Aggregation Behavior and High Charge-Carrier OFET-Mobility of Functionalized Phenanthro[9,10-d]imidazoles

Abstract

We designed and synthesized phenanthro­[9,10-d]­imidazoles (PIs) in a D–A fashion to achieve a balance of charge carriers. Solution processable bottom gate–top contact organic field-effect transistors (OFET) were fabricated using a binary solvent system. The devices exhibited excellent p-channel characteristics with a high mobility of 0.70 cm2 V–1 s–1 and an on/off ratio of 107. Frontier molecular orbital levels and packing modes obtained from computational analysis supported the observed high mobility of the synthesized PI. Solvatochromism study of the compounds marked them insensitive toward solvent polarity. Photophysical behavior of the compounds in tetrahydrofuran/H2O inferred efficient aggregate behavior. Scanning electron microscopy images of the aggregates in high water content show the formation of nanoaggregates. Dynamic light scattering experiments suggested a unimodal distribution of the nanoaggregates. This research work reports functionalized PIs with excellent OFET performance.

Donor–Acceptor Fluorophores and Macrocycles Built Upon Wedge-Shaped π-Extended Phenanthroimidazoles

“…Synthetically, the PI core can be prepared through the condensation reaction of phenanthrene-9,10-dione with an aldehyde and an amine partner under acidic conditions. , This condensation approach has led to a large number of π-extended PI derivatives in which the imidazolyl moiety is functionalized with various aryl groups at the 2 position (motif I, in Figure ). Moreover, the imidazolyl N–H group can be readily substituted with an alkyl or aryl group to further modify the solubility and intermolecular aggregation behavior. , PI -containing functional materials so far reported in the literature are predominantly derivatives based on motif I, many of which have found applications in fluorescent and phosphorescent organic light-emitting diodes (OLEDs), ratiometric fluorescent probes, fluorescent photoswitches, and medicines. ,− On the other hand, the PI group contains active sites on the phenanthrene side through which π-extensions can also be made. Of particular interest is the aryl functionalizations at the 6 and 9 positions (motif II, Figure ).…”

“…Moreover, the imidazolyl N−H group can be readily substituted with an alkyl or aryl group to further modify the solubility and intermolecular aggregation behavior. 18,19 PIcontaining functional materials so far reported in the literature are predominantly derivatives based on motif I, many of which have found applications in fluorescent and phosphorescent organic light-emitting diodes (OLEDs), ratiometric fluorescent probes, fluorescent photoswitches, and medicines. 17,20−25 On the other hand, the PI group contains active sites on the phenanthrene side through which π-extensions can also be made.…”

Functionalized D/A–A–D quinolines for application in solution-processable p-channel organic field-effect transistors

“…The field of materials chemistry is growing at an alarming speed with modifications in materials and the development of technology. 1,2 Highly pi-conjugated aromatic organic materials are the backbone of organic electronics with applications in organic light-emitting diodes (OLEDs), 3 organic field-effect transistors (OFETs), 4 organic photovoltaics, 5 organic light-emitting transistors (OLETs), 6 memory devices, nano-RFID tags, 7 modern health care devices, 8 and sensors. 9 They are swiftly replacing silicon electronics because of their many advantages.…”

Hexaarylbenzene based high-performance p-channel molecules for electronic applications

“…The p-extended organic small molecules and polymers are important classes of materials in modern technology due to their cost-effectiveness and convenient chemical modications. [48][49][50] Also, the monodispersity and high purity of small molecules promote the generation of uniform ordered lms. The HAB-based small molecules, polymers, and dendrimers have been utilized as active materials in organic electronic devices.…”