Deuteration of molecules for neutron reflectometry on organic light-emitting diode thin films
摘要:
Deuterated forms of aromatic charge transporting heterocycles 2 and 3 used in organic light-emitting diodes have been produced by hydrothermal reactions, catalyzed by Pt/C or Pd/C. Comprehensive analysis by mass spectroscopy, H-1, H-2 and C-13 NMR enables determination of the overall quantity of D atoms present, as well as the level of deuteration at each molecular site. The roles of solubility and steric availability in deuteration are discussed in the light of these results. Neutron reflectometry indicates excellent scattering contrast between protonated and deuterated forms of these molecules, with nanoscale thin films showing the same density as in their bulk molecular forms. Although used for morphological studies of thin films typically used in OLEDs, the synthetic and analysis methods described here are generic and suitable for deuteration of other conjugated aromatic heterocycles and other optoelectronic devices. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.
An organic electroluminescent device includes a pair of electrodes; and an organic layer between the pair of electrodes, which includes a light-emitting layers wherein the organic layer contains a compound represented by the following formula (I); and the light-emitting layer contains a iridium complex phosphorescent material:
wherein R
1
, R
2
, R
3
, R
4
, R
5
, R
6
, R
7
and R
8
each represents a hydrogen atom or a substituent, and contiguous substituents of R
1
to R
8
may be bonded to each other to form a condensed ring; R
9
represents an alkyl group, an alkenyl group, an aryl group, a hetero-aryl group, or a silyl group, and each of which group may be substituted with a substituent; and at least one of R
1
to R
9
represents a deuterium atom or a substituent containing a deuterium atom.