Corrosion inhibition of α,β-unsaturated carbonyl compounds on steel in acid medium

Corrosion inhibition of three α,β-unsaturated carbonyl compounds on N80 steel at high temperature and in concentrated acid medium was evaluated, and the inhibition mechanism was investigated. The results proved that both cinnamaldehyde and benzalacetone had an evident anticorrosion effect and could reduce the corrosion of steel effectively in acid medium, α,β-unsaturated carbonyl compounds with a benzene ring structure had good adsorption on steel surface. The experiments proved that polymerization of α,β-unsaturated carbonyl compounds on the steel surface at a high temperature and in concentrated acid medium resulted in a good corrosion inhibiting effect, which was attributed to the structures of α,β-unsaturated carbonyl compounds.

Emissions of volatile organic compounds and carbonyl compounds from residential coal combustion in China

Emissions of volatile organic compounds （VOCs） and carbonyls from residential coal combustion of five coals with different maturities were studied in a simulated room.The coals were burned in form of honeycomb briquettes in a domestic coal stove,one of the most common fuel/stove combinations in China.Through a dilution system,VOCs and carbonyls samples were collected by canisters and silica-gel cartridges and analyzed by gas chromatography and mass spectrum （GC/MS） and high performance liquid chromatography/ultraviolet （HPLC/UV）,respectively.The results show that the bituminous coals with medium volatile matter content produce the highest emissions while the anthracite yields the lowest.Among the identified carbonyls from the coal smoke,the aromatic compounds （benzaldehyde,2,5-dimethylbenzaldehyde and p-tolualdehyde,m/o-tolualdehyde,benzene,m,p-xylene and trimethyl-benzene） were relatively abundant,which might be due to the molecular structure of the coal.For formaldehyde,aromatic carbonyls and aliphatic alkanes,their concentrations increase up to the maximum values and then decrease with increasing coal maturity.The total carbonyls and VOCs have the same tendency,which was observed for the emission factors of organic carbon （OC）,elemental carbon （EC）,particulate matter （PM） and polycyclic aromatic hydrocarbons （PAHs） detected in the series study.

Silica sulfuric acid:A versatile reagent for oxathioacetalyzation of carbonyl compounds and deprotection of 1,3-oxathiolanes

Oxathioacetalyzation of carbonyl compounds with 2-mercaptoethanol and deprotection of the obtained 1,3-oxathiolanes is easily performed in the presence of silica sulfuric acid （SSA）. All reactions were performed under mild and completely heterogeneous reaction conditions in good to high yields.

[Hmim]_3PW_(12)O_(40):A high-efficient and green catalyst for the acetalization of carbonyl compounds

[Hmim]_3PW_(12)O_(40) was developed and used in the acetalization of carbonyl compounds in excellent yields.The ionic liquidheteropoly acid hybrid compound and reaction medium formed temperature-dependent phase-separation system with the ease of product as well as catalyst separation.The catalyst was recycled more than 10 times without any apparent loss of catalytic activity.

Trifluoromethylation of Carbonyl Compounds with Sodium Trifluoroacetate

In the presence of copper （I） halide as catalyst, a variety of carbonyl compounds could be trifluoromethylated with sodium trifluoroacetate to give the corresponding alcohols in moderate to high yields.

MICHAEL ADDITION OF NITROALKANE TO α,β-UNSATURATED CARBONYL COMPOUNDS ON KF / Al_2O_3/ PEG4000

Michael addition of nitroalkanes to α,β-unsaturated carbonyl compounds occurs in the presence of KF/AI_2O_3/PEG4000 without solvent.Yields are fair to good and work-ups are easy.

Zeolite-Catalyzed Acetalization Ⅰ. Synthesis of Some Acetals and Ketals through Reaction of Carbonyl Compounds with Ethanediol

The acetalization of a series of carbonyl compounds with ethanediolwas performed over two self-steaxned HY zeolle catalpsts' The acetal and ketaiproducts were obtained with high ytelds Espectw, the HY zeollte with highfraxnework Si/A1 ratio was proven to be suitable cataipst for the acetabotion ofunsaturated carbonyl compounds, during which the C =C double bond was notperturbed

A New HPLC Method to Determine Carbonyl Compounds in Air

In this paper, a new HPLC method was established to determine the carbonyl compounds in air. As the absorbent, 2, 4-dinitrophenylhydrazine (2, 4-DNPH) reacted with carbonyls specifically, which form the corresponding 2,4-dinitrophenylhydrazones, then analyzed by HPLC. The chromatographic conditions, the recovery rate, stability of samples, reagent blank, sampling efficiency were all studied systematically. The results showed that this established method had high sensitivity and good selectivity compared with other analytical methods, and it can determine ten carbonyl compounds in air in 26 min simultaneously.

Selectivity of Organosamarium(Ⅲ) Hydride in Reducing Unsaturated Carbonyl Compounds

The selectivity of organosamarium(Ⅲ) hydride in reducing unsaturated carbonyl compounds has been studied. Dimeric organosamarium hydride[(C_9H_7)_2SmH]_2·4THF·NaCl prepared by the reaction of (C_9H_7)_2SmCl·2THF with NaH in THF reacts with unsaturated carbonyl compounds to give the corresponding reduction products with a high selectivity. The carbonyl groups have been reduced while the carbon-carbon double bonds are not affected.

SYNTHESES， CHARACTERIZATION AND CATALYSIS OF （dppe）Rh（μ－CO）_2M（CO）_3（M＝CR，Mo，W） CARBONYL COMPOUNDS

The\dDDe)Rhly --CU)Zjw(CO)3(jab--Cr,ilo,W)heterobinuclear m,t'1carbonyl c ompQunds were synthesized and characterized by ic and h Iljlh'Their catalytic activit ies for CO hydrogecation were determined.

Asymmetric Reductive Amination of Carbonyl Compounds by Using<i>N,N,N</i>-Tributylpropanaminium Based Novel Chiral Ionic Liquid

Asymmetric reductive amination of carbonyl compounds was carried out using a novel class of aliphatic quarternary ammonium based chiral ionic liquid. S-(+)-2,3-dihydroxy-N,N,N-tributylpropanaminum bromide chiral ionic liquid has been synthesized, characterized and used for asymmetric reductive amination of carbonyl compounds in the presence of sodium borohydride. These preliminary results are encouraging and advocate dual role of novel ionic liquid as a medium and reducing agent for proficient conversion of ketones to amines, however, reductive amination reaction needs to be established for other substituents.

OXIDATION OF α-METHYL OR α-METHYLENE GROUPS IN CARBONYL COMPOUNDS WITH AMMONIUM CHLOROCHROMATE

This paper reports a new method for oxidizing the α-methyl or α-methylene groups in carbonyl compounds into 1,2-dicarbonyl compounds by ammonium chlorochromate(ACC).

Addition of Per(poly)fluoroalkyl Iodides to vinyl Cyclopropane Derivatives: Synthesis of Fluoroalkyl Substituted γ,δ-Unsaturated Carbonyl Compounds

In the presence of CrC13 /Fe bimetal couple,per(poly)fluoroalkyl iodides add to vinyl cyclopropane compounds giving addition-ring-opening products in good yields.

I₂/Nanostructured Pyrophosphate : A Mild and Efficient Catalyst for the Selective Protection of Carbonyl Compounds

A new solvent free method for protection of carbonyl compounds as their thioacetals has been accomplished through the use of iodine supported on nanostructured pyrophosphate. Advantages of the methodology include very short reaction time, the requirement for minimum amounts of catalyst, the remarkably simple experimental procedure, and no necessity for solvents or inert atmospheres, excellent yields and recyclability of the catalyst used. An efficient method for the chemoselective thioacetalization of ketones in the presence of aldehydes using I2/nanostructured pyrophosphate is also reported in this article. The nanostructured pyrophosphate was characterized by scanning electron microscopy, X-ray diffraction, infrared spectroscopy, Transmission electron microscopy and thermal gravimetric analysis, respectively.

CONVERSION OF ACETALS AND KETALS TO CARBONYL COMPOUNDS PROMOTED BY ZrCl_4-NaBH_4

In our study on the chemistry of ZrCl_4-NaBH_4,we have found that aldehydes and ketones can be regenerated from acetals and ketals at 30℃ in Et_2O in high yield The reaction mechanism was discussed.

α-C(sp^(3))-H Arylation of Cyclic Carbonyl Compounds

α-C(sp^(3))-H arylation is an important type of C-H functionalization.Various biologically significant natural products,chemi-cal intermediates,and drugs have been effectively prepared via C-H functionalization.Cyclic carbonyl compounds comprise of cyclic ketones,enones,lactones,and lactams.Theα-C(sp^(3))-H arylation of these compounds have been exhibited high efficiency in forming C(sp^(3))-C(sp^(2))bonds,played a crucial role in organic synthesis,and attracted majority of interests from organic and medicinal communities.This review focused on the most significant advances including methods,mechanism,and applications in total synthesis of natural products in the field ofα-C(sp^(3))-H arylations of cyclic carbonyl compounds in recent years.

临沂市夏季羰基化合物来源及其对大气氧化性的影响

羰基化合物在大气光化学中扮演着重要角色,影响大气自由基丰度、大气氧化性强度以及臭氧(O_(3))光化学反应产率.通过对2022年8月临沂市大气羰基化合物及相关物种外场观测,结果发现甲醛(HCHO)体积分数φ(HCHO)和乙醛(CH3CHO)体积分数φ(CH_(3)CHO)分别为(4.95±2.01)×10^(−9)和(3.34±1.40)×10^(−9).根据多元线性回归结果发现二次生成是HCHO和CH3CHO主要来源,分别贡献其总体积分数的34.28%和35.95%.用基于观测约束的模式(Observation-Based Model,OBM)分析发现影响甲醛二次净生成速率的主要前体物为生物源烯烃和人为源烯烃(主要是正丁烯、乙烯和丙烯).影响乙醛二次净生成速率的主要前体物是人为源烯烃(正丁烯和丙烯)、烷烃(正己烷和正丁烷)和苯.烯烃类物质是影响临沂市羰基化合物体积分数水平的关键前体物物种.羰基化合物对大气氧化性的贡献最强,占比高达为74.64%.本研究强调了烯烃对羰基化合物污染的重要影响,并指出光化学污染日,羰基化合物对大气氧化性的重要作用,对未来国内外中小城市羰基化合物污染控制具有指导意义.

有机正极材料在锂离子电池中的应用

锂离子电池是新能源汽车动力电池的首选,而正极材料作为锂电池的重要组成部分,对电池性能和安全性影响重大。目前常用的正极材料是氧化物基层状活性材料,如磷酸铁锂、钴酸锂等。与无机正极材料相比,有机正极材料具有理论比容量高、环境友好、结构设计灵活、安全性高、原材料来源丰富等优点,被认为是有效的正极材料之一。应用于锂离子电池领域的有机正极材料主要包括羰基化合物、自由基聚合物、导电聚合物和有机硫化物。羰基化合物因其高理论比容量、快速反应动力学、结构多样性、易于合成和可利用自然资源等特点,被认为是下一代锂离子电池最有希望的正极材料。自由基聚合物的优势是具有可逆的氧化还原反应,导电聚合物具有良好的电子导电性和可逆性,有机硫化物具有高比容量,而且矿物硫的来源丰富、价格低廉、易于精炼,分别被认为是锂电池的一类重要有机正极材料。下一代有机正极材料的开发,需要多种改性方式共用,从而开发出高性能的复合正极材料。