Synthesis and electroluminescent properties of fluorene‐based copolymers containing electron‐withdrawing thiazole derivatives

2-Aminomethylene-5-sulfonylthiazole Inhibitors of Lysyl Oxidase (LOX) and LOXL2 Show Significant Efficacy in Delaying Tumor Growth

The lysyl oxidase (LOX) family of extracellular proteins plays a vital role in catalyzing the formation of cross-links in fibrillar elastin and collagens leading to extracellular matrix (ECM) stabilization. These enzymes have also been implicated in tumor progression and metastatic disease and have thus become an attractive therapeutic target for many types of invasive cancers. Following our recently published work on the discovery of aminomethylenethiophenes (AMTs) as potent, orally bioavailable LOX/LOXL2 inhibitors, we report herein the discovery of a series of dual LOX/LOXL2 inhibitors, as well as a subseries of LOXL2-selective inhibitors, bearing an aminomethylenethiazole (AMTz) scaffold. Incorporation of a thiazole core leads to improved potency toward LOXL2 inhibition via an irreversible binding mode of inhibition. SAR studies have enabled the discovery of a predictive 3DQSAR model. Lead AMTz inhibitors exhibit improved pharmacokinetic properties and excellent antitumor efficacy, with significantly reduced tumor growth in a spontaneous breast cancer genetically engineered mouse model.

Nitrogen substitution improves the mobility and stability of electron transport materials for inverted perovskite solar cells

A suitable electron transport material (ETM) plays key roles in efficient perovskite solar cells (PSCs), because it is beneficial for exciton dissociation and charge transport at the interface thus increasing the short circuit current density. Based on the experimentally reported efficient electron transport molecule 10,14-bis(5-(2-ethylhexyl)thiophen-2-yl)-dipyrido[3,2-a:2',3'-c][1,2,5]thiadiazolo[3,4-i]phenazine (TDTP), we theoretically design a set of new ETMs (TDTP-1, TDTP-2a, TDTP-2b, TDTP-3a, and TDTP-3b) by introducing a nitrogen atom into the thiophene ring or replacing a hydrogen atom on the methyl with an amino group. Quantum-chemical calculations reveal that the designed molecules behave much better than TDTP in terms of electron mobility, air stability, and solubility, where the electron mobility of TDTP-3b is two orders of magnitude higher than that of TDTP owing to the extra SN interactions in TDTP-3b that lead to the quasi two-dimensional π packing motif which facilitates electron transport evidently. Moreover, we find that the substitution effect of the nitrogen atom strongly depends on the position, where the nitrogen atom at the β-position of the thiophene ring (TDTP-2b and TDTP-3b) is more conducive to electron transport. Importantly, our calculations show that the ETM/perovskite interface interaction is enhanced after the introduction of the nitrogen atom and amino group thanks to the added NPb interaction, which favors electron transport with the newly designed ETMs. Our results not only report a set of novel promising ETMs, but also provide a useful design strategy for efficient ETMs.

Bithiazole: An Intriguing Electron-Deficient Building for Plastic Electronic Applications

The heterocyclic thiazole unit has been extensively used as electron-deficient building block in π-conjugated materials over the last decade. Its incorporation into organic semiconducting materials is particularly interesting due to its structural resemblance to the more commonly used thiophene building block, thus allowing the optoelectronic properties of a material to be tuned without significantly perturbing its molecular structure. Here, we discuss the structural differences between thiazole- and thiophene-based organic semiconductors, and the effects on the physical properties of the materials. An overview of thiazole-based polymers is provided, which have emerged over the past decade for organic electronic applications and it is discussed how the incorporation of thiazole has affected the device performance of organic solar cells and organic field-effect transistors. Finally, in conclusion, an outlook is presented on how thiazole-based polymers can be incorporated into all-electron deficient polymers in order to obtain high-performance acceptor polymers for use in bulk-heterojunction solar cells and as organic field-effect transistors. Computational methods are used to discuss some newly designed acceptor building blocks that have the potential to be polymerized with a fused bithiazole moiety, hence propelling the advancement of air-stable n-type organic semiconductors.

Thiophene-Functionalized Hybrid Perovskite Microrods and their Application in Photodetector Devices for Investigating Charge Transport Through Interfaces in Particle-Based Materials

Particle-based semiconductor materials are promising constituents of future technologies. They are described by unique features resulting from the combination of discrete nanoparticle characteristics and the emergence of cooperative phenomena based on long-range interaction within their superstructure. (Nano)particles of outstanding quality with regards to size and shape can be prepared via colloidal synthesis using appropriate capping agents. The classical capping agents are electrically insulating, which impedes particle-particle electronic communication. Consequently, there exists a high demand for realizing charge transport through interfaces especially for semiconductors of relevance like hybrid perovskites (HYPEs), for example, CH₃NH₃PbI₃ (MAPI) as one of the most prominent representatives. Of particular interest are crystals in the micrometer range, as they possess synergistic advantages of single crystalline bulk properties, shape control as well as the possibility of being functionalized. Here we provide a synthetic strategy toward thiophene-functionalized single crystalline MAPI microrods originating from the single source precursor CH₃NH₃PbI₃TEG₂ (TEG = triethylene glycol). In the dark, the microrods show enhanced charge transport characteristics of holes over 2 orders of magnitude compared to microscale cuboids with insulating alkyl surface modifiers and nonfunctionalized random sized particles. In large-area prototype photodetector devices (2.21 cm²), the thiophene functionalization improves the response times because of the interparticle charge transport (t_ON = 190 ms, t_OFF = 430 ms) compared to alkyl-functionalized particles (t_ON = 1055 ms, t_OFF = 60 ms), at similar responsivities of 0.65 and 0.71 mA W^-1, respectively. Further, the surface functionalization and crystal grains on the micrometer scale improve the device stability. Therefore, this study provides clear evidence for the interplay and importance of crystal size, shape and surface modification of MAPI crystals, which is of major importance in every optoelectronic device.

Biaxially extended thiophene–isoindigo donor–acceptor conjugated polymers for high-performance flexible field-effect transistors

Biaxially-extended thiophene–isoindigo donor–acceptor conjugated polymers were explored for high-performance flexible field-effect transistors. A charge carrier mobility of 1.0 cm² V⁻¹ s⁻¹ was achieved under ambient atmosphere with stable electrical properties.

New poly(selenophene–thiophene) bearing π-conjugating spacers for polymer field-effect transistors and photovoltaic cells

Five new poly(selenophene–thiophene) were synthesized for polymer optoelectronic applications. The hole field effect mobility and polymer photovoltaic power conversion efficiency could be as high as 0.27 cm² V⁻¹ s⁻¹ and 2.3 %, respectively.

Thiazole-based organic semiconductors for organic electronics

Over the past two decades, organic semiconductors have been the subject of intensive academic and commercial interests. Thiazole is a common electron-accepting heterocycle due to electron-withdrawing nitrogen of imine (C=N), several moieties based on thiazole have been widely introduced into organic semiconductors, and yielded high performance in organic electronic devices. This article reviews recent developments in the area of thiazole-based organic semiconductors, particularly thiazole, bithiazole, thiazolothiazole and benzobisthiazole-based small molecules and polymers, for applications in organic field-effect transistors, solar cells and light-emitting diodes. The remaining problems and challenges, and the key research direction in near future are discussed.