Snapshots of a solid-state transformation : coexistence of three phases trapped in one crystal

Tools

Aromí, G. and Beavers, C. M. and Sánchez Costa, J. and Craig, G. A. and Mínguez Espallargas, G. and Orera, A. and Roubeau, O. (2016) Snapshots of a solid-state transformation : coexistence of three phases trapped in one crystal. Chemical Science, 7 (4). pp. 2907-2915. ISSN 2041-6539 (https://doi.org/10.1039/C5SC04287A)

[thumbnail of Aromi-etal-CS2016-Snapshots-solid-state-transformation-coexistence-three-phases-trapped-one-crystal]
Preview
 Text. Filename: Aromi_etal_CS2016_Snapshots_solid_state_transformation_coexistence_three_phases_trapped_one_crystal.pdf
Final Published Version
License: Creative Commons Attribution 4.0 logo
Download (2MB)| Preview

Abstract

Crystal-to-crystal transformations have been crucial in the understanding of solid-state processes, since these may be studied in detail by means of single crystal X-ray diffraction (SCXRD) techniques. The description of the mechanisms and potential intermediates of those processes remains very challenging. In fact, solid-state transient states have rarely been observed, at least to a sufficient level of detail. We have investigated the process of guest extrusion from the non-porous molecular material [Fe(bpp)(H2L)](ClO4)2·1.5C3H6O (bpp = 2,6-bis(pyrazol-3-yl)pyridine; H2L = 2,6-bis(5-(2-methoxyphenyl)-pyrazol-3-yl)pyridine; C3H6O = acetone), which occurs through ordered diffusion of acetone in a crystal-to-crystal manner, leading to dramatic structural changes. The slow kinetics of the transition allows thermal trapping of the system at various intermediate stages. The transiting single crystal can be then examined at these points through synchrotron SCXRD, offering a window upon the mechanism of the transformation at the molecular scale. These experiments have unveiled the development of an ordered intermediate phase, distinct from the initial and the final states, coexisting as the process advances with either of these two phases or, at a certain moment with both of them. The new intermediate phase has been structurally characterized in full detail by SCXRD, providing insights into the mechanism of this diffusion triggered solid-state phenomenon. The process has been also followed by calorimetry, optical microscopy, local Raman spectroscopy and powder X-ray diffraction. The discovery and description of an intermediate ordered state in a molecular solid-state transformation is of great interest and will help to understand the mechanistic details and reaction pathways underlying these transformations.

  • Item type:Article
    ID code:69773
    Dates:
    Date
    Event
    5 January 2016
    Published
    5 January 2016
    Accepted
    Subjects:Science > Chemistry
    Department:Faculty of Science > Pure and Applied Chemistry
    Depositing user: Pure Administrator
    Date deposited:12 Sep 2019 12:03
    Last modified:18 Nov 2024 01:13
    URI:https://strathprints.strath.ac.uk/id/eprint/69773
CORE (COnnecting REpositories)