Synthesis of Arylamine Tribenzopentaphenes and Investigation of their Hole Mobility

Abstract

We report the versatile synthesis of two tribenzo[fj,ij,rst]pentaphene (TBP) derivatives bearing two diarylamine substituents attached at the opposite ends of the aromatic core. Field effect transistor (FET) devices of the bis-diarylamine-TBP compounds were fabricated using spin coating under different concentrations, spin speed, and solvent conditions. Emission spectra and surface investigation by atomic force microscopy (AFM) reveal the formation of aggregates induced by the strong π–π stacking of the aromatic core leading to island features, and thus, unexpected low hole mobilities. The synthetic strategy we show herein, however, offers the possibility to decorate the TBP core structure with various charge-carrier peripheral groups and optimized alkyl chains, which should improve the crystalline property of their thin films upon deposition, leading consequently to a better hole transport mobility.

Direct synthesis of polyaromatic chains of tribenzopentaphene copolymers through cyclodehydrogenation of their poly‐tetraphenylbenzene precursors

“…The fluorescence quantum yields of 5a, 5b, and 5c in THF are 0.28, 0.23, and 0.45, respectively (absorption maxima were used as the excitation wavelengths). It is noteworthy that the emission spectra of polymers 5a–c further prove the efficient aromatization of the tetraphenyl benzene precursors into their TBP targets because all the final polymers portray emission with peaks contours comparable with that of the doubly substituted TBP cores …”

“…The dibrominated tetraphenylbenzene monomers 2a–b were synthesized using a two‐step reaction (Scheme ). First, a double Knoevenagel condensation reaction was carried out to make 1a and 1b . The second step consisted of a [4 + 2] Diels–Alder cycloaddition reaction where the microwave‐assisted heating of 1a with tetradec‐1‐yne in xylene afforded 2a in quantitative yield, whereas the reaction of 1b with phenylvinyl sulfoxide in refluxing toluene yielded 2b in good yield …”

“…The design of new large polycyclic aromatic hydrocarbons (PAHs) has become a major interest because of their remarkable contributions in numerous applications that encompass energy storage, porous frameworks for separation, sensors, lasers, spintronics, and optoelectronics, among others, light emitting diodes, field‐effect transistors, and photovoltaics,. Prolific synthetic pathways have been established during the first half of the 20th century and which allowed for making PAHs with molecular structures that vary from symmetrical planar, contorted, to less symmetrical geometries . Recently, extended PAHs have attracted further attention because they offer a bottom‐up approach to produce graphene ribbons, which permits a better control over the target structures, therefore extending the scope of potential applications .…”

Polymer-Based Gate Dielectrics for Organic Field-Effect Transistors

“…Some reports stated that the surface with a lower surface energy led to smaller grain sizes of pentacene, with more interconnections between the grains to enhance charge transport . Yang et al reported an increase in pentacene mobility from 0.11 to 0.56 cm 2 V –1 s –1 , with a decrease in surface energy of 18 mN m –1 . Liu et al, however, claimed that the deep and dense ground boundaries (in small grains) resulted from low surface energy would decrease the mobility.…”

Laterally stretched polycyclic aromatic hydrocarbons: synthesis of dibenzophenanthroheptaphene and tetrabenzotriphenylenopyranthrene derivatives

“…21,22 As part of our research on PAH derivatives with tapered symmetry, we reported recently the synthesis and structural characterization of a family of the trapezoidal tribenzo[ fg,ij,rst]pentaphene (TBP) derivatives bearing various aromatic side groups either at their wide or narrow bases. 23,24 Building upon this result, we aimed at synthesizing more laterally extended derivatives than TBP, 25 contorted (c-HBC), 20 less symmetrical (DDHH), 17 (TBTP,2). The higher conjugation of compounds 1 and 2 is expected to lower their respective HOMO-LUMO energy gaps and hence improve their electron/hole charge carrier mobility.…”