South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie最新文献_第7页

C-H activation: a Critical Evaluation of a Published Method and its Application Towards Inherently Chiral Calix[4]arenes C-H活化:一种已发表方法的关键评价及其在固有手性杯杯芳烃中的应用

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2020-01-01 DOI: 10.17159/0379-4350/2020/v73a3

Kevin J Visagie, Luke Hodson, G. Arnott

{"title":"C-H activation: a Critical Evaluation of a Published Method and its Application Towards Inherently Chiral Calix[4]arenes","authors":"Kevin J Visagie, Luke Hodson, G. Arnott","doi":"10.17159/0379-4350/2020/v73a3","DOIUrl":"https://doi.org/10.17159/0379-4350/2020/v73a3","url":null,"abstract":"C–H activation offers an intriguing access into inherently chiral calix[4]arenes, but has been little explored in the literature. In this article, we report our investigation into a published C–H activation method that uses carbamates to direct a palladium catalyzed C–H activation and subsequent reaction with N-bromosuccinimide. However, we show that this report is unfortunately flawed on a number of points. An earlier reported study revealed the more likely SEAr mechanism of the bromination reaction, which did not involve palladium catalysis. We nevertheless employed the SEAr bromination in an attempt to form inherently chiral calix[4]arenes, using a chiral (+)-menthyl carbamate as a directing group. Unfortunately, although the reaction was high yielding, the diastereomers formed were inseparable and we were unable to quantify their ratio. Subsequent removal of the chiral (+)-menthyl carbamate, returned a small positive optical rotation, suggesting that at least a level of asymmetric induction was achieved in the bromination to afford a non-racemic product.","PeriodicalId":49495,"journal":{"name":"South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67463600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Formation of 3,3,4-Trimethyl-1,7-dibromonorbornane-2-one: a Spectroscopic and Computational Study 3,3,4-三甲基-1,7-二溴单硼烷-2- 1的形成:光谱和计算研究

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2020-01-01 DOI: 10.17159/0379-4350/2020/v73a5

I. Sabbagh, P. Kaye

引用次数: 0

Surface-modified Water Hyacinth (Eichhornia crassipes) over Activated Carbon for Wastewater Treatment: A Comparative Account 表面改性水葫芦与活性炭处理废水的比较研究

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2020-01-01 DOI: 10.17159/0379-4350/2020/v73a11

S. Bapat, D. Jaspal

{"title":"Surface-modified Water Hyacinth (Eichhornia crassipes) over Activated Carbon for Wastewater Treatment: A Comparative Account","authors":"S. Bapat, D. Jaspal","doi":"10.17159/0379-4350/2020/v73a11","DOIUrl":"https://doi.org/10.17159/0379-4350/2020/v73a11","url":null,"abstract":"Finding an economical, efficient and easy handling alternative for commercial grade activated charcoal (AC) in textile wastewater treatment is a dire need. To address this, a noxious weed water hyacinth (WH) has been explored as a ‘biosorbent’ for the decolorization of the hazardous textile dye, Remazol Brilliant Red 3BS (RBR 3BS) in wastewater. A novel surface modification has been carried out using the quaternary ammonium salt, N-Cetyl-N,N,N–trimethyl ammonium bromide, to enhance the dye decolorization capacity of raw WH. The impact of several process parameters, viz. pH, dosage of adsorbent, temperature, concentration and contact time have been examined. Batch adsorption studies, kinetic-thermodynamics, isothermal modelling and error analysis have been studied to ascertain the efficacy of the adsorbent. A comparison of the results has been carried out with activated carbon (AC). Surface-modified WH showed the highest dye uptake of 104.26 mg g, at 27 °C, which was about 10 times more than that of AC. Isothermal, kinetic and thermodynamic studies were conducted for identification of adsorption type taking place for dye–adsorbent systems. Energy of activation was 8.65 kJ mol for treated WH and 8.98 kJ mol for AC. It was proven that surface-modified WH had a high capability to replace AC for adsorption treatments.","PeriodicalId":49495,"journal":{"name":"South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67463383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 9

A Spectroscopic, Thermodynamic and Molecular Docking Study of the Binding Mechanism of Dapoxetine with Calf Thymus DNA 达泊西汀与小牛胸腺DNA结合机制的光谱、热力学和分子对接研究

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2020-01-01 DOI: 10.17159/0379-4350/2020/v73a7

Nawaf A. Alsaif, Abdurrahman A. Al-Mehizia, A. Bakheit, Seema Zargar, T. Wani

{"title":"A Spectroscopic, Thermodynamic and Molecular Docking Study of the Binding Mechanism of Dapoxetine with Calf Thymus DNA","authors":"Nawaf A. Alsaif, Abdurrahman A. Al-Mehizia, A. Bakheit, Seema Zargar, T. Wani","doi":"10.17159/0379-4350/2020/v73a7","DOIUrl":"https://doi.org/10.17159/0379-4350/2020/v73a7","url":null,"abstract":"Dapoxetine is a selective serotonin reuptake inhibitor, used to treat premature ejaculation in men. Dapoxetine may interact with the DNA and hence this study investigated dapoxetine and calf thymus DNA (ctDNA) binding interaction. The interaction study of ligands to DNA is of importance in the development of molecular probes and therapeutic agents. Spectroscopic techniques including spectrofluorometry and spectrophotometry were employed to study this interaction. Fluorescence studies indicated a static quenching mechanism between dapoxetine and ctDNA. Groove binding was suggested as the mode of interaction between dapoxetine and ctDNA based on UV absorption, circular dichroism (CD) spectroscopy, iodide quenching and molecular docking studies. The studies conducted at three different temperatures 298, 303 and 310 K indicated a strong binding interaction at higher temperatures. Thermodynamic studies conducted indicated involvement of hydrophobic interaction between ctDNA and dapoxetine and were entropy-driven. Ethidium bromide probe study suggested that dapoxetine does not bind to ctDNA in an intercalative fashion. Iodide quenching studies further proved the non-intercalative binding of ctDNA with dapoxetine. Ionic strength studies conducted ruled out the electrostatic binding mechanism between ctDNA and dapoxetine. Molecular docking analysis performed for the dapoxetine with calf thymus DNA (ctDNA) interaction and confirmed minor groove binding of dapoxetine to ctDNA. The study helped to reveal the binding interaction mechanism between dapoxetine and ctDNA.","PeriodicalId":49495,"journal":{"name":"South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67463217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 36

The Quality Control of Alcoholic Components of Disinfectants by a Simple Colour Test 简单显色法控制消毒剂中酒精成分的质量

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2020-01-01 DOI: 10.17159/0379-4350/2020/v73a12

H. Langhals

引用次数: 2

Ultrasound Promoted Stereoselective Synthesis of 2,3-Dihydrobenzofuran Appended Chalcones at Ambient Temperature 超声促进常温下2,3-二氢苯并呋喃加查尔酮的立体选择性合成

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2020-01-01 DOI: 10.17159/0379-4350/2020/v73a6

V. A. Adole, B. Jagdale, T. B. Pawar, Abhishek A Sagane

{"title":"Ultrasound Promoted Stereoselective Synthesis of 2,3-Dihydrobenzofuran Appended Chalcones at Ambient Temperature","authors":"V. A. Adole, B. Jagdale, T. B. Pawar, Abhishek A Sagane","doi":"10.17159/0379-4350/2020/v73a6","DOIUrl":"https://doi.org/10.17159/0379-4350/2020/v73a6","url":null,"abstract":"In the present investigation, an ultrasound promoted the synthesis of a series of (E)-3-(2,3-dihydrobenzofuran 5-yl)-1-(aryl)prop2-en-1-one derivatives from 2,3-dihydrobenzofuran-5-carbaldehyde and various aromatic ketones under clean conditions. The application of ultrasound irradiation in organic reactions is one of the incredible tools of green chemistry as reactions can be carried out rapidly under neat conditions. A library of a novel (E)-3-(2,3-dihydrobenzofuran-5-yl)-1-(aryl)prop-2-en-1-one chalcone derivatives were synthesized in good to excellent yield under ultrasonic irradiation. The structures of all synthesized chalcone derivatives synthesized in this study have been established by using FT-IR, H NMR, C NMR, and HRMS techniques. The stereochemistry around C=C in the chalcones was shown to be trans by H NMR (Jab = 15.5Hz). The benefits of the present synthesis include mild reaction conditions, high yield, purification by non-chromatographic strategy and short reaction times, demonstrating the significance of this protocol in terms of waste reduction and energy efficiency.","PeriodicalId":49495,"journal":{"name":"South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67463207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 28

Photocatalytic Degradation of Direct Red 16 Dye using Ag/Ag3VO4/AgVO3/GO Nanocomposite Ag/Ag3VO4/AgVO3/GO纳米复合材料光催化降解直接红16染料

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2020-01-01 DOI: 10.17159/0379-4350/2020/v73a01

Behzad Hazizadeh Far, Parvin Gaharbani, R. R. Khojasteh

引用次数: 4

Efficient Removal of Sulfamethoxazole onto Sugarcane Bagasse-derived Biochar: Two and Three-parameter Isotherms, Kinetics and Thermodynamics 蔗渣生物炭对磺胺甲恶唑的高效去除:二参数和三参数等温线、动力学和热力学

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2020-01-01 DOI: 10.17159/0379-4350/2020/V73A16

Victor O. Shikuku, Selly Jemutai-Kimosop

{"title":"Efficient Removal of Sulfamethoxazole onto Sugarcane Bagasse-derived Biochar: Two and Three-parameter Isotherms, Kinetics and Thermodynamics","authors":"Victor O. Shikuku, Selly Jemutai-Kimosop","doi":"10.17159/0379-4350/2020/V73A16","DOIUrl":"https://doi.org/10.17159/0379-4350/2020/V73A16","url":null,"abstract":"In this work, bagasse, an agricultural waste was used for the development of environmentally benign biochar (CBG) and the thermal pyrolysis product applied for adsorption of sulfamethoxazole (SMX) from water using a batch technique. The pseudo-first-order model best described the adsorption kinetics. Equilibrium adsorption data were modelled using six twoparameter and five three-parameter isotherm equations and the best-fitting models obtained using five error functions. The Sips isotherm best predicted the equilibrium data with an estimated adsorption capacity of 128.8 mg g. Error analysis showed that three-parameter isotherms best explained the experimental data. The thermodynamic functions, viz. enthalpy (ÄH = –24.72 kJ mol), Gibbs free energy (ÄG = –15.67 kJ mol), entropy (ÄS = 32.65 kJ mol), showed that the reaction is spontaneous and exothermic. The mechanism of adsorption involved charge-assisted hydrogen bonding (-)CAHB. The amount of CBG required for the removal of 99 % of SMX in a given volume of effluent was predicted. The results attest that CBG is an effective low-cost adsorbent for SMX adsorption.","PeriodicalId":49495,"journal":{"name":"South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie","volume":null,"pages":null},"PeriodicalIF":1.5,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67463523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 14

Templated Cross-linked Nanoporous Starch 模板化交联纳米多孔淀粉

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2020-01-01 DOI: 10.17159/0379-4350/2020/V73A19

Somayeh Oftadehgan, A. P. Marjani, J. Khalafy, A. Zamani

引用次数: 0

The Activities of the Eastern Province Section of the South African Chemical Institute 1935-1965 南非化学研究所东部省科1935-1965年的活动

IF 1.5 4区化学

South African Journal of Chemistry-Suid-Afrikaanse Tydskrif Vir Chemie Pub Date : 2020-01-01 DOI: 10.17159/0379-4350/2020/v73a2

P. Loyson

引用次数: 0