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

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 diffusionmore » triggered solid-state phenomenon. Lastly, 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.« less

Authors:

Aromí, G.  ^[1];

• Search DOE PAGES for author "Aromí, G."
• Search DOE PAGES for ORCID "0000-0002-0997-9484"

Beavers, C. M.  ^[2];

• Search DOE PAGES for author "Beavers, C. M."
• Search DOE PAGES for ORCID "0000-0001-8653-5513"

Sánchez Costa, J. ^[1]; Craig, G. A. ^[1]; Mínguez Espallargas, G. ^[3]; Orera, A.  ^[4];

• Search DOE PAGES for author "Orera, A."
• Search DOE PAGES for ORCID "0000-0001-8751-0983"

Roubeau, O.  ^[4]

• Search DOE PAGES for author "Roubeau, O."
• Search DOE PAGES for ORCID "0000-0003-2095-5843"

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+ Show Author Affiliations

1. Univ. de Barcelona, Barcelona (Spain). Dept. de Quimica Inorganica
2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS)
3. Univ. de Valencia, Paterna, Valencia (Spain). Inst. de Ciencia Molecular (ICMol)
4. Univ. de Zaragoza, Zaragoza (Spain). Inst. de Ciencia de Materiales de Aragon (ICMA)

Publication Date:

Tue Jan 05 00:00:00 EST 2016

Research Org.:

Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1415953

Grant/Contract Number:  

AC02-05CH11231

Resource Type:

Accepted Manuscript

Journal Name:

Chemical Science

Additional Journal Information:

Journal Volume: 7; Journal Issue: 4; Journal ID: ISSN 2041-6520

Publisher:

Royal Society of Chemistry

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY