查找使用阿拉丁产品的科研文献

Tuning the A-site cation in spinel MAl2O4 (M = Co, Mg, Zn, Cu) supports enables superior Pd-Catalyzed hydrodechlorination of 4-Chlorophenol

Zirui Qin,Jiehao Xie,Xiaofang Wen,Hongcan Lou,Zipin Peng,Xingkun Chen,Yuan Tan,Jisong Zhang

Chlorinated phenols are priority pollutants that require efficient low-temperature removal technologies. Here, we synthesize a series of spinel-type MAl 2 O 4 (M = Co, Mg, Zn, Cu) supports and deposit 1 wt% Pd via incipient-wetness impregnation to evaluate their hydrodechlorination (HDC) performance toward 4-chlorophenol under ambient aqueous conditions (30 °C, 0.2 MPa H 2 ). Catalytic screening shows that the identity of the divalent A-site cation strongly modulates activity: Pd/Co-Al achieves 91.8 % conversion with > 98.3 % selectivity to phenol, outperforming Pd/Ni-Al (84.7 %) and the remaining analogues. Pd/Cu-Al exhibits almost no conversion (<5.0 %), while Pd/Mg-Al and Pd/Zn-Al give moderate conversions (ca.55.4–58.7 %). Detailed characterization by XRD, N 2 -physisorption, H 2 -TPR, XPS and STEM reveals that the superior performance of Pd/Co-Al is rooted in (i) strong metal–support interactions that stabilize a balanced Pd 2+ /Pd 0 surface ensemble, (ii) coherent lattice matching at Pd(1   1   1)/CoAl 2 O 4 (311) interfaces that suppress particle growth, and (iii) high spinel thermostability that mitigates leaching and coking. A 30 h continuous-flow test confirms stable operation without activity loss. This work elucidates how subtle variations in spinel composition dictate Pd electronic structure and interfacial geometry, providing design principles for next-generation HDC catalysts.

From Ca3Be(SeO3)4 to SrBe(SeO3)2: two unprecedented alkaline earth metal beryllium selenites with large band gaps and enhanced birefringence

Xinyi Wang,Xin Wen,Yuchen Yan,Jindong Chen,Guangsai Yang,Guang Peng,Ning Ye

Beryllium-based selenites have rarely been reported. Herein, the first two alkaline earth metal beryllium-based selenites, Ca3Be(SeO3)4 and SrBe(SeO3)2, have been synthesized using a mild hydrothermal method. In both crystals, Be is connected to four [SeO3]2− groups. Due to the different arrangements of [SeO3]2− groups, these two crystals exhibit significantly different optical anisotropy. From Ca3Be(SeO3)4 to SrBe(SeO3)2, the birefringence ranges from 0.005@546 nm to 0.058@546 nm. Theoretical calculations confirmed the dominant role of [SeO3]2− in the optical anisotropy of these two crystals. In addition, both of them exhibited large band gaps (5.40 and 5.28 eV) and high thermal stability (596 and 570 °C). This work demonstrates that the introduction of beryllium can effectively increase the band gap of selenites to over 5 eV and offers new ideas for the development of large-bandgap selenites.

Synthesis of fluorescent 9-(4-aminoaniline)-acridine for highly specific and rapid detection of human serum albumin by fluorescence-capillary gel electrophoresis

Ye Jing,Hu Tianxiang,Ding Hui,Dong Xiawei

In clinical practice, many diseases can lead to changes in serum albumin concentration (HSA) in patients. Accurate detection of HSA concentration is of great significance for disease diagnosis. Based on this, this study designed and synthesized 9-(4-amino-aniline)-acridine (AAA) as a fluorescent probe. By laser induction and capillary gel electrophoresis (CGE), a new rapid and highly specific HSA detection method based on fluorescence-CGE was established. Various experimental control factors were investigated, and the optimal experimental conditions were determined as follows: the running buffer was H3PO4–KH2PO4 (pH = 2.45, 15.0 mmol L−1), the separation voltage was 30 kV, and the experimental temperature was 25 °C. The sample solution injected 10 s with hydrodynamic mode (3.43×103 Pa), HSA could be directly determined by fluorescence-CGE method. The linear range was 0.10–1.0 μg L−1, the detection limit was 0.012 μg L−1, the relative standard deviation (RSD) was less than 0.30%. This method can be used for the determination of real HSA samples. In addition, in the presence of various biological macromolecules, small molecules, ions and ethanol, the accurate detection of HSA by fluorescence-CGE method will not be affected, suggesting that this method has a high specificity for HSA. The rapid and highly specific fluorescence-CGE method of HSA constructed in this study provides a new way to detect HSA, which is of great significance for the diagnosis of clinical diseases.

A sensitive and rapid HPLC-DAD method for the determination of 3-hydroxy-1,2-dimethyl-4-pyridone and its distribution in rats

Mengdi Chen,Xuejiao Zhang,Shuling Li,Qiongyao Zhang

Highly soluble phenylethynyl terminated oligoimides derived from 5(6)-amino-1-(4-aminophenyl)-1,3,3-trimethylindane, 4,4′-oxydianiline and mixed thioetherdiphthalic anhydride isomers

Li Hanyuan,Wang Wei,Chen Guofei,Liu Yinfeng,Fang Xingzhong

Novel highly soluble phenylethynyl-endcapped oligoimides derived from mixed thioetherdiphthalic anhydride isomers ( m -TDPA) and 5(6)-amino-1-(4-aminophenyl)-1,3,3-trimethylindane (DAPI), 4,4′-oxydianiline (4,4’-ODA) with 4-phenylethynylphthalic anhydride (PEPA) as a reactive endcapping agent were synthesized. The calculated molecular weights of all the oligoimides were 2500 g·mol −1 .The effect of the mole ratio of DAPI/4,4’-ODA on solubility and melt viscosity of oligoimides as well as the thermal and mechanical properties of cured polyimide films was investigated. Experimental results indicated that DAPI greatly improved the solubility (>30 wt.%) of the oligoimides in low boiling points solvents when the content of DAPI was more than 10 mol% per total diamine. All the oligoimides exhibited very good processability with minimum melt viscosity lower than 60 Pa·s at about 330 °C. Tough and brown films were obtained after thermally cured at 370 °C for 1 h and dynamic mechanical analysis (DMA) showed that glass transition temperatures of the cured films increased up to 340 °C with the increasing content of DAPI. However, the thermal stability and mechanical properties decreased with the increase of DAPI content. The temperature of 5% weight loss was higher than 470 °C in both air and N 2 atmosphere obtained by thermogravimetric analysis (TGA). And the tensile strengths of the cured films were about 60 MPa.

Polyamidoamine dendrimer decorated nanoparticles as an adsorbent for magnetic solid-phase extraction of tetrabromobisphenol A and 4-nonylphenol from environmental water samples

Yalin Wu,Chunmao Chen,Qingxiang Zhou,Qing X. Li,Yongyong Yuan,Yayan Tong,Hongyuan Wang,Xianqi Zhou,Yi Sun,Xueying Sheng

Polyamidoamine dendrimer decorated Fe 3 O 4 magnetic nanoparticles were successfully synthesized by Michael addition with methyl acrylate and amidation with ethylenediamine . The decorated magnetic particles were utilized as an effective adsorbent for magnetic solid-phase extraction of tetrabromobisphenol A and 4-nonylphenol at trace levels from environmental water samples. A number of parameters such as generation number, ionic strength , adsorbent dosage, eluent , adsorption time, elution volume, elution time, pH, humic acid and sample volume were optimized. Under the optimal conditions, a wide linearity was achieved in the range of 0.1–500 μg L −1 of the analytes with the correlation coefficients (R 2 ) of 0.9985–0.9995. The limits of detection were approximately 0.011 μg L −1 of tetrabromobisphenol A and 0.017 μg L −1 of 4-nonylphenol. Satisfactory average recoveries of the analytes ranged from 93.2% to 101.1%. The results indicated that the decorated magnetic nanoparticles can be suitable for extraction of phenols from environmental water samples. The proposed method was sensitive, effective, practical and robust for the determination of tetrabromobisphenol A and 4-nonylphenol in environmental water samples.

A self-assembly solvothermal synthesis of SiMoVn@[Cu6O(TZI)3(H2O)6]4·nH2O for the efficient selective oxidation of various alkylbenzenes

Jiabin Liu,Yuxiang Xin,Yiyang Bai,Wei She,Jing Wang,Gaungming Li

The selective oxidation of alkylbenzenes contributes greatly to the production of high-value chemicals. However, developing novel and efficient catalysts remains a great challenge. To explore new and efficient catalysts, a series of POMs of H(4+n)SiMo(12−n)VnO40 (SiMoVn, n = 1, 2 and 3) were reacted with rht-MOF-1 ([Cu6O(TZI)3(H2O)6]4·nH2O) by a one-pot self-assembly solvothermal method. As a result, three SiMoVn@rht-MOF-1 (1, n = 1; 2, n = 2 and 3, n = 3) were isolated. Single crystal analysis revealed that SiMoVn were successfully introduced in the cages of rht-MOF-1. When complex 3 was employed as a catalyst, it effectively catalyzed the selective oxidation of alkylbenzene with a conversion of 99% and selectivity of 99% under optimized reaction conditions. Recycling experiments proved that complex 3 is stable and recyclable after six cycles. In comparison with analogous catalysts, complex 3 exhibits outstanding catalytic performance. Furthermore, the kinetics and reaction mechanism were investigated and verified by EPR and XPS analysis. This approach paves a facile route to prepare POMs@MOFs for the selective oxidation of various alkylbenzenes.

3-R-4-(5-Methyleneazide-1,2,4-oxadiazol-3-yl)furazan and its ionic salts as low-sensitivity and high-detonation energetic materials

Rui Yang,Yifei Liu,Zhen Dong,Haiyan Li,Zhiwen Ye

As an environmentally friendly energetic group, the azide group can not only control the melting point but also increase the energy of the compound. Therefore, the design and synthesis of energetic compounds with azido groups have long been a focus of research in the field of energetic materials. 3-R-4-(5-methyleneazide-1,2,4-oxadiazol-3-yl)furazan energetic materials were synthesized and fully characterized. Using computational chemistry methods, the interactions of some compounds were studied, and the physical and chemical properties of all of compounds were examined. The results show that 3-amino-4-(5-methyleneazide-1,2,4-oxadiazol-3-yl)furazan (2) has a melting point similar to that of TNT and can be a potential carrier for molten-cast explosives. Hydroxylamine salt (4) has an excellent detonation velocity and detonation pressure of 9090 m s−1 and 35.76 GPa, respectively, and its energy is significantly higher than that of RDX, enabling replacement of RDX as a high-energy explosive. Although the detonation performance of compound 4 is slightly lower than that of HMX, its sensitivity is better than that of HMX, which shows that compound 4 still has a high application value. Non-covalent interactions (NCIs) and Hirshfeld surface models indicate that hydrogen bonding and π–π interactions are the key factors that reduce the sensitivity of compounds. Therefore, our results for 3-R-4-(5-methyleneazide-1,2,4-oxadiazol-3-yl)furazan energetic materials suggest that it may be competitive for application in both molten-cast explosives and high-energy explosives.

Synthesis, crystal structure and magnetic property of a new Co(II) complex based on 4-phenyl pyridine and 5-sulfoisophthalic acid anion

Jiaxing Li,Meng Ni,Chaoyi Fan,Yan Li,Xiuqing Zhang

A new cobalt complex [Co3(SIP)2(4-PP)8(H2O)6]·4H2O·2(4-PP) (1) with 5-sulfoisophthalic acid sodium (NaH2SIP) and 4-phenyl pyridine (4-PP) as ligands has been synthesized in the mixed solvents of ethanol and water. It crystallized in monoclinic, space group P21/c, with a = 20.9642(9) Å, b = 15.6091(5) Å, c = 20.0126(8) Å, α = 90.00°, β = 115.493(6)°, γ = 90.00°, V = 5911.2(4) Å3, Z = 2, Dc = 1.346 g/cm−3, F(000) = 2494, the final GOOF = 1.038, Rint = 0.0258 and wR2 = 0.1793. The complex (1) was characterized by single-crystal X-ray diffraction, magnetic susceptibility and IR spectroscopy analyses. Single-crystal X-ray diffraction shows that complex (1) is trinuclear based on cobalt units. Magnetic susceptibility measurement indicates that complex (1) shows an antiferromagnetic coupling between the Co(II) ions.

One-pot synthesis of poly(2,6-dimethyl-1,4-phenylene oxide)/polystyrene alloy with CuCl2/4-dimethylaminopyridine as a versatile catalyst in water

Huan Wang,Baoqing Shentu,Zhixue Weng

A one-pot synthetic approach for the preparation of poly(2,6-dimethyl-1,4-phenylene oxide)/polystyrene (PPO/PS) alloy in aqueous medium was developed. The method was based on the combination of the oxidative coupling polymerization of 2,6-dimethylphenol (DMP) to form PPO in the presence of a reactive swelling agent, styrene (St), and in situ reverse atom transfer radical polymerization (RATRP) of St initiated by 2,2′-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride (AIBI) in alkaline aqueous solution. The complex of CuCl2 and 4-dimethylaminopyridine (DMAP) was utilized as the catalyst to catalyze the two types of polymerization mentioned above. Oxygen was employed as the sole oxidant to synthesize PPO. The introduction of St during the oxidative polymerization of DMP could increase the molecular weight of PPO. Finally thermodynamically compatible PPO/PS alloy was successfully prepared.

β-Cyclodextrin/calix[4]arene hybrid porous organic polymer membrane for synergistic extraction of fluorescent whitening agents migrating from food contact materials

Jiana Lin,Xiaoyan Ouyang,Yuling Hu,Gongke Li,Qisheng Zhong

Acurate and sensitive determination of hazards from food contact materials is important to monitor food safety. It is necessary to excavate efficient adsorbent for simultaneous recognition and adsorption of food hazards of trace level for sample preparation. In this work, β-cyclodextrin and calix[4]arene were employed as hybrid functional monomers to prepare macrocyclic porous organic polymer (β-CD-CX4 POP). It was proved that the supramolecular cavities of β-CD-CX4 POP could form inclusion complexes with fluorescent whitening agents (FWAs) through host-guest recognition, which greatly improved the adsorption performance. The hydrophobic cavities of β-cyclodextrin and calix[4]arene of β-CD-CX4 POP exhibited synergistic effect for simultaneous recognition of FWAs. The high-throughput enrichment of FWAs was realized by β-CD-CX4 POP membranes coupled with a multiple-channel syringe pump. Based on membrane-based solid-phase extraction combined with UHPLC-MS/MS, a sensitive analytical method was established to determine six FWAs. The LODs was in range of 3-50 ng/L with the linear range of 0.02-100 μg/L. The developed method was used to quantify FWAs in bread wrapper and bread, and the spiked recoveries ranged from 78.1%-119% with RSD of 2.3%-9.7%. This work indicated that β-CD-CX4 POP was promising for the simultaneous recognition and adsorption of FWAs migrating from food contact materials.

Atomically Dispersed Ni–Cu Dual Sites: Efficient Electrocatalytic Conversion of 4-Nitrophenol to p-Aminophenol in a Hybrid Acid/Alkali Flow Electrolyzer

Hongzhong Wang,Kai Chen,Junheng Huang,Chengchao He,Qinlong Zhang,Junwei Li,Zhifang Zhang,Zhenhai Wen

4-Nitrophenol (4-NP), a toxic and recalcitrant pollutant, necessitates effective remediation strategies. Here, a noble metal-free NiCu-NC electrocatalyst is developed, where dual atomic Ni–Cu sites are elegantly anchored on a rhombic dodecahedral nitrogen-doped carbon matrix, enabling selective electrochemical reduction of 4-NP into value-added p-aminophenol (4-AP). This catalyst achieves a low overpotential and a high Faradaic efficiency of 95.7% for 4-AP production. Density functional theory (DFT) calculations reveal that the NiCu dual-atom configuration minimizes the energy barrier for the rate-determining step, thereby enhancing catalytic performance. Furthermore, a hybrid acid/alkali flow electrolysis cell is designed to couple the cathodic 4-NP reduction with the anodic oxygen evolution. This system maintains stable operation for over 400 h while maintaining a high Faradaic efficiency (>91%) and near-complete conversion (99%) for valorization of 4-NP. This work demonstrates a practical electrocatalytic approach for pollutant transformation and chemical production with potential implications for wastewater treatment and resource utilization.