Hall, Amy V. and Musa, Osama M. and Hood, David K. and Apperley, David C. and Yufit, Dmitry S. and Steed, Jonathan W. (2021) 'Alkali Metal Salts of 10,12-Pentacosadiynoic Acid and Their Dosimetry Applications.', Crystal growth & design., 21 (4). pp. 2416-2422.
Wide-dose-range 2D radiochromic films for radiotherapy, such as GAFchromic EBT, are based on the lithium salt of 10,12-pentacosadiynoic acid (Li-PCDA) as the photosensitive component. We show that there are two solid forms of Li-PCDA—a monohydrated form A and an anhydrous form B. The form used in commercial GAFchromic films is form A due to its short needle-shaped crystals, which provide favorable coating properties. Form B provides an enhanced photoresponse compared to that of form A, but adopts a long needle crystal morphology, which is difficult to process. The two forms were characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, CP-MAS 13C solid-state NMR spectroscopy, and thermogravimetric analysis. In sum, these data suggest a chelating bridging bidentate coordination mode for the lithium ions. The sodium salt of PCDA (Na-PCDA) is also reported, which is an ionic cocrystal with a formula of Na+PCDA–·3PCDA. The PCDA and PCDA– ligands display monodentate and bridging bidentate coordination to the sodium ion in contrast to the coordination sphere of the Li-PCDA forms. In contrast to its lithium analogues, Na-PCDA is photostable.
|Full text:||(AM) Accepted Manuscript|
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|Publisher Web site:||https://doi.org/10.1021/acs.cgd.1c00031|
|Publisher statement:||This document is the Accepted Manuscript version of a Published Work that appeared in final form in Crystal Growth and Design, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.cgd.1c00031|
|Date accepted:||No date available|
|Date deposited:||27 October 2021|
|Date of first online publication:||25 March 2021|
|Date first made open access:||25 March 2022|
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