Pub Date : 2023-11-25DOI: 10.3390/inorganics11120456
I. Shepa, E. Múdra, D. Capková, A. Kovalčíková, Ondrej Petrus, Frantisek Kromka, O. Milkovič, V. Antal, M. Baláž, M. Lisnichuk, Dominika Marcin-Behunova, D. Zalka, Ján Dusza
This contribution describes the preparation, coupled with detailed characterization, of Nb2O5 nanofibers and their application in lithium–sulfur batteries for the improvement of electrochemical performance. The utilization of reactive needle-less electrospinning allowed us to obtain, in a single step, amorphous pre-ceramic composite PAN/Nb2O5 fibers, which were transformed into porous ceramic Nb2O5 nanofibers via calcination. Thermogravimetric studies defined that calcination at 600 °C results in crystalline ceramic fibers without carbon residues. The fibrous morphology and mean diameter (614 ± 100 nm) of the ceramic nanofibers were analyzed via scanning and transmission electron microscopy. A surface area of 7.472 m2/g was determined through nitrogen adsorption measurements, while a combination of X-ray diffraction and Raman spectroscopy was used to show the crystallinity and composition of the fibers after calcination—single T-phase Nb2O5. Its performance in the cathode of lithium–sulfur batteries was defined through electrochemical tests, and the obtained results were compared to a similar blank electrode. The initial discharge capacity of 0.5 C reached a value of 570 mAh∙g−1, while the reversible capacity of 406 mAh∙g−1 was retained after 200 cycles, representing a capacity retention of 71.3%. The presence of Nb2O5 nanofibers in the carbon cathode inhibits the shuttle effect through polysulphide confinement, which originates from porosity and chemical trapping.
这篇论文介绍了 Nb2O5 纳米纤维的制备及其详细表征，以及它们在锂硫电池中的应用，以改善电化学性能。利用无针反应电纺丝技术，我们只需一步就能获得无定形的预陶瓷复合 PAN/Nb2O5 纤维，并通过煅烧将其转化为多孔陶瓷 Nb2O5 纳米纤维。热重研究表明，在 600 °C 下煅烧可产生无碳残留的结晶陶瓷纤维。通过扫描和透射电子显微镜分析了陶瓷纳米纤维的纤维形态和平均直径（614 ± 100 nm）。通过氮吸附测量确定了 7.472 m2/g 的表面积，同时结合 X 射线衍射和拉曼光谱显示了煅烧后纤维的结晶度和成分--单 T 相 Nb2O5。通过电化学测试确定了其在锂硫电池阴极中的性能，并将所得结果与类似的空白电极进行了比较。0.5 C 的初始放电容量达到了 570 mAh∙g-1 的值，而经过 200 次循环后，可逆容量仍为 406 mAh∙g-1 ，容量保持率为 71.3%。碳阴极中 Nb2O5 纳米纤维的存在通过多硫化物的封闭抑制了穿梭效应，这种效应源于多孔性和化学捕获。
{"title":"Porous Nb2O5 Nanofibers Prepared via Reactive Needle-Less Electrospinning for Application in Lithium–Sulfur Batteries","authors":"I. Shepa, E. Múdra, D. Capková, A. Kovalčíková, Ondrej Petrus, Frantisek Kromka, O. Milkovič, V. Antal, M. Baláž, M. Lisnichuk, Dominika Marcin-Behunova, D. Zalka, Ján Dusza","doi":"10.3390/inorganics11120456","DOIUrl":"https://doi.org/10.3390/inorganics11120456","url":null,"abstract":"This contribution describes the preparation, coupled with detailed characterization, of Nb2O5 nanofibers and their application in lithium–sulfur batteries for the improvement of electrochemical performance. The utilization of reactive needle-less electrospinning allowed us to obtain, in a single step, amorphous pre-ceramic composite PAN/Nb2O5 fibers, which were transformed into porous ceramic Nb2O5 nanofibers via calcination. Thermogravimetric studies defined that calcination at 600 °C results in crystalline ceramic fibers without carbon residues. The fibrous morphology and mean diameter (614 ± 100 nm) of the ceramic nanofibers were analyzed via scanning and transmission electron microscopy. A surface area of 7.472 m2/g was determined through nitrogen adsorption measurements, while a combination of X-ray diffraction and Raman spectroscopy was used to show the crystallinity and composition of the fibers after calcination—single T-phase Nb2O5. Its performance in the cathode of lithium–sulfur batteries was defined through electrochemical tests, and the obtained results were compared to a similar blank electrode. The initial discharge capacity of 0.5 C reached a value of 570 mAh∙g−1, while the reversible capacity of 406 mAh∙g−1 was retained after 200 cycles, representing a capacity retention of 71.3%. The presence of Nb2O5 nanofibers in the carbon cathode inhibits the shuttle effect through polysulphide confinement, which originates from porosity and chemical trapping.","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":"26 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139236241","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 : 2023-11-25DOI: 10.3390/inorganics11120457
Christian Tobeck, Heiko Wende, U. Ruschewitz
The reaction of UO2 with the respective lanthanide metal and purified graphite in an arc-melting furnace led to the formation of solid solutions of the composition LnxU1−xC2, with Ln = Tb, Dy, Ho, Tm, and Lu. They all crystallize in the tetragonal CaC2 type structure (I4/mmm, Z = 2). Elemental analyses of selected samples (EDX) confirm that the composition of the resulting solid solution is in reasonable agreement with the nominal (weighed-in) composition of the starting materials, i.e., a significant evaporation of the lanthanide metals during the arc-melting synthesis does not occur. The lattice parameters of the solid solutions were extracted using Le Bail fits of high-resolution synchrotron powder diffraction data (beamline P02.1, DESY, Hamburg, Germany; beamline BL 09, DELTA, Dortmund, Germany), revealing ideal Vegard behavior for all five solid solutions. XANES investigations on all compounds at the Ln-LIII and U-LIII edges reveal that the occupancies of the U-6d orbitals decrease with increasing x, whereas the occupancies of the Ln-5d orbitals increase, pointing to an electron transfer from the uranium to the lanthanide cations. Examination of the shifts of the absorption edge (E0) leads to the same finding.
{"title":"Solid Solutions LnxU1−xC2 with Ln = Tb, Dy, Ho, Tm, and Lu Showing Ideal Vegard Behavior","authors":"Christian Tobeck, Heiko Wende, U. Ruschewitz","doi":"10.3390/inorganics11120457","DOIUrl":"https://doi.org/10.3390/inorganics11120457","url":null,"abstract":"The reaction of UO2 with the respective lanthanide metal and purified graphite in an arc-melting furnace led to the formation of solid solutions of the composition LnxU1−xC2, with Ln = Tb, Dy, Ho, Tm, and Lu. They all crystallize in the tetragonal CaC2 type structure (I4/mmm, Z = 2). Elemental analyses of selected samples (EDX) confirm that the composition of the resulting solid solution is in reasonable agreement with the nominal (weighed-in) composition of the starting materials, i.e., a significant evaporation of the lanthanide metals during the arc-melting synthesis does not occur. The lattice parameters of the solid solutions were extracted using Le Bail fits of high-resolution synchrotron powder diffraction data (beamline P02.1, DESY, Hamburg, Germany; beamline BL 09, DELTA, Dortmund, Germany), revealing ideal Vegard behavior for all five solid solutions. XANES investigations on all compounds at the Ln-LIII and U-LIII edges reveal that the occupancies of the U-6d orbitals decrease with increasing x, whereas the occupancies of the Ln-5d orbitals increase, pointing to an electron transfer from the uranium to the lanthanide cations. Examination of the shifts of the absorption edge (E0) leads to the same finding.","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":"10 24","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139237190","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 : 2023-11-24DOI: 10.3390/inorganics11120454
Gang Han, Xiaozhi Hu
This study explores the potential for repairing small, isolated delamination areas in carbon fiber-reinforced polymer (CFRP), while preserving the integrity of the composite structures. A small drilled hole at the center of the delamination section served as a channel for the epoxy infill of the sharp delamination cracks. The pressureless infill repair was achieved through the capillary action of an acetone-diluted resin pre-coating (RPC) solution (without hardener) with CNT reinforcement, comprising 89 m/m% acetone, 10 m/m% resin, and 1 m/m% CNT. This acetone-rich resin pre-coating (RPC) solution is easily prepared and applied to the drilled hole area. Curing of the CNT-toughened resin infill was induced by filling the small drilled hole with a resin–hardener mixture toughened by CNT/aramid pulp. The effectiveness of the delamination repair was compared for curing periods of two weeks and three months. The flexural strength measurements indicated that a restoration level of 77% was achieved in this study, while the optimum 100% restoration was achieved using the same technique for edge delamination repairs.
{"title":"Repair of Small-Area Delamination in Carbon Fiber-Reinforced Polymer through Small Drilled Hole and Carbon Nanotubes-Reinforced Resin Pre-Coating Technique","authors":"Gang Han, Xiaozhi Hu","doi":"10.3390/inorganics11120454","DOIUrl":"https://doi.org/10.3390/inorganics11120454","url":null,"abstract":"This study explores the potential for repairing small, isolated delamination areas in carbon fiber-reinforced polymer (CFRP), while preserving the integrity of the composite structures. A small drilled hole at the center of the delamination section served as a channel for the epoxy infill of the sharp delamination cracks. The pressureless infill repair was achieved through the capillary action of an acetone-diluted resin pre-coating (RPC) solution (without hardener) with CNT reinforcement, comprising 89 m/m% acetone, 10 m/m% resin, and 1 m/m% CNT. This acetone-rich resin pre-coating (RPC) solution is easily prepared and applied to the drilled hole area. Curing of the CNT-toughened resin infill was induced by filling the small drilled hole with a resin–hardener mixture toughened by CNT/aramid pulp. The effectiveness of the delamination repair was compared for curing periods of two weeks and three months. The flexural strength measurements indicated that a restoration level of 77% was achieved in this study, while the optimum 100% restoration was achieved using the same technique for edge delamination repairs.","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":"74 9","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139239094","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 : 2023-11-24DOI: 10.3390/inorganics11120455
Ehsan Ezzatpour Ghadim, Marc Walker, Richard I. Walton
A rapid synthesis method is used to form multivariate metal–organic frameworks (MTV-MOFs) with the UiO-66 structure, where precipitation occurs upon mixing solutions of ligands and metal salts at temperatures less than 60 °C. The materials include mixtures of metals and ligands, Ce/Zr-UiO-66(1,4-NDC/BDC), Ce/Zr-UiO-66(1,4-NDC/2,6-NDC), Ce/Zr-UiO-66(1,4-NDC), Ce/Ti-UiO-66(1,4-NDC), and Ce/Ti-UiO-66(BDC-NH2) (NDC = naphthalene dicarboxylate, BDC = benzene-1,4-dicarboxylate, BDC-NH2 = 2-amino-benzene-1,4-dicarboxylate). Phase purity was determined by powder X-ray diffraction (PXRD), with a broadening of the profile indicative of nanoscale crystallites, verified by scanning electron microscopy (SEM). The molar ratio of metals and organic ligands in Ce/Zr-UiO-66(1,4-NDC/2,6-NDC) was confirmed by X-ray fluorescence (XRF) and solution 1H nuclear magnetic resonance (NMR) after digestion, respectively. Analysis of the adsorption of dyes by the MTV-MOFs showed that a pseudo-first-order model accounts for the kinetics. The effectiveness of photocatalytic degradation of two cationic (methylene blue and rhodamine B) and two anionic (Congo red and Alizarin Red S (AR)) dyes was studied under UV and visible light. The most effective photocatalytic degradation was found between 1 and 15 min towards both cationic and anionic dyes by Ce/Zr-UiO-66(1,4-NDC/2,6-NDC). Measurements of recyclability and photostability showed retention of crystallinity after five cycles of use and exposure to light for 17 h, as confirmed by PXRD.
采用快速合成法形成具有 UiO-66 结构的多元金属有机框架 (MTV-MOF)，在低于 60 °C 的温度下混合配体和金属盐溶液后会发生沉淀。这些材料包括金属和配体的混合物、Ce/Zr-UiO-66（1,4-NDC/BDC）、Ce/Zr-UiO-66（1,4-NDC/2,6-NDC）、Ce/Zr-UiO-66（1,4-NDC）、Ce/Ti-UiO-66（1、4-NDC）和 Ce/Ti-UiO-66（BDC-NH2）（NDC = 萘二羧酸盐，BDC = 苯-1,4-二羧酸盐，BDC-NH2 = 2-氨基苯-1,4-二羧酸盐）。粉末 X 射线衍射（PXRD）测定了相纯度，扫描电子显微镜（SEM）验证了显示纳米级结晶的拓宽剖面。消解后的 X 射线荧光 (XRF) 和溶液 1H 核磁共振 (NMR) 分别证实了 Ce/Zr-UiO-66(1,4-NDC/2,6-NDC)中金属和有机配体的摩尔比。对 MTV-MOFs 吸附染料的分析表明，其动力学符合伪一阶模型。研究了在紫外光和可见光下光催化降解两种阳离子染料（亚甲基蓝和罗丹明 B）和两种阴离子染料（刚果红和茜素红 S (AR)）的效果。发现 Ce/Zr-UiO-66（1,4-NDC/2,6-NDC）在 1 至 15 分钟内对阳离子和阴离子染料的光催化降解效果最好。经 PXRD 证实，对可回收性和光照稳定性的测量表明，在使用五个周期并在光照下暴露 17 小时后，结晶度仍保持不变。
{"title":"The Use of Rapid Precipitation to Synthesise Multivariate UiO-66 Metal–Organic Frameworks for Photocatalysis","authors":"Ehsan Ezzatpour Ghadim, Marc Walker, Richard I. Walton","doi":"10.3390/inorganics11120455","DOIUrl":"https://doi.org/10.3390/inorganics11120455","url":null,"abstract":"A rapid synthesis method is used to form multivariate metal–organic frameworks (MTV-MOFs) with the UiO-66 structure, where precipitation occurs upon mixing solutions of ligands and metal salts at temperatures less than 60 °C. The materials include mixtures of metals and ligands, Ce/Zr-UiO-66(1,4-NDC/BDC), Ce/Zr-UiO-66(1,4-NDC/2,6-NDC), Ce/Zr-UiO-66(1,4-NDC), Ce/Ti-UiO-66(1,4-NDC), and Ce/Ti-UiO-66(BDC-NH2) (NDC = naphthalene dicarboxylate, BDC = benzene-1,4-dicarboxylate, BDC-NH2 = 2-amino-benzene-1,4-dicarboxylate). Phase purity was determined by powder X-ray diffraction (PXRD), with a broadening of the profile indicative of nanoscale crystallites, verified by scanning electron microscopy (SEM). The molar ratio of metals and organic ligands in Ce/Zr-UiO-66(1,4-NDC/2,6-NDC) was confirmed by X-ray fluorescence (XRF) and solution 1H nuclear magnetic resonance (NMR) after digestion, respectively. Analysis of the adsorption of dyes by the MTV-MOFs showed that a pseudo-first-order model accounts for the kinetics. The effectiveness of photocatalytic degradation of two cationic (methylene blue and rhodamine B) and two anionic (Congo red and Alizarin Red S (AR)) dyes was studied under UV and visible light. The most effective photocatalytic degradation was found between 1 and 15 min towards both cationic and anionic dyes by Ce/Zr-UiO-66(1,4-NDC/2,6-NDC). Measurements of recyclability and photostability showed retention of crystallinity after five cycles of use and exposure to light for 17 h, as confirmed by PXRD.","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":"148 4","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139240041","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 : 2023-11-24DOI: 10.3390/inorganics11120453
A. Al-Wasidi, Ehab A. Abdelrahman
Indigo carmine dye falls into the category of toxic chemicals, potentially leading to irritation and allergic reactions in certain individuals. Thus, this study employed the Pechini sol–gel strategy to easily produce CoFe2O4 nanoparticles, which serve as an effective adsorbent for the disposal of indigo carmine dye from aqueous solutions. The maximum adsorption capacity of CoFe2O4 for indigo carmine dye was determined to be 421.94 mg/g. The synthesized CoFe2O4 nanoparticles exhibited an average crystallite size of 18.75 nm. SEM analysis revealed that these nanoparticles were nearly spherical, with an average grain size of 198.32 nm. Additionally, TEM analysis indicated a fully agglomerated spherical morphology for the CoFe2O4 sample, with an average diameter of 15.37 nm. The EDS spectrum confirmed that the synthesized CoFe2O4 nanoparticles consisted of Co, Fe, and O elements, with respective weight percentages of 17.82%, 49.46%, and 32.72%. The removal of indigo carmine dye by the synthesized CoFe2O4 is spontaneous, chemical, exothermic, closely fitting the pseudo-second-order kinetic model, and demonstrating a strong concordance with the Langmuir equilibrium isotherm.
{"title":"Simple Synthesis and Characterization of Cobalt Ferrite Nanoparticles for the Successful Adsorption of Indigo Carmine Dye from Aqueous Media","authors":"A. Al-Wasidi, Ehab A. Abdelrahman","doi":"10.3390/inorganics11120453","DOIUrl":"https://doi.org/10.3390/inorganics11120453","url":null,"abstract":"Indigo carmine dye falls into the category of toxic chemicals, potentially leading to irritation and allergic reactions in certain individuals. Thus, this study employed the Pechini sol–gel strategy to easily produce CoFe2O4 nanoparticles, which serve as an effective adsorbent for the disposal of indigo carmine dye from aqueous solutions. The maximum adsorption capacity of CoFe2O4 for indigo carmine dye was determined to be 421.94 mg/g. The synthesized CoFe2O4 nanoparticles exhibited an average crystallite size of 18.75 nm. SEM analysis revealed that these nanoparticles were nearly spherical, with an average grain size of 198.32 nm. Additionally, TEM analysis indicated a fully agglomerated spherical morphology for the CoFe2O4 sample, with an average diameter of 15.37 nm. The EDS spectrum confirmed that the synthesized CoFe2O4 nanoparticles consisted of Co, Fe, and O elements, with respective weight percentages of 17.82%, 49.46%, and 32.72%. The removal of indigo carmine dye by the synthesized CoFe2O4 is spontaneous, chemical, exothermic, closely fitting the pseudo-second-order kinetic model, and demonstrating a strong concordance with the Langmuir equilibrium isotherm.","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":"30 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139242033","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 : 2023-11-23DOI: 10.3390/inorganics11120452
J. Titiš, C. Rajnák, Roman Boča
Functional dependence of the axial zero-field splitting parameter D with respect to a properly chosen geometrical parameter (Dstr) in metal complexes is termed the magnetostructural D-correlation. In mononuclear hexacoordinate Ni(II) complexes with the ground electronic term 3B1g (3A2g in the regular octahedron), it proceeds along two intercepting straight lines, allowing for predicting the sign and magnitude of the D-parameter by knowing the X-ray structure alone; Dstr is constructed from the metal–ligand bond lengths. In hexacoordinate Co(II) complexes, it is applicable only in the segment of the compressed bipyramid where the ground electronic term 4B1g is orbitally non-degenerate so that the spin Hamiltonian formalism holds true. The D vs. Dstr correlation is strongly non-linear, and it is represented by a set of decreasing exponentials. In tetracoordinate Co(II) complexes, on the contrary, the angular distortion from the regular tetrahedron is crucial so that the appropriate structural parameter Dstr is constructed of bond angles. The most complex case is represented by pentacoordinated Co(II) systems, for which it is not yet possible to define a statistically significant correlation. All of these empirical correlations originate in the electronic structure of metal complexes that can be modelled using generalized crystal-field theory. As the barrier to spin reversal in single-molecule magnets is proportional to the D-value, for rational tuning and/or prediction of the single-molecule magnetic behaviour, knowledge/prediction of the D-parameter is beneficial. In this review, we present the statistical processing of an extensive set of structural and magnetic data on Co(II) and Ni(II) complexes, which were published over the past 15 years. Magnetostructural D-correlations defined for this data set are reviewed in detail.
在金属配合物中，轴向零场分裂参数 D 与正确选择的几何参数 (Dstr) 的函数关系被称为磁结构 D 相关性。在单核六配位镍（II）配合物中，基态电子项为 3B1g（正八面体中为 3A2g），它沿着两条相互截取的直线前进，因此只需了解 X 射线结构就能预测 D 参数的符号和大小；Dstr 是由金属配体键长构建的。在六配位 Co(II) 复合物中，它只适用于压缩双金字塔的部分，在该部分中，基态电子项 4B1g 在轨道上是非退化的，因此自旋哈密顿形式主义是成立的。D vs. Dstr 相关性具有很强的非线性，由一组递减指数表示。相反，在四配位 Co(II) 复合物中，正四面体的角度变形至关重要，因此适当的结构参数 Dstr 是由键角构成的。最复杂的情况是五配位 Co(II) 体系，目前还无法确定其统计意义上的相关性。所有这些经验相关性都源于金属复合物的电子结构，可以用广义晶场理论来模拟。由于单分子磁体的自旋反转障碍与 D 值成正比，因此要合理调整和/或预测单分子磁性，了解/预测 D 参数是非常有益的。在这篇综述中，我们介绍了对过去 15 年发表的大量有关 Co(II) 和 Ni(II) 复合物的结构和磁性数据的统计处理。文中详细回顾了为这组数据定义的磁结构 D 相关性。
{"title":"Magnetostructural D-Correlations and Their Impact on Single-Molecule Magnetism","authors":"J. Titiš, C. Rajnák, Roman Boča","doi":"10.3390/inorganics11120452","DOIUrl":"https://doi.org/10.3390/inorganics11120452","url":null,"abstract":"Functional dependence of the axial zero-field splitting parameter D with respect to a properly chosen geometrical parameter (Dstr) in metal complexes is termed the magnetostructural D-correlation. In mononuclear hexacoordinate Ni(II) complexes with the ground electronic term 3B1g (3A2g in the regular octahedron), it proceeds along two intercepting straight lines, allowing for predicting the sign and magnitude of the D-parameter by knowing the X-ray structure alone; Dstr is constructed from the metal–ligand bond lengths. In hexacoordinate Co(II) complexes, it is applicable only in the segment of the compressed bipyramid where the ground electronic term 4B1g is orbitally non-degenerate so that the spin Hamiltonian formalism holds true. The D vs. Dstr correlation is strongly non-linear, and it is represented by a set of decreasing exponentials. In tetracoordinate Co(II) complexes, on the contrary, the angular distortion from the regular tetrahedron is crucial so that the appropriate structural parameter Dstr is constructed of bond angles. The most complex case is represented by pentacoordinated Co(II) systems, for which it is not yet possible to define a statistically significant correlation. All of these empirical correlations originate in the electronic structure of metal complexes that can be modelled using generalized crystal-field theory. As the barrier to spin reversal in single-molecule magnets is proportional to the D-value, for rational tuning and/or prediction of the single-molecule magnetic behaviour, knowledge/prediction of the D-parameter is beneficial. In this review, we present the statistical processing of an extensive set of structural and magnetic data on Co(II) and Ni(II) complexes, which were published over the past 15 years. Magnetostructural D-correlations defined for this data set are reviewed in detail.","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":"1 ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139244526","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 : 2023-11-20DOI: 10.3390/inorganics11110446
Glenn Blade, Andrew J. Wessel, Karna Terpstra, Liviu M. Mirica
Two new ligands were synthesized with the goal of copper stabilization, N,N′-(2-methylpyridine)-2,11-diaza[3,3](2,6)pyridinophane (PicN4) and N-(methyl),N′-(2-methylpyridine)-2,11-diaza[3,3](2,6)pyridinophane (PicMeN4), by selective functionalization of HN4 and TsHN4. These two ligands, when reacted with various copper salts, generated both Cu(II) and Cu(I) complexes. These ligands and Cu complexes were characterized by various methods, such as NMR, UV-Vis, MS, and EA. Each compound was also examined electrochemically, and each revealed reversible Cu(II)/Cu(I) redox couples. Additionally, stability constants were determined via spectrophotometric titrations, and radiolabeling and cytotoxicity experiments were performed to assess the chelators relevance to their potential use in vivo as 64Cu PET imaging agents.
{"title":"Pentadentate and Hexadentate Pyridinophane Ligands Support Reversible Cu(II)/Cu(I) Redox Couples","authors":"Glenn Blade, Andrew J. Wessel, Karna Terpstra, Liviu M. Mirica","doi":"10.3390/inorganics11110446","DOIUrl":"https://doi.org/10.3390/inorganics11110446","url":null,"abstract":"Two new ligands were synthesized with the goal of copper stabilization, N,N′-(2-methylpyridine)-2,11-diaza[3,3](2,6)pyridinophane (PicN4) and N-(methyl),N′-(2-methylpyridine)-2,11-diaza[3,3](2,6)pyridinophane (PicMeN4), by selective functionalization of HN4 and TsHN4. These two ligands, when reacted with various copper salts, generated both Cu(II) and Cu(I) complexes. These ligands and Cu complexes were characterized by various methods, such as NMR, UV-Vis, MS, and EA. Each compound was also examined electrochemically, and each revealed reversible Cu(II)/Cu(I) redox couples. Additionally, stability constants were determined via spectrophotometric titrations, and radiolabeling and cytotoxicity experiments were performed to assess the chelators relevance to their potential use in vivo as 64Cu PET imaging agents.","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":"107 1","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139259254","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 : 2023-11-19DOI: 10.3390/inorganics11110445
Ívina P. de Souza, Júlia R. L. Silva, Amanda O. Costa, J. T. J. Freitas, Renata Diniz, Rodrigo B. Fazzi, A. M. da Costa Ferreira, E. Pereira-Maia
Two ternary copper(II) complexes with an anthraquinone and a N,N-heterocyclic donor, [Cu(dmp)(L)(H2O)](ClO4) (1), [Cu(bpy)(L)(dmso)](ClO4) (2), in which dmp = 2,9-dimethyl-1,10-phenanthroline, bpy = 2,2′-bipyridine, and HL = 1-hydroxyanthracene-9,10-dione were synthesized and fully characterized by conductivity, elemental, and spectral analyses (FTIR and UV-Vis; EPR and ESI-MS). The structure of 1 reveals that Cu(II) is bound to two oxygens of L, two nitrogens of dmp, and a molecule of water in the fifth position. In complex 2.1, Cu(II) is also pentacoordinated with an O-bonded dmso in the axial position. The presence of the heteroleptic complexes in solution was evidenced by ESI-MS, EPR in dmso solution and UV-Vis spectrophotometry. All complexes bind to CT-DNA with affinity constants of approximately 104. Complex 2 can nick plasmid DNA but no cleavage was performed by complex 1. The investigation of DNA interactions by spectrofluorimetry using ethidium bromide (EB) showed that it was displaced from DNA sites by the addition of the complexes. The complexes inhibited the growth of chronic myelogenous leukemia and human squamous carcinoma cells with low IC50 values, complex 1 being the most effective.
{"title":"Heteroleptic Copper(II) Complexes Containing an Anthraquinone and a Phenanthroline as Synthetic Nucleases and Potential Anticancer Agents","authors":"Ívina P. de Souza, Júlia R. L. Silva, Amanda O. Costa, J. T. J. Freitas, Renata Diniz, Rodrigo B. Fazzi, A. M. da Costa Ferreira, E. Pereira-Maia","doi":"10.3390/inorganics11110445","DOIUrl":"https://doi.org/10.3390/inorganics11110445","url":null,"abstract":"Two ternary copper(II) complexes with an anthraquinone and a N,N-heterocyclic donor, [Cu(dmp)(L)(H2O)](ClO4) (1), [Cu(bpy)(L)(dmso)](ClO4) (2), in which dmp = 2,9-dimethyl-1,10-phenanthroline, bpy = 2,2′-bipyridine, and HL = 1-hydroxyanthracene-9,10-dione were synthesized and fully characterized by conductivity, elemental, and spectral analyses (FTIR and UV-Vis; EPR and ESI-MS). The structure of 1 reveals that Cu(II) is bound to two oxygens of L, two nitrogens of dmp, and a molecule of water in the fifth position. In complex 2.1, Cu(II) is also pentacoordinated with an O-bonded dmso in the axial position. The presence of the heteroleptic complexes in solution was evidenced by ESI-MS, EPR in dmso solution and UV-Vis spectrophotometry. All complexes bind to CT-DNA with affinity constants of approximately 104. Complex 2 can nick plasmid DNA but no cleavage was performed by complex 1. The investigation of DNA interactions by spectrofluorimetry using ethidium bromide (EB) showed that it was displaced from DNA sites by the addition of the complexes. The complexes inhibited the growth of chronic myelogenous leukemia and human squamous carcinoma cells with low IC50 values, complex 1 being the most effective.","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":"24 7","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139260629","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 : 2023-11-18DOI: 10.3390/inorganics11110441
Tengfei Yan, Qingyun Wan
In the past decade, there have been significant advancements in the investigation of coherence-related phenomena in organic systems such as biological photosynthetic reaction centers. The d8 Pt(II) dinuclear complex or molecular aggregate with a metal–metal-to-ligand charge transfer (MMLCT) or metal-centered (MC) excited state was reported to show the vibrational coherence phenomenon in the intersystem crossing (ISC) process, due to the Metal–metal (M-M) interaction at excited state. In this study, we review the coherence effect in the Pt(II)-Pt(II) complexes which are speculated to be a coherent energy conversion system. The impacts of coherence on the photo-physics of Pt(II) dinuclear complexes have been discussed and reviewed, including the intersystem crossing process and vibrational wavepacket dynamics.
{"title":"Vibrational Coherence in the Metal–Metal-Bonded Excited State of Pt(II) Complexes","authors":"Tengfei Yan, Qingyun Wan","doi":"10.3390/inorganics11110441","DOIUrl":"https://doi.org/10.3390/inorganics11110441","url":null,"abstract":"In the past decade, there have been significant advancements in the investigation of coherence-related phenomena in organic systems such as biological photosynthetic reaction centers. The d8 Pt(II) dinuclear complex or molecular aggregate with a metal–metal-to-ligand charge transfer (MMLCT) or metal-centered (MC) excited state was reported to show the vibrational coherence phenomenon in the intersystem crossing (ISC) process, due to the Metal–metal (M-M) interaction at excited state. In this study, we review the coherence effect in the Pt(II)-Pt(II) complexes which are speculated to be a coherent energy conversion system. The impacts of coherence on the photo-physics of Pt(II) dinuclear complexes have been discussed and reviewed, including the intersystem crossing process and vibrational wavepacket dynamics.","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":"7 3","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139262068","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 : 2023-11-18DOI: 10.3390/inorganics11110443
A. Kola, Ginevra Vigni, D. Valensin
Lycorine (LYC) is an active alkaloid first isolated from Narcissus pseudonarcissus and found in most Amaryllidaceae plants. It belongs to the same family as galantamine, which is the active component of a drug used for the treatment of Alzheimer’s disease. Similarly to galantamine, LYC is able to suppress induced amyloid β (Aβ) toxicity in differentiated SH-SY5Y cell lines and it can weakly interact with the N-terminal region of Aβ via electrostatic interactions. The N-terminal Aβ domain is also involved in Cu(II)/Cu(I) binding and the formed complexes are known to play a key role in ROS production. In this study, the Aβ–LYC interaction in the absence and in the presence of copper ions was investigated by using the N-terminal Aβ peptide encompassing the first 16 residues. NMR analysis showed that Aβ can simultaneously interact with Cu(II) and LYC. The Cu(II) binding mode remains unchanged in the presence of LYC, while LYC association is favored when an Aβ–Cu(II) complex is formed. Moreover, UV-VIS studies revealed the ability of LYC to interfere with the catalytic activities of the Aβ–Cu(II) complexes by reducing the ascorbate consumption monitored at 265 nm.
{"title":"Exploration of Lycorine and Copper(II)’s Association with the N-Terminal Domain of Amyloid β","authors":"A. Kola, Ginevra Vigni, D. Valensin","doi":"10.3390/inorganics11110443","DOIUrl":"https://doi.org/10.3390/inorganics11110443","url":null,"abstract":"Lycorine (LYC) is an active alkaloid first isolated from Narcissus pseudonarcissus and found in most Amaryllidaceae plants. It belongs to the same family as galantamine, which is the active component of a drug used for the treatment of Alzheimer’s disease. Similarly to galantamine, LYC is able to suppress induced amyloid β (Aβ) toxicity in differentiated SH-SY5Y cell lines and it can weakly interact with the N-terminal region of Aβ via electrostatic interactions. The N-terminal Aβ domain is also involved in Cu(II)/Cu(I) binding and the formed complexes are known to play a key role in ROS production. In this study, the Aβ–LYC interaction in the absence and in the presence of copper ions was investigated by using the N-terminal Aβ peptide encompassing the first 16 residues. NMR analysis showed that Aβ can simultaneously interact with Cu(II) and LYC. The Cu(II) binding mode remains unchanged in the presence of LYC, while LYC association is favored when an Aβ–Cu(II) complex is formed. Moreover, UV-VIS studies revealed the ability of LYC to interfere with the catalytic activities of the Aβ–Cu(II) complexes by reducing the ascorbate consumption monitored at 265 nm.","PeriodicalId":13572,"journal":{"name":"Inorganics","volume":"41 04","pages":""},"PeriodicalIF":2.9,"publicationDate":"2023-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139261883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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