PubAg

Main content area

Magnetic Bistability in Naphtho-1,3,2-dithiazolyl: Solid State Interconversion of a Thiazyl π-Radical and Its N–N σ-Bonded Dimer

Author:
Bates, Demetris, Robertson, Craig M., Leitch, Alicea A., Dube, Paul A., Oakley, Richard T.
Source:
Journal of the American Chemical Society 2018 v.140 no.11 pp. 3846-3849
ISSN:
1520-5126
Subject:
X-ray diffraction, crystals, free radicals, magnetism, phase transition, solids, temperature
Abstract:
Crystals of the heterocyclic radical naphtho-1,3,2-dithiazolyl NDTA display magnetic bistability with a well-defined hysteretic phase transition at Tc↓ = 128(2) K and Tc↑ = 188(2) K. The magnetic signature arises from a radical/dimer interconversion involving one of the two independent π-radicals in the P1̅ unit cell. Variable temperature X-ray crystallography has established that while all the radicals in HT-NDTA serve as paramagnetic (S = 1/2) centers, half of the radicals in LT-NDTA form closed-shell N–N σ-bonded dimers (S = 0) and half retain their S = 1/2 spin state. The wide window of bistability (60 K) may be attributed to the large structural changes that accompany the phase transition.
Agid:
6033106