language||English (US)|
|Number of pages||7|
|Journal||Journal of the Chemical Society, Dalton Transactions|
|State||Published - Jan 1 1983|
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