Magnetic tuning of all-organic binary alloys between two stable radicals

Gonca Seber, Rafael S. Freitas, Joel T. Mague, Armando Paduan-Filho, Xavier Gratens, Valdir Bindilatti, Nei Fernandes Oliveira, Naoki Yoshioka, Paul M. Lahti

研究成果: Article査読

21 被引用数 (Scopus)


Mixtures of 2-(4,5,6,7-tetrafluorobenzimidazol-2-yl)-4,4,5,5-tetramethyl-4, 5-dihydro-1H-imidazole-3-oxide-1-oxyl (F4BImNN) and 2-(benzimidazol-2-yl)-4,4,5, 5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl (BImNN) crystallize as solid solutions (alloys) across a wide range of binary compositions. (F4BImNN) x(BImNN) (1-x) with x < 0.8 gives orthorhombic unit cells, while x ≥ 0.9 gives monoclinic unit cells. In all crystalline samples, the dominant intermolecular packing is controlled by one-dimensional (1D) hydrogen-bonded chains that lead to quasi-1D ferromagnetic behavior. Magnetic analysis over 0.4-300 K indicates ordering with strong 1D ferromagnetic exchange along the chains (J/k = 12-22 K). Interchain exchange is estimated to be 33- to 150-fold weaker, based on antiferromagnetic ordered phase formation below Néel temperatures in the 0.4-1.2 K range for the various compositions. The ordering temperatures of the orthorhombic samples increase linearly as (1 - x) increases from 0.25 to 1.00. The variation is attributed to increased interchain distance corresponding to decreased interchain exchange, when more F4BImNN is added into the orthorhombic lattice. The monoclinic samples are not part of the same trend, due to the different interchain arrangement associated with the phase change.

ジャーナルJournal of the American Chemical Society
出版ステータスPublished - 2012 2月 29

ASJC Scopus subject areas

  • 触媒
  • 化学 (全般)
  • 生化学
  • コロイド化学および表面化学


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