Pressure-induced enhancement of magnetic-ordering temperature in an organic radical to 70 K: a magnetostructural correlation.
Chemistry
; 18(28): 8629-33, 2012 Jul 09.
Article
em En
| MEDLINE
| ID: mdl-22689501
ABSTRACT
The structure of the canted antiferromagnet ß-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 Fdd2, 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.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Chemistry
Ano de publicação:
2012
Tipo de documento:
Article