Issue 43, 2020

Methods for easy recognition of isostructurality – lab jack-like crystal structures of halogenated 2-phenylbenzimidazoles

Abstract

Tools to describe isostructurality are important in the understanding of close packing principles and in the fine-tuning of crystal properties. In order to present how different methods work in practice, a series of 2-phenylbenzimidazole derivatives substituted on the phenyl ring in the ortho, meta and para positions or simultaneously in two different positions by F, Cl and Br were selected. The flexibility of the phenylbenzimidazole frame permits a gradual isostructural change of the structures with step-by-step alteration of the internal arrangement as well as of the lengths of the unit cells perpendicular to the determining N–H⋯N hydrogen bonded chains. The exchange of the different halogen substituents alters the angle between the neighbouring benzimidazole moieties and the system of the secondary interactions, and finally the isostructurality is terminated. The series of isostructural crystals look like a lab jack lifted at different heights. Although the neighbouring members of the series are highly similar, the extremes of the list vary deliberately keeping the space group and Z. This raises the question about the extents of structural differences what we still consider isostructural. The preference of certain intermolecular interactions divides the investigated isostructural Pbca crystals into two subgroups like a switch. The definition of isostructurality does not consider supramolecular similarity, although it may have a determining role as shown. It is presented how isostructurality can be described by numerical descriptors. Cell similarity (π), isostructurality (Is), and molecular isometricity indices are calculated. Correlations of the molecular conformation, secondary interactions and the crystallographic parameters are revealed by statistical methods. With the use of these methods, we provide an easy way to recognise and to characterize isostructurality. We show that the prerequisites of isostructurality are the similar composition and conformation of the compounds, with their analogous molecular and supramolecular arrangement in the crystals having the same space group and Z. Exploitation of the Cambridge Structural Database for systematical investigations to complete the isostructural series is essential.

Graphical abstract: Methods for easy recognition of isostructurality – lab jack-like crystal structures of halogenated 2-phenylbenzimidazoles

Supplementary files

Article information

Article type
Paper
Submitted
17 Mac 2020
Accepted
17 Mei 2020
First published
18 Mei 2020
This article is Open Access
Creative Commons BY-NC license

CrystEngComm, 2020,22, 7193-7203

Methods for easy recognition of isostructurality – lab jack-like crystal structures of halogenated 2-phenylbenzimidazoles

P. Bombicz, N. V. May, D. Fegyverneki, A. Saranchimeg and L. Bereczki, CrystEngComm, 2020, 22, 7193 DOI: 10.1039/D0CE00410C

This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. You can use material from this article in other publications, without requesting further permission from the RSC, provided that the correct acknowledgement is given and it is not used for commercial purposes.

To request permission to reproduce material from this article in a commercial publication, 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 commercial 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