Related Experiment Video
Updated: Sep 21, 2025

Time-resolved Photophysical Characterization of Triplet-harvesting Organic Compounds at an Oxygen-free Environment Using an iCCD Camera
Published on: December 27, 2018
Polyimides with Heavy Halogens Exhibiting Room-Temperature Phosphorescence with Very Large Stokes Shifts
1Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, Ookayama 2-12-1-E4-5, Meguro-ku, Tokyo 152-8552, Japan.
Abstract:
Semiaromatic polyimides (PIs) and imide compounds containing heavy halogens (Br, I) in pyromellitic moieties were designed and synthesized to examine their photoluminescence properties. Solutions of imides and PI films exhibited reddish-color room-temperature phosphorescence (RTP) with very large Stokes shifts (ca. 10000 cm-1). In addition, the PI films showed small-Stokes-shifted fluorescence emissions at around 540 nm with absorption bands arising from aggregated PI chains at 400-500 nm. Enhanced phosphorescence observed for the PI films under vacuum indicates that the RTP lifetime is significantly influenced by the triplet-triplet energy transfer to atmospheric oxygen. These PIs with very-large-Stokes-shifted RTP are applicable as spectral conversion materials in displays, photovoltaic devices, and crop cultivators, as well as to oxygen/air sensors.
More Related Videos
14:11Synthesis of pH Dependent Pyrazole, Imidazole, and Isoindolone Dipyrrinone Fluorophores using a Claisen-Schmidt Condensation Approach
Published on: June 10, 2021
08:51Scale-up Chemical Synthesis of Thermally-activated Delayed Fluorescence Emitters Based on the Dibenzothiophene-S,S-Dioxide Core
Published on: October 24, 2017
Related Concept Videos
Photoluminescence: Applications
Photoluminescence: Fluorescence and Phosphorescence
A pair of electrons in a...
Variables Affecting Phosphorescence and Fluorescence
Fluorescence and Phosphorescence: Instrumentation
Gas Chromatography: Types of Detectors-II
Alkyl Halides
Alkyl halides are halogen-substituted alkanes wherein one or more hydrogen atoms of an alkane is replaced by a halogen atom such as fluorine, chlorine, bromine, or iodine. The carbon atom in an alkyl halide is bonded to the halogen atom, which is sp3-hybridized and exhibits a tetrahedral shape.
Unlike alkyl halides, compounds in which a halogen atom is bonded to an sp2 -hybridized carbon atom of a carbon-carbon double bond (C=C) are called vinyl halides. Whereas aryl...