Yang Zhiwang

Triphenylamine-decorated BODIPY fluorescent probe for trace detection of picric acid

Triphenylamine-decorated BODIPY derivative TBMA was designed and synthesized. Luminogen aggregation was developed by taking advantage of twisted intramolecular charge transfer (TICT) and aggregation-induced emission (AIE) processes. In non-polar solvents, the locally excited (LE) states of BODIPY luminogens emitted intense yellow light. Increasing solvent polarity brought the luminogens from an LE to a TICT state, causing a large bathochromic shift in the emission color and a dramatic decrease in emission efficiency. The red emission was greatly boosted by aggregate formation or AIE effect. We also discovered that TBMA could be applied as an efficient chemical sensor for picric acid (PA) detection. The detection limit and quenching constant (KSV) were determined as 30 ppb and 2.1 × 10−6 M−1 respectively. 19F NMR and 1H NMR titration analysis verified that F⋯H hydrogen bonding is demonstrated as the mode of interaction, which possibly facilitates effective exciton migration.

Preparation and Characterization of Wool-Pd(0)Catalyst and Its Catalytic Performance for Oxidation of Alcohol in Water

Wool-Pd(0) catalyst was prepared successfully using nature biopolymer wool as stabilizer and supporter. The structure of the palladium catalyst was characterized by field emission scanning electron microscopy and X-ray photoelectron spectroscopy, and the results showed that Pd(0) particles are well dispersed on the surface of wool. Applying wool-Pd(0) catalyst in the oxidation of alcohol under optimized conditions, several parameters such as catalyst amount, base, reaction temperature, and reaction time were screened. It was found that 35 mg wool-Pd(0) catalyst is available for the oxidation of 0.2 mmol alcohol to corresponding aldehyde or ketone with higher conversion and selectivity in the presence of 0.2 mmol K 2 CO 3 and using water as reaction medium. The heterogeneous catalyst is of good reusability in this reaction system.Wool-Pd(0)catalyst was prepared successfully using nature biopolymer wool as stabilizer and supporter.The structure of the palladium catalyst was characterized by field emission scanning electron microscopy and X-ray photoelectron spectroscopy,and the results showed that Pd(0)particles are well dispersed on the surface of wool.Applying wool-Pd(0)catalyst in the oxidation of alcohol under optimized conditions,several parameters such as catalyst amount,base,reaction temperature,and reaction time were screened.It was found that 35 mg wool-Pd(0)catalyst is available for the oxidation of 0.2mmol alcohol to corresponding aldehyde or ketone with higher conversion and selectivity in the presence of0.2mmol K2CO3 and using water as reaction medium.The heterogeneous catalyst is of good reusability in this reaction system.

Baeyer-Villiger Oxidation of Cyclohexanone Catalyzed by SBA-15 Supported Silicotungstic Acid

Silicotungstic acid (H4O40SiW12) was supported on SBA-15 with the content of 20% by impregnation. The structure and proper-ties of the catalyst were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, N2 adsorption-desorption, and transmis-sion electron microscopy. H4O40SiW12 was highly dispersed on SBA-15 without structural change. The material was applied as an efficient catalyst for the Baeyer-Villiger oxidation of cyclohexanone under different conditions such as the catalyst amount, reaction temperature, and reaction time. When 10 mg of catalyst was used, the cyclohexanone conversion and selectivity for lactone were up to 86% and 99%, respec-tively, at 70 oC for 8 h. The catalyst had moderate reusability in the oxidation system.

Preparation and Application of SO 4 2– /SnO 2 /SBA-15 Solid Acid Catalyst for Acetalization of Cyclic Ketones: Preparation and Application of SO 4 2– /SnO 2 /SBA-15 Solid Acid Catalyst for Acetalization of Cyclic Ketones

SO42-/SnO2/SBA-15 catalyst samples with different amounts of SnO2 were prepared by a wetness impregnation method and characterized by X-ray diffraction,N2 adsorption-desorption,and transmission electron microscopy.Their catalytic performance for the acetalization of 4-tert-butylcyclohexanone with glycol was investigated.The results showed that SBA-15 supported SO42-/SnO2 improved the catalytic activity markedly,which was caused by the increasing surface area of the sulfated tin oxide.The catalytic performance of SO42-/20%SnO2/SBA-15 for acetalization of several cyclic ketones with diols was also explored.Under the optimum conditions,a series of cyclic ketones such as cyclohexanone,4-methylcyclohexanone,and 4-tert-butylcyclohexanone were well transformed into the corresponding products.The catalyst can be reused for several times without any significant loss in catalytic activity.