A series of geometry‐constrained iminopyridyl‐palladium chlorides were synthesized and characterized. These phosphine‐free palladium complexes were explored for their catalytic activities in both Suzuki and Heck cross‐coupling reactions, achieving turnover numbers as high as 106 towards various aryl bromides, even those containing various functionalities. In addition, the influence of substituents with steric and electronic factors was reflected by the differences observed in their activities.
Catalysis Letters - The attractive challenge in green chemistry is exploring novel heterogeneous catalyst system for catalyst-controlled product selectivity for oxidation of olefins. Hence, we... 相似文献
Silicon - A novel low-loss and good-robustness silicon-on-insulator lateral insulated gate bipolar transistor (LIGBT) is proposed and investigated by simulation for the first time. The device is... 相似文献
Two porphyrin derivatives with different substituents were investigated as dyes for the titanium dioxide (TiO2) film electrode to construct new two-compartment photoelectrochemical biofuel cells (PEBFCs). The two porphyrin derivatives were tetrakis(4-carboxyphenyl)porphyrin (TCPP) and meso-tetra(p-hydroxyphenyl)porphine (THPP). To determine how cell performance was affected by the dye with different substituents, we analyzed the photochemical and photoelectrochemical properties of the two dyes by physical characterization and photoelectrochemical experiments. The UV–Vis absorption spectra and X-ray photoelectron spectra indicated that the interactions between the dye and TiO2 decreased in the order of TCPP > THPP, which was also in accord with the results of Fourier transform infrared. In addition, TCPP and THPP were calculated using the density functional theory and the time-dependent density functional theory, and the calculation result exhibited that the radiative lifetime decreased in the order of TCPP > THPP. Compared with THPP, TCPP with longer excited-state was expected to enhance the performance of a PEBFC. We measured and compared the incident photon-to-collected electron conversion efficiency and the light-to-electrical conversion efficiency (η) of the porphyrin-sensitized photoelectrochemical biofuel cell. The photovoltaic characteristics showed the TCPP was more effective compared to the THPP, which obviously showed that the experimental results were consistent with theoretical expectation. These results revealed that the kind of the substituent for the porphyrin influenced the photovoltaic properties of the PEBFC. 相似文献
An accurate prediction of the critical gas velocity for the liquid loading is of great importance for operators to select the tubing diameter for the newly dril... 相似文献
Recently, electric vehicles (EVs) have been widely used under the call of green travel and environ-mental protection, and diverse requirements for charg-ing are... 相似文献