108306-60-1Relevant articles and documents
Utilization of σ-holes on sulfur and halogen atoms for supramolecular cation...anion interactions in bilayer Ni(dmit)2 anion radical salts
Kusamoto, Tetsuro,Yamamoto, Hiroshi M.,Kato, Reizo
, p. 4533 - 4541 (2013)
We prepared novel Ni(dmit)2 anion radical salts with ethyl-4-halothiazolium cations (Et-4XT, with X denoting the halogen: I, Br, or Cl), (Et-4IT)[Ni(dmit)2]2 (1), (Et-4BrT)[Ni(dmit) 2]2 (2), and (Et-4ClT)2[Ni(dmit) 2]5 (3). Single-crystal X-ray diffraction analysis of 1-3 indicates that, unlike the halogen atoms that have only one σ-hole each, the cations' sulfur atoms each have two σ-holes that lie approximately along the extensions of the C-S bonds. The presence of the σ-holes is supported by electrostatic potential of the cations calculated based on the density functional theory method. In the crystals of 1-3, these σ-holes interact with lone pairs on the terminal thioketone moieties in the Ni(dmit)2 anion radicals to form electrostatic σ-hole bonds (halogen bonds and chalcogen bonds). This results in supramolecular cation...anion networks. Crystal and electronic structure analyses, and electrical and magnetic measurements reveal that the salts 1 and 2 are isostructural bilayer Mott systems, in which two crystallographically different Mott-insulating anion layers coexist in one crystal. The unusual magnetic properties, including the ferromagnetic anomalies of 1 and 2, are consistent with one of the anion layers forming an antiferromagnetic short-range ordering (SRO) state and the other layer forming a ferromagnetic SRO state. The spin-polarization of the Ni(dmit)2 anion radical was shown to influence significantly the observed ferromagnetic interactions, while the antiferromagnetic interactions resulted from π-π overlapping in the anions. The competition between these two interactions dominates the low-temperature magnetic properties of the present bilayer Mott systems. This study reveals that noncovalent intermolecular interactions mediated by σ-holes are influential in preparing novel crystal and electronic structures and that they have the potential to allow the development of materials with unusual physical properties.
Amino-5-(5-membered)hetero-arylimidazolone compounds and the use thereof for beta-secretase modulation
-
Page/Page column 21, (2008/06/13)
The present invention provides a 2-amino-5-heteroaryl-5-phenylimidazolone compound of formula I The present invention also provides methods for the use thereof to inhibit β-secretase (BACE) and treat β-amyloid deposits and neurofibrillary tangles
