The circular chemistry conceptual framework: A way forward to sustainability in industry 4.0

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Ruthenium(II) complexes with mono and ditertiary arsines and phosphines and their reaction with small molecules

Dichlorotetrakis(dimethylsulphoxide)ruthenium(II) reacts with AsPh₃ AsMePh₂, AsMe₂Ph and SbPh₃ in ethanolic hydrochloric acid solution to yield the complexes RuCl₂(DMSO)₂(AsPh₃)₂, RuCl₂(DMSO) L₂ (L = AsMePh₂, AsMe₂Ph, SbPh₃) respectively. The treatment of ruthenium(II) blue solution with AsMePh₂, AsMe₂Ph and SbPh₃ in alcohol resulted in the formation of the complexes; RuCl₂L₃ (L = AsMePh₂, AsMe₂Ph and SbPh₂), respectively. The reaction of RuCl₂(DMSO)₄ with the bidentate ligands 1,2 bis (diphenylarsino)methane (DPAM), 1,2 bis(diphenylarsino)ethane (DPAE) and 1,2 bis (diphenylphosphino)methane (DPPM). 1,2 bis(diphenylphosphino)ethane (DPPE), in ethanol gave the complexes RuCl₂(DPAM)₂, RuCl₂(DPAE)₂, RuCl₂ (DPPM)₂ RuCl₂(DPPE)₂, respectively. The complexes thus obtained undergo reaction with carbon monoxide, hydrogen, molecular nitrogen and nitric oxide to yield a variety of mixed ligand complexes.     

Radical-Mediated Photocatalysis for Lignocellulosic Biomass Conversion into Value-Added Chemicals and Hydrogen: Facts,Opportunities and Challenges

Photocatalytic biomass conversion into high-value chemicals and fuels is considered one of the hottest ongoing research and industrial topics toward sustainable development. In short, this process can cleave C_β−O/C_α−C_β bonds in lignin to aromatic platform chemicals, and further conversion of the polysaccharides to other platform chemicals and H₂. From the chemistry point of view, the optimization of the unique cooperative interplay of radical oxidation species (which are activated via molecular oxygen species, ROSs) and substrate-derived radical intermediates by appropriate control of their type and/or yield is key to the selective production of desired products. Technically, several challenges have been raised that face successful real-world applications. This review aims to discuss the recently reported mechanistic pathways toward selective biomass conversion through the optimization of ROSs behavior and materials/system design. On top of that, through a SWOT analysis, we critically discussed this technology from both chemistry and technological viewpoints to help the scientists and engineers bridge the gap between lab-scale and large-scale production.     

废弃塑料光催化转化制备低碳数有机化合物

大量废弃塑料引发了一系列的环境和生态问题,其转化和利用一直受到广泛关注.塑料中含有丰富的碳元素,但这些碳元素往往以惰性的C–C键和C–H键形式存在,因此如何利用这些碳资源成为一大难题和挑战.以往部分研究已经提供了塑料催化转化制备碳材料、化学品和燃料的可能性,但是自然界中的废弃塑料总量庞大,需要考虑其转化过程中的能量来源.地球上有丰富的太阳能资源,光催化过程有可能利用太阳能来实现温和条件下的废弃塑料转化.在以往的研究中,光催化塑料降解和光催化塑料重整过程主要关注的目标产物分别是CO₂和H₂.相较而言,光催化塑料转化制备低碳数有机化合物的过程有望助力碳循环经济的发展.近年来报道了一些光催化塑料转化制备低碳数有机化合物的研究工作,这些研究为获取和利用塑料中的碳资源提供了新的研究思路和策略.本文概括对比了光催化塑料降解、光催化塑料重整和光催化塑料转化制备低碳数有机化合物三种过程的差异,包括其中的目标产物和相应的反应活性物种.此外,本文总结了光催化塑料转化制备低碳数化合物的反应方法.简要地说,塑料可以经过光催化选择性氧化、氧化偶联和水解脱氢等策略来得到低碳数的化学品和燃料,涉及利用光催化氧化过程断裂塑料中的C–C键,利用水解过程断裂塑料的C–N和C–O键,以及利用光催化脱氢过程断裂中间产物的O–H键和N–H键等关键步骤.在光催化塑料转化到低碳数有机产物的文献报道中,主要涉及液固相反应体系和反应器,需要考虑反应溶剂的选择.水是理想的溶剂,但对塑料的溶解能力有限.当使用其他有机溶剂时,需要利用同位素标记实验验证产物中的碳物种来源.此外,实际废弃塑料上残留的其他杂质会影响光催化剂的吸光过程,降低光催化反应效率,因此亟需设计和开发合理的光反应器来提高对光能的利用率,实现塑料的高效转化.虽然塑料制备低碳数化学品和燃料的光催化转化策略已有研究报道,但未来仍需探索更加高效的转化路线.此外,塑料主要呈现高分子聚合物的结构,未来的研究可以借鉴对生物质等天然聚合物分子的转化策略.     

Microalgae and bioremediation of domestic wastewater

Domestic wastewaters are produced in huge volumes and abundant with carbon, nitrogen and phosphorous, which are a promising source of nutrients for production of microalgae. Microalgae-based bioremediation of domestic wastewater offers various advantages over traditional treatment approaches because the process consumes CO₂, completely removes nitrogen and phosphorous for production of green biomass and oxygen. Moreover, the abundance of biochemical compositions (e.g., lipids, proteins, carbohydrates, bioactive compounds) of microalgae biomass is superior to terrestrial plant biomass in refining to multi-products having variety of commercial values. In this review, the most dominant microalgae used for simultaneous removal of pollutants and production of biomass and metabolites from domestic wastewater are presented. Biorefinery of microalgae biomass produced from domestic wastewater for production of multiple products is also explored. Finally, challenges and perspectives of successful microalgae-based bioremediation of domestic wastewater toward the biorefinery are briefly discussed.     

液液萃取-气相色谱/质谱法同时测定水样中3种三烷基硫代磷酸酯类化合物

本文建立了液液萃取-气相色谱/质谱同时测定水中O,O,S-三甲基硫代磷酸酯(TMPT)、O,O,S-三甲基二硫代磷酸酯(TMDTP)和O,O,O-三乙基硫代磷酸酯(TETP)3种三烷基硫代磷酸酯类化合物的分析方法。采用电子轰击(EI)-选择离子模式(SIM)进行定性与定量分析。考察了萃取剂种类、pH值以及盐度对萃取效率的影响。在优化的实验条件下,3种目标化合物的线性范围在0.01~2.0μg/mL之间,检出限(S/N=3)为0.26~1.1ng/L,定量限(S/N=10)为0.87~3.7ng/L。以该方法测定自来水、池塘水和湖水样品,3种目标化合物均未检出,不同加标水平(0.05、0.25和1.0μg/L)回收率在85.7%~104.2%之间,相对标准偏差在1.5%~12.2%之间。     

Thermodynamic favorable CO2 conversion via vicinal diols and propargylic alcohols: A metal-free catalytic method

Organocatalysis represents a promising field in chemical fixation of CO2.Herein,a facile metal-free strategy was reported for the one-pot preparation of cyclic carbonates and a-hydroxy ketones from vicinal diols,propargylic alcohols and CO2.Wide scope of vicinal diols and propargylic alcohols was demonstrated to be efficient under the DBU-catalyzed conditions.A plausible mechanism was proposed,which included detailed main and side reactions under the metal-free conditions.     

Reconstruction of glycan chains of glycoprotein : Branching mannopentaoside and mannohexaoside

Synthetic routes to the branching mannopentaoside 4 and mannohexaoside 5 are described employing properly protected mannobioside 13 as a key intermediate.     

Effects of γ-radiation on spectrophotometric determination of uranium as thiocyanate

The effects of γ-radiation on the spectrophotometric determination of uranium as the thiocyanate complex in water and acetone-water solutions have been studied. When tin(II) chloride is present, the absorbance of uranium thiocyanate in aqueous solution decreases with increasing radiation dose until the appcarance of radiolytic elemental sulfur causes an apparent increase. In the absence of tin(II) chloride, the turbidity caused by radiolytic sulfur causes an increase in absorbance over the whole dose range studied. In acetone-water solution, similar but much more severe effects occur. Observations of radiation effects of some of the individual reagents used in the spectrophotometric determinations are included, as well as indications of the errors caused by specific radiation doses.