Luminescent mesogenic dimeric borondifluoride complexes

  • Gene Hsiang Leea (Contributor)
  • Chung K. Lai (National Central University) (Contributor)
  • Zih Yang Lei (Contributor)
  • Yi Hong Cai (Contributor)



Two new families of dimeric borondifluoride complexes derived from β-enaminoketones containing terminal phenyl and naphthalenyl groups were prepared, and their mesomorphic and optical properties investigated. One single crystallographic structure of mesogenic complex 1a-BF2 (n = 12) was determined by X-ray analysis; it crystallises in a monoclinic space group P21/c and the geometry on boron atoms was all tetrahedral. The crystal was considered as linear-shaped with a length of ~51.95 Å. A relatively large dihedral angle of ~38.85° between the central phenyl spacer and tetrahedral BF2 moiety was observed. Mesomorphic properties were crucially impacted by the structure of the central spacer and terminal group; all bis(borondifluoride) complexes formed SmC or SmA phase except complexes 1b-BF2 (m = 2, 3) and 1c-BF2. H–bond interactions supported by FT-IR spectra were attributed to the induction of SmA phase in compound 2 c-BF2. The optical property of the boron complexes was related with their molecular structures, and they emitted blue-to-green emissions at λmax = 420–538 nm in CH2Cl2. This is the first twin liquid crystal of bis(BF2) complexes derived from Schiff baseβ-enaminoketones.
Date made available1 Jan 2020
Publisherfigshare Academic Research System

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