Relaxation dynamics and structural characterization of organic nanoparticles with enhanced emission

Chetan Jagdish Bhongale, Chih Wei Chang, Chi Shen Lee, Eric Wei Guang Diau, Chain Shu Hsu

研究成果: Article同行評審

161 引文 斯高帕斯(Scopus)

摘要

With a reprecipitation method, we prepared fluorescent organic nanoparticles of 1,4-di[(E)-2-phenyl-1-propenyl]-benzene (PPB) that feature weak emission in solution but exhibit blue-shifted absorption and strong emission as aggregates. Picosecond fluorescent transients of these PPB nanoparticles showed biexponential decay, described with a consecutive kinetic model involving two emissive states. X-ray diffraction patterns of PPB nanocrystals indicate long-range packing structures of two types, one the same as in a single crystal and the other not yet determined. PPB molecules in a crystal show an arrangement of a herringbone type with three benzene rings in a PPB unit being nearly planar and two methyl groups of the unit pointing along the same direction, in contrast to the twisted structure of an isolated PPB molecule. Fluorescence transients of PPB on a femtosecond scale indicate an efficient channel for isomerization that is activated for free PPB in solution but inhibited in PPB forming nanoparticles, demonstrating the significance of molecular geometry and twisting motions that affect the relaxation dynamics in the excited state. The versatile techniques combined in this work provide strong evidence to improve our understanding of optical properties in organic nanoparticles dependent on size.

原文English
頁(從 - 到)13472-13482
頁數11
期刊Journal of Physical Chemistry B
109
發行號28
DOIs
出版狀態Published - 2005 七月 21

All Science Journal Classification (ASJC) codes

  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films
  • Materials Chemistry

指紋 深入研究「Relaxation dynamics and structural characterization of organic nanoparticles with enhanced emission」主題。共同形成了獨特的指紋。

引用此