User 870ab5b546
06-03-2011 16:04:49
JChem 5.4.1 indicates the pKa of C(2) of ethyl propionate to be 21.0. This number is way too high; it should be around 25.
Even worse, it indicates the pKa of C(2) of ethyl 4-cyanobutyrate to be 17.7, and that of diethyl glutarate to be 18.4.
User 851ac690a0
06-03-2011 20:55:34
Hi,
I will have a couple of hour for correcting the pKa calculator with your proposal tomorrow ,even before the deadline of the release compilation.
Please continue your test. You may reveal more interesting problems with the "CH" acids in the extraordinary aqueous pKa domain.
Thank you indeed.
Jozsi
User 870ab5b546
07-03-2011 14:38:15
methyl crotonate, CH3CH=CHCO2Me, the terminal C is calculated as having a pKa of over 40, when in fact it is around 23.
User 851ac690a0
25-03-2011 09:16:35
Hi,
Ok. Thanks. I improved the pKa calculation of the "CH" acids with your "hint".
Jozsi
User 870ab5b546
06-04-2011 03:55:06
Here's another one. JChem correctly predicts a pKb of 10 for C4 of [O-][N+](=O)[CH-]C=C, but it incorrectly predicts a pKb of 39.6 for C6 of [O-][N+](=O)C=C[CH-], even though these two compounds are resonance structures of one another.
Actually, JChem should predict the same pKa values regardless of which resonance form the user submits. So C4 of [O-][N+](=O)C=C[CH-] should show the same pKb as C4 of [O-][N+](=O)[CH-]C=C.
User 851ac690a0
06-04-2011 21:09:40
Hi,
Thank you for testing of the pKa calculator.
I've fixed this bug. The new version will be available soon.
Jozsi