Synthesis of indolocarbazole derivatives

Start date October 2012

Client University of Manchester
Investigator

Dr David Nugent
david.nugent@elucidare.co.uk


Abstract

University of Manchester researchers have invented a novel method for synthesising polycyclic π-conjugated heteroaromatic molecules. More specifically, indolo[3,2-b]carbazole derivatives are produced via a bidirectional cyclisation through transition metal catalysed oxidative C-H amination reactions. This method allows an expedient, flexible synthesis route to maximise yields, minimise waste and readily permit solution phase processing of the products. Target applications include hole transport layer (HTL) materials within organic electroluminescent (EL) devices, organic field effect transistors (OFETs), and pharmaceutical compounds.

 


Indolocarbazole derivatives

To demonstrate the diversity of the technology a range of derviatives has been produced. These include indolo[3,2-b]carbazoles, diindolo-thieno[3,2-b]thiophenes, carbazolo[3,2-b]carbazole and benzo[1,2-b:3,4-b']dicarbazoles.

 

 

A more comprehensive yet non-limiting range of chemicals manufactured by the method is available on request from David Nugent.

 

 

 

a: Cyclic voltammetry (CV) was performed at a concentration of 10-3 M in CH2Cl2 (Bu4NPF6 0.2 M) at 100 mV s-1 in a BASI Epsilon electrochemical workstation with a three-electrode cell, Ag/AgNO3 as reference electrode,
platinum wire as counter electrode and using a Pt disk electrode (diameter 1 mm) as working electrode. Ferrocene was added to the electrolyte solution at the end of a series of experiments. The ferrocene/ferrocenium (Fc/Fc+) couple served as internal standard. For a further comparison of the electrochemical and optical properties, all potentials are referred to the SCE electrode that was calibrated at – 0.405 V vs. Fc/Fc+ system. The HOMO level was estimated from: HOMO (eV) = -[Eonsetox (vs SCE) + 4.4], based on an SCE energy level of 4.4 eV relative to the vacuum.
b HOMO (onset of oxidation) vs Fc/Fc+ at -0.405V vs SCE
c LUMO = HOMO – ΔEopt
d ΔEopt calculated from λonset


Organic Electronics

Indolocarbazoles have been studied extensively as an organic semiconductor material for manufacturing organic light emitting diodes (OLEDs) and organic thin film transistors (OFETs). In the former, indole compounds are combined with an electroluminescent material to create a photoactive layer.

 


Documents available for download

 

PCT Application WO 2012/076886 A2 "Novel Process and Compounds",