Photoinduced metal-free atom transfer radical polymerization (ATRP) activated by highly conjugated electron-rich thienothiophene derivatives, namely 4-[2-(4-diphenylaminophenyl)-thieno­[3,2-b]­thiophen-3-yl]­benzonitrile (TT-TPA), 4-[2,5-bis­(4-diphenylaminophenyl)-thieno­[3,2-b]­thiophen-3-yl]­benzonitrile (TPA-TT-TPA), 4-(2-(4-(1,2,2-triphenylvinyl)­phenyl) thieno­[3,2-b]­thiophen-3-yl)­benzonitrile (TT-TPE) and 4-(2,5-bis­(4-(1,2,2-triphenylvinyl)­phenyl)­thieno­[3,2-b]­thiophen-3- yl)­benzonitrile (TPE-TT-TPE) is reported. Polymerization of methyl methacrylate (MMA) is efficiently activated and deactivated with light, forming polymers with controlled the molecular weight characteristics, dispersity, and chain end functionality. Polymerization studies and DFT calculations revealed that TT-TPA is the most efficient activator due to the favorable thermodynamic properties.

TPE units at the periphery of two TTs and a DTT affect the structures, properties and OLED characteristics of these three synthetically easily accessible novel conjugated compounds for materials chemistry.

We herein report photoinduced step‐growth polymerization of highly conjugated 2,5‐dithiophenyl (thieno[3,4‐b] thiophene) (TTs) derivatives possessing 4‐cyanophenyl or 4‐methoxyphenyl or 3‐(4‐fluorophenyl) groups substituted at the terminal position. Upon irradiation at 350 nm, the excited state of these molecules forms exciplex with diphenyliodonium hexafluorophosphate (DPI) that undergoes electron transfer reaction forming radical cations. Successive proton release and radical coupling reactions yield corresponding oligothienothiophenes with overall yields varying between 19–74%. Structural and molecular weight characteristics of the oligomers thus formed were investigated by Ultraviolet, fluorescence, NMR (Nuclear Magnetic Resonance) and infrared (IR) spectroscopic methods, and GPC (Gel Permeation Chromatography), respectively. The effect of substitution and dithiophene side groups on the reactivity of the monomer and band gap of the oligomers formed was evaluated by using cyclic voltammetry.

Today, more disciplines are intercepting each other, giving rise to “cross-disciplinary” research. Technological advancements in material science and device structure and production have paved the way towards development of new classes of multi-purpose sensory devices. Organic phototransistors (OPTs) are photo-activated sensors based on organic field-effect transistors that convert incident light signals into electrical signals. The organic semiconductor (OSC) layer and three-electrode structure of an OPT offer great advantages for light detection compared to conventional photodetectors and photodiodes, due to their signal amplification and noise reduction characteristics. Solution processing of the active layer enables mass production of OPT devices at significantly reduced cost. The chemical structure of OSCs can be modified accordingly to fulfil detection at various wavelengths for different purposes. Organic phototransistors have attracted substantial interest in a variety of fields, namely biomedical, medical diagnostics, healthcare, energy, security, and environmental monitoring. Lightweight and mechanically flexible and wearable OPTs are suitable alternatives not only at clinical levels but also for point-of-care and home-assisted usage. In this review, we aim to explain different types, working mechanism and figures of merit of organic phototransistors and highlight the recent advances from the literature on development and implementation of OPTs for a broad range of research and real-life applications.

Two novel copolymers of 4-thieno[3,2-b]thiophen-3-ylbenzonitrile (TT-CN), possessing electron withdrawing cyano moiety, with anthracene (P1) and biphenyl (P2) were prepared via Suzuki coupling. Optic, electronic, and thermal properties of the copolymers were investigated through UV-Vis spectroscopy, cyclic voltammetry, gel permeation chromatography, and thermal gravimetric analysis. The polymers with anthracene and biphenyl had electronic band gaps of 2.01 and 1.90 eV, respectively. Both polymers demonstrated excellent large Stokes shifts of 101 (anthracene) and 105 nm (biphenyl) as well as very good thermal properties. As they had good optical, electronic, and thermal properties, they are promising candidates for electronic applications.