Thermodynamic Control of Isotopic Polymorphism

DOI

Co-crystals of 4-methylpyridine and pentachlorophenol (MP-PCP) exhibit the very unusual property of isotopic polymorphism, formation of different phases by samples differing only in isotopic composition. Isotopically normal MP and PCP co-crystals are triclinic, but when the phenolic oxygen is deuterated, the structure is monoclinic. The triclinic deuterated and the isotopically normal monoclinic phases have not been described. Statistical thermodynamic modelling based on DFT calculations indicates that the triclinic deuterated form should become competitive at low temperature, and this has been confirmed by crystal growth at 243 K which yields a mixed monoclinic and triclinic sample. The aim of this proposal is to follow crystal growth of this form by in situ by neutron powder diffraction, confirming the calculations and obtaining unambiguously phase pure sample of the triclinic deuter

Identifier
DOI https://doi.org/10.5286/ISIS.E.83572757
Metadata Access https://icatisis.esc.rl.ac.uk/oaipmh/request?verb=GetRecord&metadataPrefix=oai_datacite&identifier=oai:icatisis.esc.rl.ac.uk:inv/83572757
Provenance
Creator Dr Ron Smith; Dr Nicholas Funnell; Professor Simon Parsons
Publisher ISIS Neutron and Muon Source
Publication Year 2019
Rights CC-BY Attribution 4.0 International; https://creativecommons.org/licenses/by/4.0/
OpenAccess true
Contact isisdata(at)stfc.ac.uk
Representation
Resource Type Dataset
Discipline Chemistry; Natural Sciences
Temporal Coverage Begin 2016-12-04T08:00:00Z
Temporal Coverage End 2016-12-05T08:00:00Z