Issue 3, 2019

The canonical behavior of the entropic component of thermodynamic effective molarity. An attempt at unifying covalent and noncovalent cyclizations

Abstract

This review article is concerned with the measurement, significance and applications of the concept of effective molarity (EM) in a large variety of cyclization reactions ranging from the formation of giant macromolecules in polymeric equilibrates to the self-assembly of cyclic supermolecules and supramolecular aggregates. Based on a dissection of EM into enthalpic and entropic components (EM = EMH × EMS), a careful examination of a large number of often overlooked quantitative studies of reversible cyclizations led to the definition of a set of “canonical” values of the entropic component EMS, expressed in graphical form by the plot of EMS* vs. n, where the asterisk denotes statistically corrected quantities, and n is the number of single bonds in the ring product. It is proposed that, to a useful approximation, all cyclization reactions comply with the “canonical” EMS* values, independent of the chemical nature of end groups and of the intervening chain, but solely dependent on the number n of rotatable bonds. The entropic component EMS* is approximately the same for cyclizations carried out under kinetic or thermodynamic control, and does not appear to be altered to a very significant extent by replacement of covalent with noncovalent bonds.

Graphical abstract: The canonical behavior of the entropic component of thermodynamic effective molarity. An attempt at unifying covalent and noncovalent cyclizations

Article information

Article type
Perspective
Submitted
11 окт. 2018
Accepted
16 дек. 2018
First published
17 дек. 2018

Phys. Chem. Chem. Phys., 2019,21, 955-987

The canonical behavior of the entropic component of thermodynamic effective molarity. An attempt at unifying covalent and noncovalent cyclizations

S. Di Stefano and L. Mandolini, Phys. Chem. Chem. Phys., 2019, 21, 955 DOI: 10.1039/C8CP06344C

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements