From owner-chemistry # - at - # ccl.net Fri Mar 30 02:35:00 2012 From: "Kenneth Ruud kenneth.ruud a uit.no" To: CCL Subject: CCL: calcualtion of kinetic isotopic effect values Message-Id: <-46597-120329164851-1453-HEJAzWVahPRiXnzZwJJNdg{}server.ccl.net> X-Original-From: Kenneth Ruud Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=WINDOWS-1252; format=flowed; delsp=yes Date: Thu, 29 Mar 2012 22:48:41 +0200 Mime-Version: 1.0 (Apple Message framework v936) Sent to CCL by: Kenneth Ruud [kenneth.ruud^^^uit.no] Hi! Any program that can calculate vibrationally averaged molecular properties ought to be able to calculate vibrationally averaged geometries, thus the difference in geometry for X-D and X-H. Thus, I would expect CFOUR to be able to do this, as well as Dalton. In Dalton, this would correspond to what had been denoted the "effective" geometry, see e.g. J.Chem.Phys. 112, 2655 (2000). Best regards, Kenneth Kenneth Ruud Director, CTCC President, Norwegian Chemical Society Telephone: +47 77623101 http://www.ctcc.no/people/ruud On Mar 29, 2012, at 7:17 PM, Sebastian Kozuch kozuchs,,yahoo.com wrote: > Although the X-D and X-H bond distances are very slightly different, > I don't know any program that can calculate that difference. The > optimizations are done in the Born-Oppenheimer approximation and the > mass of the nuclei are not taken into account, only their charge. As > far as I know (and as far as all QM software know) deuterium and > protium have the same charge, so no reoptimization is necessary. > Anyway, the error of the theoretical method is way bigger than the > difference in the real bond lengths. > > Maybe this is a good opportunity to recommend an essay by Simmons > and Hartwig that just appeared in ACIE regarding the analysis of the > KIE for inter and intramolecular competition, an issue that has been > overlooked an has been the root of more than one error: > Angewandte Chemie International Edition 2012, 51, 3066–3072. > Best, > Sebastian. > > > > ________________________________ > From: Jaccob Madhavan chemjaccob(~)yahoo.co.in ~ccl.net> > To: "Kozuch, Sebastian " > Sent: Thursday, March 29, 2012 5:26 PM > Subject: CCL: calcualtion of kinetic isotopic effect values > > > Sent to CCL by: "Jaccob Madhavan" [chemjaccob _ yahoo.co.in] > Dear Friends, > > Greetings! For the calculation of kinetic isotopic effect(KIE) > values, optimization with deutrium is needed or only frequency > calcualtion is enough. Any help in this regard will be highily > appreciated. > > with best regards > Jaccob > > > > -= This is automatically added to each message by the mailing script > =- > To recover the email address of the author of the message, please > change > the strange characters on the top line to the ~!~ sign. You can also> > E-mail to subscribers: CHEMISTRY~!~ccl.net or use:> > > Conferences: http://server.ccl.net/chemistry/announcements/ > conferences/> > --630850330-1120368410-1333041429=455 > Content-Type: text/html; charset=f-8 > Content-Transfer-Encoding: quoted-printable > >
Although the X-D and X-H span>bond distances are very slightly different, I don't know > any program that can calculate that difference. The optimizations > are done in the Born-Oppenheimer approximation and the mass of the > nuclei are not taken into account, only their charge. As far as I > know (and as far as all QM software know) deuterium and protium have > the same charge, so no reoptimization is necessary. Anyway, the > error of the theoretical method is way bigger than the difference in > the real bond lengths.

 div>
Maybe this is a good opportunity to recommend an > essay by Simmons and Hartwig that just appeared in ACIE regarding > the analysis of the KIE for inter and intramolecular competition, an > issue that has been overlooked an has been the root of more than one > error:
Angewandte Chemie International > Edition 2012, 51, 3066–3072.
style="clear: left; "> >
> title="url_ver=Z39.88-2004&ctx_ver=Z39.88-2004&rfr_id=info > %3Asid%2Fzotero.org%3A2&rft_id=info%3Adoi%2F10.1002%2Fanie. > 201107334&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx > %3Ajournal&rft.genre=article&rft.atitle=On%20the > %20Interpretation%20of%20Deuterium%20Kinetic%20Isotope%20Effects%20in > %20C%EF%A3%BFH%20Bond%20Functionalizations%20by%20Transition > %E2%80%90Metal%20Complexes&rft.jtitle=Angewandte%20Chemie > %20International > %20Edition&rft.volume=51&rft.issue=13&rft.aufirst=Eric > %20M&rft.aulast=Simmons&rft.au=Eric%20M > %20Simmons&rft.au=John%20F > %20Hartwig > & > ;rft > .date > = > 2012 > -03 > -26 > & > ;rft > .pages > = > 3066 > -3072&rft.spage=3066&rft.epage=3072&rft.issn=1521-3773"> >

div>Best,
Sebastian.

dir="ltr">
style="font-weight:bold;">From: Jaccob Madhavan > chemjaccob(~)yahoo.co.in <owner-chemistry~!~ccl.net>
> To: "Kozuch, > Sebastian " <kozuchs~!~yahoo.com>
Sent: Thursday, March 29, 2012 5:26 PM
> Subject: CCL: > calcualtion of kinetic isotopic effect values

>
Sent to CCL by: "Jaccob  Madhavan" [chemjaccob _ > yahoo.co.in]
Dear Friends,

Greetings! For the calculation > of kinetic isotopic effect(KIE) values, optimization with deutrium > is needed or only frequency calcualtion is enough. Any help in this > regard will be highily appreciated.

with best > regards
Jaccob



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