Diamond Publications - Search Results

Search Again...

These results only include publications that have been reviewed and processed by Diamond Light Source. To also view papers that have not yet been processed click here.

You can use the folder icon under Actions to collate papers as required. You can then click on View Folder in the left-hand navigation to review and/or download your folder.

One item found (0 items not approved).

Instruments / Technical Area	Publication Details	Published	Actions
I19-Small Molecule Single Crystal Diffraction	The rich solid-state phase behaviour of DL-aminoheptanoic acid: five polymorphic forms and their phase transitions Mireille H. Smets , Mateusz B. Pitak , Joseph Cadden , Vincent R. Kip , Gilles A. De Wijs , Ernst R. H. Van Eck , Paul Tinnemans , Hugo Meekes , Elias Vlieg , Simon J. Coles , Herma M. Cuppen Crystal Growth & Design DOI: 10.1021/acs.cgd.7b01175 Diamond Proposal Number(s): [6916] Open Access Show Abstract ▼ Abstract: The rich landscape of enantiotropically related polymorphic forms and their solid-state phase transitions of DL-2-aminoheptanoic acid (DL-AHE) has been explored using a range of complementary characterisation techniques, and is largely exemplary of the polymorphic behaviour of linear aliphatic amino acids. As many as five new polymorphic forms were found, connected by four fully reversible solid-state phase transitions. Two low temperature forms were refined in a high Z' crystal structure, which is a new phenomenon for linear aliphatic amino acids. All five structures consist of 2D hydrogen-bonded bilayers interconnected by weak Van der Waals interactions. The single-crystal-to-single-crystal phase transitions involve shifts of bilayers and/or conformational changes in the aliphatic chain. Compared to two similar phase transitions of the related amino acid DL-norleucine, the enthalpies of transition and NMR chemical shift differences are notably smaller in DL-aminoheptanoic acid. This is explained to be a result of both the nature of the conformational changes, and the increased chain length, weakening the interactions between the bilayers.	Nov 2017

Instruments / Technical Area

Publication Details

Published

Actions

I19-Small Molecule Single Crystal Diffraction

The rich solid-state phase behaviour of DL-aminoheptanoic acid: five polymorphic forms and their phase transitions