So the concept of rate determining state has been around for about a decade now, it came out of the same work as the energetic span model, from Sebastian Kozuch and Saison Shaik. It’s valid, I’m not contesting that, but there isn’t really a conflict. The “rate determining step” is also a valid concept, you just have to define a “step” as done in kinetics, and apply the Curtin-Hammett principle. In short, if a “step” is considered to go to a transition state from the lowest preceding point, not the closest minimum, then the models work out the same. A simple trick really, you calculate the barrier associated with each transition state by looking back to the lowest preceding point that you can reach without passing a higher barrier. In catalysis, that lowest preceding point could be the resting state, another very useful concept that has also been considered dead, but which is handy when trying to predict what will be observable.

Also note that the lowest preceding point does not have to lie on the productive reaction path, it can easily be a side path, a thermodynamic dump that just slows the overall kinetics.

I haven’t found an article that summarizes this view. It underlies how many of us handled potential energy surfaces decades back, but I never saw it stated explicitly, it was just handed down as essential knowledge in computational groups with expertise in kinetics. I did write a summary in a book chapter a while back, can be found here: http://dx.doi.org/10.1002/9783527646586.ch8

/Per-Ola

Per-Ola Norrby

Principal Scientist, Computational Pharmaceutics

Pharmaceutical Sciences, AstraZeneca-Gothenburg

From: owner-chemistry+per-ola.norrby==astrazeneca.com===ccl.net [mailto:owner-chemistry+per-ola.norrby==astrazeneca.com===ccl.net] On Behalf Of Andrew Rosen rosen__u.northwestern.edu
Sent: den 24 maj 2018 05:34
To: Norrby, Per-Ola <Per-Ola.Norrby===astrazeneca.com>
Subject: CCL: RateDetermining State

Anyao,

I refer you to the following two papers:

1) "Degree of Rate Control: How Much the Energies of Intermediates and Transition States Control Rates" (https://pubs.acs.org/doi/abs/10.1021/ja9000097)

2) "The Rate‐Determining Step is Dead. Long Live the Rate‐Determining State!" (https://onlinelibrary.wiley.com/doi/full/10.1002/cphc.201100137)

From a detailed mechanistic point of view, it is often much more insightful to talk about about a rate-determining state (either transition state or intermediate) than a rate-determining step. The first paper describes the widely used definition of a rate-controlling state and how to compute it. The second paper contains a few short examples of how the rate-determining state differs from the rate-determining step.

On Wed, May 23, 2018 at 10:19 PM Anyao Jiao 1425623121(_)qq.com <owner-chemistry*ccl.net> wrote:

Sent to CCL by: "Anyao Jiao" [1425623121^qq.com]
Dear All,
I have a simple question regarding RateDetermining State. My reviewers
suggest me to use RateDetermining State rather than Rate-Determining Step
owning to its inaccuracy. Is that right? If we use the Canonical variational
transition-state theory method, how do you calculate the reaction rate of the
RateDetermining State ?
Sincerely

Anyao Jiao

E-mail to subscribers: CHEMISTRY*ccl.net or use:

E-mail to administrators: CHEMISTRY-REQUEST*ccl.net or use

<br

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/chemistry/searchccl/index.shtml
<br

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

Confidentiality Notice: This message is private and may contain confidential and proprietary information. If you have received this message in error, please notify us and remove it from your system and note that you must not copy, distribute or take any action in reliance on it. Any unauthorized use or disclosure of the contents of this message is not permitted and may be unlawful.

-- ═════════════════════════════════════ Sebastian Kozuch ═════════════════════════════════════ Department of Chemistry Ben-Gurion University of the Negev Beer Sheva, Israel kozuch-.-bgu.ac.il http://www.bgu.ac.il/~kozuch ═════════════════════════════════════CHEMISTRY*o*ccl.net or use: http://www.ccl.net/cgi-bin/ccl/send_ccl_message E-mail to administrators: CHEMISTRY-REQUEST*o*ccl.net or use http://www.ccl.net/cgi-bin/ccl/send_ccl_messagehttp://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/chemistry/searchccl/index.shtmlhttp://www.ccl.net/spammers.txt RTFI: http://www.ccl.net/chemistry/aboutccl/instructions/