Aromatic glyoxalimines in criss-cross cycloaddition reactions

Aromatic 1,4-diazabuta-1,3-dienes in glacial acetic acid with thiocyanates produce via criss-cross cycloaddition reactions the corresponding perhydroimidazo[4,5-d]imidazole-2,5-dithiones. When a mixture of thiocyanate and cyanate in a proper ratio was reacted together, nonsymmetrical 5-thioxo-perhydroimidazo[4,5-d]imidazole-2-ones were isolated. With cyanates substituted aromatic 1,4-diazabuta-1,3-dienes afforded product of acetic acid addition to primary formed 1,3-dipole intermediate 5-(4-substituted phenylamino)-3-(4-substituted phenyl)-2-oxoimidazolidin-4-yl acetate.     

Solvent-free Rapid Synthesis of Styryl Dyes with Benzimidazole Nucleus Using Microwave Irradiation

The reactions of 2-methylbenzimidazole or 2-methylbenzimidazolium iodide with aromatic aldehydes are accelerated under microwave irradiation by using Ac2O or piperidine as dehydrant or catalyst in the absence of any solvent. The approach provides an attractive and environmentally friendly pathway to several useful styryl dyes with benzimidazole nucleus.     

Comparison of different trapping methods for pressurised hot water extraction

Four trapping methods for pressurised hot water extraction were compared in terms of recovery and selectivity. Also, robustness, repeatability and solvent consumption of the trapping systems were investigated. The trapping methods were collection into solvent following liquid-liquid extraction, solid-phase trapping into Tenax TA (SPE), flat sheet microporous membrane liquid-liquid extraction and hollow fibre microporous membrane liquid-liquid extraction. Polycyclic aromatic hydrocarbons were extracted with these systems from four soil and sediment matrices and the extracts were analysed by GC-MS and size-exclusion chromatography. Clear differences were observed in the selectivity and extraction efficiencies of the trapping systems.     

The metabolism of aromatic compounds by thermophilicBacilli

A range of thermophilicBacilli were screened for the ability to grow on aromatic compounds. Five out of ten of those studied were able to utilize aromatic acids as a sole carbon source. OtherBacilli were purified after enrichment on aromatic compounds. One of these isolates, a strain ofBacillus stearothermophilus, degraded both phenol and benzoic acid. Phenol degradation proceeded via catechol, and thereafter by oxidative and nonoxidativemeta-cleavage routes. The catalytic properties of cell-free extracts displaying the activities of the initial oxygenases have been described.     

磷酸基多孔芳香骨架材料用于提取铀离子

采用联苯为建筑基元，合成了价格低廉、操作简便、易于工业化的多孔芳香骨架材料PAF-45.通过后修饰方法，制备了带有磷酸基团的多孔芳香材料（PAF-45-PG）.通过FTIR（傅里叶变换红外光谱），TGA（热重分析），PXRD（多晶粉末X射线衍射），SEM（扫描电子显微镜），TEM（透射电子显微镜）以及N₂吸附实验，对PAF-45-PG的结构及孔道性质进行了系统的表征.由于骨架中引入了磷酸基团，PAF-45-PG具有优良的铀离子吸附性能，在pH=6的条件下可以达到100 mg·g^-1.另外，该材料成本低廉，具有可观的工业化前景，为多孔材料在能源方面的应用提供了广阔前景.     

Aerobic oxidation of benzylic aldehydes to acids catalyzed by iron （Ⅲ） meso-tetraphenylporphyrin chloride under ambient conditions

Highly efficient aerobic oxidation of benzylic aldehydes to the corresponding acids catalyzed by iron (Ⅲ) meso-tetraphe- nylporphyrin chloride (Fe(TPP)Cl) under ambient conditions was developed.The catalyst has been proved to be an excellent catalyst for the system in the presence of molecular oxygen and isobutryaldehyde at room temperature.     

The quantitative effect of microextractor cell geometry on the analytical supercritical fluid extraction efficiencies of environmentally important compounds

Summary The quantitative effect of microextractor cell geometries on supercritical fluid extraction (SFE) efficiencies of polycyclic aromatic hydrocarbons (PAHs) and methoxychlor from octadecyl-bonded sorbents has been evaluated and compared to similar effects seen upon increasing the supercritical fluid density. For the PAHs studied, correlations between the fused ring number and the relative increase in recoveries have been established. SFE recoveries can be increased by greater than a factor of two by decreasing the diameter to length ratio from 120 to 11. The relative recovery increase upon decreasing the diameter to length ratio of the extraction vessel is dependent on the analyte extractability, increasing in proportion to the fused ring number for the PAHs. Recoveries increased linearly as a function of supercritical fluid density for the PAHs studied. The change in the relative recovery upon increasing the supercritical carbon dioxide density again was dependent on the analyte type, decreasing linearly with fused ring number. Although fluid density generally had the greatest effect on achievable SFE recoveries, the cell geometry had effects of a similar order of magnitude, highly dependent on the initial extractability of the analyte.     

手性方酰胺基醇钛合物诱导的芳醛的不对称呐醇偶联反应

合成了两个手性方酰胺基醇, 与TiC1₄(THF)₂-Zn形成了手性配合物, 并用来催化芳醛的不对称呐醇偶联反应, 反应取得很高的化学产率和较高的光学收率, 同时考察了芳醛结构和共还原剂对反应的化学产率和光学收率影响.     

α-氨基肟配合物[M(Ⅱ)(PnAO)-H]的循环伏安研究

利用循环伏安法研究了脂族配合物〔Ｍ（Ⅱ）（ＰｎＡＯ）－Ｈ〕＾＋（Ｍ＝Ｃｏ，Ｎｉ，Ｃｕ，Ｐｄ）的氧化还原行为，得到了相应的电化学参数，提出了电化学－化学偶联过程的反应机理。讨论了不同金属离子及溶液的ｐＨ值对类芳香金属配合物生成的影响，阐明了这类化合物形成的动力学因素。     

Study of SNAr Reactions of Halobenzenes with Imidazole under Ultrasonic and Microwave Irradiation

Summary. Nucleophilic aromatic substitution reactions with imidazole of haloarenes having strongly electron-withdrawing groups were studied under ultrasonic and microwave irradiations. The course of the S_NAr reactions was found to be strongly dependent on the electron-withdrawing properties of the substituents as well as on the leaving ability of the halogen atom. Microwave irradiation allowed to shorten the reaction time and to increase the yields compared with ultrasonic irradiation.