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We are grateful for the financial support from the King Abdullah University of Science and Technology (KAUST), the Ministry of Science and Technology of Taiwan (MOST 109-2113-M-110-004), Guangxi Natural Science Foundation of China (No. 2020GXNSFAA297213), and the State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (No. CMEMR2020-A12) in China. The service of Ibex, Shaheen 2 High Performance Computing Facilities was provided by KAUST.

The ligand of an organometallic complex is typically considered as a spectator which can be modified to tune the steric and electronic properties of the coordination environment. We herein demonstarted a PN3P*Rh-CO pincer system where one of the C–H bonds of the pseudo-dearomatized pyridine ring was oxidized by O2 at room temperature to create an α,β-unsaturated carbonyl functionality on the ligand backbone. The resulting metal complex with the post-modified PN3P ligand readily reacts with thiophenol and 4-methylaniline to afford the corresponding oxidative Michael addition products.

Formic acid possesses many desirable properties as a promising hydrogen energy carrier. Density functional theory (DFT) was utilized to design new Rh complexes with 2,2′-biimidazoline ligands to explore their potential as catalysts for formic acid dehydrogenation. These designed complexes were prepared and examined as catalysts under various temperatures and ratios of formic acid to sodium formate. It was found that although our complexes gave a high TOF of 20,000 h−1 at 90 °C under certain formic acid/sodium formate ratios, the dehydrogenation reaction was prematurely deactivated once 30% of the formic acid was consumed. Possible deactivation mechanisms were investigated by NMR and HRMS. Our observations suggest that while guided rational design of catalysts by DFT has much potential, the method does have limitations as evidenced by our experimental comparisons and thus pure DFT design should be conducted with caution.

A PN3P pincer ligand (1) bearing dicyclopentylphosphine substituents reacts with [Rh(COD)Cl]2 (COD = 1,5-cyclooctadiene) to produce the complex (PN3P)RhCl (2). Treatment of a benzene solution of 2 with KN(SiMe3)2 stimulates a dearomatization process, and C–H activation of benzene is achieved through the rearomatization of the central pyridine ring. This deprotonation/reprotonation of the NH arm of 2 gives the phenyl complex (PN3P)Rh(C6H5) (3). The subsequent introduction of CO gas into 3 yields the benzoyl complex (PN3P)RhCO (C6H5) (4), which can release benzaldehyde upon treatment with diluted HCl solution and regenerates 2.

Objective:Melioidosis is a zoonotic disease caused by Burkholderia pseudomallei (B. pseudomallei). Because B. pseudomallei is naturally resistant to a variety of antibiotics, such as penicillin, ampicillin, first-and second-generation cephalosporins, macrolides, aminoglycosides, streptomycin, polymyxin, etc., the selection of drugs is limited. The present study aimed to evaluate the antibacterial activity of piperacillin/tazobactam against B. pseudomallei in vitro to provide a theoretical basis and a variety of therapeutic options for clinical application.The antimicrobial susceptibilities of all B. pseudomallei isolated from melioidosis patients were detected by Etest method. Results: The MIC50 values of piperacillin/tazobactam, imipenem, meropenem, doxycycline, trimethoprim–sulfamethoxazole, ceftazidime, tetracycline, and amoxicillin/clavulanic acid were 0.25 μg/ml, 0.5 μg/ml, 0.5 μg/ml, 0.5 μg/ml, 1 μg/ml, 1 μg/ml, 2 μg/ml, and 2 μg/ml, respectively. Their MIC90 values were 0.5 μg/ml, 0.5 μg/ml, 1 μg/ml, 2 μg/ml, 2 μg/ml, 2 μg/ml, 4 μg/ml, and 4 μg/ml, respectively. All the isolates were uniformly sensitive (100%) to ceftazidime, imipenem and amoxicillin–clavulanic acid. The rate of antimicrobial sensitivity for doxycycline was 99.08%, for tetracycline-sulfamethoxazole 94.50%, and for tetracycline 94.49%.Both the MIC50 and MIC90 values of piperacillin/tazobactam were lower than those of the seven other antibiotics, indicating that it has strong antibacterial activity against B. pseudomallei in vitro.

Well-defined ruthenium(II) PN3P pincer complexes were developed for the hydrogenation of carbon dioxide. Excellent product selectivity and catalytic activity with TOF (turnover frequency) and TON (turnover number) up to 13 000 h−1 and 33 000, respectively, in a THF/H2O biphasic system were achieved. Notably, effective conversion of carbon dioxide from air into formate was conducted in the presence of an amine, allowing easy product separation and catalyst recycling.

Financial support for this work was provided by the King Abdullah University of Science and Technology (URF/1/3018–01-01).

We report a ruthenium complex containing an N,N′-diimine ligand for the selective decomposition of formic acid to H2 and CO2 in water in the absence of any organic additives. A turnover frequency of 12 000 h–1 and a turnover number of 350 000 at 90 °C were achieved in the HCOOH/HCOONa aqueous solution. Efficient production of high-pressure H2 and CO2 (24.0 MPa (3480 psi)) was achieved through the decomposition of formic acid with no formation of CO. Mechanistic studies by NMR and DFT calculations indicate that there may be two competitive pathways for the key hydride transfer rate-determining step in the catalytic process.

Aerobic denitrifying bacteria, a fast and efficient strain, is extensively adopted in the wastewater sphere, and immobilized aerobic denitrifying bacteria denitrification Technology, to some extent, solves many problems existing in the direct application of aerobic denitrifying bacteria. Concentrated sulfuric acid, nitric acid, potassium permanganate, ferric chloride etc. are used to pretreat carbon fiber respectively, and then the modified the carbon fiber is applied to fix the activated aerobic denitrifying bacteria to investigate the effects of the modification of the carbon fiber and the effects of wastewater treatment with immobilized aerobic denitrifying bacteria. The results showed that the fixed efficiency of the strain with carbon fiber pretreated by nitric acid reached 50% and when the strain fixed by the modified carbon fiber in adsorption method treated wastewater, the ammonia nitrogen removal rate reached 78% and the COD removal rate was always stabilized above 40% in three days.

Background The purpose of this study was to explore the expression and biological functions of glycoprotein 130 (gp130) in Epstein-Barr virus (EBV)-associated nasopharyngeal carcinoma (NPC). A prospective study was performed. Methods Ten patients with NPC and 10 patients with nasopharyngeal lymphoid hyperplasia (LH) were enrolled in this study. The transcripts of IL-27 receptors (gp130 and WSX-1) in the biopsy specimens derived from NPC were compared with that from LH by using reverse-transcription polymerase chain reaction. Cell lines including EBV−, Burkitt-like lymphoma (BJAB) cells, human adult peripheral blood mononuclear cells, and lymphoblastoid cell lines were used to provide evidence of the biological function of gp130. In addition, killing assay for natural killer (NK) cells was performed in the presence of gp130. Results There was significantly stronger expression of gp130 on the LH specimens than on the NPC specimens. The levels of gp130 mRNA were reduced in the EBV-transformed cells. The cytotoxicity ratio against gp130-deficient B cells was diminished compared with gp130-existent B cells. Conclusion The expression of gp130 is down-regulated in patients with NPC. We presume that EBV controls the functions of NK cells through regulation of gp130 cytokine receptor.

A series of diamagnetic divalent nickel complexes supported by a tridentate amido diphosphine ligand [N(o-C6H4PR2)2]- ([R-PNP]-; R = Ph, iPr, Cy) have been prepared and characterized. Deprotonation of H[Ph-PNP], H[iPr-PNP], and H[Cy-PNP] with n-BuLi in ethereal solutions at −35 °C produced the lithium complexes [Ph-PNP]Li(THF)2, [iPr-PNP]Li(solv) (solv = THF, Et2O), and [Cy-PNP]Li(solv) (solv = THF, Et2O), respectively. The reactions of [R-PNP]Li(solv)n with NiCl2(DME) in THF at −35 °C generated [R-PNP]NiCl, which was then reacted with a variety of Grignard reagents to afford the corresponding hydrocarbyl complexes [R-PNP]NiR‘ (R = Ph, R‘ = Me, Et, n-Bu, i-Bu, n-hexyl, CH2SiMe3, Ph; R = iPr, R‘ = Me, Et, n-Bu; R = Cy, R‘ = Me, Et, n-Bu). Of particular interest among the compounds isolated are alkyl complexes that contain β-hydrogen atoms. Treatment of the hydrocarbyl complexes with halogenated hydrocarbons such as dichloromethane, benzyl bromide, and phenyl iodide produced the corresponding nickel halide ...

The new complex PAP is used as a catalyst precursor for cross-coupling reactions of terminal alkynes with aryl halides in the presence of copper bromide and aliphatic amines under mild conditions.

The primary crystallization field of Bi 2 Sr 2 CaCu 2 O x was determined by differential thermal analysis, crystal-growth experiments, and X-ray analysis. The optimal composition region was: Bi 0.33±001 (Sr 2/3 Ca 1/3 ) 0.43±001 Cu 0.24±001 O y . Liquid-phase-epitaxy growth experiments were performed on six different compositions from this region. These experiments confirmed the primary crystallization of the 2212 phase at temperatures near 895°C. The crystalline films exhibited a relatively uniform composition, and the composition was Bi 2.10 Sr 2.00 Ca 0.08 Cu 2.03 O x .

Treatment of PdCl2(PhCN)2 with [NP]Li(THF)2 ([NP]- = N-(2-(diphenylphosphino)phenyl)-2,6-diisopropylanilide) in THF affords dimeric {[NP]PdCl}2, which reacts with tricyclohexylphosphine to produce [NP]PdCl(PCy3). The two phosphorus donors in [NP]PdCl(PCy3) are mutually cis, as indicated by the solution NMR and X-ray crystallographic studies. Both {[NP]PdCl}2 and [NP]PdCl(PCy3) are highly active catalyst precursors for Suzuki coupling reactions of a wide array of aryl halides, including those featuring electronically deactivated and sterically hindered characteristics.

Palladium complexes containing an o-phenylene-derived amido diphosphine ligand efficiently catalyze the Heck olefination of a wide array of aryl halides, leading to extremely high turnover numbers of up to 4.5 × 107.

This work describes the efficacy of [PNP]PdCl (1a), where [PNP]− = bis(2-diphenylphosphinophenyl)amide, as a catalyst precursor for Csp–Csp2 bond-forming cross-coupling reactions of terminal alkynes with aryl halides in the presence of copper bromide and aliphatic amines in ethereal solutions under mild conditions. This catalysis is compatible with acetylenes that are alkyl, alkenyl, (hetero)aryl, or silyl substituted and aryl iodides or bromides that are electronically activated, neutral, or deactivated. The low reaction constants of 0.82(6) and 0.97(7) obtained from Hammett plots of competitive reactions employing electronically distinct aryl iodides and terminal alkynes, respectively, are likely suggestive of irrelevance of the rate-determining step in these catalytic transformations to oxidative addition of aryl halides or generation of mono-substituted acetylides. In sharp contrast, reactions employing a phosphorus-bound isopropyl derived 1b gave rather unsatisfactory results, highlighting a profound phosphorus substituent effect on this aryl alkynylation catalysis.

A series of amido phosphinoxide and amido phosphinimine ligands that are electronic variations of monoanionic N,O- and N,N-ketiminates have been prepared and employed to examine the coordination chemistry of aluminium. Oxidation of the previously established N-(2-diphenylphosphinophenyl)-2,6-dialkylaniline in the presence of H(2)O(2) or organic azides RN(3) (R = 2,6-C(6)H(3)(i)Pr(2), SiMe(3)) led to phosphinoxides (H[NO] 1a-b) and phosphinimines (H[NN] 1c-d), respectively. Alkane elimination reactions of these protio-ligand precursors with trialkylaluminium in toluene or pentane solutions afforded cleanly the corresponding organoaluminium complexes, including dimethyl 2a-d, diethyl 3a-d and diisobutyl derivatives 4a-b and 4d. Solution NMR studies revealed Cs symmetry for these organoaluminium species, in which the α-hydrogen atoms are all diastereotopic. The correlation between the steric congestion of these molecules and the degree of resolution of the multiplet signals corresponding to the diastereotopic α-hydrogen atoms observed by the (1)H NMR spectroscopy is of particular interest. Dichloroaluminium complexes 5c-d were prepared in high yields by protonolysis of MeAlCl(2) with 1c-d. Single-crystal X-ray diffraction analyses of 2c-d, 3a, 3d, 4a, and 4d elucidated a mononuclear, distorted tetrahedral core for all of these aluminium species. Interestingly, complexes 2c-d are active initiators for catalytic ring-opening oligomerization of ε-caprolactone, whereas 2a-b are rather inactive, highlighting the significance of the steric hindrance imposed by the amido phosphinimine ligands, as compared to that imposed by the phosphinoxide counterparts.