Cooperation between the Cu+ and Cu2+ species in CuCoAl layered double hydroxide and the substrate promoting effect afford a really simple protocol for the efficient synthesis of quinazolines.

In this study, a really simple and efficient catalytic protocol for the construction of quinazolines from alcohol and diamine has been developed based on CuCoAl layered double hydroxide (CuCoAl-LDH). The developed CuCoAl-LDH catalyst could accelerate the cascade reactions without any additives and tolerate various alcohols with satisfactory yields. Cooperation between the Cu+ and Cu2+ species in CuCoAl-LDH was observed in the cascade reaction, and they are believed to be responsible for the oxidation of alcohol and dehydrogenation of the intermediate, respectively. The promoting effect of the substrate diamine was observed in the oxidation of alcohol, which simplifies the reaction system by eliminating the requirement for a base additive. The catalytic system exhibited highly practical potential for the synthesis of quinazolines, as demonstrated through recyclability investigations and scale-up experiments. A possible catalytic mechanism has been proposed based on a series of control experiments and EPR analysis.

Visible light-assisted hydrogen generation from ammonia borane over Z-Scheme NiO-CuO heterostructures.

The design and fabrication of cheap and high-efficiency catalysts for ammonia borane (AB) hydrolysis for hydrogen production is crucial for its commercial applications. Improvement of the catalytic performance of the catalysts with the assistance of sunlight, a costless resource, is extremely attractive. Herein, we have constructed Z-scheme heterostructured VO-NiO-CuO catalysts with strong interfacial electronic interactions and abundant oxygen vacancies to enhance hydrogen production from NH3BH3 solution under visible light illumination. The as-prepared VO-NiO-CuO catalysts exhibit excellent catalytic activity with a high turnover frequency (TOF) of 35.3 molH2 molcat.-1 min-1 toward AB hydrolysis under visible light. It is demonstrated that excellent catalytic performance is highly related to the effective separation and migration of charge on the catalyst surface. As a result, dual active sites were created, making it easier for various reactants to be adsorbed and activated on the catalyst surface. Furthermore, the density functional theory (DFT) calculations indicate that the adsorption and activation of H2O occurred mainly at the Ni site of VO-NiO-CuO. When the VO-NiO-CuO is irradiated with visible light, the photogenerated electrons assembled on the conduction band were transferred to the O atom through the Ni-O bond, which made the bond length of H2O molecules longer and OH bonds more prone to breaking, thus facilitating AB hydrolysis under illumination. The findings in this work pave the way to design novel and efficient heterostructured catalysts for fast hydrogen release from NH3BH3 under visible light irradiation.

Tailoring Dye Emissions within Metal-Organic Frameworks for Tunable Luminescence and Ratiometric Temperature Sensing.

Metal-organic frameworks (MOFs) have emerged as powerful platforms for tuning the luminescence characteristics of guests due to their various structures and functions. Tunable and stimuli-responsive luminescence of guests within MOFs can be achieved through a judicious choice of guests and hosts. Herein, we demonstrate a dramatic change in the luminescence of dye excimers encapsulated in MOFs. A polar dye presented largely red-shifted excimer emissions in MOFs with higher polarities, while a nonpolar dye showed very different excimer emissions. Interestingly, the excimer emissions tailored by the MOFs showed strong thermal quenching. Cz-Ant@ZIF-8, containing two luminescent dyes (carbazole (Cz) and anthracene (Ant)), was prepared, and it presented ratiometric temperature sensing properties (1.55% K-1) in the temperature range of 278-353 K. This work sheds light on the luminescence tuning of dyes confined in MOFs and the design of sensitive ratiometric thermometers.

Transformation of CO2 with Glycerol to Glycerol Carbonate over ETS-10 Zeolite-Based Catalyst.

Catalytic conversion of CO2 with the surplus glycerol (GL) produced from biodiesel manufacturing has attracted much academic and industrial attention, which proves the urgent requirement for developing high-performance catalysts to afford significant environmental benefits. Herein, titanosilicate ETS-10 zeolite-based catalysts with active metal species introduced by impregnation were employed for coupling CO2 with GL to efficiently synthesize glycerol carbonate (GC). The catalytic GL conversion at 170 °C miraculously reached 35.0% and a 12.7% yield of GC was obtained on Co/ETS-10 with CH3CN as a dehydrating agent. For comparison, Zn/ETS- Cu/ETS-10, Ni/ETS-10, Zr/ETS-10, Ce/ETS-10, and Fe/ETS-10 were also prepared, which showed inferior coordination between GL conversion and GC selectivity. Comprehensive analysis revealed that the presence of moderate basic sites for CO2 adsorption-activation played a crucial role in regulating catalytic activity. Moreover, the appropriate interaction between cobalt species and ETS-10 zeolite was also of great significance for improving the glycerol activation capacity. A plausible mechanism was proposed for the synthesis of GC from GL and CO2 in the presence of CH3CN solvent over Co/ETS-10 catalyst. Moreover, the recyclability of Co/ETS-10 was also measured and it proved to be recycled at least eight times with less than 3% decline in GL conversion and GC yield after a simple regeneration process through calcination at 450 °C for 5 h in air.

Solvent Extraction for Separation of Indonesian Oil Sands.

Based on the examination of the basic properties, the solvent extraction process (SEP) was applied with high efficiency in the extraction of bitumen from Indonesian oil sands. To separate the oil sands, different organic solvents were first screened, and the extraction effects were analyzed to select a suitable solvent. Then, the effects of operating conditions on the extraction rate of bitumen were investigated. Finally, the compositions and structures of the bitumen obtained under suitable conditions were analyzed. The results showed that the Indonesian oil sands were oil-wet oil sands with a bitumen content of 24.93%, containing a large number of asphaltenes and resins with high polarity and complex structures. The separation performance was affected by different organic solvents and operating conditions. It was shown that the closer the structure and polarity of the selected solvent is to the solute, the better the extraction effect. The extraction rate of bitumen reached 18.55% when toluene was used as the extraction solvent under the operating conditions of V (solvent):m (oil sands) 3:1, temperature 40 °C, stirring velocity 300 r/min, time 30 min. The method could also be applied to the separation of other oil-wet oil sands. The compositions and structures of bitumen can guide the separation and comprehensive use of industrial oil sands.

Catalytic behavior of a ZnO/TiO2 composite in the synthesis of polycarbonate diol.

ZnO/TiO2 catalysts with different ZnO contents have been prepared through equal volume impregnation method, characterized by XRD, SEM, Py-IR, ICP, XPS, NH3-TPD and N2 adsorption/desorption, and evaluated in the synthesis of polycarbonate diol (PCDL) through transesterification. The results showed that titanium zinc oxide formed in these catalysts, and the content of acidic sites varied with the ZnO content, and ZnO/TiO2 (10%) has the highest acid amount. The ZnO/TiO2 (20%) with medium acidic sites showed the highest catalytic activity. The synthesis process of polycarbonate glycol was also optimized. Under the optimal reaction conditions, the yield of PCDL was 72.5%, and the M n reached 4829 g mol-1 with a PDI of 1.6.

Construction of Indoline-Fused Tetrahydroisoquinolines through a Domino Coupling Reaction Catalyzed by CuCoFe Layered Double Hydroxide.

A convenient catalytic protocol for efficiently constructing indoline-fused tetrahydroisoquinolines based on CuCoFe layered double hydroxide (LDH) has been described. Preliminary mechanistic studies show that indoline-fused tetrahydroisoquinolines are produced via domino coupling/cyclization reactions between tetrahydroisoquinolines and active methylene compounds, including malononitrile, malonates, and analogues. CuCoFe-LDH can accelerate the Csp3-Csp3 and Csp3-Csp2 formation reactions in a single step. The research thus presents a unique opportunity to develop a synthetic methodology for N-containing polycyclic compounds.

Effect of L-cysteine on the oxidation of cyclohexane catalyzed by manganeseporphyrin.

Effect of L-cysteine as the cocatalyst on the oxidation of cyclohexane by tert-butylhydroperoxide (TBHP) catalyzed by manganese tetraphenylporphyrin (MnTPP) has been investigated. The results showed that L-cysteine could moderately improve the catalytic activity of MnTPP and significantly increase the selectivity of cyclohexanol. Different from imidazole and pyridine, the L-cysteine may perform dual roles in the catalytic oxidation of cyclohexane. Besides as the axial ligand for MnTPP, the L-cysteine could also react with cyclohexyl peroxide formed as the intermediate to produce alcohol as the main product.

Investigations on the demetalation of metalloporphyrins under ultrasound irradiation.

An efficiently facile method for the demetalation from metalloporphyrins has been developed, which uses high-intensity ultrasound to initiate the ligand dissociation in a mixed solvent of (CH(3)CO)(2)O/HCl with FeSO(4). The influences of substituents, bath temperature and reaction time on the reactions were also investigated, on the base of which the mechanism of demetalation and the effect of ultrasound irradiation on metal-ligand cleavage have been discussed in detail.

Isolation and characterization of an abamectin-degrading Burkholderia cepacia-like GB-01 strain.

Abamectin is widely used in agriculture as an insecticide and in veterinary as an anti-parasitic agent, and has caused great environmental pollution by posing potential risk to non-target soil invertebrates and nearby aquatic systems. A bacterium designated GB-01, which was capable of degrading abamectin, was isolated from soil by enrichment culture method. On the basis of morphological, physiological and biochemical characteristics, combined with phylogenetic analysis of 16S rRNA gene, the bacterium GB-01 was identified as Burkholderia cepacia-like species. The bacterium GB-01 was able to utilize abamectin as its sole carbon source for growth, and could degrade more than 90% of abamectin at initial concentrations of 50 and 100 mg l(-1) in mineral salt medium in 30 and 36 h, respectively. The longer degradation cycle was observed with abamectin concentrations higher than 100 mg l(-1). Optimal growth temperatures and pH values with highest degradation rate were 30-35 degrees C and 7-8, respectively. Two new degradation products were identified and characterized by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) based mass spectral data and a plausible partial degradation pathway of abamectin was proposed. This is the first report in which an abamectin-degrading Burkholderia species isolated from soil was identified and characterized.

A facile synthesis of deuteroporphyrins derivatives under ultrasound irradiation.

A facile, efficient and general method for preparing deuteroporphyrin derivatives by using concentrated H(2)SO(4) and alcohol under ultrasound irradiation has been developed. A series of new deuteroporphyrin derivatives bearing different propionic ester groups have been synthesized in good yields starting from readily accessible deuterohemin. The characterization of these compounds confirms the synthetic methodology. Compared with conventional methods, the main advantages of the present procedure are shorter reaction time and higher yields.