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Pressure‐Induced Enhancement of Magnetic‐Ordering Temperature in an Organic Radical to 70 K: A Magnetostructural Correlation
Author(s) -
Thomson Richard I.,
Pask Christopher M.,
Lloyd Gareth O.,
Mito Masaki,
Rawson Jeremy M.
Publication year - 2012
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201200760
Subject(s) - materials science , condensed matter physics , nuclear magnetic resonance , thermodynamics , physics
The structure of the canted antiferromagnet β‐ p ‐NCC 6 F 4 CNSSN ( 1 ) was determined from synchrotron powder‐diffraction studies in the pressure range 0–21.6 kbar. Radical 1 crystallizes in the orthorhombic space group Fdd 2, but undergoes an asymmetric contraction of the unit‐cell size with increasing pressure. At the molecular level, this contraction of the unit cell is simultaneously accommodated by: 1) an increase in twist angle between aryl and heterocyclic rings; and 2) a shortening of the intermolecular S ⋅⋅⋅ N contacts, which propagate the magnetic‐exchange pathway. DFT calculations based on the structures in this pressure range revealed an increase in the magnetic‐exchange interaction ( J ) with increasing pressure, and an excellent correlation was observed between J and the magnetic‐ordering temperature, which increased from 36 K at ambient pressure up to 70 K at 16 kbar.