The Asian citrus psyllid, Diaphorina citri Kuwayama, is one of the most damaging pests of citrus-producing regions throughout the world. The use of insecticides is the main strategy for controlling psyllid and has increased year by year. In this study, four field populations of D. citri were evaluated for resistance to nine different insecticides using the leaf-dip method. The results showed that the highest level of resistance for D. citri was found in imidacloprid with a resistance ratio of 15.12 in the Zengcheng population compared with the laboratory susceptible population. This was followed by chlorpyriphos (6.47), dinotefuran (6.16), thiamethoxam (6.04), lambda-cyhalothrin (4.78), and bifenthrin (4.16). Piperonyl butoxide (PBO) and triphenyl phosphate (TPP) showed significant synergism on imidacloprid effects in the Zengcheng population (3.84- and 2.46-fold, respectively). Nevertheless, diethyl maleate (DEM) had no synergism on imidacloprid. Biochemical enzyme assays suggested that general esterase, glutathione S-transferase and cytochrome P450 monooxygenase activities were higher in the field-collected populations than in the laboratory susceptible population. However, glutathione S-transferase may play a minor role in the resistance of adult D. citri to insecticides. At the molecular level, resistance of D. citri to imidacloprid is mainly related to the increased expression of CYP4C68 and CYP4G70 (>5-fold).

Interconversion between CO 2 + H 2 and FA/formate is the most promising strategy for the fixation of carbon dioxide and reversible hydrogen storage; however, FA dehydrogenation and CO 2 hydrogenation are usually studied separately using different catalysts for each reaction. This report describes of the catalysis of [Cp*Ir(N∧N)(X)] n+ (Cp* = 1,2,3,4,5-pentamethylcyclopentadienyl; X = Cl, n = 0; X = H 2 O, n = 1) bearing a proton-responsive N∧N pyridylpyrrole ligand for both reactions. Complex 2-H 2 O catalyzes FA dehydrogenation at 90 °C with a TOF max of 45 900 h −1 . Its catalysis is more active in aqueous solution than in neat solution under base-free conditions. These complexes also catalyze CO 2 hydrogenation in the presence of base to formate under atmospheric pressure (CO 2 /H 2 = 0.05 MPa/0.05 MPa) at 25 °C with a TOF value of 4.5 h −1 in aqueous solution and with a TOF value of 29 h −1 in a methanol/H 2 O mixture solvent. The possible mechanism is proposed by intermediate characterization and KIE experiments. The extraordinary activity of these complexes are mainly attributed to the metal−ligand cooperative effect of the the pyrrole group to accept a proton in the dehydrogenation of formic acid and assist cooperative heterolytic H−H bond cleavage in CO 2 hydrogenation.

To explore structure–activity relationships with respect to light-harvesting behavior, a family of neutral iridium complexes [Ir­(ppy)2(LR)] 1–4 (where ppy = 2-phenylpyridine, and N̂N = 2-(1H-pyrrol-2-yl)­pyridine and its functionalized derivatives) were designed and synthesized. The structural modifications in metal complexes are accomplished through the attributions of electron-donating CH3 in 2, OCH3 in 3, and electron-withdrawing CF3 in 4. The structural analysis displays that the pyridylpyrrole acts as one-negative charged bidentated ligand to chelate the iridium center. The electrochemical and photophysical properties of these complexes were systematically studied. The neutral 1–4 as well as the ionic structurally analogous [Ir­(ppy)2(bpy)]­(PF6) (5) were utilized as PSs in photocatalytic hydrogen generation from water with [Co­(bpy)3]­(PF6)2 as catalyst and triethanolamine (TEOA) as electron sacrificial agent in the presence of salt LiCl. Complex 1 maintains activity for more than 144 h under irradiation, and the total turnover number is up to 1768. The electrochemical properties and the quenching reaction indicate the H2 generation by neutral complexes 1–4 is involved exclusively in the oxidative quenching process.

A family of energetic derivatives based on functionalized bridged 1,2,4-triazole-N-oxides was designed. Their properties and comprehensive correlations were investigated. The excellent performance makes them promising candidates of the new environmentally friendly HEDMs.

New dipyridylpyrrole N-oxide ligands HL1 and HL2 are designed and synthesized via oxidation of 2-(5-(pyridin-2-yl)-1H-pyrrol-2-yl)pyridine (Hdpp) by 3-chloroperbenzoic acid (m-CPBA) in CH2Cl2. Treatment of ZnEt2 and two equiv. of HL1...