A thermally and electrochemically stable organic hole-transporting material with an adamantane central core and triarylamine moieties

Hole transporting materials (HTMs) play an important role in constructing optoelectronic devices. Herein, we report the design and synthesis of a novel HTM 4,4',4 '',4'''-(adamantane-1,3,5,7-tetrayl)tetrakis(N,N-bis(4-methoxyphenyl)aniline) (ad-OMeTPA) containing a central unit of adamantine and peripheral groups of triarylamine moieties. Its molecular structure was identified by H-1 NMR, FT-IR, and Raman spectroscopy. The glass-transition temperature (T-g) of ad-OMeTPA was measured by differential scanning calorimetry (DSC), indicating its thermal stability. The optical and electrochemical properties of ad-OMeTPA were investigated by UV-vis absorption spectroscopy, fluorenscence spectroscopy, and cyclic voltammetry (CV). In addition, the harmonic vibrational wavenumbers and frontier molecular orbitals were calculated using density functional theory (DFT) method. The results reveal that ad-OMeTPA has favorable optical adsorption/emission properties, suitable energy levels and high electrochemical stability, indicating its potential application in organic optoelectronic devices. (C) 2012 Elsevier B.V. All rights reserved.