In the present work, the electrospun fibers of poly (vinyl alcohol) (PVA) are fabricated from its solution in water under ambient conditions, and the effect of altered working parameters used such as tip‐to‐collector distance (TCD), applied voltage, flow rate and solution concentration on the average diameter and frequency distribution of them is deeply discussed. The mean electrospun PVA fiber diameters and its distributions are estimated by combination of Scanning electron microscope (SEM) and ImageJ analyzer program which is extensively utilized in respective sciences. The achieved results from the experiments indicate that higher both TCD and applied voltage used decrease the average electrospun PVA fiber diameter. Conversely, when the flow rate or solution concentration is increased, diameters of achieved fibers are soared. It is anticipated that this comprehensive study will be beneficial to academia and industry worked on potential PVA fiber applications.
{"title":"A comprehensive study on electrospinning of poly (vinyl alcohol): effects of the TCD, applied voltage, flow rate and solution concentration","authors":"G. Acik","doi":"10.18596/jotcsa.741452","DOIUrl":"https://doi.org/10.18596/jotcsa.741452","url":null,"abstract":"In the present work, the electrospun fibers of poly (vinyl alcohol) (PVA) are fabricated from its solution in water under ambient conditions, and the effect of altered working parameters used such as tip‐to‐collector distance (TCD), applied voltage, flow rate and solution concentration on the average diameter and frequency distribution of them is deeply discussed. The mean electrospun PVA fiber diameters and its distributions are estimated by combination of Scanning electron microscope (SEM) and ImageJ analyzer program which is extensively utilized in respective sciences. The achieved results from the experiments indicate that higher both TCD and applied voltage used decrease the average electrospun PVA fiber diameter. Conversely, when the flow rate or solution concentration is increased, diameters of achieved fibers are soared. It is anticipated that this comprehensive study will be beneficial to academia and industry worked on potential PVA fiber applications.","PeriodicalId":17402,"journal":{"name":"Journal of the Turkish Chemical Society, Section A: Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41550029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Geopolymers are considered an alternative to conventional cement recently. The use of fly ash and blast furnace slag in geopolymer, which are waste products considered as an environmentally friendly product due to the solution to the storage of wastes also. Geopolymer concrete production is also reported to be 44-64% less than the cement that causes the most CO2 emissions. CO2 emissions are reduced due to the minimum processed natural minerals and industrial waste products used in the geopolymer system. For this reason, this study comes to the fore in terms of the evaluation of wastes. Production of porous geopolymers is potential in use in many industrial applications such as filtering, thermal insulation, light structural material, and catalysis. By controlling the pore type, pore size distribution, pore connectivity, and shape of porosities, potential usages are differentiated. In this study, closed porosity geopolymer foams were produced by the geopolymerization technique with the help of hydrogen peroxide and calcium stearate (CaS) as a surfactant. The thermal conductivity, density, and strength values was correlated with the changing pore size distribution depending on the amount of surfactant and foaming agent. In this study, porous geopolymers with density values 450-500 kg/m3, 0.069 W/mK thermal conductivity, and 2.1 MPa strength value was reached. The reduction in pore sizes due to CaS increase was analyzed. However, we did not observe a decrease in thermal conductivity values due to the reduction of the pore size. Exciting results for CaS content on thermal conductivity were reported.
{"title":"Effect of Pore Morphology on the Thermal Conductivity of Geopolymer Foam","authors":"C. Kurtulus, M. Baspinar","doi":"10.18596/jotcsa.660727","DOIUrl":"https://doi.org/10.18596/jotcsa.660727","url":null,"abstract":"Geopolymers are considered an alternative to conventional cement recently. The use of fly ash and blast furnace slag in geopolymer, which are waste products considered as an environmentally friendly product due to the solution to the storage of wastes also. Geopolymer concrete production is also reported to be 44-64% less than the cement that causes the most CO2 emissions. CO2 emissions are reduced due to the minimum processed natural minerals and industrial waste products used in the geopolymer system. For this reason, this study comes to the fore in terms of the evaluation of wastes. Production of porous geopolymers is potential in use in many industrial applications such as filtering, thermal insulation, light structural material, and catalysis. By controlling the pore type, pore size distribution, pore connectivity, and shape of porosities, potential usages are differentiated. In this study, closed porosity geopolymer foams were produced by the geopolymerization technique with the help of hydrogen peroxide and calcium stearate (CaS) as a surfactant. The thermal conductivity, density, and strength values was correlated with the changing pore size distribution depending on the amount of surfactant and foaming agent. In this study, porous geopolymers with density values 450-500 kg/m3, 0.069 W/mK thermal conductivity, and 2.1 MPa strength value was reached. The reduction in pore sizes due to CaS increase was analyzed. However, we did not observe a decrease in thermal conductivity values due to the reduction of the pore size. Exciting results for CaS content on thermal conductivity were reported.","PeriodicalId":17402,"journal":{"name":"Journal of the Turkish Chemical Society, Section A: Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41854835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A novel anthracene-based dipodal Schiff base ‘‘turn-on’’ fluorescent sensor (FS) was designed and synthesized by accessible and straightforward Schiff base reaction of salicylaldehyde and 9,10-bis(aminomethyl)anthracene with high yield. The chemical characterization of fluorescent sensor FS was performed by standard spectroscopic techniques (MALDI-MS, FT-IR, 1H, and 13C NMR), and photophysical properties were exanimated by UV-vis and fluorescent spectroscopies. The fluorescent sensor FS can coordinate with Hg2+ via Schiff base moiety when analytical signal as a “turn on” fluorescent response was obtained via anthracene moiety after coordination. Also, spectrofluorimetric analysis of Hg2+ was carried out using fluorescent sensor FS in environmental water samples after optimization required experimental conditions such as pH, the time before measurements, and photostability. According to obtained results, the presented fluorescent sensor can be used for selective and sensitive spectrofluorimetric determination of Hg2+.
{"title":"A novel selective “turn-on’’ fluorescent sensor for Hg2+ and its utility for spectrofluorimetric analysis of real samples","authors":"S. Tümay","doi":"10.18596/jotcsa.733160","DOIUrl":"https://doi.org/10.18596/jotcsa.733160","url":null,"abstract":"A novel anthracene-based dipodal Schiff base ‘‘turn-on’’ fluorescent sensor (FS) was designed and synthesized by accessible and straightforward Schiff base reaction of salicylaldehyde and 9,10-bis(aminomethyl)anthracene with high yield. The chemical characterization of fluorescent sensor FS was performed by standard spectroscopic techniques (MALDI-MS, FT-IR, 1H, and 13C NMR), and photophysical properties were exanimated by UV-vis and fluorescent spectroscopies. The fluorescent sensor FS can coordinate with Hg2+ via Schiff base moiety when analytical signal as a “turn on” fluorescent response was obtained via anthracene moiety after coordination. Also, spectrofluorimetric analysis of Hg2+ was carried out using fluorescent sensor FS in environmental water samples after optimization required experimental conditions such as pH, the time before measurements, and photostability. According to obtained results, the presented fluorescent sensor can be used for selective and sensitive spectrofluorimetric determination of Hg2+.","PeriodicalId":17402,"journal":{"name":"Journal of the Turkish Chemical Society, Section A: Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47610177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. E. Khatabi, I. Aanouz, R. El-mernissi, A. Khaldan, M. A. Ajana, M. Bouachrine, T. Lakhlifi
The α-amylase is an enzyme of a highly conserved glycoside hydrolase family, α-amylase inhibitors can be used as clinical agents for the treatment of Diabetes Mellitus (DM). A 3D-QSAR study was performed on 45 2-aryl benzimidazole derivatives, which have been identified as insulin-independent antidiabetic agents. The 3D-QSAR technique includes CoMFA with Q2 of 0.696 and R2 of 0.860 and CoMSIA with Q2 of 0.514 and R2 of 0.852. Both models were derived from a training set of 37 compounds based on an appropriate method of alignment, while the predictive ability was approved by a test set containing 8 compounds with rext2 values of 0.990 and 0.987, respectively. Moreover, contour maps generated from CoMFA and CoMSIA models provided much helpful information to figure out the features requirements that have control over the activity. To further reinforce the 3D-QSAR results, the molecular docking method was implemented which led to design new potent insulin-independent antidiabetic compounds with high predicted activity values.
{"title":"Designing of Novel Potential Inhibitors of a-amylase by 3D-QSAR Modeling and Molecular Docking Studies","authors":"K. E. Khatabi, I. Aanouz, R. El-mernissi, A. Khaldan, M. A. Ajana, M. Bouachrine, T. Lakhlifi","doi":"10.18596/jotcsa.703026","DOIUrl":"https://doi.org/10.18596/jotcsa.703026","url":null,"abstract":"The α-amylase is an enzyme of a highly conserved glycoside hydrolase family, α-amylase inhibitors can be used as clinical agents for the treatment of Diabetes Mellitus (DM). A 3D-QSAR study was performed on 45 2-aryl benzimidazole derivatives, which have been identified as insulin-independent antidiabetic agents. The 3D-QSAR technique includes CoMFA with Q2 of 0.696 and R2 of 0.860 and CoMSIA with Q2 of 0.514 and R2 of 0.852. Both models were derived from a training set of 37 compounds based on an appropriate method of alignment, while the predictive ability was approved by a test set containing 8 compounds with rext2 values of 0.990 and 0.987, respectively. Moreover, contour maps generated from CoMFA and CoMSIA models provided much helpful information to figure out the features requirements that have control over the activity. To further reinforce the 3D-QSAR results, the molecular docking method was implemented which led to design new potent insulin-independent antidiabetic compounds with high predicted activity values.","PeriodicalId":17402,"journal":{"name":"Journal of the Turkish Chemical Society, Section A: Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67537292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Catalytic performance of polyvinylidene fluoride (PVDF) supported TiO2 additive at microwave conditions","authors":"H. Gümüş","doi":"10.18596/jotcsa.610886","DOIUrl":"https://doi.org/10.18596/jotcsa.610886","url":null,"abstract":"","PeriodicalId":17402,"journal":{"name":"Journal of the Turkish Chemical Society, Section A: Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43713971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fluorescent sensors have attracted an important interest due to their advantages such as high selectivity, rapid response, easy to use etc. In this study, a rhodamine based fluorescent sensor, RhDP, was synthesized, and used for selective detection of Cd 2+ ions. The sensor responds to Cd 2+ via the coordination induced fluorescence activation (CIFA) mechanism. RhDP gives a very fast and reversible fluorescence response to Cd 2+ in the presence of the metal ions tested. The complex stoichiometry between RhDP and Cd 2+ was found to be 1:1 and the binding constant was calculated as 2.70 × 10 7 M -1 in ACN/HEPES buffer (10 mM, pH: 7.05, v/v 1:1). The fluorescent detection limit of RhDP for Cd 2+ was found to be 0.218 µ M, which gave a marked sensitivity towards Cd 2+ .
{"title":"A Turn-on Fluorescent Sensor For Cadmium Ion Detection In Aqueous Solutions","authors":"Ziya Aydin","doi":"10.18596/jotcsa.638912","DOIUrl":"https://doi.org/10.18596/jotcsa.638912","url":null,"abstract":"Fluorescent sensors have attracted an important interest due to their advantages such as high selectivity, rapid response, easy to use etc. In this study, a rhodamine based fluorescent sensor, RhDP, was synthesized, and used for selective detection of Cd 2+ ions. The sensor responds to Cd 2+ via the coordination induced fluorescence activation (CIFA) mechanism. RhDP gives a very fast and reversible fluorescence response to Cd 2+ in the presence of the metal ions tested. The complex stoichiometry between RhDP and Cd 2+ was found to be 1:1 and the binding constant was calculated as 2.70 × 10 7 M -1 in ACN/HEPES buffer (10 mM, pH: 7.05, v/v 1:1). The fluorescent detection limit of RhDP for Cd 2+ was found to be 0.218 µ M, which gave a marked sensitivity towards Cd 2+ .","PeriodicalId":17402,"journal":{"name":"Journal of the Turkish Chemical Society, Section A: Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45621352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Antibiotic resistance in bacteria has become a worrying phenomenon in today's world. K. pneumoniae is a member of the Enterobacteriaceae family, which causes nosocomial infections as an opportunistic pathogen but inherently harboured as a part of natural human microbiota. Carbapenem resistance of K. pneumoniae was a rare occurrence up to ten years ago, but in recent years many types of carbapenemase producing K. pneumoniae have become common. The aim of this retrospective study; analyzing susceptibility to various antibiotics, commonly used in treatment, against K. pneumoniae strains isolated from various infection sites. Antibiotic susceptibility tests were performed by using the VITEK 2 Compact ® automated system. In this study, 502 K. pneumoniae strains isolated from patients that treated at various services of a university hospital with 515 bed capacity were examined. When compared to the data available with studies of recent years in Turkey, especially in intensive care and inpatient services, resistance of K. pneumoniae strains to antibiotics, against most carbapenems, are rapidly increasing in the degree of high concern. Therefore, in all hospitals, antibiotic management policies should be implemented with a multidisciplinary approach.
{"title":"Antibiotic Susceptibility Of Klebsiella pneumoniae Strains Isolated From Clinical Samples","authors":"Ahmet Ozan Özgen, O. E. Eyüpoğlu","doi":"10.18596/jotcsa.635088","DOIUrl":"https://doi.org/10.18596/jotcsa.635088","url":null,"abstract":"Antibiotic resistance in bacteria has become a worrying phenomenon in today's world. K. pneumoniae is a member of the Enterobacteriaceae family, which causes nosocomial infections as an opportunistic pathogen but inherently harboured as a part of natural human microbiota. Carbapenem resistance of K. pneumoniae was a rare occurrence up to ten years ago, but in recent years many types of carbapenemase producing K. pneumoniae have become common. The aim of this retrospective study; analyzing susceptibility to various antibiotics, commonly used in treatment, against K. pneumoniae strains isolated from various infection sites. Antibiotic susceptibility tests were performed by using the VITEK 2 Compact ® automated system. In this study, 502 K. pneumoniae strains isolated from patients that treated at various services of a university hospital with 515 bed capacity were examined. When compared to the data available with studies of recent years in Turkey, especially in intensive care and inpatient services, resistance of K. pneumoniae strains to antibiotics, against most carbapenems, are rapidly increasing in the degree of high concern. Therefore, in all hospitals, antibiotic management policies should be implemented with a multidisciplinary approach.","PeriodicalId":17402,"journal":{"name":"Journal of the Turkish Chemical Society, Section A: Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45204995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract: In this study, a novel, low-cost, natural, and highly effective adsorbent, chitosan (Ch) -diatomite (D) composite was synthesized. Ch-D composite was tested as an effective and alternative adsorbent for the removal of Pb 2+ ions. The Ch-D composite was characterized by FT-IR, SEM-EDX and PZC analyses. The adsorption process of Pb 2+ ions onto Ch-D as initial lead concentration, s olution pH, temperature, contact time and recovery was investigated . From the adsorption process results, it has been observed that the highest removal efficiency is approximately 95% at a contact time of 4-hour, initial Pb 2+ concentration of 500 mg L -1 and agitation speed of 150 rpm at natural pH 4.0. The maximum Pb 2+ adsorption capacity from the Langmuir model was f ound as 0.154 mol kg -1 at 25 o C. Besides, adsorption kinetics was also explained with pseudo-first-order models. Adsorption thermodynamics have shown that Pb 2+ adsorption onto Ch-D is possible, spontaneous and exothermic. Ch-D composite can become an alternative adsorbent for the treatment of lead ions in the wastewater.
{"title":"Removal of Pb2+ ions from aqueous medium by using chitosan-diatomite composite: equilibrium, kinetic and thermodynamic studies","authors":"Zeynep Mine Şenol, S. Şimşek","doi":"10.18596/jotcsa.634590","DOIUrl":"https://doi.org/10.18596/jotcsa.634590","url":null,"abstract":"Abstract: In this study, a novel, low-cost, natural, and highly effective adsorbent, chitosan (Ch) -diatomite (D) composite was synthesized. Ch-D composite was tested as an effective and alternative adsorbent for the removal of Pb 2+ ions. The Ch-D composite was characterized by FT-IR, SEM-EDX and PZC analyses. The adsorption process of Pb 2+ ions onto Ch-D as initial lead concentration, s olution pH, temperature, contact time and recovery was investigated . From the adsorption process results, it has been observed that the highest removal efficiency is approximately 95% at a contact time of 4-hour, initial Pb 2+ concentration of 500 mg L -1 and agitation speed of 150 rpm at natural pH 4.0. The maximum Pb 2+ adsorption capacity from the Langmuir model was f ound as 0.154 mol kg -1 at 25 o C. Besides, adsorption kinetics was also explained with pseudo-first-order models. Adsorption thermodynamics have shown that Pb 2+ adsorption onto Ch-D is possible, spontaneous and exothermic. Ch-D composite can become an alternative adsorbent for the treatment of lead ions in the wastewater.","PeriodicalId":17402,"journal":{"name":"Journal of the Turkish Chemical Society, Section A: Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47209869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The initial step of the rational drug design pipeline extremely needs an increase in effectiveness. This can be done using molecular modeling: docking and molecular dynamics. Docking programs are popular now due to their simple idea, quickness and ease of use. Nevertheless accuracy of these programs still leaves much to be desired and discovery by chance and experimental screening still play an important role. Docking performs ligand positioning in the target protein and estimates the protein-ligand binding free energy. While in many cases positioning accuracy of docking is satisfactory, the accuracy of binding energy calculations is insufficient to perform the hit-to-lead optimization. The accuracy depends on many approximations which are built into the respective model. We show that all simplifications restricting docking accuracy can be withdrawn and this can be done on the basis of modern supercomputer facilities allowing to perform docking of one ligand using many thousand computing cores. We describe in short the SOL docking program which is used during years for virtual screening of large ligand databases using supercomputer resources of LomonosovMoscow State University. SOL to some extent is organized similarly to popular docking programs and reflects their limitations and advantages. We present our supercomputer docking programs, FLM and SOL-P, developed over the past 5 years for Lomonosov supercomputer of Moscow State University. These programs are free of most important simplifications and their performance shows the road map of the docking accuracy improvement. Some results of their performance for very flexible ligand docking into the rigid protein and docking of flexible ligands into the protein with some moveable protein atoms are presented. The so-called quasi-docking approach combining a force field and quantum chemical methods is described and it is shown that best docking accuracy is reached with the PM7 method and the COSMO solvent model.
{"title":"Development of docking programs for Lomonosov supercomputer","authors":"V. Sulimov, I. Ilin, D. Kutov, A. Sulimov","doi":"10.18596/jotcsa.634130","DOIUrl":"https://doi.org/10.18596/jotcsa.634130","url":null,"abstract":"The initial step of the rational drug design pipeline extremely needs an increase in effectiveness. This can be done using molecular modeling: docking and molecular dynamics. Docking programs are popular now due to their simple idea, quickness and ease of use. Nevertheless accuracy of these programs still leaves much to be desired and discovery by chance and experimental screening still play an important role. Docking performs ligand positioning in the target protein and estimates the protein-ligand binding free energy. While in many cases positioning accuracy of docking is satisfactory, the accuracy of binding energy calculations is insufficient to perform the hit-to-lead optimization. The accuracy depends on many approximations which are built into the respective model. We show that all simplifications restricting docking accuracy can be withdrawn and this can be done on the basis of modern supercomputer facilities allowing to perform docking of one ligand using many thousand computing cores. We describe in short the SOL docking program which is used during years for virtual screening of large ligand databases using supercomputer resources of LomonosovMoscow State University. SOL to some extent is organized similarly to popular docking programs and reflects their limitations and advantages. We present our supercomputer docking programs, FLM and SOL-P, developed over the past 5 years for Lomonosov supercomputer of Moscow State University. These programs are free of most important simplifications and their performance shows the road map of the docking accuracy improvement. Some results of their performance for very flexible ligand docking into the rigid protein and docking of flexible ligands into the protein with some moveable protein atoms are presented. The so-called quasi-docking approach combining a force field and quantum chemical methods is described and it is shown that best docking accuracy is reached with the PM7 method and the COSMO solvent model.","PeriodicalId":17402,"journal":{"name":"Journal of the Turkish Chemical Society, Section A: Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45640851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hydrothermal reactions of lanthanide(III) salt with 2,3-pyrazinedicarboxylic (2,3-pzdc) acid yielded the coordination polymers [La 2 (2,3-pzdc) 3 (H 2 O)] n .3nH 2 O (1) and [La 2 (2,3-pzdc) 3 (H 2 O)] n .2nH 2 O (2) . Compounds were obtained in a three dimensional form with different pH values under subcritical water conditions. The structures had variable coordination numbers . In addition, pH values play an important role in the structural chemistry of these materials. Different characterization techniques (Elemental analysis, FT-IR, ICP-OES, TG/DTA, FESEM, PXRD, BET and single crystal X-ray) were carried out to confirm crystallinity, porosity, purity and chemical composition of the coordination polymers. Crystal structures of the polymers were examined in detail. Their thermal stability, luminescence and electrical conductivity properties were investigated in the solid state.
镧系盐与2,3-吡嗪二羧酸(2,3-pzdc)水热反应得到配位聚合物[la2 (2,3-pzdc) 3 (h2o)] n . 3nh2o(1)和[la2 (2,3-pzdc) 3 (h2o)] n . 2nh2o(2)。在亚临界水条件下，以不同pH值的三维形式得到化合物。结构的配位数是可变的。此外，pH值在这些材料的结构化学中起着重要的作用。采用不同的表征技术(元素分析、FT-IR、ICP-OES、TG/DTA、FESEM、PXRD、BET和单晶x射线)来确定配位聚合物的结晶度、孔隙度、纯度和化学成分。对聚合物的晶体结构进行了详细的研究。研究了它们在固态下的热稳定性、发光性能和电导率。
{"title":"pH effect on hydrothermal synthesis of the coordination polymers containing pyrazine-2,3-dicarboxylate: Investigation of thermal stability, luminescence and electrical conductivity properties","authors":"Burak Ay, E. Yıldız, J. Zubieta","doi":"10.18596/jotcsa.565700","DOIUrl":"https://doi.org/10.18596/jotcsa.565700","url":null,"abstract":"Hydrothermal reactions of lanthanide(III) salt with 2,3-pyrazinedicarboxylic (2,3-pzdc) acid yielded the coordination polymers [La 2 (2,3-pzdc) 3 (H 2 O)] n .3nH 2 O (1) and [La 2 (2,3-pzdc) 3 (H 2 O)] n .2nH 2 O (2) . Compounds were obtained in a three dimensional form with different pH values under subcritical water conditions. The structures had variable coordination numbers . In addition, pH values play an important role in the structural chemistry of these materials. Different characterization techniques (Elemental analysis, FT-IR, ICP-OES, TG/DTA, FESEM, PXRD, BET and single crystal X-ray) were carried out to confirm crystallinity, porosity, purity and chemical composition of the coordination polymers. Crystal structures of the polymers were examined in detail. Their thermal stability, luminescence and electrical conductivity properties were investigated in the solid state.","PeriodicalId":17402,"journal":{"name":"Journal of the Turkish Chemical Society, Section A: Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46026721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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