Pub Date : 2023-12-15DOI: 10.3390/inorganics11120481
Sophia Kurig, Fabian Ketter, Anne Frommelius, B. V. Hakala, J. van Leusen, Karen Friese, R. Dronskowski
Vanadium (IV) chalcogenide materials are of increasing interest for use in catalysis and energy conversion-related applications. Since no ternary compounds are yet known in the V–Se–Te system, we studied ternary VwSeyTe2−y (w = 1.10, 1.13; y = 0.42, 0.72) phases crystallizing in space group Pm1 (no. 164). Two single-crystal specimens with differing compositions of a solid solution were obtained using the ceramic method. All products were characterized by either single-crystal or powder X-ray diffraction. The lattice parameters increase with rising tellurium content in accordance with the larger ionic radius of the tellurium anion compared to selenium. The chemical compositions were confirmed by energy-dispersive X-ray spectroscopy. Furthermore, magnetic measurements mostly revealed antiferromagnetic properties. Simultaneous differential scanning calorimetry/thermogravimetric analyses in a nitrogen atmosphere showed endothermic decomposition accompanied by the formation of VN. The decomposition of VSe and VTe was observed in an argon atmosphere. The results of this work can serve as a basis for the synthesis of new phases in the V–Se–Te and related vanadium chalcogenide systems.
钒（IV）瑀材料在催化和能源转换相关应用中的应用越来越受到关注。由于 V-Se-Te 系统中尚未发现三元化合物，我们研究了在空间群 Pm1（编号 164）中结晶的三元 VwSeyTe2-y（w = 1.10，1.13；y = 0.42，0.72）相。利用陶瓷法获得了固溶体成分不同的两个单晶试样。所有产品都通过单晶或粉末 X 射线衍射进行了表征。与硒相比，碲阴离子的离子半径更大，因此晶格参数随着碲含量的增加而增加。能量色散 X 射线光谱法确认了化学成分。此外，磁性测量大多显示出反铁磁性。在氮气环境中同时进行的差示扫描量热法/热重分析表明，在形成 VN 的同时发生了内热分解。在氩气环境中观察到了 VSe 和 VTe 的分解。这项工作的结果可作为合成 V-Se-Te 和相关钒瑀体系新相的基础。
{"title":"Exploring the Structure and Properties of VwSeyTe2−y Mixed Crystals in the VTe2–VSe2 System","authors":"Sophia Kurig, Fabian Ketter, Anne Frommelius, B. V. Hakala, J. van Leusen, Karen Friese, R. Dronskowski","doi":"10.3390/inorganics11120481","DOIUrl":"https://doi.org/10.3390/inorganics11120481","url":null,"abstract":"Vanadium (IV) chalcogenide materials are of increasing interest for use in catalysis and energy conversion-related applications. Since no ternary compounds are yet known in the V–Se–Te system, we studied ternary VwSeyTe2−y (w = 1.10, 1.13; y = 0.42, 0.72) phases crystallizing in space group Pm1 (no. 164). Two single-crystal specimens with differing compositions of a solid solution were obtained using the ceramic method. All products were characterized by either single-crystal or powder X-ray diffraction. The lattice parameters increase with rising tellurium content in accordance with the larger ionic radius of the tellurium anion compared to selenium. The chemical compositions were confirmed by energy-dispersive X-ray spectroscopy. Furthermore, magnetic measurements mostly revealed antiferromagnetic properties. Simultaneous differential scanning calorimetry/thermogravimetric analyses in a nitrogen atmosphere showed endothermic decomposition accompanied by the formation of VN. The decomposition of VSe and VTe was observed in an argon atmosphere. The results of this work can serve as a basis for the synthesis of new phases in the V–Se–Te and related vanadium chalcogenide systems.","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":"225 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138997286","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}
Pub Date : 2023-12-14DOI: 10.3390/inorganics11120480
Guillermo D. Aquino, M. S. Moreno, Cristian M. Piqueras, Germán P. Benedictto, Andrea M. Pereyra
We explore the use of industrial sources of silicon and surfactant for obtaining low-cost MCM-41 materials and evaluate their performances as CO2 adsorbents. All of them presented a high specific surface area with different structural characteristics and textural properties. Interestingly, the MCM-41 manufactured with the most economical reagents presented a SBET of 1602 m2·g−1. The template was removed by using thermal treatments in an air atmosphere or a washing process. Preservation of silanol groups proved to be more effective under washing or mild thermal treatment conditions with the advantage of their lower cost and environmental benefit. Surface reactivity against CO2 was enhanced by anchoring APTS to silanol groups through wet grafting. All amino-functionalized materials showed a performance as CO2 adsorbents comparable to those reported in the literature, reaching values close to 30 cm3·g−1 at 25 °C and 760 mmHg. Samples with a higher concentration of silanol groups showed better performance. Our studies indicate that adsorbed CO2 is retained at least up to 50 °C, and the CO2 is chemisorbed on the silica modified with amine groups. The chemisorbed gas at very low pressures points to the potential use of these materials for CO2 storage.
{"title":"Alternative Synthesis of MCM-41 Using Inexpensive Precursors for CO2 Capture","authors":"Guillermo D. Aquino, M. S. Moreno, Cristian M. Piqueras, Germán P. Benedictto, Andrea M. Pereyra","doi":"10.3390/inorganics11120480","DOIUrl":"https://doi.org/10.3390/inorganics11120480","url":null,"abstract":"We explore the use of industrial sources of silicon and surfactant for obtaining low-cost MCM-41 materials and evaluate their performances as CO2 adsorbents. All of them presented a high specific surface area with different structural characteristics and textural properties. Interestingly, the MCM-41 manufactured with the most economical reagents presented a SBET of 1602 m2·g−1. The template was removed by using thermal treatments in an air atmosphere or a washing process. Preservation of silanol groups proved to be more effective under washing or mild thermal treatment conditions with the advantage of their lower cost and environmental benefit. Surface reactivity against CO2 was enhanced by anchoring APTS to silanol groups through wet grafting. All amino-functionalized materials showed a performance as CO2 adsorbents comparable to those reported in the literature, reaching values close to 30 cm3·g−1 at 25 °C and 760 mmHg. Samples with a higher concentration of silanol groups showed better performance. Our studies indicate that adsorbed CO2 is retained at least up to 50 °C, and the CO2 is chemisorbed on the silica modified with amine groups. The chemisorbed gas at very low pressures points to the potential use of these materials for CO2 storage.","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":"20 19","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138972280","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}
Pub Date : 2023-12-14DOI: 10.3390/inorganics11120477
Carlos Morales, A. Mahmoodinezhad, Rudi Tschammer, Julia Kosto, Carlos Alvarado Chavarin, Markus Andreas Schubert, C. Wenger, Karsten Henkel, J. Flege
This work presents a new ultra-high vacuum cluster tool to perform systematic studies of the early growth stages of atomic layer deposited (ALD) ultrathin films following a surface science approach. By combining operando (spectroscopic ellipsometry and quadrupole mass spectrometry) and in situ (X-ray photoelectron spectroscopy) characterization techniques, the cluster allows us to follow the evolution of substrate, film, and reaction intermediates as a function of the total number of ALD cycles, as well as perform a constant diagnosis and evaluation of the ALD process, detecting possible malfunctions that could affect the growth, reproducibility, and conclusions derived from data analysis. The homemade ALD reactor allows the use of multiple precursors and oxidants and its operation under pump and flow-type modes. To illustrate our experimental approach, we revisit the well-known thermal ALD growth of Al2O3 using trimethylaluminum and water. We deeply discuss the role of the metallic Ti thin film substrate at room temperature and 200 °C, highlighting the differences between the heterodeposition (<10 cycles) and the homodeposition (>10 cycles) growth regimes at both conditions. This surface science approach will benefit our understanding of the ALD process, paving the way toward more efficient and controllable manufacturing processes.
{"title":"Combination of Multiple Operando and In-Situ Characterization Techniques in a Single Cluster System for Atomic Layer Deposition: Unraveling the Early Stages of Growth of Ultrathin Al2O3 Films on Metallic Ti Substrates","authors":"Carlos Morales, A. Mahmoodinezhad, Rudi Tschammer, Julia Kosto, Carlos Alvarado Chavarin, Markus Andreas Schubert, C. Wenger, Karsten Henkel, J. Flege","doi":"10.3390/inorganics11120477","DOIUrl":"https://doi.org/10.3390/inorganics11120477","url":null,"abstract":"This work presents a new ultra-high vacuum cluster tool to perform systematic studies of the early growth stages of atomic layer deposited (ALD) ultrathin films following a surface science approach. By combining operando (spectroscopic ellipsometry and quadrupole mass spectrometry) and in situ (X-ray photoelectron spectroscopy) characterization techniques, the cluster allows us to follow the evolution of substrate, film, and reaction intermediates as a function of the total number of ALD cycles, as well as perform a constant diagnosis and evaluation of the ALD process, detecting possible malfunctions that could affect the growth, reproducibility, and conclusions derived from data analysis. The homemade ALD reactor allows the use of multiple precursors and oxidants and its operation under pump and flow-type modes. To illustrate our experimental approach, we revisit the well-known thermal ALD growth of Al2O3 using trimethylaluminum and water. We deeply discuss the role of the metallic Ti thin film substrate at room temperature and 200 °C, highlighting the differences between the heterodeposition (<10 cycles) and the homodeposition (>10 cycles) growth regimes at both conditions. This surface science approach will benefit our understanding of the ALD process, paving the way toward more efficient and controllable manufacturing processes.","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":"15 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139002538","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}
Pub Date : 2023-12-14DOI: 10.3390/inorganics11120478
S. Mangelsen, Patrick Zimmer, Christian Näther, W. Bensch
Transition metal inserted NbS2 (TxNbS2) compounds receive great attention due to their intriguing and diverse magnetic and electric transport properties. Typically, these compounds are prepared by high-temperature synthesis from the elements, which is time and energy-consuming and yields highly crystalline products. So far, no route for preparing these compounds from precursors by thermal decomposition has been reported. Herein, we report the synthesis of a dithiocarbamate of niobium Nb2S4(CS2NH2)4 as a precursor for the synthesis of NbS2 by this preparative strategy. Furthermore, we demonstrate that a co-decomposition with dithiocarbamates of transition metals (here, Co and Pd) is a viable route for the synthesis of TxNbS2-type compounds. This is a promising route for the exploration of these compounds’ properties in the form of, e.g., nanocrystalline or thin film samples.
过渡金属插入 NbS2（TxNbS2）化合物因其引人入胜的多样化磁性和电传输特性而备受关注。通常情况下，这些化合物是通过元素高温合成法制备的，这种方法耗时耗能，而且生成的产品结晶度很高。迄今为止，还没有报道过通过热分解从前驱体制备这些化合物的路线。在此，我们报告了铌的二硫代氨基甲酸盐 Nb2S4(CS2NH2)4 的合成，以此为前驱体，通过这种制备策略合成 NbS2。此外，我们还证明了与过渡金属（此处为 Co 和 Pd）的二硫代氨基甲酸酯共分解是合成 TxNbS2 型化合物的可行路线。这对于探索这些化合物的特性（如纳米晶体或薄膜样品）是一条很有前景的途径。
{"title":"Nb2S4(CS2NH2)4—A New Precursor for NbS2 and Its Transition Metal Inserted Derivatives","authors":"S. Mangelsen, Patrick Zimmer, Christian Näther, W. Bensch","doi":"10.3390/inorganics11120478","DOIUrl":"https://doi.org/10.3390/inorganics11120478","url":null,"abstract":"Transition metal inserted NbS2 (TxNbS2) compounds receive great attention due to their intriguing and diverse magnetic and electric transport properties. Typically, these compounds are prepared by high-temperature synthesis from the elements, which is time and energy-consuming and yields highly crystalline products. So far, no route for preparing these compounds from precursors by thermal decomposition has been reported. Herein, we report the synthesis of a dithiocarbamate of niobium Nb2S4(CS2NH2)4 as a precursor for the synthesis of NbS2 by this preparative strategy. Furthermore, we demonstrate that a co-decomposition with dithiocarbamates of transition metals (here, Co and Pd) is a viable route for the synthesis of TxNbS2-type compounds. This is a promising route for the exploration of these compounds’ properties in the form of, e.g., nanocrystalline or thin film samples.","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":"26 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138973318","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}
Pub Date : 2023-12-14DOI: 10.3390/inorganics11120479
Chourouk Kefi, J. Huot
In this paper, we report the effect of the Cr/Mn ratio on the thermodynamic properties of Ti30V60Mn(10−x)Crx (x = 0, 3.3, 6.6 and 10) + 4 wt.% Zr alloys. It was found that the enthalpy and entropy change with the Cr/MN ratio and that the entropy and entropy variation is coupled in an enthalpy-entropy compensation fashion. Using a compensation quality factor, it was established that the enthalpy-entropy compensation is not due to a statistical origin, with a confidence of more than 95%.
{"title":"Entropy-Enthalpy Compensation in Ti-V-Mn-Cr BCC Alloys Used as Hydrogen Storage Materials","authors":"Chourouk Kefi, J. Huot","doi":"10.3390/inorganics11120479","DOIUrl":"https://doi.org/10.3390/inorganics11120479","url":null,"abstract":"In this paper, we report the effect of the Cr/Mn ratio on the thermodynamic properties of Ti30V60Mn(10−x)Crx (x = 0, 3.3, 6.6 and 10) + 4 wt.% Zr alloys. It was found that the enthalpy and entropy change with the Cr/MN ratio and that the entropy and entropy variation is coupled in an enthalpy-entropy compensation fashion. Using a compensation quality factor, it was established that the enthalpy-entropy compensation is not due to a statistical origin, with a confidence of more than 95%.","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":"34 2","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139003209","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}
Pub Date : 2023-12-11DOI: 10.3390/inorganics11120476
T. Humphries, C. Buckley, M. Paskevicius, Torben R. Jensen
Hydrogen is heralded as a future global energy carrier [...]
氢被誉为未来的全球能源载体 [...]
{"title":"State-of-the-Art and Progress in Metal-Hydrogen Systems","authors":"T. Humphries, C. Buckley, M. Paskevicius, Torben R. Jensen","doi":"10.3390/inorganics11120476","DOIUrl":"https://doi.org/10.3390/inorganics11120476","url":null,"abstract":"Hydrogen is heralded as a future global energy carrier [...]","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":"14 7","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138980065","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 prediction of stack output power in solid oxide fuel cell (SOFC) systems is a key technology that urgently needs improvement, which will promote SOFC systems towards high-power multi-stack applications. The accuracy of power prediction directly determines the control effect and working condition recognition accuracy of the SOFC system controller. In order to achieve this goal, a genetic algorithm back propagation (GA-BP) neural network is constructed to predict output power in the SOFC system. By testing 40 sets of sample data collected from the experimental platform, it is found that the GA-BP method overcomes the limitation of the traditional back propagation (BP) method—falling into local optima. Further analysis shows that the average relative error of GA-BP has decreased to 1%. The reduction of the relative error improves the accuracy of the prediction results and the average prediction accuracy. Compared with the long short-term memory (LSTM) and BP algorithm, the GA-BP prediction model significantly reduces the relative error of power output prediction, which provides a solid foundation for multi-stack SOFC systems.
{"title":"A Single-Stack Output Power Prediction Method for High-Power, Multi-Stack SOFC System Requirements","authors":"Daihui Zhang, Jiangong Hu, Wei Zhao, Meilin Lai, Zilin Gao, Xiaolong Wu","doi":"10.3390/inorganics11120474","DOIUrl":"https://doi.org/10.3390/inorganics11120474","url":null,"abstract":"The prediction of stack output power in solid oxide fuel cell (SOFC) systems is a key technology that urgently needs improvement, which will promote SOFC systems towards high-power multi-stack applications. The accuracy of power prediction directly determines the control effect and working condition recognition accuracy of the SOFC system controller. In order to achieve this goal, a genetic algorithm back propagation (GA-BP) neural network is constructed to predict output power in the SOFC system. By testing 40 sets of sample data collected from the experimental platform, it is found that the GA-BP method overcomes the limitation of the traditional back propagation (BP) method—falling into local optima. Further analysis shows that the average relative error of GA-BP has decreased to 1%. The reduction of the relative error improves the accuracy of the prediction results and the average prediction accuracy. Compared with the long short-term memory (LSTM) and BP algorithm, the GA-BP prediction model significantly reduces the relative error of power output prediction, which provides a solid foundation for multi-stack SOFC systems.","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":"2 3","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138595729","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}
Pub Date : 2023-12-06DOI: 10.3390/inorganics11120475
Trent Quist, Jiahua Chen, Alex MacNeil, M. Pandelia
Fe-S clusters are ubiquitous inorganic cofactors found in proteins across all domains of life, including viruses. Their prevalence stems from their unique redox and structural plasticity that supports functions ranging from electron transfer and catalysis to stabilization of protein structure. Although the ability of Fe-S clusters to exchange electrons is often functionally crucial, it can also act as an Achilles heel when these cofactors are exposed to oxidizing conditions, often leading to their degradation. This O2 sensitivity has rendered certain Fe-S clusters untraceable, particularly when the nascent proteins are isolated under ambient conditions. As a consequence of this O2 sensitivity, a growing number of proteins with roles in viral infection have been found to harbor Fe-S clusters rather than the annotated Zn2+ cofactor. The enigmatic protein X (HBx) of the Hepatitis B Virus is a multifunctional protein essential for viral replication and development of liver disease. Although HBx has defied biochemical characterization for over forty years, it has been shown to coordinate a redox-active Fe-S cluster that represents a significant feature for establishing its molecular function. The present review narrates the approaches to validate the HBx metallocofactor that can be broadly applied as a guide for uncovering the presence of Fe-S clusters in proteins with non-canonical sequence motifs.
{"title":"The Cryptic Nature of Fe-S Clusters: A Case Study of the Hepatitis B HBx Oncoprotein","authors":"Trent Quist, Jiahua Chen, Alex MacNeil, M. Pandelia","doi":"10.3390/inorganics11120475","DOIUrl":"https://doi.org/10.3390/inorganics11120475","url":null,"abstract":"Fe-S clusters are ubiquitous inorganic cofactors found in proteins across all domains of life, including viruses. Their prevalence stems from their unique redox and structural plasticity that supports functions ranging from electron transfer and catalysis to stabilization of protein structure. Although the ability of Fe-S clusters to exchange electrons is often functionally crucial, it can also act as an Achilles heel when these cofactors are exposed to oxidizing conditions, often leading to their degradation. This O2 sensitivity has rendered certain Fe-S clusters untraceable, particularly when the nascent proteins are isolated under ambient conditions. As a consequence of this O2 sensitivity, a growing number of proteins with roles in viral infection have been found to harbor Fe-S clusters rather than the annotated Zn2+ cofactor. The enigmatic protein X (HBx) of the Hepatitis B Virus is a multifunctional protein essential for viral replication and development of liver disease. Although HBx has defied biochemical characterization for over forty years, it has been shown to coordinate a redox-active Fe-S cluster that represents a significant feature for establishing its molecular function. The present review narrates the approaches to validate the HBx metallocofactor that can be broadly applied as a guide for uncovering the presence of Fe-S clusters in proteins with non-canonical sequence motifs.","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":"97 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138596095","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}
Pub Date : 2023-12-05DOI: 10.3390/inorganics11120473
Sophie Riedel, Maik Gerwig, D. Gerlach, Erica Brendler, R. Gericke, E. Kroke, J. Wagler
4-Azidopyridine (1) and SiCl4 react with the formation of the hexacoordinate silicon complex SiCl4(4-azidopyridine)2 (2). Upon dissolving in warm chloroform, the complex dissociates into the constituents 1 and SiCl4 and forms back upon cooling. Depending on the cooling, two different crystalline modifications of 2 were obtained, which feature two different trans-conformers. Slow cooling to room temperature afforded conformer 2′, which features coplanar pyridine rings. Rapid cooling to −39 °C afforded crystals of conformer 2″, in which the planes of the pyridine ligands are nearly orthogonal to one another. Whereas 2′ resembles the molecular arrangement of various other known SiX4(pyridine)2 (X = halide) complexes, 2″ represents the first crystallographically confirmed example of a SiX4(pyridine)2 complex in this conformation. Conformers 2′ and 2″ were studied with 13C and 29Si solid state NMR spectroscopy. Their differences in 29Si chemical shift anisotropy, as well as energetic differences, were further investigated with computational analyses. In spite of the similar stabilities of the two conformers as isolated molecules, the crystal packing of 2″ is less stable, and its crystallization is interpreted as a kinetically controlled effect of seed formation. (3+2)-cycloaddition of 1 and phenylacetylene in toluene at 110 °C yields a mixture of 1-(4-pyridyl)-4-phenyl-1,2,3-triazole (1,4-3) and 1-(4-pyridyl)-5-phenyl-1,2,3-triazole (1,5-3) in approximate 1:2 molar ratio. The crystal structures of the two isomers were determined via X-ray diffraction. In chloroform (at 60 °C), this reaction is slow (less than 2% conversion within 4 h), but the presence of SiCl4 enhanced the rate of the reaction slightly, and it shifted the triazole isomer ratio to ca. 1:6 in favor of 1,5-3.
{"title":"The Hexacoordinate Si Complex SiCl4(4-Azidopyridine)2—Crystallographic Characterization of Two Conformers and Probing the Influence of SiCl4-Complexation on a Click Reaction with Phenylacetylene","authors":"Sophie Riedel, Maik Gerwig, D. Gerlach, Erica Brendler, R. Gericke, E. Kroke, J. Wagler","doi":"10.3390/inorganics11120473","DOIUrl":"https://doi.org/10.3390/inorganics11120473","url":null,"abstract":"4-Azidopyridine (1) and SiCl4 react with the formation of the hexacoordinate silicon complex SiCl4(4-azidopyridine)2 (2). Upon dissolving in warm chloroform, the complex dissociates into the constituents 1 and SiCl4 and forms back upon cooling. Depending on the cooling, two different crystalline modifications of 2 were obtained, which feature two different trans-conformers. Slow cooling to room temperature afforded conformer 2′, which features coplanar pyridine rings. Rapid cooling to −39 °C afforded crystals of conformer 2″, in which the planes of the pyridine ligands are nearly orthogonal to one another. Whereas 2′ resembles the molecular arrangement of various other known SiX4(pyridine)2 (X = halide) complexes, 2″ represents the first crystallographically confirmed example of a SiX4(pyridine)2 complex in this conformation. Conformers 2′ and 2″ were studied with 13C and 29Si solid state NMR spectroscopy. Their differences in 29Si chemical shift anisotropy, as well as energetic differences, were further investigated with computational analyses. In spite of the similar stabilities of the two conformers as isolated molecules, the crystal packing of 2″ is less stable, and its crystallization is interpreted as a kinetically controlled effect of seed formation. (3+2)-cycloaddition of 1 and phenylacetylene in toluene at 110 °C yields a mixture of 1-(4-pyridyl)-4-phenyl-1,2,3-triazole (1,4-3) and 1-(4-pyridyl)-5-phenyl-1,2,3-triazole (1,5-3) in approximate 1:2 molar ratio. The crystal structures of the two isomers were determined via X-ray diffraction. In chloroform (at 60 °C), this reaction is slow (less than 2% conversion within 4 h), but the presence of SiCl4 enhanced the rate of the reaction slightly, and it shifted the triazole isomer ratio to ca. 1:6 in favor of 1,5-3.","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":"129 5","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138599289","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}
Pub Date : 2023-12-04DOI: 10.3390/inorganics11120471
Ludwig Zapf, Maik Finze
Novel hexafluoroisopropylboranes (CF3)(CF2H)CFBH2·L and -borate anions [(CF3)(CF2H)CFBH2X]− with Lewis basic heterocyclic ligands L and the anionic substituents X = F− and CN− were obtained. The syntheses were accomplished by substitution reactions of the dimethyl sulfide adduct (CF3)(CF2H)CFBH2·SMe2, which was synthesized on a large scale. The hexafluoroisopropylboranes and -borates were characterized by NMR and vibrational spectroscopy, elemental analysis, and single-crystal X-ray diffraction. In addition, the thermal and electrochemical stabilities were investigated by DSC measurements and cyclic voltammetry and selected experimental data and trends are compared with theoretical ones.
{"title":"Hexafluoroisopropylboranes and -Borates","authors":"Ludwig Zapf, Maik Finze","doi":"10.3390/inorganics11120471","DOIUrl":"https://doi.org/10.3390/inorganics11120471","url":null,"abstract":"Novel hexafluoroisopropylboranes (CF3)(CF2H)CFBH2·L and -borate anions [(CF3)(CF2H)CFBH2X]− with Lewis basic heterocyclic ligands L and the anionic substituents X = F− and CN− were obtained. The syntheses were accomplished by substitution reactions of the dimethyl sulfide adduct (CF3)(CF2H)CFBH2·SMe2, which was synthesized on a large scale. The hexafluoroisopropylboranes and -borates were characterized by NMR and vibrational spectroscopy, elemental analysis, and single-crystal X-ray diffraction. In addition, the thermal and electrochemical stabilities were investigated by DSC measurements and cyclic voltammetry and selected experimental data and trends are compared with theoretical ones.","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":"35 24","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138602642","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：