Synthesis of Dicycloheptano- and Dicyclooctanothiacrown Ethers Their Properties as Extractants

12- and 15-Membered thia- and oxathiacrown ethers and podands containing cycloheptane and cyclooctane fragments have been synthesized. The properties of the synthesized compounds as extractants for Ra²⁺ and Pd²⁺ ions have been studied.     

Heterogeneous Photocatalytic Reactions of Sulfur Aromatic Compounds

Sulfur aromatic compounds, such as mono‐, di‐, tri‐, and tetraalkyl‐substituted thiophene, benzothiophenes, dibenzothiophenes, are the molecular components of many fossils (petroleum, oil shale, tar sands, bitumen). Structural units of natural, cross‐linked heteroaromatic polymers present in brown coals, turf, and soil are similar to those of sulfur aromatic compounds. Many sulfur aromatic compounds are found in the streams of petroleum refining and upgrading (naphthas, gas oils) and in the consumer products (gasoline, diesel, jet fuels, heating fuels). Besides fossils, the structural fragments of sulfur aromatic compounds are present in molecules of certain organic semiconductors, pesticides, small molecule drugs, and in certain biomolecules present in human body (pheomelanin pigments). Photocatalysis is the frontier area of physical chemistry that studies chemical reactions initiated by absorption of photons by photocatalysts, that is, upon electronic rather than thermal activation, under “green” ambient conditions. This review provides systematization and critical review of the fundamental chemical and physicochemical information on heterogeneous photocatalysis of sulfur aromatic compounds accumulated in the last 20–30 years. Specifically, the following topics are covered: physicochemical properties of sulfur aromatic compounds, major classes of heterogeneous photocatalysts, mechanisms and reactive intermediates of photocatalytic reactions of sulfur aromatic compounds, and the selectivity of these reactions. Quantum chemical calculations of properties and structures of sulfur aromatic compounds, their reactive intermediates, and the structure of adsorption complexes formed on the surface of the photocatalysts are also discussed.     

Determination of Sulfur Compounds in Air by Chemiluminescence

Abstract

The present review is devoted to applications of chemiluminescence to the analysis of trace sulfur species in air. Determinations of oxidized (sulfur dioxide and sulfite), reduced (hydrogen sulfide, dimethyl sulfide, carbonyl sulfide, carbon disulfide and mercaptans) and/or sulfur compounds in general are described and some practical considerations are discussed. The development of detectors based on chemiluminescence in the aproximately last fifteen years is also reviewed.     

Synthesis of Heterocyclic Compounds from Metallated Unsaturated Compounds and Isothiocyanates. (Review)

Novel syntheses of heterocyclic compounds resulting from reactions of metallated acetylenes, allenes, and conjugated dienes with isothiocyanates and from reactions of the latter with strong bases are reviewed.     

A Regioselective Synthesis of Novel Functionalized Organochalcogen Compounds by Chalcogenocyclofunctionalization Reactions Based on Chalcogen Halides and Natural Products

The regioselective synthesis of novel functionalized condensed organochalcogen compounds by chalcogenocyclofunctionalization reactions based on chalcogen halides and the natural products thymol and carvacrol has been developed. The reactions of selenium dibromide with allyl thymol and allyl carvacrol proceeded in methylene chloride at room temperature in the presence of NaHCO₃ affording bis[(7-isopropyl-4-methyl-2,3-dihydro-1-benzofuran-2-yl)methyl] and bis[(4-isopropyl-7-methyl-2,3-dihydro-1-benzofuran-2-yl)methyl] selenides in 90–92% yield. Similar sulfides were obtained in 70–72% yields by the reaction of sulfur dichloride in chloroform under reflux. Trihalotellanes containing the same organic moieties were synthesized from allyl thymol, allyl carvacrol and tellurium tetrachloride or tetrabromide in quantitative yields. Corresponding functionalized ditellurides were prepared in 91–92% yields by the reduction of the trichlorotellanes with sodium metabisulfite in two-phase solvent system. The comparison of reactivity of sulfur, selenium and tellurium halides in chalcogenocyclofunctionalization and distinguishing features of each reaction were discussed.     

二苄基二氯化锡三苯基氧膦的合成及晶体结构研究

利用二苄基二氯化锡与三苯基氧膦反应 ,合成了目标化合物二苄基二氯化锡三苯基氧膦 ,其结构经元素分析表征。用X 射线单晶衍射测定其晶体结构属于三方晶系 ,空间群为P2 1,a =2 .0 2 7( 4 )nm ,b =0 .9714 ( 17)nm ,c =1.5 5 9( 3)nm ,α =90° ,β =90° ,γ =90° ,Z =4 ,V =3.0 4 9( 10 )nm3 ,Dc =1.4 0 7mg·m-3 ,u =1.0 81mm-1,F( 0 0 0 )=1312 ,R1=0 .0 370 ,wR2 =0 .0 6 88,晶体中心的Sn原子为五配位的畸变三角双锥构型     

催化裂化汽油中硫化物类型分布的气相色谱-硫化学发光检测的方法研究

采用气相色谱-硫化学发光检测器(GC-SCD),建立了催化裂化汽油(FCC汽油)中各种硫化物类型分布的分析方法。考察了色谱条件对催化裂化汽油中各种硫化物分离的影响,定性了某催化裂化汽油中的58个硫化物。采用该方法,硫化物中的硫在其质量浓度为0.5~800.0 mg/L时,其峰面积与质量浓度呈较好的线性关系,相关系数达0.999,其响应与硫化物的类型无关。FCC汽油中几种主要硫化物(噻吩、正丁硫醇、2-甲基噻吩、3-甲基噻吩、2,4-二甲基噻吩)的浓度测定值的相对标准偏差(RSD)均小于5.0%。当信噪     

Extraction,Isolation and Characterization of Bioactive Compounds from Artemisia and Their Biological Significance: A Review

Diverse medicinal plants such as those from the genus Artemisia have been employed globally for centuries by individuals belonging to different cultures. Universally, Artemisia species have been used to remedy various maladies that range from simple fevers to malaria. A survey conducted by the World Health Organization (WHO) demonstrated that 80% of the global population is highly reliant on herbal medicine for their primary healthcare. WHO recommends artemisinin-based combination therapies (ACT) for the treatment of global diseases such as malaria. Artemisinin is a bioactive compound derived from Artemisia annua leaves. It is a sesquiterpene endoperoxide with potent antimalarial properties. This review strives to instill natural products to chemists and others in diverse fields with a heterogeneous set of knowledge compiled from multifaceted researchers and organizations in literature. In particular, the various Artemisia species and effective extraction, isolation, and characterization methodologies are discussed in detail. An in-depth investigation into the literature reveals that divergent species of Artemisia exhibit a vast array of biological activities such as antimalarial, antitumor, and anti-inflammatory activities. There is substantial potential for bioactive compounds from Artemisia to provide significant relief from differing human ailments, but more meticulous research in this field is needed.     

二(对-氯苄基)二氯化锡的合成及晶体结构

用 X射线方法测定了二 (对氯苄基 )二氯化锡的晶体结构,该化合物晶体属单斜晶系,空间群为 C2/c,晶体学参数： a=2.8010(3), b=0.4882(2), c=1.2174(3)nm,β =111.71(1)°, V=1.5467(7) nm3, Z=4, Dx=1.893g· cm－ 3,μ (MoKα )=23.24cm－ 1, F(000)=856.00, R=0.025, Rw=0.038, Sn C键长为 0.2148(3)nm, Sn Cl键长为 0.23754(9)nm。空间构型为畸变四面体构型的单分子有机锡化合物。     

硫、硒杯[4]芳烃萃取银

以5,11,17,23-四（1,1-二甲基乙基）-25,27-二羟基-26,28-二[（2-乙基硫）乙氧基]杯[4]芳烃（1）和5,11,17,23-四（1,1-二甲基乙基）-25,27-二羟-26,28-二[（2-乙基硒）]乙氧基杯[4]芳烃（2）为萃取剂,研究了在弱酸性条件下杯芳烃衍生物与银的络合行为。杯芳烃衍生物与银形成1：1萃取络合物,在大量碱金属、碱土金属、常见过渡金属离子存在下,对银离子有很高的萃取率和选择性。     

气相色谱法测定催化柴油中硫化物类型分布及数据对比

采用气相色谱-氢火焰离子化检测器-硫化学发光检测器（GC—FID—SCD）联用技术,建立了催化柴油中各种硫化物类型分布的分析方法。考察了色谱条件对催化柴油中各种硫化物分离的影响,定性了某催化柴油中的120多个硫化物,该方法还可以同时提供催化柴油中正构烷烃含量的分布信息。硫化物中的硫在1．5—700mg／L时其峰面积与质量浓度呈较好的线性关系,相关系数达0．9999,响应与硫化物的类型无关。催化柴油中苯并噻吩、4-甲基苯并噻吩、二苯并噻吩、4-甲基二苯并噻吩和4,6-二甲基二苯并噻吩等主要硫化物浓度测定的相对标准偏差（RSD）均小于5．0％。当信噪比（S／N）为3时,测得苯并噻吩硫的检出限为0．1mg／L。将该方法用于不同来源柴油中各种硫化物类型分布的研究,并与气相色谱一原子发射光谱检测器（GC—AED）测硫的数据进行了对比,两种检测器的定量结果大多数具有较好的相关性,相关系数大于0．95。     

裂解色谱法研究渣油中硫化物的结构及组成特征

采用裂解气相色谱(PY-GC)方法研究重油中的大分子硫化物。实验考察了裂解时间和裂解温度对裂解反应的影响,在此基础上确定了裂解色谱条件,并分析了渣油裂解产物的组成。通过对大港、俄罗斯、前郭、孤岛及俄罗斯-大庆混合减压渣油等5种渣油的裂解实验,发现不同来源的渣油裂解产物中硫化物的组成和含量存在较大差异。实验中所得到的裂解产物中硫化物的组成为渣油中硫化物的组成提供了重要信息。     

钙钛矿型复合氧化物La_(0.9)K_(0.1)CoO_3催化合成甲基二氯化膦

以甲烷(CH4)和三氯化磷(PCl3)为原料,钙钛矿型复合氧化物La0.9K0.1CoO3为催化剂,通过气固相催化法合成了甲基二氯化膦.重点考察了反应物摩尔比和反应温度对转化率的影响.最适宜的反应条件为: n(CH4) ∶ n(PCl3)=5 ∶ 1,催化剂(40目～60目) 1 g,反应温度300 ℃,转化率7.02%.     

催化裂化汽油中硫化物的气相色谱-原子发射光谱分析方法及应用

采用气相色谱-原子发射光谱联用(GC-AED)技术，建立了催化裂化汽油中各种硫化物类型分布的分析方法。考察了色谱条件对催化汽油中各种硫化物分离的影响，定性了催化汽油中的60余种硫化物，首次计算了程序升温条件下汽油馏分中各种硫化物的保留指数，为不同实验室的定性比较提供了依据。该方法可应用于不同来源汽油中各种硫化物类型分布的研究。     

桑色素荧光光度法测定二氯化双(丁氧羰乙基)锡

在ｐＨ３．０的ＨＡｃ－ＮａＡｃ缓冲溶液中和有Ｔｒｉｔｏｎ Ｘ－１００存在下,二氯化双（丁氧羰乙基）锡（简写为Ｒ２ＳｎＣｌ２）与桑色素形成１：１的荧光络合物。络合物的激发波长和发射波长分别为４４３．２ｎｍ和５１４。４ｎｍ。Ｒ２ＳｎＣｌ２中的Ｓｎ浓度在０￣３．０ｍｇ／Ｌ范围内,与络合物荧光强度呈线性关系。方法检出限为７．８１μｇ／Ｌ Ｓｎ,用于ＰＶＣ中间产品和污水中Ｒ２ＳｎＣｌ２的测定,结果满意,相对     

Synthesis and X-Ray Crystal Structure of New Oxathiacrown Ethers Containing Sulfoxide Group and Their Metal-Binding Properties: Highly Selective Receptors for Ag+ and Cu2+

Three new oxathiacrown ethers 1, 2 and 3 containing a sulfoxide group were synthesized in a simple way. Conductometric titration studies in pure acetonitrile were employed to invistigate their binding affinities towards Ag ⁺, Cu ²⁺, Pb ²⁺, Cd ²⁺, Zn ²⁺, Co ²⁺, Ni ²⁺, Cr ³⁺and Hg ²⁺. They were found to be selective for Ag ⁺ and Cu ²⁺ over the other metals investigated. Ligand 1 has the highest selectivity towards Ag ⁺. The structure of compound 3 was confirmed by X-ray crystallography.Supplementary Data relevant to this article have been deposited at the Cambridge Crystallographic Data Centre under the deposition number 232076.