Herein, we report a direct photochemical dehydrogenative C–N coupling of unactivated C­(sp2)–H and N­(sp2)–H bonds. The catalysts or additive-free transformation of 2-([1,1′-biphenyl]-2-yl)-1H-benzo­[d]­imidazole to benzo­[4,5]­imidazo­[1,2-f]­phenanthridine was achieved at ∼350 nm of irradiation via ε-hydrogen abstraction. DFT calculations helped to understand that the N–H···π interaction was essential for the reaction to proceed at a lower energy than expected.

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Defect-activated ultrathin graphitic carbon nitride nanosheets (g-C3N4) show an enhanced visible light absorption, better charge-separation, and facile charge transport properties. These are requisite for the designing of an active photocatalyst....

On-the-fly dynamics simulations are performed for the reaction of catechol + O3. The post transition state (TS) dynamics is studied at temperatures of 400 and 500 K. The PM7 semiempirical method is employed for calculating the potential energy gradient needed for integrating Hamilton’s equations of motion. This semiempirical method provides excellent agreement in terms of energy and geometry of the TSs as well as minimum energy states of the system with respect to B3LYP/6-311+G (2df, 2p) calculated results. In the dynamics, first, a peroxyacid is formed, which further dissociates to different fragments. Four major channels forming CO, CO2, H2O, and small carboxylic acid (SCA) fragments are seen in this reaction. Rates of each of the channels and the overall unimolecular reaction are calculated at both temperatures. Branching ratios of all these product channels are calculated and compared with experiment. The minimum energy profile of CO2, CO, and H2O channels are calculated. A qualitative estimate of activation energies for all the channels are obtained and compared with the explicit TS energies of three product channels, which ultimately correlate with the reaction probabilities.

Atmospheric pressure non-thermal plasma jets are becoming subject of great attention in various fields such as plasma processing and biomedical applications due to their ability to produce highly reactive species and good reaction chemistry at low gas temperatures. In the present study, a non-thermal plasma jet operating on argon gas at atmospheric pressure aimed mainly towards surface modification and thin film deposition applications has been developed. Optical emission spectroscopy is used to evaluate the plasma parameters. The gas temperature (800 ± 50 K) is estimated from OH(A-X) rotational band. The excitation temperature is measured using intensity ratio of two argon lines and is found to be 0.241–0.273 eV and the corresponding electron temperatures have been measured. Electron density of the order of 1014 cm−3 has been obtained from the Stark broadening of Balmer H β line. The plasma jet has been successfully employed to deposit a superhydrophobic thin film of SiwCxHyOz using hexamethyldisiloxane (HMDSO) precursor monomer. The deposited film has been analyzed using XRD, FTIR, SEM, AFM, and contact angle analyzer. All the treated surfaces have shown superhydrophobic property with a contact angle greater than 150° showing numerous potential in various applications. This method is a relatively easy and environmental friendly way of fabricating superhydrophobic surfaces.

This report describes the synthesis of thiol-protected Pd nanoparticles (NPs) (Pd-MUA) (MUA = 11-mercaptoundecanoic acid) supported on oxidized charcoal (OC-Pd-MUA) at room temperature. The Pd-MUA NPs and OC-Pd-MUA nanocomposites (NCs) were characterized with Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), energy-dispersive X-ray spectrometry (EDX), X-ray photoelectron spectroscopy (XPS), and Brunauer–Emmett–Teller (BET) techniques. The size distribution curve revealed that the diameter of the nanoparticles was in the range of ∼8–12 nm, and the surface area of the NCs was found to be 138.449 m2/g. The as-prepared OC-Pd-MUA NCs were used as a catalyst for the cross dehydrogenative coupling (CDC) of two different heteroarenes. Remarkably, the catalyst was found to be very efficient in activating various heteroarenes under mild reaction conditions. Most importantly, no homocoupled or other byproducts were observed during the heterocoupling reactions. Moreover, the catalyst can be potentially used for the homocoupling reaction of various heteroarenes. It is noteworthy that only 0.22 mol % catalyst loading was required to activate a broad substrate scope with large functional group tolerance. Notwithstanding, the efficacy of the catalyst was found to be retained even after six reaction cycles. The reusability and hot filtration tests validated the heterogeneous nature of the catalysis. In addition, the experimental and computational studies collectively suggested that thiophene derivatives react to produce energetically stable products compared with other heteroarenes during the reaction.

A mild and eco-friendly visible-light-induced synthesis of 2-(2-Hydrazinyl) thiazole from readily accessible thiosemicarbazide, carbonyl, and phenacyl bromide in the absence of a metal catalyst and/or any extrinsic photosensitizer is reported....

A facile and eco‐friendly sustainable synthesis of functionalized quinoxaline derivatives from 1,2‐diaminobenzenes and 2‐bromoacetophenones via a one‐pot two‐component reaction using choline chloride (ChCl): glycerol as a bio‐renewable DES has been developed. In this protocol, nucleophilic 1,2‐diaminobenzenes are mixed with phenacyl bromides or 3‐(bromoacetyl) coumarin to produce quinoxaline derivatives in a high yield (up to 96 %), with a clean reaction profile without the use of a solvent or catalyst at ambient temperature (80 °C). The presence of DES is proven to be essential for assuring efficient transformation, as the product yield was extremely low with a slow reaction profile in the absence of this media. The DES media could be recycled and reused up to five times without losing its efficiency or affecting the chemical yield of the reaction. In the showcase study, the reaction was also scaled up to the gram scale (10 mmol scale), revealing the synthetic potential of the current approach. A DFT calculation has been also performed to probe the mechanism and reversal of the regioselectivity in the products formation.