User f52820d97e
27-02-2009 14:45:03
Hi,
I tried to calculate the pKa of the Wittig reagent, but only one form gives me the pKa of the reactive Carbon, the phosphorane form, whereas the ylide form (frequently used by chemists to draw the reaction) does not... and the other pKas change (even if not relevant). Furthermore, the ylide form is the first resonance form the plugin gives me!
Cheers,
Nicolas
User f52820d97e
06-03-2009 08:28:30
Hi,
I'm surprised at your non-response... Maybe I wasn't clear in my explanations?
No worry though, there is no urgency, I came across this problem but it's not life-threatening ;-)
Cheers,
Nicolas
User 851ac690a0
06-03-2009 08:53:52
Hi,
I'm sorry not inform you about the fixing of this bug.
I'm working on the solution on this problem. The pKa calculation will be availabe for this resonance structure in the next patch release.
Jozsi
User 25d107bd42
06-03-2009 10:21:03
Hi, I have some more questions here.
Does I see it right? The "pKa" values above are in reality the pKa of the conjugate acid ?
1) So I tried to calculate the pKa for this conjugate acid, see screenshot. But here is also no value for the alfa atom of the ethyl group. Why?
2) And the values for the three phenyl groups are different, even for the equivalent ortho- and meta-positions.
What are the options for the calculations above? I my case these are: macro / dynamic, min -30 / max 40, 298 K.
Regards, Hans-Ulrich
User f52820d97e
06-03-2009 11:07:23
Oh great, I'm glad I made a point. Thank you for the answer.
Hans-Ulrich, I think your follow-up question is a corollary...
User 25d107bd42
06-03-2009 11:45:29
"... a corollary... "
Does this also concern the second question about the phenylgroup results ?
User f52820d97e
06-03-2009 12:02:00
you're right, not the 2nd...
User f52820d97e
17-03-2009 16:00:56
Hi Jozsi,
I tried it with 5.2.0, it still makes the same mistake, and it takes the wrong tautomer: the C- is protonated instead of makeing a double bond between C and P...
Nicolas