On Lunn-Senior's Mathematical Model of Isomerism in Organic Chemistry. Part II

TL;DR

This paper extends Lunn-Senior's mathematical model to identify isomers of organic molecules using only their type properties, providing a theoretical framework for distinguishing structural formulas.

Contribution

It develops a mathematical machinery within Lunn-Senior's model to identify isomers based on their properties, including limitations like chiral pairs.

Findings

Members of a chiral pair cannot be distinguished via substitution reactions.

The model applies to molecules like ethene, benzene, and cyclopropane.

Provides a theoretical basis for isomer identification using structural properties.

Abstract

The second part of this paper is devoted to the following important question in organic chemistry: given two isomers of a molecule, how to identify them with their structural formulae using only type properties of that molecule? A classical answer of this question is given for benzene by the identification of its di-substituted (para, ortho, and meta), and tri-substituted (asymmetric, vicinal, and symmetric) derivatives via the Korner substitution reactions among them. Here we develop a machinery within the framework of the Lunn-Senior's mathematical model of isomerism in organic chemistry, which, in principle, answers this question. In particular, it is shown that the members of a chiral pair cannot be distinguished via substitution reactions. The examples of ethene, benzene, and cyclopropane are discussed.