Why Does ACD/pK_a DB Sometimes Report the Dissociation of a Centre Twice?

Ed Kolovanov & Sanji Bhal

Abstract

For complex compounds with more than one centre of dissociation, ACD/pK_a DB occasionally reports the dissociation of one centre twice. Although these results can be confusing, they can be explained by studying the real dissociation pathways involved when a substance is dissolved in an aqueous medium. This note compares dissociation of a simple compound with a complex substance to explain this phenomenon.

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