Chunhai Yang, Xue Li, N. Zhou, Beihua Chen, Huilong Dong, Junxun Jin, Xiuli Hu, Tao Huang, Lei Shen, Jun Yi, Wang Quan, D. Ouyang
Tetrazole compounds are a category of energetic materials with great potential. Their stability is inherently related to their aromatics. On the basis of research in DFT at b3lyp/6-311** level on three compounds interested, viz. 5-amino-1H-tetrazole, 5-Carboxyl-1H-tetrazole, 2-methyl-5-Carboxyl-tetrazole, their aromatic characters are extensively analyzed by virtue of different estimation method. Analyses show that these methods, NICS, ICSS, AdNDP, π-electrons density and LOL-pi, are efficient for substituted-tetrazole ring aromaticity estimation. Conclusion denotes that both substituent and substituted position can significantly affect the aromaticity of tetrazole ring of tetrazole compound. Among these given substituents, electro-withdrawing group -COOH significantly increases the aromaticity of the tetrazole rings due to the withdrawing to π-electrons thereof but electro-donating group -NH2 weakens the one of the tetrazole rings due to the donating to π-electrons thereof. But for 2-methyl-5-Carboxyl-tetrazole, the aromaticity increasing of -COOH imposed on π-electrons of tetrazole ring thereof is partially balanced by the existence of the electron-donating group -CH3 at asymmetric meta-position of tetrazole ring. Consequently, the aromaticity order is 5-Carboxyl-1H-tetrazole > 2-methyl-5-Carboxyl-tetrazole > 5-amino-1H-tetrazole.
{"title":"Theoretical Study on Effect of Substituent on Aromaticity of Tetrazole Ring","authors":"Chunhai Yang, Xue Li, N. Zhou, Beihua Chen, Huilong Dong, Junxun Jin, Xiuli Hu, Tao Huang, Lei Shen, Jun Yi, Wang Quan, D. Ouyang","doi":"10.1139/cjc-2023-0014","DOIUrl":"https://doi.org/10.1139/cjc-2023-0014","url":null,"abstract":"Tetrazole compounds are a category of energetic materials with great potential. Their stability is inherently related to their aromatics. On the basis of research in DFT at b3lyp/6-311** level on three compounds interested, viz. 5-amino-1H-tetrazole, 5-Carboxyl-1H-tetrazole, 2-methyl-5-Carboxyl-tetrazole, their aromatic characters are extensively analyzed by virtue of different estimation method. Analyses show that these methods, NICS, ICSS, AdNDP, π-electrons density and LOL-pi, are efficient for substituted-tetrazole ring aromaticity estimation. Conclusion denotes that both substituent and substituted position can significantly affect the aromaticity of tetrazole ring of tetrazole compound. Among these given substituents, electro-withdrawing group -COOH significantly increases the aromaticity of the tetrazole rings due to the withdrawing to π-electrons thereof but electro-donating group -NH2 weakens the one of the tetrazole rings due to the donating to π-electrons thereof. But for 2-methyl-5-Carboxyl-tetrazole, the aromaticity increasing of -COOH imposed on π-electrons of tetrazole ring thereof is partially balanced by the existence of the electron-donating group -CH3 at asymmetric meta-position of tetrazole ring. Consequently, the aromaticity order is 5-Carboxyl-1H-tetrazole > 2-methyl-5-Carboxyl-tetrazole > 5-amino-1H-tetrazole.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"29 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77526434","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}
Mercury (II) ion (Hg2+) is one of the most widespread pollutants that poses a serious threat to public health and the environment. Research efforts on selective and sensitive detection of Hg2+, have therefore drawn considerable attention in recent years. Herein, we report a facile approach to detect Hg2+ based on quantum dots (QDs)-based nanosensor. The two single-stranded DNA (ssDNA) used in this work are modified with biotin (ssDNA-biotin) and fluorescence quencher BHQ2 (ssDNA-BHQ2). These two strands are complementary but with TTT-recognized base sequences for the Hg2+ to form a T-Hg2+-T complex. The biotin-modified ssDNA (ssDNA-biotin) is first bound to the streptavidin-modified QDs, forming a QDs/ssDNA-biotin assembly, which may be further hybridized with the ssDNA-BHQ2, producing a complex of QDs/ssDNA-biotin/ssDNA-BHQ2. The BHQ2 serves as an effective quencher of QDs with the QDs and BHQ2 in a proximity within the QDs/ssDNA-biotin/ssDNA-BHQ2 complex. The decrease of fluorescence intensity therefore serves as an indication of the presence of Hg2+. The fluorescence reduction is observed linearly correlated with the concentration of Hg2+ in the range of 1.0-20.0 nM, with a detection limit at 0.87 nM. The presented QDs-based method is expected to provide a simple, rapid and sensitive method for the detection of Hg2+ in environmental water samples.
{"title":"A fluorescence sensor based on quantum dots for the detection of mercury ions","authors":"Yang Qin, Yunhan Yang, Y. Ho, Ling Zhang","doi":"10.1139/cjc-2022-0145","DOIUrl":"https://doi.org/10.1139/cjc-2022-0145","url":null,"abstract":"Mercury (II) ion (Hg2+) is one of the most widespread pollutants that poses a serious threat to public health and the environment. Research efforts on selective and sensitive detection of Hg2+, have therefore drawn considerable attention in recent years. Herein, we report a facile approach to detect Hg2+ based on quantum dots (QDs)-based nanosensor. The two single-stranded DNA (ssDNA) used in this work are modified with biotin (ssDNA-biotin) and fluorescence quencher BHQ2 (ssDNA-BHQ2). These two strands are complementary but with TTT-recognized base sequences for the Hg2+ to form a T-Hg2+-T complex. The biotin-modified ssDNA (ssDNA-biotin) is first bound to the streptavidin-modified QDs, forming a QDs/ssDNA-biotin assembly, which may be further hybridized with the ssDNA-BHQ2, producing a complex of QDs/ssDNA-biotin/ssDNA-BHQ2. The BHQ2 serves as an effective quencher of QDs with the QDs and BHQ2 in a proximity within the QDs/ssDNA-biotin/ssDNA-BHQ2 complex. The decrease of fluorescence intensity therefore serves as an indication of the presence of Hg2+. The fluorescence reduction is observed linearly correlated with the concentration of Hg2+ in the range of 1.0-20.0 nM, with a detection limit at 0.87 nM. The presented QDs-based method is expected to provide a simple, rapid and sensitive method for the detection of Hg2+ in environmental water samples.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"19 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82129840","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}
Article presents mole fraction solubilities of l-tryptophan in binary aqueous methanol solvent systems and applied to estimate thermodynamical parameters like transfer Gibbs free energetics and entropies of solutions. The estimated thermodynamic energies were linked with interaction parameters like dipole-dipole interactions, enthalpy due to transfer of l-tryptophan from water to binary water-methanol solvent mixtures. The transfer Gibbs free energetics for chemical interactions and entropies for solvent-solvent interaction were calculated by mathematical relations. The chemical transfer energetics was applied to explain the probable stability of l-tryptophan in the mixed solvents. Many associated thermophysical parameters were also calculated at standard temperature (298.15 K).
{"title":"Solubility and Solvation Thermodynamics of L-tryptophan in Aqueous Methanol Solvent mixtures","authors":"Avishek Saha, K. Mahali, Sanjay Dhar Roy","doi":"10.1139/cjc-2022-0308","DOIUrl":"https://doi.org/10.1139/cjc-2022-0308","url":null,"abstract":"Article presents mole fraction solubilities of l-tryptophan in binary aqueous methanol solvent systems and applied to estimate thermodynamical parameters like transfer Gibbs free energetics and entropies of solutions. The estimated thermodynamic energies were linked with interaction parameters like dipole-dipole interactions, enthalpy due to transfer of l-tryptophan from water to binary water-methanol solvent mixtures. The transfer Gibbs free energetics for chemical interactions and entropies for solvent-solvent interaction were calculated by mathematical relations. The chemical transfer energetics was applied to explain the probable stability of l-tryptophan in the mixed solvents. Many associated thermophysical parameters were also calculated at standard temperature (298.15 K).","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"27 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79483919","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}
Using sonication and mediated by piperazine, new arene-linked bis(thieno[2,3-b]pyridine) hybrids were efficiently prepared in this study. The target hybrids were prepared by reacting bis(α-haloketone) with two equivalents of the appropriate pyridine-2(1H)-thiones in the presence of 1.4 equivalents of piperazine. The reaction mixture was subjected to sonication at 60 °C for 30-40 min to produce the desired products in 88-95% yields. When tested against six different ATCC bacterial strains, the new products demonstrated a wide range of antibacterial activity. The 4-(4-methoxyphenyl)-linked hybrids 1i, and 1j, attached to 6-(4-methoxyphenyl) and 6-(p-tolyl) units, respectively, had the best efficacy against S. aureus, E. faecalis, E. coli, and P. aeruginosa strains. Both hybrids showed more effective potency than the reference ciprofloxacin with MIC and MBC values in the ranges from 2.0-2.1, and 4.1-4.2 μM, respectively. Additionally, hybrids 1i, and 1j demonstrated stronger efficacy than linezolid with MIC values ranging from 2.0-4.2 µM, and MBC values ranging from 8.2-8.5 µM, respectively, against the MRSA ATCC:33591, and ATCC:43300 strains. Furthermore, hybrids 1i, and 1j showed inhibitory antibacterial biofilm activity comparable to the standard ciprofloxacin. They had IC50 values ranging from 3.8-4.6 μM against S. aureus, E. faecalis, E. coli, and P. aeruginosa strains. The cytotoxicity of hybrids 1i, and 1j against the human breast epithelial cell line MCF-10A lends credence to both hybrids' potential as safe antibacterial agents.
{"title":"New bis(thieno[2,3-b]pyridine) hybrids linked to arene units as potential bacterial biofilm and MRSA inhibitors","authors":"S. Sanad, Ahmed E. M. Mekky","doi":"10.1139/cjc-2022-0236","DOIUrl":"https://doi.org/10.1139/cjc-2022-0236","url":null,"abstract":"Using sonication and mediated by piperazine, new arene-linked bis(thieno[2,3-b]pyridine) hybrids were efficiently prepared in this study. The target hybrids were prepared by reacting bis(α-haloketone) with two equivalents of the appropriate pyridine-2(1H)-thiones in the presence of 1.4 equivalents of piperazine. The reaction mixture was subjected to sonication at 60 °C for 30-40 min to produce the desired products in 88-95% yields. When tested against six different ATCC bacterial strains, the new products demonstrated a wide range of antibacterial activity. The 4-(4-methoxyphenyl)-linked hybrids 1i, and 1j, attached to 6-(4-methoxyphenyl) and 6-(p-tolyl) units, respectively, had the best efficacy against S. aureus, E. faecalis, E. coli, and P. aeruginosa strains. Both hybrids showed more effective potency than the reference ciprofloxacin with MIC and MBC values in the ranges from 2.0-2.1, and 4.1-4.2 μM, respectively. Additionally, hybrids 1i, and 1j demonstrated stronger efficacy than linezolid with MIC values ranging from 2.0-4.2 µM, and MBC values ranging from 8.2-8.5 µM, respectively, against the MRSA ATCC:33591, and ATCC:43300 strains. Furthermore, hybrids 1i, and 1j showed inhibitory antibacterial biofilm activity comparable to the standard ciprofloxacin. They had IC50 values ranging from 3.8-4.6 μM against S. aureus, E. faecalis, E. coli, and P. aeruginosa strains. The cytotoxicity of hybrids 1i, and 1j against the human breast epithelial cell line MCF-10A lends credence to both hybrids' potential as safe antibacterial agents.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"23 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73168988","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}
Dion B. Nemez, Baldeep K. Sidhu, Kevin Carlin, A. Friesen, David E. Herbert
The synthesis of a series of 2- and 8-substituted 4-amino-7-chloroquinolines is presented. The chloro in the 7-position can be effectively substituted using amino alcohols to yield novel analogues of the antimalarial (hydroxy)chloroquine. Both short chain (2-aminoethanol) and long chain (5-[N-ethyl-N-(2-hydroxyethyl)amino]-2-aminopentane) coupling partners can be used. While ketone and nitro functionalities were found to be incompatible with the coupling conditions, electron-donating amino and dimethylamino substituents were tolerated. In addition to characterization in solution using multinuclear NMR spectroscopy and high-resolution mass spectrometry, single-crystal X-ray structures are presented of two 4,7-dichloroquinolines as well as three of the N-alkylated products including a unique species in which a pyrrole heterocycle formed at the 2-position of the quinoline sub-unit and a rare example of a 4-aza-1,10-phenanthroline.
介绍了一系列2-和8-取代4-氨基-7-氯喹啉的合成。7位上的氯可以用氨基醇有效地取代，得到抗疟药(羟基)氯喹的新型类似物。短链(2-氨基乙醇)和长链(5-[n -乙基- n -(2-羟乙基)氨基]-2-氨基戊烷)偶联物均可使用。虽然酮基和硝基官能团与偶联条件不相容，但给予电子的氨基和二甲胺取代基是可以耐受的。除了在溶液中使用多核核磁共振波谱和高分辨率质谱进行表征外，还展示了两种4,7-二氯喹啉以及三种n -烷基化产物的单晶x射线结构，其中包括一种独特的物种，其中在喹啉亚基的2位形成了吡咯杂环，以及一种罕见的4-杂氮-1,10-菲罗啉。
{"title":"Synthesis of Novel 2- and 8-Substituted 4-Amino-7-chloroquinolines and their N-Alkylated Coupling Products","authors":"Dion B. Nemez, Baldeep K. Sidhu, Kevin Carlin, A. Friesen, David E. Herbert","doi":"10.1139/cjc-2023-0005","DOIUrl":"https://doi.org/10.1139/cjc-2023-0005","url":null,"abstract":"The synthesis of a series of 2- and 8-substituted 4-amino-7-chloroquinolines is presented. The chloro in the 7-position can be effectively substituted using amino alcohols to yield novel analogues of the antimalarial (hydroxy)chloroquine. Both short chain (2-aminoethanol) and long chain (5-[N-ethyl-N-(2-hydroxyethyl)amino]-2-aminopentane) coupling partners can be used. While ketone and nitro functionalities were found to be incompatible with the coupling conditions, electron-donating amino and dimethylamino substituents were tolerated. In addition to characterization in solution using multinuclear NMR spectroscopy and high-resolution mass spectrometry, single-crystal X-ray structures are presented of two 4,7-dichloroquinolines as well as three of the N-alkylated products including a unique species in which a pyrrole heterocycle formed at the 2-position of the quinoline sub-unit and a rare example of a 4-aza-1,10-phenanthroline.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"39 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78713069","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. Babapoor, B. Mirzayi, Laleh Salehghadimi, Raha Hadi, S. Farhoudian, Meysam Paar
A novel nanocomposite of CoMnFeO4-MWCNT has been synthesized via green and simple hydrothermal method and the structure characterization has been done through FT-IR, X-ray diffraction, scanning electron microscopy, EDX, and high-resolution transmission electron microscopy analysis in this research. Cyclic voltammetry and galvanostatic charge–discharge methods are picked as the strategies to compare their supercapacitor behavior. The specific capacitance of about 1310 F g−1 (at 1 A g−1) in 3 mol L−1 KOH has been recorded for CoMnFeO4-MWCNT nanocomposite when the working voltage is 1.2 V. Moreover, this nanocomposite retains 89% of its initial capacitance after 10 000 charge–discharge cycles. Also, some initial mechanistic studies are performed to achieve a deeper insight into the electrochemical behavior of the nanocomposite implying that the oxidation-reduction process of CoMnFeO4-MWCNT nanocomposite is generally quasi-reversible and diffusion-controlled. From the view of time, coat, and environment, the hydrothermal process is much more reliable and beneficial regarding higher performance.
本研究采用绿色简单水热法合成了一种新型的CoMnFeO4-MWCNT纳米复合材料，并通过FT-IR、x射线衍射、扫描电镜、EDX和高分辨率透射电镜分析对其结构进行了表征。选择循环伏安法和恒流充放电法作为策略来比较它们的超级电容器性能。在3mol L−1 KOH溶液中，当工作电压为1.2 V时，CoMnFeO4-MWCNT纳米复合材料的比电容约为1310 F g−1 (1a g−1)。此外，这种纳米复合材料在10000次充放电循环后仍保持89%的初始电容。此外，还进行了一些初步的机理研究，以更深入地了解纳米复合材料的电化学行为，这意味着CoMnFeO4-MWCNT纳米复合材料的氧化还原过程通常是准可逆的和扩散控制的。从时间、涂层和环境的角度来看，水热法更可靠、更有利、性能更高。
{"title":"Novel CoMnFeO4-MWCNT nanocomposite based on a green synthesized method for supercapacitor applications","authors":"A. Babapoor, B. Mirzayi, Laleh Salehghadimi, Raha Hadi, S. Farhoudian, Meysam Paar","doi":"10.1139/cjc-2022-0117","DOIUrl":"https://doi.org/10.1139/cjc-2022-0117","url":null,"abstract":"A novel nanocomposite of CoMnFeO4-MWCNT has been synthesized via green and simple hydrothermal method and the structure characterization has been done through FT-IR, X-ray diffraction, scanning electron microscopy, EDX, and high-resolution transmission electron microscopy analysis in this research. Cyclic voltammetry and galvanostatic charge–discharge methods are picked as the strategies to compare their supercapacitor behavior. The specific capacitance of about 1310 F g−1 (at 1 A g−1) in 3 mol L−1 KOH has been recorded for CoMnFeO4-MWCNT nanocomposite when the working voltage is 1.2 V. Moreover, this nanocomposite retains 89% of its initial capacitance after 10 000 charge–discharge cycles. Also, some initial mechanistic studies are performed to achieve a deeper insight into the electrochemical behavior of the nanocomposite implying that the oxidation-reduction process of CoMnFeO4-MWCNT nanocomposite is generally quasi-reversible and diffusion-controlled. From the view of time, coat, and environment, the hydrothermal process is much more reliable and beneficial regarding higher performance.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"17 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91097748","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}
Langman Xing, H. Quan, Jinyang Zhao, Xiaomei Huang
The viscosity of the heavy oil was closely correlated with its own resin content by comparing of three types of crude oil. In this paper, two novel viscosity reducers with characteristic groups in molecular structures were synthesized for Xinjiang heavy oil, namely viscosity reducer 1 (VR-1) and viscosity reducer 2(VR-2), both of them showed the better viscosity reduction effect on Xinjiang heavy oil and the VR-2 was better than VR-1. The measurement results of UV-visible spectrophotometer and scanning electron microscope (SEM) showed that the VR-2 had the better separation effect for resin than the VR-1. By analyzing the infrared spectrum results of resin molecule, it could be seen that the resin molecule contained more heteroatoms, which could more easily form the stronger hydrogen bonding with VR-2 with more polar groups to result the better resin dispersion effect. Hence, the phenomenon that the VR-1 was not as good as VR-2 in improving fluidity of Xinjiang heavy oil was explained.
{"title":"The viscosity reducers exhibit dispersing ability for resin in heavy oil","authors":"Langman Xing, H. Quan, Jinyang Zhao, Xiaomei Huang","doi":"10.1139/cjc-2022-0165","DOIUrl":"https://doi.org/10.1139/cjc-2022-0165","url":null,"abstract":"The viscosity of the heavy oil was closely correlated with its own resin content by comparing of three types of crude oil. In this paper, two novel viscosity reducers with characteristic groups in molecular structures were synthesized for Xinjiang heavy oil, namely viscosity reducer 1 (VR-1) and viscosity reducer 2(VR-2), both of them showed the better viscosity reduction effect on Xinjiang heavy oil and the VR-2 was better than VR-1. The measurement results of UV-visible spectrophotometer and scanning electron microscope (SEM) showed that the VR-2 had the better separation effect for resin than the VR-1. By analyzing the infrared spectrum results of resin molecule, it could be seen that the resin molecule contained more heteroatoms, which could more easily form the stronger hydrogen bonding with VR-2 with more polar groups to result the better resin dispersion effect. Hence, the phenomenon that the VR-1 was not as good as VR-2 in improving fluidity of Xinjiang heavy oil was explained.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"29 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76036376","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}
Solvent as a complex environment can surround solute molecules and modify their function. In this work, different solute-solvent interaction effects on the nonlinear optical behavior of some azo dyes were studied at the molecular level. In this case, spectroscopic technique and density functional theory (DFT) were used. According to the results, molecular dipole transition, changes between ground and excited state dipole moments, substituent, and environment polarity play considerable effects on the molecular nonlinear optical responses. In addition to solvent effects on the molecular first and second-order hyperpolarizability, the two-photon absorption cross section is also modified due to solvent-induced interactions. Moreover, the determination of the contribution of dominant solvent effects on the molecular nonlinear optical behavior can facilitate the studies on the application of optical samples in designing various optical systems.
{"title":"Environment polarity effects on the microscopic nonlinear optical properties of some asymmetrical azobenzene molecules","authors":"M. Khadem Sadigh, A. Shamkhali","doi":"10.1139/cjc-2022-0083","DOIUrl":"https://doi.org/10.1139/cjc-2022-0083","url":null,"abstract":"Solvent as a complex environment can surround solute molecules and modify their function. In this work, different solute-solvent interaction effects on the nonlinear optical behavior of some azo dyes were studied at the molecular level. In this case, spectroscopic technique and density functional theory (DFT) were used. According to the results, molecular dipole transition, changes between ground and excited state dipole moments, substituent, and environment polarity play considerable effects on the molecular nonlinear optical responses. In addition to solvent effects on the molecular first and second-order hyperpolarizability, the two-photon absorption cross section is also modified due to solvent-induced interactions. Moreover, the determination of the contribution of dominant solvent effects on the molecular nonlinear optical behavior can facilitate the studies on the application of optical samples in designing various optical systems.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"3 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77536635","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}
M. P. Lourenço, A. Tchagang, K. Shankar, V. Thangadurai, D. Salahub
Finding the optimum material with improved properties for a given application is challenging because data acquisition in materials science and chemistry is time consuming and expensive. Therefore, dealing with small datasets is a reality in chemistry, whether the data is obtained from synthesis or computational experiments. In this work, we propose a new artificial intelligence method based on active learning (AL) to guide new experiments with as little data as possible, for optimum experimental design. The AL method is applied to ABO3 perovskites where a descriptor based on atomic properties was developed. Several regressor algorithms were employed: artificial neural network, Gaussian process and support vector regressor. The developed AL method was applied in the experimental design of two important materials: non-stoichiometric perovskites (Ba(1-x)AxTi(1-y)ByO3) due to substituting ionic sites with different concentrations and elements (A = Ca, Sr, Cd; B = Zr, Sn, Hf), aiming at the maximization of the energy storage density; stoichiometric ABO3 perovskites where different elements are changed in the A and B sites for the minimization of the formation energy. AL for experimental design is implemented in the machine learning agent for chemistry and design (MLChem4D) software; which has the potential to be applied in inorganic and organic synthesis (e.g.: search for the optimum concentrations, catalysts, reactants, temperatures and pH to improve the yield) and materials science (e.g.: search the periodic table for the proper elements and their concentrations to improve the materials properties). The latter marks the first MLChem4D application for the design of perovskites.
为特定应用寻找具有改进性能的最佳材料具有挑战性，因为材料科学和化学中的数据采集既耗时又昂贵。因此，处理小数据集在化学中是一个现实，无论数据是通过合成还是计算实验获得的。在这项工作中，我们提出了一种新的基于主动学习(AL)的人工智能方法，以尽可能少的数据指导新的实验，以优化实验设计。AL方法应用于ABO3钙钛矿，并开发了基于原子性质的描述符。采用了几种回归算法:人工神经网络、高斯过程和支持向量回归。所开发的AL方法应用于两种重要材料的实验设计:非化学计量钙钛矿(Ba(1-x)AxTi(1-y)ByO3)，这是由于取代了不同浓度和元素的离子位点(A = Ca, Sr, Cd;B = Zr, Sn, Hf)，以储能密度最大化为目标;化学计量ABO3钙钛矿，其中不同的元素改变在A和B位，以最小化的形成能量。实验设计人工智能在化学与设计机器学习代理(MLChem4D)软件中实现;它具有应用于无机和有机合成(例如:寻找最佳浓度、催化剂、反应物、温度和pH值以提高产量)和材料科学(例如:搜索元素周期表以寻找适当的元素及其浓度以改善材料性能)的潜力。后者标志着MLChem4D在钙钛矿设计中的首次应用。
{"title":"Active Learning for Optimum Experimental Design – Insight into Perovskite Oxides","authors":"M. P. Lourenço, A. Tchagang, K. Shankar, V. Thangadurai, D. Salahub","doi":"10.1139/cjc-2022-0198","DOIUrl":"https://doi.org/10.1139/cjc-2022-0198","url":null,"abstract":"Finding the optimum material with improved properties for a given application is challenging because data acquisition in materials science and chemistry is time consuming and expensive. Therefore, dealing with small datasets is a reality in chemistry, whether the data is obtained from synthesis or computational experiments. In this work, we propose a new artificial intelligence method based on active learning (AL) to guide new experiments with as little data as possible, for optimum experimental design. The AL method is applied to ABO3 perovskites where a descriptor based on atomic properties was developed. Several regressor algorithms were employed: artificial neural network, Gaussian process and support vector regressor. The developed AL method was applied in the experimental design of two important materials: non-stoichiometric perovskites (Ba(1-x)AxTi(1-y)ByO3) due to substituting ionic sites with different concentrations and elements (A = Ca, Sr, Cd; B = Zr, Sn, Hf), aiming at the maximization of the energy storage density; stoichiometric ABO3 perovskites where different elements are changed in the A and B sites for the minimization of the formation energy. AL for experimental design is implemented in the machine learning agent for chemistry and design (MLChem4D) software; which has the potential to be applied in inorganic and organic synthesis (e.g.: search for the optimum concentrations, catalysts, reactants, temperatures and pH to improve the yield) and materials science (e.g.: search the periodic table for the proper elements and their concentrations to improve the materials properties). The latter marks the first MLChem4D application for the design of perovskites.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"23 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87460670","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}
The synthesis and characterisation (IR, NMR, HR-MS, X-ray crystallography) of six oxazoline Zn complexes, containing enolate ligands derived from a series of (Z)-1-R-2-(4’,4’-dimethyl-2’-oxazolin-2’-yl)-eth-1-en-1-ols (R = C6H5, C6H4-p-NO2, C6H4-p-OCH3, CF3, CH3 or CMe3), is detailed. All derivatives are air-stable solids of formula Zn(Ln)2 and are formed in the presence of the title ligands and NEt3. Reasonable yields (53-82%) are obtained with the exception of R = CMe3 (9%); in this case by-product formation and high solubility affected complex isolation. Crystallographic characterisation reveals that in all cases the ligands are bound in a κ2-N, O bonding motif. Little structural diversity is noted within the series; these complexes are further placed into structural context with related Zn materials containing oxazoline, phenolate and / or Schiff base ligands.
{"title":"Synthesis and Structural Studies of Group 12 Oxazoline-Enolate Coordination Complexes of (Z)-1-R-2-(4’,4’-Dimethyl-2’-oxazolin-2’-yl)-eth-1-en-1-ates; Part I: the Zinc Derivatives","authors":"Matthew C. Hill, A. Lough, Robert A. Gossage","doi":"10.1139/cjc-2022-0307","DOIUrl":"https://doi.org/10.1139/cjc-2022-0307","url":null,"abstract":"The synthesis and characterisation (IR, NMR, HR-MS, X-ray crystallography) of six oxazoline Zn complexes, containing enolate ligands derived from a series of (Z)-1-R-2-(4’,4’-dimethyl-2’-oxazolin-2’-yl)-eth-1-en-1-ols (R = C6H5, C6H4-p-NO2, C6H4-p-OCH3, CF3, CH3 or CMe3), is detailed. All derivatives are air-stable solids of formula Zn(Ln)2 and are formed in the presence of the title ligands and NEt3. Reasonable yields (53-82%) are obtained with the exception of R = CMe3 (9%); in this case by-product formation and high solubility affected complex isolation. Crystallographic characterisation reveals that in all cases the ligands are bound in a κ2-N, O bonding motif. Little structural diversity is noted within the series; these complexes are further placed into structural context with related Zn materials containing oxazoline, phenolate and / or Schiff base ligands.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"2 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73070432","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}
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