Nanofabrication via SEM Electron‐beam Stimulated Suzuki‐Miyura Type Reaction: Fingerprints of Carbazole Derivative Revealed by Synchrotron‐IR Nanospectroscopy and Mass Spectrometry

Abstract

Carbazole‐based compounds have demonstrated interesting physical and chemical properties for OLED devices. 3,6‐diphenylcarbazole has a direct application in the composition of structures with potential to suppress the loss of efficiency under high luminance conditions along with its use in the emitting layer. In this study, we reveal and explore the conditions in which a triggered electron beams (e‐beams) solid state Suzuki‐Miyaura type reaction between 3,6‐diiodocarbazole and phenylboronic acid could be carried out. Applying typical SEM acceleration voltage (30 keV), sufficient energy transfer enabled the activation of the reaction. Synchrotron Infrared Nano Spectroscopy (SINS) was used to acquire nanoscale molecular vibrational spectra and compare with conventional FTIR absorption spectra for chemical characterization. Evidences obtained by mass spectrometry confirmed the formation of the 3,6‐diphenyl‐9H‐carbazole under higher e‐beam dose (30 keV, 10 minutes), when compared to 5 and 10 keV. In addition, the phenylboronic acid seems to have a role in the reaction outcome. Both samples irradiated in the presence and in the absence of palladium exhibited the fingerprints of the expected product 3,6‐diphenylcarbazole shedding light on possible alternative mechanisms and the straightforward construction of nanodevices.