The University of Southampton
University of Southampton Institutional Repository

Packing similarity in polymorphs of sulfathiazole

Packing similarity in polymorphs of sulfathiazole
Packing similarity in polymorphs of sulfathiazole
The packing of molecules in polymorphs I-V of sulfathiazole is compared using the XPac method (CrystEngComm, 2005, 7, 324). The forms denoted III, IV, V in the pharmaceutical literature, equivalent to forms III, II and IV of the CSD, exhibit 2D packing similarity. Linking this purely geometrical analysis with H-bonding information reveals that the common building unit of III-V is a 2D layer composed of rows of helical chains of doubly H-bonded sulfathiazole molecules. The H-bonded chains are further H-bonded in the third direction to chains of adjacent layers. However, these connections involve different combinations of H-bond donor and acceptor sites in each polymorph. One consequence of this relationship is the presence of sets of local (non-crystallographic) symmetry elements in polymorph III (Z' = 2), while forms IV and V may be interpreted as its two Z' = 1 parent phases. The connectivity of the doubly bonded chain of modifications III-V is also present in form II, which additionally contains 2D H-bonded sheets, but the conformation of the chain and its further connectivity is quite different to forms III-V. The molecular packing and hydrogen bonding of form I is unique among the investigated structures. This study shows that useful new information is obtained from a strictly geometric comparison of crystal structures. Forms III-V provide yet another example for the connection between polymorphism, packing similarity and the formation of a structure with Z' > 1 exhibiting non-crystallographic symmetry.
1466-8033
1328-1334
Gelbrich, Thomas
42309d69-eaf1-4bb7-ba2e-db61f338e370
Hughes, David S.
4da49887-fff7-4724-8036-f73c0a0e8079
Hursthouse, Michael B.
57a2ddf9-b1b3-4f38-bfe9-ef2f526388da
Threlfall, Terence L.
26a8854d-5a4e-46fa-b2fd-00ebe67747d8
Gelbrich, Thomas
42309d69-eaf1-4bb7-ba2e-db61f338e370
Hughes, David S.
4da49887-fff7-4724-8036-f73c0a0e8079
Hursthouse, Michael B.
57a2ddf9-b1b3-4f38-bfe9-ef2f526388da
Threlfall, Terence L.
26a8854d-5a4e-46fa-b2fd-00ebe67747d8

Gelbrich, Thomas, Hughes, David S., Hursthouse, Michael B. and Threlfall, Terence L. (2008) Packing similarity in polymorphs of sulfathiazole. CrystEngComm, 10 (10), 1328-1334. (doi:10.1039/b807898j).

Record type: Article

Abstract

The packing of molecules in polymorphs I-V of sulfathiazole is compared using the XPac method (CrystEngComm, 2005, 7, 324). The forms denoted III, IV, V in the pharmaceutical literature, equivalent to forms III, II and IV of the CSD, exhibit 2D packing similarity. Linking this purely geometrical analysis with H-bonding information reveals that the common building unit of III-V is a 2D layer composed of rows of helical chains of doubly H-bonded sulfathiazole molecules. The H-bonded chains are further H-bonded in the third direction to chains of adjacent layers. However, these connections involve different combinations of H-bond donor and acceptor sites in each polymorph. One consequence of this relationship is the presence of sets of local (non-crystallographic) symmetry elements in polymorph III (Z' = 2), while forms IV and V may be interpreted as its two Z' = 1 parent phases. The connectivity of the doubly bonded chain of modifications III-V is also present in form II, which additionally contains 2D H-bonded sheets, but the conformation of the chain and its further connectivity is quite different to forms III-V. The molecular packing and hydrogen bonding of form I is unique among the investigated structures. This study shows that useful new information is obtained from a strictly geometric comparison of crystal structures. Forms III-V provide yet another example for the connection between polymorphism, packing similarity and the formation of a structure with Z' > 1 exhibiting non-crystallographic symmetry.

Full text not available from this repository.

More information

Published date: 8 August 2008
Organisations: Organic Chemistry: Synthesis, Catalysis and Flow, Chemistry, Faculty of Natural and Environmental Sciences

Identifiers

Local EPrints ID: 352878
URI: http://eprints.soton.ac.uk/id/eprint/352878
ISSN: 1466-8033
PURE UUID: bd2ec923-c131-4be2-949d-d229ed2e483a

Catalogue record

Date deposited: 21 May 2013 13:48
Last modified: 16 Jul 2019 21:32

Export record

Altmetrics

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×