Complexes linked by various interactions are analysed in this study. They are characterized by the tetrahedral configuration of the Lewis acid centre. Interactions, being a subject of this study, are classified as σ-hole bonds, such as the halogen, chalcogen, pnicogen, and tetrel bonds. In the case of strong interactions, the tetrahedral configuration of the Lewis acid centre changes into the trigonal bipyramid configuration. This change is in line with the Valence-Shell Electron-Pair Repulsion model, VSEPR, and this is supported here by the results of high-level ab initio calculations. The theoretical results concerning the geometries are supported mainly by the Natural Bond Orbital, NBO, method.
{"title":"σ-Hole Bonds and the VSEPR Model—From the Tetrahedral Structure to the Trigonal Bipyramid","authors":"S. J. Grabowski","doi":"10.3390/sci4020017","DOIUrl":"https://doi.org/10.3390/sci4020017","url":null,"abstract":"Complexes linked by various interactions are analysed in this study. They are characterized by the tetrahedral configuration of the Lewis acid centre. Interactions, being a subject of this study, are classified as σ-hole bonds, such as the halogen, chalcogen, pnicogen, and tetrel bonds. In the case of strong interactions, the tetrahedral configuration of the Lewis acid centre changes into the trigonal bipyramid configuration. This change is in line with the Valence-Shell Electron-Pair Repulsion model, VSEPR, and this is supported here by the results of high-level ab initio calculations. The theoretical results concerning the geometries are supported mainly by the Natural Bond Orbital, NBO, method.","PeriodicalId":10987,"journal":{"name":"Decis. Sci.","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75064693","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}
Tuǧce Kalkan, F. Nichita, T. Oner, Ibrahim Senturk, Mehmet Terzier
The current paper explores the potential of the areas between mathematics and poetry. We will first recall some definitions and results that are needed to construct solutions of the Yang–Baxter equation. A new duality principle is presented and Boolean coalgebras are introduced. A section on poetry dedicated to the Yang–Baxter equation is presented, and a discussion on a poem related to a mathematical formula follows. The final section presents our conclusions and further information on these topics.
{"title":"Mathematics and Poetry · Yang–Baxter Equations, Boolean Algebras, and BCK-Algebras","authors":"Tuǧce Kalkan, F. Nichita, T. Oner, Ibrahim Senturk, Mehmet Terzier","doi":"10.3390/sci4020016","DOIUrl":"https://doi.org/10.3390/sci4020016","url":null,"abstract":"The current paper explores the potential of the areas between mathematics and poetry. We will first recall some definitions and results that are needed to construct solutions of the Yang–Baxter equation. A new duality principle is presented and Boolean coalgebras are introduced. A section on poetry dedicated to the Yang–Baxter equation is presented, and a discussion on a poem related to a mathematical formula follows. The final section presents our conclusions and further information on these topics.","PeriodicalId":10987,"journal":{"name":"Decis. Sci.","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87239594","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}
Vishakha Singh, Amit Khurana, Umashanker Navik, P. Allawadhi, K. Bharani, R. Weiskirchen
Apoptosis is an evolutionarily conserved sequential process of cell death to maintain a homeostatic balance between cell formation and cell death. It is a vital process for normal eukaryotic development as it contributes to the renewal of cells and tissues. Further, it plays a crucial role in the elimination of unnecessary cells through phagocytosis and prevents undesirable immune responses. Apoptosis is regulated by a complex signaling mechanism, which is driven by interactions among several protein families such as caspases, inhibitors of apoptosis proteins, B-cell lymphoma 2 (BCL-2) family proteins, and several other proteases such as perforins and granzyme. The signaling pathway consists of both pro-apoptotic and pro-survival members, which stabilize the selection of cellular survival or death. However, any aberration in this pathway can lead to abnormal cell proliferation, ultimately leading to the development of cancer, autoimmune disorders, etc. This review aims to elaborate on apoptotic signaling pathways and mechanisms, interacting members involved in signaling, and how apoptosis is associated with carcinogenesis, along with insights into targeting apoptosis for disease resolution.
{"title":"Apoptosis and Pharmacological Therapies for Targeting Thereof for Cancer Therapeutics","authors":"Vishakha Singh, Amit Khurana, Umashanker Navik, P. Allawadhi, K. Bharani, R. Weiskirchen","doi":"10.3390/sci4020015","DOIUrl":"https://doi.org/10.3390/sci4020015","url":null,"abstract":"Apoptosis is an evolutionarily conserved sequential process of cell death to maintain a homeostatic balance between cell formation and cell death. It is a vital process for normal eukaryotic development as it contributes to the renewal of cells and tissues. Further, it plays a crucial role in the elimination of unnecessary cells through phagocytosis and prevents undesirable immune responses. Apoptosis is regulated by a complex signaling mechanism, which is driven by interactions among several protein families such as caspases, inhibitors of apoptosis proteins, B-cell lymphoma 2 (BCL-2) family proteins, and several other proteases such as perforins and granzyme. The signaling pathway consists of both pro-apoptotic and pro-survival members, which stabilize the selection of cellular survival or death. However, any aberration in this pathway can lead to abnormal cell proliferation, ultimately leading to the development of cancer, autoimmune disorders, etc. This review aims to elaborate on apoptotic signaling pathways and mechanisms, interacting members involved in signaling, and how apoptosis is associated with carcinogenesis, along with insights into targeting apoptosis for disease resolution.","PeriodicalId":10987,"journal":{"name":"Decis. Sci.","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86827985","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}
Maria-Elena Ignatiadou, M. Kostaki, Z. Kabouche, P. Chatzopoulou, M. Rallis, A. Karioti
The present study aimed to investigate the chemical profile and the protective activity on fibroblasts of two Matricaria species: M. pubescens, which grows wild in Algeria, and M. recutita, which is cultivated in Greece. A comparative phytochemical investigation using High-Performance Liquid Chromatography, coupled with Photodiode Array Detection and Mass Spectrometry (HPLC–PDA–MS) combined with Nuclear Magnetic Resonance (NMR), was performed for the identification of the main constituents in the flowerheads of these medicinal plants. In M. pubescens more than 25 compounds were identified and/or isolated; among them are quercetagenin-3-O-glucopyranoside, reported for the first time in Matricaria sp., and two polyamines previously reported in other Asteraceae species. In M. recutita, which is the officially recognized species in Europe, 19 constituents were identified. To minimize time analysis, the structure elucidation was based on a multi-analytical approach directly on subfractions. Two representative polar extracts from each species were characterized chemically and further screened for their protective effects on 3T3 fibroblasts. The cells were exposed to a mild toxic dose of UVA light (6 J/cm2), in the presence of different concentrations of the extracts. Both M. recutita and M. pubescens extracts were effective. The methanolic extract was the best protective agent at lower concentrations (0.1 to 10 μg/mL), and hydromethanolic was best at higher ones (100–200 μg/mL). M. recutita exhibited the most enhanced cell viability in relation to those not exposed to UV control; it ranged from of 28 to 49% higher viability, depending on the dose, leading to the conclusion that the latter seems to exhibit potent cytoprotective activity and significant regeneration activity.
{"title":"HPLC–NMR-Based Chemical Profiling of Matricaria pubescens (Desf.) Schultz and Matricaria recutita and Their Protective Effects on UVA-Exposed Fibroblasts","authors":"Maria-Elena Ignatiadou, M. Kostaki, Z. Kabouche, P. Chatzopoulou, M. Rallis, A. Karioti","doi":"10.3390/sci4010014","DOIUrl":"https://doi.org/10.3390/sci4010014","url":null,"abstract":"The present study aimed to investigate the chemical profile and the protective activity on fibroblasts of two Matricaria species: M. pubescens, which grows wild in Algeria, and M. recutita, which is cultivated in Greece. A comparative phytochemical investigation using High-Performance Liquid Chromatography, coupled with Photodiode Array Detection and Mass Spectrometry (HPLC–PDA–MS) combined with Nuclear Magnetic Resonance (NMR), was performed for the identification of the main constituents in the flowerheads of these medicinal plants. In M. pubescens more than 25 compounds were identified and/or isolated; among them are quercetagenin-3-O-glucopyranoside, reported for the first time in Matricaria sp., and two polyamines previously reported in other Asteraceae species. In M. recutita, which is the officially recognized species in Europe, 19 constituents were identified. To minimize time analysis, the structure elucidation was based on a multi-analytical approach directly on subfractions. Two representative polar extracts from each species were characterized chemically and further screened for their protective effects on 3T3 fibroblasts. The cells were exposed to a mild toxic dose of UVA light (6 J/cm2), in the presence of different concentrations of the extracts. Both M. recutita and M. pubescens extracts were effective. The methanolic extract was the best protective agent at lower concentrations (0.1 to 10 μg/mL), and hydromethanolic was best at higher ones (100–200 μg/mL). M. recutita exhibited the most enhanced cell viability in relation to those not exposed to UV control; it ranged from of 28 to 49% higher viability, depending on the dose, leading to the conclusion that the latter seems to exhibit potent cytoprotective activity and significant regeneration activity.","PeriodicalId":10987,"journal":{"name":"Decis. Sci.","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75399371","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 development of methods for converting nitrogen oxides in water into valuable resources such as ammonia and hydrazine has been given some attention. By utilizing the nitrite-reducing catalytic activity of nitrite reductase (NiR), nitrite in water can be converted into ammonium. However, there are few reports in the research that synthesized ammonium from nitrite using nitrite reductase. Therefore, we aimed to investigate the effect of temperature on the nitrite-reducing catalytic activity of NiR from spinach in the presence of one-electron reduced riboflavin by kinetic analysis to find the optimum temperature conditions. The results of this study showed that the reaction temperature does not need to be higher than 296.15 K in order to improve the efficiency of ammonium production from nitrite using NiR.
{"title":"Kinetic Analysis of Nitrite Reduction Reactions by Nitrite Reductase Derived from Spinach in the Presence of One-Electron Reduced Riboflavin","authors":"Shusaku Ikeyama, H. Tabe","doi":"10.3390/sci4010013","DOIUrl":"https://doi.org/10.3390/sci4010013","url":null,"abstract":"The development of methods for converting nitrogen oxides in water into valuable resources such as ammonia and hydrazine has been given some attention. By utilizing the nitrite-reducing catalytic activity of nitrite reductase (NiR), nitrite in water can be converted into ammonium. However, there are few reports in the research that synthesized ammonium from nitrite using nitrite reductase. Therefore, we aimed to investigate the effect of temperature on the nitrite-reducing catalytic activity of NiR from spinach in the presence of one-electron reduced riboflavin by kinetic analysis to find the optimum temperature conditions. The results of this study showed that the reaction temperature does not need to be higher than 296.15 K in order to improve the efficiency of ammonium production from nitrite using NiR.","PeriodicalId":10987,"journal":{"name":"Decis. Sci.","volume":"65 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75264285","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}
Azhagu Raj Ramakrishnan, Krishna Kumar, Palavesam Arunachalam, M. Sankar, Prathap Selvaraj, S. Jheeta
Ultraviolet (UV) radiation is a part of the spectrum of electromagnetic radiation emitted by the Sun. The present study was conducted to examine the deleterious effects of UV radiation on the stratum corneum of fish—namely, Glossogobius giuris. In this study, healthy living specimens of G. giuris species weighing (1.20 g) and length (4.06 cm) were collected from Thandavarayankulam lake, Srivaikuntam Taluk, Thoothukudi District, Tamil Nadu. They were transported to the laboratory in well-aerated containers. During the experiment, the fish G. giuris (n = 6) was introduced into the UV Chamber (UVA and UVB) for one hour. After that, experimental fishes were collected from the UV Chamber were dissected for histological and biochemical studies using standard methodology. The short-term exposure of UVA and UVB rays on freshwater G. giuris muscle tissue showed marked degeneration of the epithelium, the disappearance of striations, thickened septal wall, broken fibre, and the disappearance of striation, followed by branchial arterial rupture. It was also determined that carbohydrate, protein, and lipid contents of the muscle tissue were significantly reduced. This study confirmed the destructive effects of UV radiation on the stratum corneum of fish G. giuris. The ultrastructural and biochemical changes occur depending largely on the energy of the UV rays; in this case, the UVB radiation, with higher destructive energy (4.4 eV), had a greater detrimental effect on the muscles of G. giuris than UVA, with its energy level of 3.9 eV.
{"title":"Deleterious Effect of Ultraviolet Radiation on Glossogobius giuris: A Short Experimental Study","authors":"Azhagu Raj Ramakrishnan, Krishna Kumar, Palavesam Arunachalam, M. Sankar, Prathap Selvaraj, S. Jheeta","doi":"10.3390/sci4010012","DOIUrl":"https://doi.org/10.3390/sci4010012","url":null,"abstract":"Ultraviolet (UV) radiation is a part of the spectrum of electromagnetic radiation emitted by the Sun. The present study was conducted to examine the deleterious effects of UV radiation on the stratum corneum of fish—namely, Glossogobius giuris. In this study, healthy living specimens of G. giuris species weighing (1.20 g) and length (4.06 cm) were collected from Thandavarayankulam lake, Srivaikuntam Taluk, Thoothukudi District, Tamil Nadu. They were transported to the laboratory in well-aerated containers. During the experiment, the fish G. giuris (n = 6) was introduced into the UV Chamber (UVA and UVB) for one hour. After that, experimental fishes were collected from the UV Chamber were dissected for histological and biochemical studies using standard methodology. The short-term exposure of UVA and UVB rays on freshwater G. giuris muscle tissue showed marked degeneration of the epithelium, the disappearance of striations, thickened septal wall, broken fibre, and the disappearance of striation, followed by branchial arterial rupture. It was also determined that carbohydrate, protein, and lipid contents of the muscle tissue were significantly reduced. This study confirmed the destructive effects of UV radiation on the stratum corneum of fish G. giuris. The ultrastructural and biochemical changes occur depending largely on the energy of the UV rays; in this case, the UVB radiation, with higher destructive energy (4.4 eV), had a greater detrimental effect on the muscles of G. giuris than UVA, with its energy level of 3.9 eV.","PeriodicalId":10987,"journal":{"name":"Decis. Sci.","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81938659","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}
Marinella Difonzo, Louise Fliedel, N. Mignet, K. Andrieux, Khair Alhareth
Pregnancy is a delicate state, during which timely investigation of possible physiological anomalies is essential to reduce the risk of maternal and fetal complications. Medical imaging encompasses different technologies to image the human body for the diagnosis, course of treatment management, and follow-up of diseases. Ultrasound (US) is currently the imaging system of choice for pregnant patients. However, sonographic evaluations can be non-effective or give ambiguous results. Therefore, magnetic resonance imaging (MRI), due to its excellent tissue penetration, the possibility of acquisition of three-dimensional anatomical information, and its high spatial resolution, is considered a valid diagnostical alternative. Nevertheless, currently employed contrast agents to improve the MRI image quality are harmful to the fetus. Because of their ability to cross the placenta, their use on pregnant patients is avoided. This review will firstly recapitulate the most common non-obstetrical, obstetrical, and fetal indications for magnetic resonance imaging on pregnant women. Fetal safety risks, due to the use of strong magnetic fields and exogenous contrast agents, will be presented. Then, possible advantages of nanostructured contrast agents compared to current molecular ones are explored. Nanosystems’ characteristics affecting contrast efficiency, and their potential for improving contrast-enhanced MRI’s safety in pregnant women, are discussed. Lastly, promising examples of nanoparticles as safer alternatives to current MRI contrast agents in pregnancy are discussed.
{"title":"How Could Nanomedicine Improve the Safety of Contrast Agents for MRI during Pregnancy?","authors":"Marinella Difonzo, Louise Fliedel, N. Mignet, K. Andrieux, Khair Alhareth","doi":"10.3390/sci4010011","DOIUrl":"https://doi.org/10.3390/sci4010011","url":null,"abstract":"Pregnancy is a delicate state, during which timely investigation of possible physiological anomalies is essential to reduce the risk of maternal and fetal complications. Medical imaging encompasses different technologies to image the human body for the diagnosis, course of treatment management, and follow-up of diseases. Ultrasound (US) is currently the imaging system of choice for pregnant patients. However, sonographic evaluations can be non-effective or give ambiguous results. Therefore, magnetic resonance imaging (MRI), due to its excellent tissue penetration, the possibility of acquisition of three-dimensional anatomical information, and its high spatial resolution, is considered a valid diagnostical alternative. Nevertheless, currently employed contrast agents to improve the MRI image quality are harmful to the fetus. Because of their ability to cross the placenta, their use on pregnant patients is avoided. This review will firstly recapitulate the most common non-obstetrical, obstetrical, and fetal indications for magnetic resonance imaging on pregnant women. Fetal safety risks, due to the use of strong magnetic fields and exogenous contrast agents, will be presented. Then, possible advantages of nanostructured contrast agents compared to current molecular ones are explored. Nanosystems’ characteristics affecting contrast efficiency, and their potential for improving contrast-enhanced MRI’s safety in pregnant women, are discussed. Lastly, promising examples of nanoparticles as safer alternatives to current MRI contrast agents in pregnancy are discussed.","PeriodicalId":10987,"journal":{"name":"Decis. Sci.","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86468478","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}
Sci (ISSN 2413-4155) is an international, open-access journal that covers most fields of scientific research. It has set out to challenge the conventional single- and double-blind peer review processes by adopting a post-publication public peer review (P4R) model. The model faced some difficulties with indexing and archiving services, prolongated the peer review process and its transparency received some opposition. It was therefore necessary to revisit the P4R model and modify it, resulting in the hybrid model (P4R hybrid) which is implemented in Sci today. Sci remains open to the whole scientific community as an inclusive and multidisciplinary scientific journal. In this context, we present you with six valuable contributions to the first Special Issue of Feature Papers Editors Collection 2020. The topics of the contributions address relevant and compelling issues ranging from data protection, material science, COVID-19 to the environment and climate change.
{"title":"Sci: An Inclusive, Multidisciplinary Scientific Journal","authors":"Ahmad Yaman Abdin, Claus Jacob","doi":"10.3390/sci4010010","DOIUrl":"https://doi.org/10.3390/sci4010010","url":null,"abstract":"Sci (ISSN 2413-4155) is an international, open-access journal that covers most fields of scientific research. It has set out to challenge the conventional single- and double-blind peer review processes by adopting a post-publication public peer review (P4R) model. The model faced some difficulties with indexing and archiving services, prolongated the peer review process and its transparency received some opposition. It was therefore necessary to revisit the P4R model and modify it, resulting in the hybrid model (P4R hybrid) which is implemented in Sci today. Sci remains open to the whole scientific community as an inclusive and multidisciplinary scientific journal. In this context, we present you with six valuable contributions to the first Special Issue of Feature Papers Editors Collection 2020. The topics of the contributions address relevant and compelling issues ranging from data protection, material science, COVID-19 to the environment and climate change.","PeriodicalId":10987,"journal":{"name":"Decis. Sci.","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73939110","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}
Cyclic dimers and trimers of tetra-substituted benzenes, ((HOOC)2-C6H2-(NHI)2), are selected as convenient model systems for investigating NI…O=C halogen bond strength and cooperativity. The four substituents in benzene are chosen so that two of them act as halogen bond acceptors (COOH) and two act as halogen bond donors (NHI), as shown in the graphical abstract below. The potential for metal ion binding by each of the halogen-bonded aggregates is also investigated using the monoatomic sodium ion, Na+. Density functional theory calculations performed using the wB97XD functional and the DGDZVP basis set confirmed the ability of halogen bonding to drive the formation of the cyclic dimers and trimers of the model system chosen for this study. Evidence of halogen bond cooperativity is seen, for example, in a 9% shortening of each NI…O=C halogen bond distance with a corresponding 53% increase in the respective critical point density value, ρNI…O=C. Cooperativity also results in a 36% increase in the magnitude of the complexation energy per halogen-bond of the trimer relative to that of the dimer. The results of this study confirm the potential for binding a single Na+ ion by either the dimer or the trimer through their respective halogen-bond networks. Binding of two metal ions was shown to be possible by the dimer. Likewise, the trimer was also found to bind three metal ions. Lastly, the overall structure of the halogen-bonded dimer or trimer endured after complexation of the Na+ ions.
{"title":"Halogen-Bonded Driven Tetra-Substituted Benzene Dimers and Trimers: Potential Hosts for Metal Ions","authors":"R. Parra","doi":"10.3390/sci4010009","DOIUrl":"https://doi.org/10.3390/sci4010009","url":null,"abstract":"Cyclic dimers and trimers of tetra-substituted benzenes, ((HOOC)2-C6H2-(NHI)2), are selected as convenient model systems for investigating NI…O=C halogen bond strength and cooperativity. The four substituents in benzene are chosen so that two of them act as halogen bond acceptors (COOH) and two act as halogen bond donors (NHI), as shown in the graphical abstract below. The potential for metal ion binding by each of the halogen-bonded aggregates is also investigated using the monoatomic sodium ion, Na+. Density functional theory calculations performed using the wB97XD functional and the DGDZVP basis set confirmed the ability of halogen bonding to drive the formation of the cyclic dimers and trimers of the model system chosen for this study. Evidence of halogen bond cooperativity is seen, for example, in a 9% shortening of each NI…O=C halogen bond distance with a corresponding 53% increase in the respective critical point density value, ρNI…O=C. Cooperativity also results in a 36% increase in the magnitude of the complexation energy per halogen-bond of the trimer relative to that of the dimer. The results of this study confirm the potential for binding a single Na+ ion by either the dimer or the trimer through their respective halogen-bond networks. Binding of two metal ions was shown to be possible by the dimer. Likewise, the trimer was also found to bind three metal ions. Lastly, the overall structure of the halogen-bonded dimer or trimer endured after complexation of the Na+ ions.","PeriodicalId":10987,"journal":{"name":"Decis. Sci.","volume":"93 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91401160","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 stability of malonaldehyde is governed by intramolecular hydrogen bonds (IMHBs) as well as in malonaldehyde-like systems where oxygen is replaced by N or S at any of the basic sites. As beryllium bonds have been shown to strongly cooperate with hydrogen bonds, this work explores at the high level ab initio G4 level of theory the effect of including this non-covalent interaction in the system through its association with BeF2. Although malonaldehyde follows the expected trends, where the formation of a pseudocyclic form is favored also when IMHB and Be bonds are present, the subtle balance between both non-covalent interactions leads to some surprising results when other heteroatoms are involved, to the point that interaction energies can be much larger than expected or even cyclization is not favored. A complete analysis using different computational tools gives an answer to those cases escaping the predictable trends.
{"title":"Malonaldehyde-like Systems: BeF2 Clusters—A Subtle Balance between Hydrogen Bonds, Beryllium Bonds, and Resonance","authors":"M. M. Montero‐Campillo, O. Mó, M. Yáñez","doi":"10.3390/sci4010007","DOIUrl":"https://doi.org/10.3390/sci4010007","url":null,"abstract":"The stability of malonaldehyde is governed by intramolecular hydrogen bonds (IMHBs) as well as in malonaldehyde-like systems where oxygen is replaced by N or S at any of the basic sites. As beryllium bonds have been shown to strongly cooperate with hydrogen bonds, this work explores at the high level ab initio G4 level of theory the effect of including this non-covalent interaction in the system through its association with BeF2. Although malonaldehyde follows the expected trends, where the formation of a pseudocyclic form is favored also when IMHB and Be bonds are present, the subtle balance between both non-covalent interactions leads to some surprising results when other heteroatoms are involved, to the point that interaction energies can be much larger than expected or even cyclization is not favored. A complete analysis using different computational tools gives an answer to those cases escaping the predictable trends.","PeriodicalId":10987,"journal":{"name":"Decis. Sci.","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83729692","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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