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.
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.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.