Lingling Zhang, Xia Wang, Chong Gong, Weiyan Sun, Zihan Lu
Co3O4 nanoparticles were sandwiched into interlayers between ZIF-8 and ZIF-67 to form ZIF-Co3O4@ZIF precursors. Pyrolysis of ZIF-Co3O4@ZIF yielded an urchin-like hierarchically porous carbon (Co@CNT/NC), the thorns of which were carbon nanotubes embedded Co nanoparticles. With large specific surface area and hierarchically porous structure, as-prepared Co@CNT/NC exhibited excellent bifunctional oxygen electrocatalytic performances. It has good ORR performance with E1/2 of 0.85 V, which exceeds the Pt/C half-wave potential (E1/2=0.83 V). In addition, Co@CNT/NC has an OER performance close to that of RuO2. To further demonstrate the effect of Co modifying on the properties, the samples were subjected to acid washing treatment. Co-based nanoparticles were proved to After acid washing, there was obvious loss of Co particles in Co@CNT/NC, resulting in poor oxygen electrocatalysis. So, the pyrolysis products of ZIF-8-Co3O4@ZIF-67 retained large specific surface area and porous structure can be retained, and on the other hand, the carbon tube structure and original polyhedron framework. Besides, existence of Co nanoparticle@carbon nanotube provided more active sites and improved the ORR and OER performances.
Co3O4 纳米粒子被夹在 ZIF-8 和 ZIF-67 之间的夹层中,形成 ZIF-Co3O4@ZIF 前体。热解 ZIF-Co3O4@ZIF 得到了海胆状分层多孔碳(Co@CNT/NC),其刺是嵌入 Co 纳米粒子的碳纳米管。制备的 Co@CNT/NC 具有较大的比表面积和分层多孔结构,表现出优异的双功能氧电催化性能。它具有良好的 ORR 性能,E1/2 为 0.85 V,超过了 Pt/C 半波电位(E1/2=0.83 V)。此外,Co@CNT/NC 的 OER 性能接近 RuO2。为了进一步证明 Co 修饰对性能的影响,对样品进行了酸洗处理。结果表明,酸洗后,Co@CNT/NC 中的 Co 颗粒明显减少,导致氧电催化性能变差。因此,ZIF-8-Co3O4@ZIF-67 的热解产物一方面保留了较大的比表面积和多孔结构,另一方面保留了碳管结构和原有的多面体框架。此外,Co 纳米粒子@碳纳米管的存在提供了更多的活性位点,提高了 ORR 和 OER 性能。
{"title":"ZIF-Co<sub>3</sub>O<sub>4</sub>@ZIF-Derived Urchin-Like Hierarchically Porous Carbon as Efficient Bifunctional Oxygen Electrocatalysts.","authors":"Lingling Zhang, Xia Wang, Chong Gong, Weiyan Sun, Zihan Lu","doi":"10.1002/open.202400057","DOIUrl":"https://doi.org/10.1002/open.202400057","url":null,"abstract":"<p><p>Co<sub>3</sub>O<sub>4</sub> nanoparticles were sandwiched into interlayers between ZIF-8 and ZIF-67 to form ZIF-Co<sub>3</sub>O<sub>4</sub>@ZIF precursors. Pyrolysis of ZIF-Co<sub>3</sub>O<sub>4</sub>@ZIF yielded an urchin-like hierarchically porous carbon (Co@CNT/NC), the thorns of which were carbon nanotubes embedded Co nanoparticles. With large specific surface area and hierarchically porous structure, as-prepared Co@CNT/NC exhibited excellent bifunctional oxygen electrocatalytic performances. It has good ORR performance with E<sub>1/2</sub> of 0.85 V, which exceeds the Pt/C half-wave potential (E<sub>1/2</sub>=0.83 V). In addition, Co@CNT/NC has an OER performance close to that of RuO<sub>2</sub>. To further demonstrate the effect of Co modifying on the properties, the samples were subjected to acid washing treatment. Co-based nanoparticles were proved to After acid washing, there was obvious loss of Co particles in Co@CNT/NC, resulting in poor oxygen electrocatalysis. So, the pyrolysis products of ZIF-8-Co<sub>3</sub>O<sub>4</sub>@ZIF-67 retained large specific surface area and porous structure can be retained, and on the other hand, the carbon tube structure and original polyhedron framework. Besides, existence of Co nanoparticle@carbon nanotube provided more active sites and improved the ORR and OER performances.</p>","PeriodicalId":9831,"journal":{"name":"ChemistryOpen","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141295649","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}
A hydrogen sulfide (H2S) stimuli-responsive hydrogel was constructed based on the coordination and bonding principle of metal ions and chitosan (CS). The hydrogel can be rapidly prepared within 5 s. In the presence of H2S, the cross-linking agent Cu2+ can compete out, and release of the electrochemical probe. The prepared hydrogel has a good linear relationship with H2S.
{"title":"One-Step Synthesis of Chitosan Hydrogel as Electrochemical Chemosensor for Hydrogen Sulfide Detection in Pregnancy-Induced Hypertension Syndrome Serum Sample","authors":"Lishan Fang, Jinqiu Li, Wei Lin, Lili Zeng, Liumin Yu, Zhanfei Chen, Jianlin Shen, Yu Chen, Zhonghui Chen, Zhenyu Lin","doi":"10.1002/open.202400107","DOIUrl":"https://doi.org/10.1002/open.202400107","url":null,"abstract":"A hydrogen sulfide (H<sub>2</sub>S) stimuli-responsive hydrogel was constructed based on the coordination and bonding principle of metal ions and chitosan (CS). The hydrogel can be rapidly prepared within 5 s. In the presence of H<sub>2</sub>S, the cross-linking agent Cu<sup>2+</sup> can compete out, and release of the electrochemical probe. The prepared hydrogel has a good linear relationship with H<sub>2</sub>S.","PeriodicalId":9831,"journal":{"name":"ChemistryOpen","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141257735","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}
R Pereira-Pinto, M Barros, M Vaz-Velho, F Mata, P Pires
Boar taint is an unpleasant odour found in the carcasses of entire male pigs, resulting from androstenone and skatole accumulation during pubertal development, and impacting pork quality. This study proposes the validation of an adapted chromatographic method for quantifying skatole and androstenone in the pigs' liquid fat using fluorescence detection. A good chromatographic separation was achieved, with skatole (SKA) and androstenone (AND) elution at 4.4 and 9.9 min., respectively. An external calibration method was applied, with calibration curves correlation coefficient of 0.9999 for both analytes. Detection limit values were 1.53 and 16.02 ng/g for SKA and AND, respectively. SKA recovery was 99.72±2.34 % (2.34 % RSD) and 102.84±1.62 % (1.57 % RSD) for AND. Results showed good precision values (repeatability <2.46 % RSD for SKA, <6.85 % RSD for AND; intermediate precision <2.87 % RSD for SKA, <6.98 % RSD for AND). The method's robustness was tested and the values were within the reference ranges. The validation results proved that the adaptation of an existing method resulted in good assessments of robustness, reliability and accuracy.
{"title":"Enhanced HPLC Method for Boar Taint Quantification.","authors":"R Pereira-Pinto, M Barros, M Vaz-Velho, F Mata, P Pires","doi":"10.1002/open.202300283","DOIUrl":"https://doi.org/10.1002/open.202300283","url":null,"abstract":"<p><p>Boar taint is an unpleasant odour found in the carcasses of entire male pigs, resulting from androstenone and skatole accumulation during pubertal development, and impacting pork quality. This study proposes the validation of an adapted chromatographic method for quantifying skatole and androstenone in the pigs' liquid fat using fluorescence detection. A good chromatographic separation was achieved, with skatole (SKA) and androstenone (AND) elution at 4.4 and 9.9 min., respectively. An external calibration method was applied, with calibration curves correlation coefficient of 0.9999 for both analytes. Detection limit values were 1.53 and 16.02 ng/g for SKA and AND, respectively. SKA recovery was 99.72±2.34 % (2.34 % RSD) and 102.84±1.62 % (1.57 % RSD) for AND. Results showed good precision values (repeatability <2.46 % RSD for SKA, <6.85 % RSD for AND; intermediate precision <2.87 % RSD for SKA, <6.98 % RSD for AND). The method's robustness was tested and the values were within the reference ranges. The validation results proved that the adaptation of an existing method resulted in good assessments of robustness, reliability and accuracy.</p>","PeriodicalId":9831,"journal":{"name":"ChemistryOpen","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141160735","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}
Pyrolysis-based saccharification consisting of fast pyrolysis followed by hydrolysis of the resulting anhydrosugars such as levoglucosan is a promising method for converting cellulosic biomass into glucose that can be used for producing biofuels and biochemicals. In the present study, hydrolysis of levoglucosan was evaluated in water with a polystyrene sulfonic acid resin (a solid acid catalyst) by heating under microwave irradiation or in an oil bath at 95 °C-120 °C. When the equilibrium temperature of the solution was the same, the conversion rate of levoglucosan was greater under microwave irradiation than in an oil bath. Model experiments indicate that the sulfonyl groups of the solid acid catalyst were selectively heated by microwave irradiation. The temperature of the reaction solution in the vicinity of the catalyst was locally higher than the equilibrium temperature of the solution, which enabled hydrolysis to proceed efficiently.
{"title":"Microwave Effect in Hydrolysis of Levoglucosan with a Solid Acid Catalyst for Pyrolysis-Based Cellulose Saccharification.","authors":"Takashi Nomura, Eiji Minami, Haruo Kawamoto","doi":"10.1002/open.202300311","DOIUrl":"https://doi.org/10.1002/open.202300311","url":null,"abstract":"<p><p>Pyrolysis-based saccharification consisting of fast pyrolysis followed by hydrolysis of the resulting anhydrosugars such as levoglucosan is a promising method for converting cellulosic biomass into glucose that can be used for producing biofuels and biochemicals. In the present study, hydrolysis of levoglucosan was evaluated in water with a polystyrene sulfonic acid resin (a solid acid catalyst) by heating under microwave irradiation or in an oil bath at 95 °C-120 °C. When the equilibrium temperature of the solution was the same, the conversion rate of levoglucosan was greater under microwave irradiation than in an oil bath. Model experiments indicate that the sulfonyl groups of the solid acid catalyst were selectively heated by microwave irradiation. The temperature of the reaction solution in the vicinity of the catalyst was locally higher than the equilibrium temperature of the solution, which enabled hydrolysis to proceed efficiently.</p>","PeriodicalId":9831,"journal":{"name":"ChemistryOpen","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141160744","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}
Among the natural tetramic acids with a decalinoyl part, signermycin B is unique because it contains a cis-decalin. In this paper, we demonstrate that the cis-decalin section of signermycin B can be accessed by an anionic oxy-Cope rearrangement. The substrate, a tricyclic dienol was prepared by an intramolecular Diels-Alder reaction of a masked ortho-benzoquinone, generated by oxidation of an α-methoxyphenol in presence of cis-2-hexenol. After a superfluous bromine on the cycloadduct was removed, reaction of the tricyclic ketone with isopropenylmagnesium bromide led to the tricyclic trienol that underwent the oxy-Cope rearrangement to a cis-decalinone. While we could show, that introduction of the 4-ethyl substituent (signermycin B numbering) is possible by enolate alkylation, the 4-epi-isomer was formed.
在具有癸醛酰基部分的天然四元酸中,符号霉素 B 是独一无二的,因为它含有顺式癸醛。在本文中,我们证明了通过阴离子氧-科普重排可以获得签霉素 B 的顺式癸醛部分。底物是一种三环二烯醇,由α-甲氧基苯酚在顺式-2-己烯醇存在下氧化生成的被掩蔽的邻苯醌通过分子内 Diels-Alder 反应制备而成。除去环加合物上多余的溴后,三环酮与异丙烯基溴化镁反应生成三环三烯醇,三环三烯醇经过氧-科普重排生成顺式癸酮。虽然我们可以证明,通过烯醇烷基化可以引入 4-乙基取代基(符号霉素 B 编号),但形成的是 4-表异构体。
{"title":"Approach to the Core Structure of Signermycin B.","authors":"Khoa Linh Pham, Martin E Maier","doi":"10.1002/open.202400103","DOIUrl":"https://doi.org/10.1002/open.202400103","url":null,"abstract":"<p><p>Among the natural tetramic acids with a decalinoyl part, signermycin B is unique because it contains a cis-decalin. In this paper, we demonstrate that the cis-decalin section of signermycin B can be accessed by an anionic oxy-Cope rearrangement. The substrate, a tricyclic dienol was prepared by an intramolecular Diels-Alder reaction of a masked ortho-benzoquinone, generated by oxidation of an α-methoxyphenol in presence of cis-2-hexenol. After a superfluous bromine on the cycloadduct was removed, reaction of the tricyclic ketone with isopropenylmagnesium bromide led to the tricyclic trienol that underwent the oxy-Cope rearrangement to a cis-decalinone. While we could show, that introduction of the 4-ethyl substituent (signermycin B numbering) is possible by enolate alkylation, the 4-epi-isomer was formed.</p>","PeriodicalId":9831,"journal":{"name":"ChemistryOpen","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141160730","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}
Plasma-facing liquids (PFLs) facilitate the storage of reactive O and N species (RONS), including H2O2 and NO2−, which remain in the PFL after plasma treatment, and they can continuously influence the target immersed in the liquid. However, their behaviors and levels of generation and extinction depend strongly on the plasma characteristics and liquid condition. Therefore, understanding the effects of the liquid type on the plasma discharge characteristics and the RONS generated via plasma discharge is necessary. We compared the RONS generation and storage trends of deionized H2O and a high-conductivity PFL, RPMI 1640, which is a well-known cell culture medium commonly used to culture mammalian cells. RPMI 1640 acted as an electrode and enhanced the plasma discharge power by supplying abundant radicals and RONS. The production of gaseous hydroxyl radicals and NO markedly increased, which facilitated H2O2 and NO2− production in the PFL for the first 200 s, and then the increase in the RONS concentration stagnated. With respect to storage, as the components within RMPI 1640 exhibited high reaction constants for their reactions with H2O2, H2O2 elimination was completed in <30 min. Unlike H2O2, the concentration of NO2− in the PFL was unchanged.
{"title":"Characteristics of Aqueous Chemical Species Generation in Plasma-Facing Liquid Systems Using Helium Jet Plasma","authors":"Joo Young Park, Jin Hee Bae, Seunghun Lee","doi":"10.1002/open.202300213","DOIUrl":"10.1002/open.202300213","url":null,"abstract":"<p>Plasma-facing liquids (PFLs) facilitate the storage of reactive O and N species (RONS), including H<sub>2</sub>O<sub>2</sub> and NO<sub>2</sub><sup>−</sup>, which remain in the PFL after plasma treatment, and they can continuously influence the target immersed in the liquid. However, their behaviors and levels of generation and extinction depend strongly on the plasma characteristics and liquid condition. Therefore, understanding the effects of the liquid type on the plasma discharge characteristics and the RONS generated via plasma discharge is necessary. We compared the RONS generation and storage trends of deionized H<sub>2</sub>O and a high-conductivity PFL, RPMI 1640, which is a well-known cell culture medium commonly used to culture mammalian cells. RPMI 1640 acted as an electrode and enhanced the plasma discharge power by supplying abundant radicals and RONS. The production of gaseous hydroxyl radicals and NO markedly increased, which facilitated H<sub>2</sub>O<sub>2</sub> and NO<sub>2</sub><sup>−</sup> production in the PFL for the first 200 s, and then the increase in the RONS concentration stagnated. With respect to storage, as the components within RMPI 1640 exhibited high reaction constants for their reactions with H<sub>2</sub>O<sub>2</sub>, H<sub>2</sub>O<sub>2</sub> elimination was completed in <30 min. Unlike H<sub>2</sub>O<sub>2</sub>, the concentration of NO<sub>2</sub><sup>−</sup> in the PFL was unchanged.</p>","PeriodicalId":9831,"journal":{"name":"ChemistryOpen","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11230930/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141154614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bingyang Wang, Yanhui Liu, Chenyang Jia, Zhenfang Lan, Xuepeng Yang
(-)-Ambrox, a highly prized and commercially significant component of ambergris, finds widespread application in perfumery, cigarettes, cosmetics, and the food industry. Despite considerable attention to this research area over the years, an environmentally friendly and practical method for synthesizing (-)-ambrox has remained elusive. This study presents a succinct and efficient approach to (-)-ambrox synthesis, involving two consecutive alkylations at C-6, followed by an acid-catalyzed cyclization to give bicyclic ketones starting from (R)-carvone. Subsequent reduction, Barton Vinyl Iodide synthesis, alkylation, and an acid-catalyzed cyclization collectively achieved the synthesis of (-)-ambrox with a satisfactory yield of 26.2 %.
{"title":"A Concise Synthesis of (-)-Ambrox.","authors":"Bingyang Wang, Yanhui Liu, Chenyang Jia, Zhenfang Lan, Xuepeng Yang","doi":"10.1002/open.202400006","DOIUrl":"https://doi.org/10.1002/open.202400006","url":null,"abstract":"<p><p>(-)-Ambrox, a highly prized and commercially significant component of ambergris, finds widespread application in perfumery, cigarettes, cosmetics, and the food industry. Despite considerable attention to this research area over the years, an environmentally friendly and practical method for synthesizing (-)-ambrox has remained elusive. This study presents a succinct and efficient approach to (-)-ambrox synthesis, involving two consecutive alkylations at C-6, followed by an acid-catalyzed cyclization to give bicyclic ketones starting from (R)-carvone. Subsequent reduction, Barton Vinyl Iodide synthesis, alkylation, and an acid-catalyzed cyclization collectively achieved the synthesis of (-)-ambrox with a satisfactory yield of 26.2 %.</p>","PeriodicalId":9831,"journal":{"name":"ChemistryOpen","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141075245","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}
Abderrahman El Bouakher, Jérôme Lhoste, Arnaud Martel, Sébastien Comesse
The synthesis of polycyclic γ- and δ-lactams bearing up to four contiguous fully controlled stereocenters is presented. For that purpose, we developed an original approach based on the use of 2,3-epoxyamides in domino reactions by taking advantage of the nucleophilic nitrogen atom and electrophilic epoxide. In reaction with enol ethers bearing gem bis-electrophiles on the double bond as Michael acceptors, four different reaction pathways were observed. They all started with a domino oxa-Michael/aza-Michael/epoxide opening sequence and depending on substrates engaged could be followed either by a lactonization or a hemiketalization/retro-aldol cascade. Thus, four original fully-substituted piperidine- or pyrrolidine-2-one scaffolds were selectively synthesized in good to high yields. Moreover, these polycyclic lactams were obtained in high stereo- and chemo-selectively highlighting the efficiency and molecular diversity offered by this new methodology that should offer various synthetic opportunities in the future.
{"title":"2,3-Epoxyamide-alcohols in Domino Reactions: En Route to Molecular Diversity.","authors":"Abderrahman El Bouakher, Jérôme Lhoste, Arnaud Martel, Sébastien Comesse","doi":"10.1002/open.202400115","DOIUrl":"https://doi.org/10.1002/open.202400115","url":null,"abstract":"<p><p>The synthesis of polycyclic γ- and δ-lactams bearing up to four contiguous fully controlled stereocenters is presented. For that purpose, we developed an original approach based on the use of 2,3-epoxyamides in domino reactions by taking advantage of the nucleophilic nitrogen atom and electrophilic epoxide. In reaction with enol ethers bearing gem bis-electrophiles on the double bond as Michael acceptors, four different reaction pathways were observed. They all started with a domino oxa-Michael/aza-Michael/epoxide opening sequence and depending on substrates engaged could be followed either by a lactonization or a hemiketalization/retro-aldol cascade. Thus, four original fully-substituted piperidine- or pyrrolidine-2-one scaffolds were selectively synthesized in good to high yields. Moreover, these polycyclic lactams were obtained in high stereo- and chemo-selectively highlighting the efficiency and molecular diversity offered by this new methodology that should offer various synthetic opportunities in the future.</p>","PeriodicalId":9831,"journal":{"name":"ChemistryOpen","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140944163","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}
Dr. Selina Ama Saah, Patrick Opare Sakyi, Prof. Nathaniel Owusu Boadi, Franklyn Addai Tieku, Ampem Kwabena Boampong
This study explores the synthesis of nanoparticles through the thermal decomposition of single-source precursors, a method gaining popularity due to its low cost, minimal environmental toxicity, rapidity, scalability, and the ability to form nanoparticles with few defects. Zinc ethyl carbamate was synthesized and characterized using 1H NMR and infrared spectroscopy. Its purity was confirmed through microelemental analysis and melting point determination. The melting point of the complex was determined to be 165 °C. The thermogravimetric analyses indicated a one-step decomposition of zinc ethyl carbamate with a decomposition onset of of 200 °C, yielding a stable ZnS residue. Further thermal decomposition led to the formation of wurtzite phase ZnS nanoparticles, as evidenced by XRD. SEM micrographs displayed mixed spherical, and cubic unevenly sized, polydispersed nanoparticles, while EDX revealed approximately a 1 : 1 Zn to S ratio. Estimated band gap from the Tauc's plot gave 3.93 eV and 3.42 eV for the nanoparticles synthesized at 300 and 400 °C respectively. The wide difference in the band gaps may be as a result of the larger particles observed at 400 °C and the deformations in the sample as observed in the SEM.
本研究探讨了通过单一来源前体的热分解合成纳米粒子的方法,这种方法因其成本低、环境毒性小、快速、可扩展以及能够形成缺陷少的纳米粒子而越来越受欢迎。我们合成了乙基氨基甲酸锌,并使用 1H NMR 和红外光谱对其进行了表征。通过微量元素分析和熔点测定确认了其纯度。经测定,该复合物的熔点为 165 ℃。热重分析表明,氨基甲酸乙酯锌一步分解,分解起始温度为 200 ℃,产生稳定的 ZnS 残留物。XRD 显示,进一步的热分解导致形成了钨锌相 ZnS 纳米颗粒。扫描电镜显微照片显示出混合球形和立方体大小不均的多分散纳米颗粒,而电离辐射X 显示出大约 1 :1 的锌锡比。根据陶氏图谱估计,在 300 和 400 °C 下合成的纳米粒子的带隙分别为 3.93 eV 和 3.42 eV。带隙差异较大的原因可能是在 400 °C 时观察到的颗粒较大,以及扫描电镜观察到的样品变形。
{"title":"Solventless Synthesis of Zinc Sulphide Nanoparticles from Zinc Bis(diethyldithiocarbamate) as a Single Source Precursor","authors":"Dr. Selina Ama Saah, Patrick Opare Sakyi, Prof. Nathaniel Owusu Boadi, Franklyn Addai Tieku, Ampem Kwabena Boampong","doi":"10.1002/open.202400050","DOIUrl":"10.1002/open.202400050","url":null,"abstract":"<p>This study explores the synthesis of nanoparticles through the thermal decomposition of single-source precursors, a method gaining popularity due to its low cost, minimal environmental toxicity, rapidity, scalability, and the ability to form nanoparticles with few defects. Zinc ethyl carbamate was synthesized and characterized using <sup>1</sup>H NMR and infrared spectroscopy. Its purity was confirmed through microelemental analysis and melting point determination. The melting point of the complex was determined to be 165 °C. The thermogravimetric analyses indicated a one-step decomposition of zinc ethyl carbamate with a decomposition onset of of 200 °C, yielding a stable ZnS residue. Further thermal decomposition led to the formation of wurtzite phase ZnS nanoparticles, as evidenced by XRD. SEM micrographs displayed mixed spherical, and cubic unevenly sized, polydispersed nanoparticles, while EDX revealed approximately a 1 : 1 Zn to S ratio. Estimated band gap from the Tauc's plot gave 3.93 eV and 3.42 eV for the nanoparticles synthesized at 300 and 400 °C respectively. The wide difference in the band gaps may be as a result of the larger particles observed at 400 °C and the deformations in the sample as observed in the SEM.</p>","PeriodicalId":9831,"journal":{"name":"ChemistryOpen","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/open.202400050","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140944167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This article explores the possible presence of a pentacle valence bond structure in C cyclic molecules. At this end, we have used quantum chemistry tools to elucidate the possible arrangement and the nature of chemical bonds within linear, cyclic, and three-dimensional structures only formed by five carbon atoms. While the linear structure is clearly the most stable one, local minima were obtained for both bi- and three-dimensional structures. Using the localization-delocalization matrices approach, we characterize both the minimum linear structure and the cyclic ones. Interestingly, the linear structure is a combination of ionic and covalent bonds, albeit the four distances are almost identical, when using Density Functional Theory. For cyclic C , the pentacle bonding arrangement emerges as a significant Lewis structure, indicative of an unusual formal configuration characterized by five intersecting C-C bonds. Our calculations show that this pentacle arrangement in cyclic C scheme is also present in the more known cyclo-pentadienyl molecule.
本文探讨了 C 5 ${_5 }$ 环状分子中可能存在的五价键结构。为此,我们利用量子化学工具阐明了仅由五个碳原子形成的线性结构、环状结构和三维结构中化学键的可能排列方式和性质。虽然线性结构显然是最稳定的结构,但二维和三维结构都获得了局部最小值。利用定位-非定位矩阵方法,我们确定了最小线性结构和环状结构的特征。有趣的是,线性结构是离子键和共价键的结合,尽管在使用密度泛函理论时,四个距离几乎相同。对于环状 C 5 ${_5 }$,五角成键排列是一种重要的路易斯结构,表明了一种不寻常的形式构型,其特点是有五个相交的 C-C 键。我们的计算表明,环 C 5 ${_5 }$ 方案中的这种五角形排列也存在于更广为人知的环戊二烯分子中。
{"title":"C<sub>5</sub> Pentacle Structures: A Localization-Delocalization Matrices Approach.","authors":"Julien Pilmé, Riccardo Spezia","doi":"10.1002/open.202300277","DOIUrl":"https://doi.org/10.1002/open.202300277","url":null,"abstract":"<p><p>This article explores the possible presence of a pentacle valence bond structure in C <math> <semantics><msub><mrow></mrow> <mn>5</mn></msub> <annotation>${_5 }$</annotation> </semantics> </math> cyclic molecules. At this end, we have used quantum chemistry tools to elucidate the possible arrangement and the nature of chemical bonds within linear, cyclic, and three-dimensional structures only formed by five carbon atoms. While the linear structure is clearly the most stable one, local minima were obtained for both bi- and three-dimensional structures. Using the localization-delocalization matrices approach, we characterize both the minimum linear structure and the cyclic ones. Interestingly, the linear structure is a combination of ionic and covalent bonds, albeit the four distances are almost identical, when using Density Functional Theory. For cyclic C <math> <semantics><msub><mrow></mrow> <mn>5</mn></msub> <annotation>${_5 }$</annotation> </semantics> </math> , the pentacle bonding arrangement emerges as a significant Lewis structure, indicative of an unusual formal configuration characterized by five intersecting C-C bonds. Our calculations show that this pentacle arrangement in cyclic C <math> <semantics><msub><mrow></mrow> <mn>5</mn></msub> <annotation>${_5 }$</annotation> </semantics> </math> scheme is also present in the more known cyclo-pentadienyl molecule.</p>","PeriodicalId":9831,"journal":{"name":"ChemistryOpen","volume":null,"pages":null},"PeriodicalIF":2.3,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140944165","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}