Theoretical calculation pKa values of phthalhydrazide derivatives in its aqueous solutions

The p K a values of some phthalhydrazide derivatives were calculated using ab initio and two density functional methods to obtain information about their reaction conditions. The results showed that p K a1 was influenced by structural modification as it varied between 0.47 and 6.99, and that p K a2 was relatively less variable from 16.66 to 21.53. The high values of p K a2 revealed that a strong alkaline solution was necessary for all chemiluminescent reactions of discussed phthalhydrazide derivatives.