From owner-chemistry@ccl.net Mon Aug 6 09:55:01 2007 From: "Dr. Robert C. Mawhinney dr.robert.mawhinney+/-gmail.com" To: CCL Subject: CCL: Quantifying/estimating donor/acceptor strength Message-Id: <-34883-070805192149-19800-SBxvc/JAXOs2+LjD45Y4zQ-x-server.ccl.net> X-Original-From: "Dr. Robert C. Mawhinney" Content-Type: multipart/alternative; boundary="----=_Part_56618_20493087.1186352634316" Date: Sun, 5 Aug 2007 18:23:54 -0400 MIME-Version: 1.0 Sent to CCL by: "Dr. Robert C. Mawhinney" [dr.robert.mawhinney]![gmail.com] ------=_Part_56618_20493087.1186352634316 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline Hi Gustavo, Check out a paper by RJ Boyd and coworkers (don't have the exact reference at the moment). They published two papers demonstrating how one can Use Bader's Atoms-in-Molecules to assess group electronegativities. Good luck. Rob On 8/3/07, Gustavo L.C. Moura gustavo]~[mercury.chem.pitt.edu < owner-chemistry===ccl.net> wrote: > > > Sent to CCL by: "Gustavo L.C. Moura" [gustavo!^!mercury.chem.pitt.edu] > Dear CCL readers, > I am looking for ways of computationally quantifying/estimating the > donor/acceptor strength of groups connected to larger molecules. I want to > correlate some spectral properties of these molecules with the > donor/acceptor strength of these groups. > If the groups I am interested were only substituted benzenes, I > could > rely on the Hammett sigma values. Because I am also interested in > connecting > heterocyclic groups to my molecules, I need to find a computational way of > quantifying/estimating the donor/acceptor strength of these groups. I am > aware > of a property called absolute electronegativity (one half of the sum of > the > ionization potential with the electroaffinity of the group), but this > property > is unable to differentiate between the different positions of the group > (meta > or para substitution, for example). > Does anyone in the list have any suggestion or paper that could > help me > with my problem? > Sincerely yours, > Gustavo L.C. Moura > Gustavo at mercury.chem.pitt.edu> > > > ------=_Part_56618_20493087.1186352634316 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline Hi Gustavo,

Check out a paper by RJ Boyd and coworkers (don't have the exact reference at the moment).  They published two papers demonstrating how one can Use Bader's Atoms-in-Molecules to assess group electronegativities.  Good luck.

Rob

On 8/3/07, Gustavo L.C. Moura gustavo]~[mercury.chem.pitt.edu < owner-chemistry===ccl.net> wrote:

Sent to CCL by: "Gustavo L.C. Moura" [gustavo!^!mercury.chem.pitt.edu]
Dear CCL readers,
       I am looking for ways of computationally quantifying/estimating the
donor/acceptor strength of groups connected to larger molecules. I want to
correlate some spectral properties of these molecules with the
donor/acceptor strength of these groups.
       If the groups I am interested were only substituted benzenes, I could
rely on the Hammett sigma values. Because I am also interested in connecting
heterocyclic groups to my molecules, I need to find a computational way of
quantifying/estimating the donor/acceptor strength of these groups. I am aware
of a property called absolute electronegativity (one half of the sum of the
ionization potential with the electroaffinity of the group), but this property
is unable to differentiate between the different positions of the group (meta
or para substitution, for example).
       Does anyone in the list have any suggestion or paper that could help me
with my problem?
       Sincerely yours,
                Gustavo L.C. Moura
           Gustavo at mercury.chem.pitt.edu



E-mail to subscribers: CHEMISTRY===ccl.net or use:
      http://www.ccl.net/cgi-bin/ccl/send_ccl_message

E-mail to administrators: CHEMISTRY-REQUEST===ccl.net or use
      http://www.ccl.net/cgi-bin/ccl/send_ccl_message

Subscribe/Unsubscribe:
      

Before posting, check wait time at: http://www.ccl.net

Job: http://www.ccl.net/jobs
Conferences: http://server.ccl.net/chemistry/announcements/conferences/

Search Messages: http://www.ccl.net/htdig   (login: ccl, Password: search)
      http://www.ccl.net/spammers.txt

RTFI: http://www.ccl.net/chemistry/aboutccl/instructions/




------=_Part_56618_20493087.1186352634316-- From owner-chemistry@ccl.net Mon Aug 6 14:04:01 2007 From: "Wai-To Chan chan###curl.gkcl.yorku.ca" To: CCL Subject: CCL: Quantifying/estimating donor/acceptor strength Message-Id: <-34884-070806133823-3523-v6lGafrV6RatJ+nivftnTA**server.ccl.net> X-Original-From: Wai-To Chan Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii Date: Mon, 6 Aug 2007 13:00:11 -0400 (EDT) MIME-Version: 1.0 Sent to CCL by: Wai-To Chan [chan]|[curl.gkcl.yorku.ca] This paper reports a study of the correlation between non-linear optical properties and donor-acceptor strenth. Not sure if it is of relevance. J phys chem A vol 101 pg 9773-9777 (1997) Sastre et al. "Push-Pull Phthalocyanines: A Hammett Correlation between the Cubic Hyperpolarizability and the Donor-Acceptor Character of the Substituents" Wai-To Chan From owner-chemistry@ccl.net Mon Aug 6 20:46:00 2007 From: "Andrew D. Fant fant]![pobox.com" To: CCL Subject: CCL: Intel quad core processors Message-Id: <-34885-070806201912-20208-DTtrD+KcA25SOtUczIMz/w^_^server.ccl.net> X-Original-From: "Andrew D. Fant" Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-8859-1 Date: Mon, 06 Aug 2007 19:13:31 -0400 MIME-Version: 1.0 Sent to CCL by: "Andrew D. Fant" [fant]^[pobox.com] John McKelvey jmmckel**gmail.com wrote: > Hello, > > Has anyone tried Intel quad core processors? Opinions? > > Thanks! > Hey John, We're going to be getting one in my wife's new Mac any day now. I'll be doing mostly MD on it, under both OS X and Linux, and I'll let you know how it does. Andy From owner-chemistry@ccl.net Mon Aug 6 23:04:01 2007 From: "Yousef Sharifi ysharifi##gmail.com" To: CCL Subject: CCL: Intel quad core processors Message-Id: <-34886-070806214720-29330-vcTZEDKhWLqd55fr9YW1UQ:-:server.ccl.net> X-Original-From: "Yousef Sharifi" Content-Type: multipart/alternative; boundary="----=_Part_51857_19814448.1186450842824" Date: Mon, 6 Aug 2007 21:40:42 -0400 MIME-Version: 1.0 Sent to CCL by: "Yousef Sharifi" [ysharifi===gmail.com] ------=_Part_51857_19814448.1186450842824 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline I have two quad core q6600 on Abit motherboard. Overclocked to 3.4 works perfectly fine. On 8/6/07, Andrew D. Fant fant]![pobox.com wrote: > > > Sent to CCL by: "Andrew D. Fant" [fant]^[pobox.com] > John McKelvey jmmckel**gmail.com wrote: > > Hello, > > > > Has anyone tried Intel quad core processors? Opinions? > > > > Thanks! > > > > Hey John, > We're going to be getting one in my wife's new Mac any day now. > I'll be doing mostly MD on it, under both OS X and Linux, and I'll let > you know how it does. > > Andy> > > > ------=_Part_51857_19814448.1186450842824 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline I have two quad core q6600 on Abit motherboard. Overclocked to 3.4 works perfectly fine.

On 8/6/07, Andrew D. Fant fant]![pobox.com <owner-chemistry/a\ccl.net> wrote:

Sent to CCL by: "Andrew D. Fant" [fant]^[pobox.com]
John McKelvey jmmckel**gmail.com wrote:
> Hello,
>
> Has anyone tried Intel quad core processors?  Opinions?
>
> Thanks!
>

Hey John,
    We're going to be getting one in my wife's new Mac any day now.
I'll be doing mostly MD on it, under both OS X and Linux, and I'll let
you know how it does.

Andy



E-mail to subscribers: CHEMISTRY/a\ccl.net or use:
      http://www.ccl.net/cgi-bin/ccl/send_ccl_message

E-mail to administrators: CHEMISTRY-REQUEST/a\ccl.net or use
      http://www.ccl.net/cgi-bin/ccl/send_ccl_message

Subscribe/Unsubscribe:
      http://www.ccl.net/chemistry/sub_unsub.shtml

Before posting, check wait time at: http://www.ccl.net

Job: http://www.ccl.net/jobs
Conferences: http://server.ccl.net/chemistry/announcements/conferences/

Search Messages: http://www.ccl.net/htdig  (login: ccl, Password: search)
      

RTFI: http://www.ccl.net/chemistry/aboutccl/instructions/




------=_Part_51857_19814448.1186450842824-- From owner-chemistry@ccl.net Mon Aug 6 23:39:00 2007 From: "John W Daily john.daily+*+colorado.edu" To: CCL Subject: CCL: Intel quad core processors Message-Id: <-34887-070806225610-5798-q7WCQBJchYjE5tu8ipngBA(!)server.ccl.net> X-Original-From: John W Daily Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Date: Mon, 6 Aug 2007 20:22:43 -0600 Mime-Version: 1.0 (Apple Message framework v752.3) Sent to CCL by: John W Daily [john.daily{=}colorado.edu] John, I have a MacPro dual Quad (i.e.8 processors) on which I run Amber and some other parallelized software. I have not done comparisons with any other machines, but for the price and ease of use it works great for me. I use the Intel Fortran compiler. John On Aug 4, 2007, at 8:05 AM, John McKelvey jmmckel**gmail.com wrote: > Hello, > > Has anyone tried Intel quad core processors? Opinions? > > Thanks! > > John McKelvey