Header menu link for other important links
X
Iso-oriented fluorescent colloidal nanocrystals of bis-cyanostyryl thiophenes: Crucial secondary halogen interactions toward stability and transport
Nivarthi G. Ramesh,
Published in American Chemical Society
2016
Volume: 120
   
Issue: 3
Pages: 1909 - 1917
Abstract
Water-dispersible, single-crystalline, and fluorescent colloidal crystals with curved edges were fabricated from π-conjugated chromophores 2,5-bis(α-cyano-4-bromostyryl)thiophene (CN-BST) and 2,5-bis(α-cyanostyryl)thiophene (CN-ST) via reprecipitation. The colloidal crystal growth occurred in a nonclassical pathway through alignment of seed particles. The effects of torsion and planarity were examined through DFT calculations and photoluminescence spectroscopy. The bromine end groups were shown not to have a significant role in bringing absorption or fluorescent spectral changes, however, had endowed the molecules to interact in an angular geometry, conferring additional stability and rigidity to the CN-BST colloidal crystals. Most importantly, secondary Br-Br interactions in the solid state shielded and stabilized the associative dimeric interactions of the type, (i) face-to-face π-stack, (ii) slip-stack, (iii) C-H···N, and (iv) C-H···π with different strengths. Both classes of colloidal crystals exhibited rectifying diodic behavior with a higher threshold voltage of 3.0 V for CN-BST versus 2.4 V for CN-ST. The characteristic transport is attributed to the compact molecular stacking in the crystalline state, along with the electron-withdrawing nature of the CN functionality integrated into the thiophenic molecular structure. © 2016 American Chemical Society.
About the journal
JournalData powered by TypesetJournal of Physical Chemistry C
PublisherData powered by TypesetAmerican Chemical Society
ISSN19327447
Open AccessNo
Concepts (15)
  •  related image
    Chromophores
  •  related image
    Colloids
  •  related image
    Crystalline materials
  •  related image
    Fluorescence
  •  related image
    Photoluminescence spectroscopy
  •  related image
    Threshold voltage
  •  related image
    COLLOIDAL CRYSTALS
  •  related image
    COLLOIDAL NANOCRYSTALS
  •  related image
    CRYSTALLINE STATE
  •  related image
    Electronwithdrawing
  •  related image
    MOLECULAR STACKING
  •  related image
    Re-precipitation
  •  related image
    Single-crystalline
  •  related image
    WATER DISPERSIBLE
  •  related image
    Thiophene