Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

Unraveling the Complex Solid-State Phase Transition Behavior of 1-Iodoadamantane, a Material for Which Ostensibly Identical Crystals Undergo Different Transformation Pathways

Al Rahal, Okba, Kariuki, Benson M. ORCID: https://orcid.org/0000-0002-8658-3897, Hughes, Colan E., Williams, P.Andrew, Xu, Xiaoyan, Gaisford, Simon, Iuga, Dinu and Harris, Kenneth D. M. ORCID: https://orcid.org/0000-0001-7855-8598 2023. Unraveling the Complex Solid-State Phase Transition Behavior of 1-Iodoadamantane, a Material for Which Ostensibly Identical Crystals Undergo Different Transformation Pathways. Crystal Growth and Design 23 (5) , pp. 3820-3833. 10.1021/acs.cgd.3c00223

[thumbnail of acs.cgd.3c00223.pdf]
Preview
PDF - Published Version
Available under License Creative Commons Attribution.

Download (4MB) | Preview
License URL: http://creativecommons.org/licenses/by/4.0/
License Start date: 12 April 2023

Abstract

Phase transitions in crystalline molecular solids have important implications in the fundamental understanding of materials properties and in the development of materials applications. Herein, we report the solid-state phase transition behavior of 1-iodoadamantane (1-IA) investigated using a multi-technique strategy [synchrotron powder X-ray diffraction (XRD), single-crystal XRD, solid-state NMR, and differential scanning calorimetry (DSC)], which reveals complex phase transition behavior on cooling from ambient temperature to ca. 123 K and on subsequent heating to the melting temperature (348 K). Starting from the known phase of 1-IA at ambient temperature (phase A), three low-temperature phases are identified (phases B, C, and D); the crystal structures of phases B and C are reported, together with a re-determination of the structure of phase A. Remarkably, single-crystal XRD shows that some individual crystals of phase A transform to phase B, while other crystals of phase A transform instead to phase C. Results (from powder XRD and DSC) on cooling a powder sample of phase A are fully consistent with this behavior while also revealing an additional transformation pathway from phase A to phase D. Thus, on cooling, a powder sample of phase A transforms partially to phase C (at 229 K), partially to phase D (at 226 K) and partially to phase B (at 211 K). During the cooling process, each of the phases B, C, and D is formed directly from phase A, and no transformations are observed between phases B, C, and D. On heating the resulting triphasic powder sample of phases B, C, and D from 123 K, phase B transforms to phase D (at 211 K), followed by the transformation of phase D to phase C (at 255 K), and finally, phase C transforms to phase A (at 284 K). From these observations, it is apparent that different crystals of phase A, which are ostensibly identical at the level of information revealed by XRD, must actually differ in other aspects that significantly influence their low-temperature phase transition pathways. This unusual behavior will stimulate future studies to gain deeper insights into the specific properties that control the phase transition pathways in individual crystals of this material.

Item Type: Article
Date Type: Publication
Status: Published
Schools: Chemistry
Publisher: American Chemical Society
ISSN: 1528-7483
Funders: EPSRC, BBSRC
Date of First Compliant Deposit: 13 April 2023
Date of Acceptance: 21 March 2023
Last Modified: 05 Jan 2024 08:29
URI: https://orca.cardiff.ac.uk/id/eprint/158807

Actions (repository staff only)

Edit Item Edit Item

Downloads

Downloads per month over past year

View more statistics