Issue 4, 2018

New electron delocalization tools to describe the aromaticity in porphyrinoids

Abstract

The role of aromaticity in porphyrinoids is a current subject of debate due to the intricate structure of these macrocycles, which can adopt Hückel, Möbius and even figure-eight conformers. One of the main challenges in these large π-conjugated structures is identifying the most conjugated pathway because, among aromaticity descriptors, there are very few that can be applied coherently to this variety of conformers. In this paper, we have investigated the conjugated pathways in nine porphyrinoid compounds using several aromaticity descriptors, including BLA, BOA, FLU and HOMA, as well as the recently introduced AV1245 and AVmin indices. All the indices agree on the general features of these compounds, such as the fulfillment of Hückel's rule or which compounds should be more or less aromatic from the series. However, our results evince the difficulty of finding the most aromatic pathway in the macrocycle for large porphyrinoids. In fact, only AVmin is capable of recognizing the annulene pathway as the most aromatic one in the nine studied structures. Finally, we study the effect of the exchange in DFT functionals on the description of the aromaticity of the porphyrinoids. The amount of exact exchange quantitatively changes the picture for most aromaticity descriptors, AVmin being the only exception that shows the same qualitative results in all cases.

Graphical abstract: New electron delocalization tools to describe the aromaticity in porphyrinoids

Supplementary files

Article information

Article type
Paper
Submitted
09 Nov 2017
Accepted
19 Dec 2017
First published
19 Dec 2017

Phys. Chem. Chem. Phys., 2018,20, 2787-2796

New electron delocalization tools to describe the aromaticity in porphyrinoids

I. Casademont-Reig, T. Woller, J. Contreras-García, M. Alonso, M. Torrent-Sucarrat and E. Matito, Phys. Chem. Chem. Phys., 2018, 20, 2787 DOI: 10.1039/C7CP07581B

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