Chiral bicyclic guanidine 1 was found to be an excellent catalyst for reactions between anthrones and various dienophiles. The catalyst can tolerate a range of substituents and substitution patterns, making several anthrone derivatives suitable for this reaction. Both Diels-Alder and Michael adducts were obtained in excellent yields, high regioselectivities, and high enantioselectivities. This is the first case of a highly enantioselective base-catalyzed anthrone Diels-Alder reaction.

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Silver nanoparticles have attracted great interests widely in medicine due to its great characteristics of antibacterial activity. In this research, the antibacterial activity and biocompatibility of a topical gel synthesized from polyvinyl alcohol, chitosan, and silver nanoparticles were studied. Hydrogels with different concentrations of silver nanoparticles (15 ppm, 30 ppm, and 60 ppm) were evaluated to compare their antibacterial activity, nanoparticles’ sizes, and in vivo behaviors. The resulted silver nanoparticles in the hydrogel were characterized by TEM showing the nanoparticles’ sizes less than 22 nm. The in vitro results prove that the antibacterial effects of all of the samples are satisfied. However, the in vivo results demonstrate the significant difference among different hydrogels in wound healing, where hydrogel with 30 ppm shows the best healing rate.

The incorporation of a p-nitrophenoxy moiety in substrates has enabled the development of colorimetric assays to rapidly screen for O-demethylation activity of P450 enzymes. For the light-driven hybrid P450 BM3 enzymes, where a Ru(II) photosensitizer powers the enzyme upon visible light irradiation, we have investigated a family of p-nitrophenoxy derivatives as useful chromogenic substrates compatible with the light-driven approach. The validation of this assay and its adaptability to a 96-well plate format will enable the screening of the next generation of hybrid P450 BM3 enzymes towards C-H bond functionalization of non-natural substrates.

Ru(II)-diimine complexes covalently attached near the heme active site of P450 BM3 enzymes have been used to rapidly inject electrons and drive selective C-H functionalization upon visible light irradiation. Herein, we have generated a series of hybrid P450 BM3 enzymes containing a photosensitizer of general formula [Ru(4,4′-X2bpy)2(PhenA)]2+ where X = Cl, H, tBu, Me OPhe, OMe, or NMe2, bpy = 2, 2′-bipyridine, and PhenA = 5-acetamido-1,10-phenanthroline. We then probed the effect of electron-withdrawing and -donating groups at the para position of the 4,4′-X2bpy ligands on the corresponding hybrid enzymes photocatalytic activity. A three-fold improvement in initial reaction rate was noted when varying the substituent from Cl to tBu however, the reaction rates decrease thereafter with the more electron donating groups. In order to rationalize those effects, we investigated the variation of the substitutent on the photophysical properties of the corresponding [Ru(4,4′-X2bpy)2(bpy)]2+ model complexes. Several linear correlations were established between the E(III/II) potential, the MLCT emission and absorption energies as well as the logarithm of the luminescence quenching rate vs. the summative Brown-Okamoto parameter (Σσp+). Moreover, a downward curved Hammett plot is observed with the hybrid enzyme initial reaction rate revealing mechanistic details about the overall light-driven enzymatic process.

The effects of triorganotins on the 4th instar stage of Aedes aegypti larvae were evaluated. The most effective of the 15 triorganotins used in the study was tributyltin chloride with an LC 50 value of 0.57 AE 0.07 mg dm À3 . The low LC 50 values obtained indicated that this class of compounds is an effective larvicide against the larvae of this species of mosquito. The toxicity of the compounds was found to be primarily dependent on the R group attached to the tin atom. The order of activity for the triorganotins tested was Bu b Ph b Cy b Me. However, a limited order, based on two series of the compounds tested, was also observed for the anionic X group on the tin atom.

This research aims to develop a new type of electrolyte for dye-sensitized solar cells (DSCs) which can be produced in cost-effective and large scale. DSCs using deep eutectic solvents (DESs) mixed with ethanol (50% w/w DES content), as an electrolyte medium, was studied herein for the first time. Ten types of DESs were synthesized and three among them were potential candidates for DSC electrolytes. Compared to toxic and volatile organic solvents, this mixed solvent is more eco-friendly and inexpensive. According to J-V curve measurements, DSCs that used DES-ethanol medium showed promising photovoltaic performance.

Gold nanoparticle catalysts have attracted much attention due to their catalytic efficiency under mild conditions. We report here the synthesis of a series of shapes of gold nanocrystals by simple reduction of HAuCl4⋅3H2O and application them as the catalysts for multicomponent Biginelli reaction. Amongst these, unsupported gold nanorods show the best catalytic activity. Its efficiency allows one‐pot synthesis of 3,4‐dihydropyrimidin‐2(1H)‐ones to proceed in high yield under mild conditions.