Pub Date : 2024-07-02DOI: 10.1021/acs.inorgchem.4c01617
Xiangchao Xu, Heng You, Beixuan Dong, Yiqian He, Feng Li
An efficient method for the selective conversion of glycerol, the major byproduct of the biodiesel manufacturing process, to lactic acid in water via acceptorless dehydrogenation has been developed. In the presence of a water-soluble [Cp*Ir(6,6'-(OH)2-2,2'-bpy)(H2O)][OTf]2 (0.1 mol %) and KOH (1.1 equiv), the reaction proceeded at 120 °C for 24 h to afford the desired product in >99% yield with >99% selectivity. It was confirmed that OH functional groups in the ligand were crucial for the activity of the iridium complex. Furthermore, density functional theory calculations and mechanistic experiments were also undertaken.
{"title":"Selective Conversion of Glycerol to Lactic Acid in Water via Acceptorless Dehydrogenation Catalyzed by a Water-Soluble Metal-Ligand Bifunctional Iridium Catalyst.","authors":"Xiangchao Xu, Heng You, Beixuan Dong, Yiqian He, Feng Li","doi":"10.1021/acs.inorgchem.4c01617","DOIUrl":"https://doi.org/10.1021/acs.inorgchem.4c01617","url":null,"abstract":"<p><p>An efficient method for the selective conversion of glycerol, the major byproduct of the biodiesel manufacturing process, to lactic acid in water via acceptorless dehydrogenation has been developed. In the presence of a water-soluble [Cp*Ir(6,6'-(OH)<sub>2</sub>-2,2'-bpy)(H<sub>2</sub>O)][OTf]<sub>2</sub> (0.1 mol %) and KOH (1.1 equiv), the reaction proceeded at 120 °C for 24 h to afford the desired product in >99% yield with >99% selectivity. It was confirmed that OH functional groups in the ligand were crucial for the activity of the iridium complex. Furthermore, density functional theory calculations and mechanistic experiments were also undertaken.</p>","PeriodicalId":40,"journal":{"name":"Inorganic Chemistry","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141489936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-02DOI: 10.1021/acs.inorgchem.4c02290
Lan Li, Chengjie Yin, Rong Han, Fujie Zhong, Jinsong Hu
Rechargeable aqueous zinc-ion batteries (AZIBs) have developed into one of the most attractive materials for large-scale energy storage owing to their advantages such as high energy density, low cost, and environmental friendliness. Nevertheless, the sluggish diffusion kinetics and inherent impoverished conductivity affect their practical application. Herein, the β-MnO2 composited with carbon nanotubes (CNT@M) is prepared through a simple hydrothermal approach as a high-performance cathode for AZIBs. The CNT@M electrode exhibits excellent cycling stability, in which the maximum specific discharge capacity is 259 mA h g–1 at 3 A g–1, and there is still 220 mA h g–1 after 2000 cycles. The specific capacity is obviously better than that of β-MnO2 (32 mA h g–1 after 2000 cycles). The outstanding electrochemical performance of the battery is inseparable from the structural framework of CNT and inherent high conductivity. Furthermore, CNT@M can form a complex conductive network based on CNTs to provide excellent ion diffusion and charge transfer. Therefore, the active material can maintain a long-term cycle and achieve stable capacity retention. This research provides a reasonable solution for the reliable conception of Mn-based electrodes and indicates its potential application in high-performance AZIB cathode materials.
可充电锌离子水电池(AZIBs)具有能量密度高、成本低和环境友好等优点,已发展成为最有吸引力的大规模储能材料之一。然而,缓慢的扩散动力学和固有的低导电性影响了它们的实际应用。在此,我们通过简单的水热法制备了与碳纳米管(CNT@M)复合的β-MnO2,作为 AZIBs 的高性能阴极。CNT@M 电极表现出优异的循环稳定性,在 3 A g-1 条件下,最大比放电容量为 259 mA h g-1,循环 2000 次后仍有 220 mA h g-1。比容量明显优于β-MnO2(2000 次循环后为 32 mA h g-1)。该电池出色的电化学性能与 CNT 的结构框架和固有的高导电性密不可分。此外,CNT@M 还能在 CNT 的基础上形成复杂的导电网络,提供出色的离子扩散和电荷转移。因此,活性材料可以保持长期循环,实现稳定的容量保持。这项研究为锰基电极的可靠构想提供了合理的解决方案,并预示着其在高性能 AZIB 阴极材料中的潜在应用。
{"title":"CNT Composite β-MnO2 with Fiber Cable Shape as Cathode Materials for Aqueous Zinc-Ion Batteries","authors":"Lan Li, Chengjie Yin, Rong Han, Fujie Zhong, Jinsong Hu","doi":"10.1021/acs.inorgchem.4c02290","DOIUrl":"https://doi.org/10.1021/acs.inorgchem.4c02290","url":null,"abstract":"Rechargeable aqueous zinc-ion batteries (AZIBs) have developed into one of the most attractive materials for large-scale energy storage owing to their advantages such as high energy density, low cost, and environmental friendliness. Nevertheless, the sluggish diffusion kinetics and inherent impoverished conductivity affect their practical application. Herein, the β-MnO<sub>2</sub> composited with carbon nanotubes (CNT@M) is prepared through a simple hydrothermal approach as a high-performance cathode for AZIBs. The CNT@M electrode exhibits excellent cycling stability, in which the maximum specific discharge capacity is 259 mA h g<sup>–1</sup> at 3 A g<sup>–1</sup>, and there is still 220 mA h g<sup>–1</sup> after 2000 cycles. The specific capacity is obviously better than that of β-MnO<sub>2</sub> (32 mA h g<sup>–1</sup> after 2000 cycles). The outstanding electrochemical performance of the battery is inseparable from the structural framework of CNT and inherent high conductivity. Furthermore, CNT@M can form a complex conductive network based on CNTs to provide excellent ion diffusion and charge transfer. Therefore, the active material can maintain a long-term cycle and achieve stable capacity retention. This research provides a reasonable solution for the reliable conception of Mn-based electrodes and indicates its potential application in high-performance AZIB cathode materials.","PeriodicalId":40,"journal":{"name":"Inorganic Chemistry","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141489664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-02DOI: 10.1021/acs.inorgchem.4c00783
Sarah Costa, Michael M. Aristov, Sang Ho Lim, Sarah M. Chui, Katelyn A. Espinoza, Marilyn M. Olmstead, James C. Fettinger, John F. Berry, Alan L. Balch
We report the ability to trap the dimer Au2(μ-dppe)2I2 (dppe is 1,2-bis(diphenylphosphino)ethane) with different separations between the three-coordinate gold ions in crystalline solvates. All of these solvates ((Au2(μ-dppe)2I2·4(CH2Cl2) (1), Au2(μ-dppe)2I2·2(CH2Cl2) (2), the polymorphs α-Au2(μ-dppe)2I2·2(HC(O)NMe2) (3) and β-Au2(μ-dppe)2I2·2(HC(O)NMe2) (4), and Au2(μ-dppe)2I2·4(CHCl3) (5)) along with polymeric {Au(μ-dppe)I}n·n(CHCl3) (6)) originated from the same reaction, only the solvent system used for crystallization differed. In the different solvates of Au2(μ-dppe)2I2, the Au···Au separation varied from 3.192(1) to 3.7866(3) Å. Computational studies undertaken to understand the flexible nature of these dimers indicated that the structural differences were primarily a result of crystal packing effects with aurophillic interactions having a minimal effect.
{"title":"Molecular Flexibility in Solvated Crystals of the Dimer, Au2(μ-1,2-bis(diphenylphosphino)ethane)2I2, with Three-Coordinate Gold(I)","authors":"Sarah Costa, Michael M. Aristov, Sang Ho Lim, Sarah M. Chui, Katelyn A. Espinoza, Marilyn M. Olmstead, James C. Fettinger, John F. Berry, Alan L. Balch","doi":"10.1021/acs.inorgchem.4c00783","DOIUrl":"https://doi.org/10.1021/acs.inorgchem.4c00783","url":null,"abstract":"We report the ability to trap the dimer Au<sub>2</sub>(μ-dppe)<sub>2</sub>I<sub>2</sub> (dppe is 1,2-bis(diphenylphosphino)ethane) with different separations between the three-coordinate gold ions in crystalline solvates. All of these solvates ((Au<sub>2</sub>(μ-dppe)<sub>2</sub>I<sub>2</sub>·4(CH<sub>2</sub>Cl<sub>2</sub>) (<b>1</b>), Au<sub>2</sub>(μ-dppe)<sub>2</sub>I<sub>2</sub>·2(CH<sub>2</sub>Cl<sub>2</sub>) (<b>2</b>), the polymorphs α-Au<sub>2</sub>(μ-dppe)<sub>2</sub>I<sub>2</sub>·2(HC(O)NMe<sub>2</sub>) (<b>3</b>) and β-Au<sub>2</sub>(μ-dppe)<sub>2</sub>I<sub>2</sub>·2(HC(O)NMe<sub>2</sub>) (<b>4</b>), and Au<sub>2</sub>(μ-dppe)<sub>2</sub>I<sub>2</sub>·4(CHCl<sub>3</sub>) (<b>5</b>)) along with polymeric {Au(μ-dppe)I}<i><sub>n</sub></i>·<i>n</i>(CHCl<sub>3</sub>) (<b>6</b>)) originated from the same reaction, only the solvent system used for crystallization differed. In the different solvates of Au<sub>2</sub>(μ-dppe)<sub>2</sub>I<sub>2</sub>, the Au···Au separation varied from 3.192(1) to 3.7866(3) Å. Computational studies undertaken to understand the flexible nature of these dimers indicated that the structural differences were primarily a result of crystal packing effects with aurophillic interactions having a minimal effect.","PeriodicalId":40,"journal":{"name":"Inorganic Chemistry","volume":null,"pages":null},"PeriodicalIF":4.6,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141489812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
2,2'-Bipyridyl (bpy) is widely used as a chelating unit for metal complexation but is not usually considered as a hydrogen-bonding unit. This is because the metal-free bpy units are usually in a transoid conformation, and the two nitrogen lone pairs are pointed to the opposite sides. We now report a metallomacrocycle whose three metal-free bpy units are in a cisoid conformation and are fixed in the cavity. The complexation of nickel(II) only at the salen units of the triangular bpytrisalen ligand produced this rigid and planar macrocycle. Its cavity is surrounded by hydrogen-bond acceptors (N of bpy and O of salen), and it was found that unique pentagonal prism clusters of water molecules templated by the cavity were formed in the crystal. This study has not only increased the variation of the synthetic methodologies of multinuclear complexes but has also provided the structural platform on which multiple bpy units exert hydrogen-bonding functions.
{"title":"Formation of a Metallomacrocycle Possessing Nitrogen Donors Assembled in the Cavity and Unique Water Clusters.","authors":"Takashi Nakamura, Syuhei Yano, Yi-Fu Liu, Tatsuya Nabeshima","doi":"10.1021/acs.inorgchem.4c01542","DOIUrl":"https://doi.org/10.1021/acs.inorgchem.4c01542","url":null,"abstract":"<p><p>2,2'-Bipyridyl (bpy) is widely used as a chelating unit for metal complexation but is not usually considered as a hydrogen-bonding unit. This is because the metal-free bpy units are usually in a transoid conformation, and the two nitrogen lone pairs are pointed to the opposite sides. We now report a metallomacrocycle whose three metal-free bpy units are in a cisoid conformation and are fixed in the cavity. The complexation of nickel(II) only at the salen units of the triangular bpytrisalen ligand produced this rigid and planar macrocycle. Its cavity is surrounded by hydrogen-bond acceptors (N of bpy and O of salen), and it was found that unique pentagonal prism clusters of water molecules templated by the cavity were formed in the crystal. This study has not only increased the variation of the synthetic methodologies of multinuclear complexes but has also provided the structural platform on which multiple bpy units exert hydrogen-bonding functions.</p>","PeriodicalId":40,"journal":{"name":"Inorganic Chemistry","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141475388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1021/acs.inorgchem.4c02313
Li Xiong, Mingwei Xu, Jin Wang, Zhihao Chen, Luoning Li, Fa Yang, Qiaowen Zhang, Guocan Jiang, Zhengquan Li
In recent years, halide perovskites have attracted considerable attention for photocatalytic CO2 reduction. However, the presence of surface defects and the lack of specific catalytic sites for CO2 reduction lead to low photocatalytic performance. In this study, we demonstrate a facile method that post-treats CsPbBr3 with ZnBr2 for photocatalytic CO2 reduction. Our experimental and characterization results show that ZnBr2 has a dual role: the Br- ions in ZnBr2 passivate Br vacancies (VBr) on the CsPbBr3 surface, while Zn2+ cations act as catalytic sites for CO2 reduction. The ZnBr2-CsPbBr3 achieves a photocatalytic CO evolution rate of 57 μmol g-1 h-1, which is nearly three times higher than that of the pristine CsPbBr3. The enhanced performance over ZnBr2-CsPbBr3 is mainly due to the decreased VBr and lower reaction energy barrier for CO2 reduction. This work presents an effective method to simultaneously passivate surface defects and introduce catalytic sites, providing useful guidance for the regulation of perovskite photoelectric properties and the design of efficient photocatalysts.
{"title":"Passivating Defects and Constructing Catalytic Sites on CsPbBr<sub>3</sub> with ZnBr<sub>2</sub> for Photocatalytic CO<sub>2</sub> Reduction.","authors":"Li Xiong, Mingwei Xu, Jin Wang, Zhihao Chen, Luoning Li, Fa Yang, Qiaowen Zhang, Guocan Jiang, Zhengquan Li","doi":"10.1021/acs.inorgchem.4c02313","DOIUrl":"https://doi.org/10.1021/acs.inorgchem.4c02313","url":null,"abstract":"<p><p>In recent years, halide perovskites have attracted considerable attention for photocatalytic CO<sub>2</sub> reduction. However, the presence of surface defects and the lack of specific catalytic sites for CO<sub>2</sub> reduction lead to low photocatalytic performance. In this study, we demonstrate a facile method that post-treats CsPbBr<sub>3</sub> with ZnBr<sub>2</sub> for photocatalytic CO<sub>2</sub> reduction. Our experimental and characterization results show that ZnBr<sub>2</sub> has a dual role: the Br<sup>-</sup> ions in ZnBr<sub>2</sub> passivate Br vacancies (V<sub>Br</sub>) on the CsPbBr<sub>3</sub> surface, while Zn<sup>2+</sup> cations act as catalytic sites for CO<sub>2</sub> reduction. The ZnBr<sub>2</sub>-CsPbBr<sub>3</sub> achieves a photocatalytic CO evolution rate of 57 μmol g<sup>-1</sup> h<sup>-1</sup>, which is nearly three times higher than that of the pristine CsPbBr<sub>3</sub>. The enhanced performance over ZnBr<sub>2</sub>-CsPbBr<sub>3</sub> is mainly due to the decreased V<sub>Br</sub> and lower reaction energy barrier for CO<sub>2</sub> reduction. This work presents an effective method to simultaneously passivate surface defects and introduce catalytic sites, providing useful guidance for the regulation of perovskite photoelectric properties and the design of efficient photocatalysts.</p>","PeriodicalId":40,"journal":{"name":"Inorganic Chemistry","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141464253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Actinide +IV complexes with six nitrates [AnIV(NO3)6]2- (An = Th, U, Np, and Pu) have been studied by 15N and 17O NMR spectroscopy in solution and first-principles calculations. Magnetic susceptibilities were evaluated experimentally using the Evans method and are in good agreement with the ab initio values. The evolution in the series of the crystal field parameters deduced from ab initio calculations is discussed. The NMR paramagnetic shifts are analyzed based on ab initio calculations. Because the cubic symmetry of the complex quenches the dipolar contribution, they are only of Fermi contact origin. They are evaluated from first-principles based on a complete active space/density functional theory (DFT) strategy, in good accordance with the experimental one. The ligand hyperfine coupling constants are deduced from paramagnetic shifts and calculated using unrestricted DFT. The latter are decomposed in terms of the contribution of molecular orbitals. It highlights two pathways for the delocalization of the spin density from the metallic open-shell 5f orbitals to the NMR active nuclei, either through the valence 5f hybridized with 6d to the valence 2p molecular orbitals of the ligands, or by spin polarization of the metallic 6p orbitals which interact with the 2s-based molecular orbitals of the ligands.
通过溶液中的 15N 和 17O NMR 光谱以及第一原理计算,研究了含有六种硝酸盐 [AnIV(NO3)6]2-(An = Th、U、Np 和 Pu)的锕系元素 +IV 复合物。使用埃文斯方法对磁感应强度进行了实验评估,结果与原子弹初始值十分吻合。讨论了根据 ab initio 计算推导出的一系列晶体场参数的演变。根据 ab initio 计算分析了 NMR 顺磁位移。由于复合物的立方对称性淬灭了双极性贡献,因此它们只源于费米接触。它们是根据完整的活性空间/密度泛函理论(DFT)策略从第一原理上进行评估的,与实验结果十分吻合。配体超正弦耦合常数是通过顺磁偏移推导出来的,并使用非限制性 DFT 进行计算。后者根据分子轨道的贡献进行分解。它强调了自旋密度从金属开壳 5f 轨道向核磁共振活性核脱位的两种途径,一种是通过价 5f 与配体的价 2p 分子轨道的 6d 杂化,另一种是通过与配体的 2s 基分子轨道相互作用的金属 6p 轨道的自旋极化。
{"title":"Paramagnetic Properties of [An<sup>IV</sup>(NO<sub>3</sub>)<sub>6</sub>]<sup>2-</sup> Complexes (An = U, Np, Pu) Probed by NMR Spectroscopy and Quantum Chemical Calculations.","authors":"Matthieu Autillo, Marie-Claire Illy, Luca Briscese, Md Ashraful Islam, Hélène Bolvin, Claude Berthon","doi":"10.1021/acs.inorgchem.4c01694","DOIUrl":"https://doi.org/10.1021/acs.inorgchem.4c01694","url":null,"abstract":"<p><p>Actinide +IV complexes with six nitrates [An<sup>IV</sup>(NO<sub>3</sub>)<sub>6</sub>]<sup>2-</sup> (An = Th, U, Np, and Pu) have been studied by <sup>15</sup>N and <sup>17</sup>O NMR spectroscopy in solution and first-principles calculations. Magnetic susceptibilities were evaluated experimentally using the Evans method and are in good agreement with the ab initio values. The evolution in the series of the crystal field parameters deduced from ab initio calculations is discussed. The NMR paramagnetic shifts are analyzed based on ab initio calculations. Because the cubic symmetry of the complex quenches the dipolar contribution, they are only of Fermi contact origin. They are evaluated from first-principles based on a complete active space/density functional theory (DFT) strategy, in good accordance with the experimental one. The ligand hyperfine coupling constants are deduced from paramagnetic shifts and calculated using unrestricted DFT. The latter are decomposed in terms of the contribution of molecular orbitals. It highlights two pathways for the delocalization of the spin density from the metallic open-shell 5f orbitals to the NMR active nuclei, either through the valence 5f hybridized with 6d to the valence 2p molecular orbitals of the ligands, or by spin polarization of the metallic 6p orbitals which interact with the 2s-based molecular orbitals of the ligands.</p>","PeriodicalId":40,"journal":{"name":"Inorganic Chemistry","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141475389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1021/acs.inorgchem.4c01219
Xuyang Yan, Wentao Chen, Wang Xie, Xiuling Wang, Yat-Ming So, Xiaochao Shi
We have synthesized a series of binuclear rare-earth metal complexes bearing the newly designed enamino-oxazolinate ligands that feature bridging para-phenyl, meta-phenyl, 1,5-naphthalenyl, and 1,5-naphthalenyl moieties. NMR and X-ray diffraction analyses confirmed the binuclear structures of the obtained complexes with two enamino-oxazolinate-metal units located at a trans position against the bridged aryl plane. After activation by [Ph3C][B(C6F5)4], all the rare-earth metal complexes served as efficient catalysts for isoprene polymerization, producing polymers with high cis-1,4 regularity (up to 96.1%) and high molecular weight. The steric and electronic effects exerted on the active metal centers, as well as the radius of metal centers, were the major contributing factors for determining both the catalytic activity and cis-1,4-selectivity of the binuclear catalytic systems. Compared to its mononuclear analogue, the binuclear yttrium catalytic system with a para-phenyl bridge exhibited a higher thermostability and catalytic efficiency during polymerization, revealing a special binuclear effect in this binuclear catalytic system.
我们合成了一系列双核稀土金属配合物,这些配合物含有新设计的烯酰胺恶唑酸配体,具有桥接对位苯基、偏苯基、1,5-萘基和 1,5-萘基等分子。核磁共振和 X 射线衍射分析证实了所获复合物的双核结构,其中两个烯氨基恶唑金属单元位于桥接芳基平面的反式位置。经 [Ph3C][B(C6F5)4] 活化后,所有稀土金属配合物均可作为异戊二烯聚合的高效催化剂,生成具有高顺式-1,4 规则性(高达 96.1%)和高分子量的聚合物。活性金属中心的立体效应和电子效应以及金属中心的半径是决定双核催化体系的催化活性和顺式-1,4 选择性的主要因素。与单核类似物相比,具有对位苯桥的双核钇催化体系在聚合过程中表现出更高的热稳定性和催化效率,揭示了该双核催化体系中的特殊双核效应。
{"title":"Binuclear Enamino-Oxazolinate Rare-Earth Metal Complexes: Synthesis and Their Catalytic Performance in Isoprene Polymerization.","authors":"Xuyang Yan, Wentao Chen, Wang Xie, Xiuling Wang, Yat-Ming So, Xiaochao Shi","doi":"10.1021/acs.inorgchem.4c01219","DOIUrl":"https://doi.org/10.1021/acs.inorgchem.4c01219","url":null,"abstract":"<p><p>We have synthesized a series of binuclear rare-earth metal complexes bearing the newly designed enamino-oxazolinate ligands that feature bridging <i>para</i>-phenyl, <i>meta</i>-phenyl, 1,5-naphthalenyl, and 1,5-naphthalenyl moieties. NMR and X-ray diffraction analyses confirmed the binuclear structures of the obtained complexes with two enamino-oxazolinate-metal units located at a <i>trans</i> position against the bridged aryl plane. After activation by [Ph<sub>3</sub>C][B(C<sub>6</sub>F<sub>5</sub>)<sub>4</sub>], all the rare-earth metal complexes served as efficient catalysts for isoprene polymerization, producing polymers with high <i>cis-</i>1,4 regularity (up to 96.1%) and high molecular weight. The steric and electronic effects exerted on the active metal centers, as well as the radius of metal centers, were the major contributing factors for determining both the catalytic activity and <i>cis-</i>1,4-selectivity of the binuclear catalytic systems. Compared to its mononuclear analogue, the binuclear yttrium catalytic system with a <i>para</i>-phenyl bridge exhibited a higher thermostability and catalytic efficiency during polymerization, revealing a special binuclear effect in this binuclear catalytic system.</p>","PeriodicalId":40,"journal":{"name":"Inorganic Chemistry","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141464249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1021/acs.inorgchem.4c01309
Joshua R Dunbar, Mark P Jensen
The effects of simulated radiolytic degradation of tri-n-butyl phosphate (TBP) on the chemical speciation of cerium were studied by spectrophotometry and electrochemistry of TBP solutions containing increasing amounts of di-n-butyl phosphoric acid (HDBP), a common degradation product of TBP. Tetravalent cerium was found to exchange coordinated nitrate for the dibutyl phosphate anion, forming dinuclear complexes of the formula (CeOCe)(NO3)(6-d)(DBP)d·3TBP (d = 0-3). Compared to Ce(IV), Ce(III) was complexed less strongly by HDBP in TBP, but HDBP displaced both nitrate and TBP to form the series of mononuclear complexes Ce(NO3)(3-d)(HDBP·DBP)d·(3-d)TBP (d = 0-3). Dibutyl phosphate coordination caused large negative shifts in the Ce(IV/III) reduction potential in TBP, indicating a strong stabilization of the tetravalent state. Electrochemical investigation of the reduction of Ce(IV) in TBP revealed it to be a two-electron process in accordance with the dinuclear nature of the organic-phase Ce(IV) complexes. The diffusion coefficients of the d = 0 dinuclear Ce(IV)-nitrate-TBP complex and mononuclear Ce(III)-nitrate-TBP complex in TBP equilibrated with 7 M HNO3 were determined to be (1.16 ± 0.06) × 10-7 cm2/s and (1.9 ± 0.4) × 10-7 cm2/s, respectively, which also is consistent with the larger molecular volume of the dinuclear Ce(IV) complexes.
{"title":"Influence of Di-<i>n</i>-butyl Phosphoric Acid on Cerium Redox and Speciation in Tri-<i>n</i>-butyl Phosphate.","authors":"Joshua R Dunbar, Mark P Jensen","doi":"10.1021/acs.inorgchem.4c01309","DOIUrl":"https://doi.org/10.1021/acs.inorgchem.4c01309","url":null,"abstract":"<p><p>The effects of simulated radiolytic degradation of tri-<i>n-</i>butyl phosphate (TBP) on the chemical speciation of cerium were studied by spectrophotometry and electrochemistry of TBP solutions containing increasing amounts of di-<i>n</i>-butyl phosphoric acid (HDBP), a common degradation product of TBP. Tetravalent cerium was found to exchange coordinated nitrate for the dibutyl phosphate anion, forming dinuclear complexes of the formula (CeOCe)(NO<sub>3</sub>)<sub>(6-<i>d</i>)</sub>(DBP)<sub><i>d</i></sub>·3TBP (<i>d</i> = 0-3). Compared to Ce(IV), Ce(III) was complexed less strongly by HDBP in TBP, but HDBP displaced both nitrate and TBP to form the series of mononuclear complexes Ce(NO<sub>3</sub>)<sub>(3-<i>d</i>)</sub>(HDBP·DBP)<sub><i>d</i></sub>·(3-<i>d</i>)TBP (<i>d</i> = 0-3). Dibutyl phosphate coordination caused large negative shifts in the Ce(IV/III) reduction potential in TBP, indicating a strong stabilization of the tetravalent state. Electrochemical investigation of the reduction of Ce(IV) in TBP revealed it to be a two-electron process in accordance with the dinuclear nature of the organic-phase Ce(IV) complexes. The diffusion coefficients of the <i>d</i> = 0 dinuclear Ce(IV)-nitrate-TBP complex and mononuclear Ce(III)-nitrate-TBP complex in TBP equilibrated with 7 M HNO<sub>3</sub> were determined to be (1.16 ± 0.06) × 10<sup>-7</sup> cm<sup>2</sup>/s and (1.9 ± 0.4) × 10<sup>-7</sup> cm<sup>2</sup>/s, respectively, which also is consistent with the larger molecular volume of the dinuclear Ce(IV) complexes.</p>","PeriodicalId":40,"journal":{"name":"Inorganic Chemistry","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141464252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Piscidins, antimicrobial peptides isolated from fish, are potent against a variety of human pathogens; they show minimum inhibitory concentration values comparable to those of commercially used antimicrobials. Piscidins 1 and 2 are generally more effective than piscidin 3 when applied alone; the contrary is observed for their metal complexes: Zn(II) and Cu(II) coordination does not enhance the efficacy of piscidins 1 and 2, while a moderate enhancement is observed for piscidin 3. All three piscidins bind Cu(II) in a so-called albumin-like binding mode, while for Zn(II) complexes, two coordination modes are observed: piscidins 1 and 2 bind Zn(II) by imidazole nitrogens from His4, His11, and His17 side chains; piscidin 3 coordinates Zn(II) by His3, His4, and His11 imidazole nitrogens and additionally supports the interaction, formed by carbonyl oxygen from His4. Most likely, the high antimicrobial activity of piscidin complexes is due to neither the stability of their complexes nor the change in their secondary structure. Copper(II) complexes with piscidins 1 and 2 can form hydroxyl radicals, which could be responsible for the antimicrobial membrane damaging activity of these complexes. Clearly, a different mechanism (most likely an intercellular targeted one) is observed for piscidin 3 metal complexes; in most cases, the coordination of Cu(II) and Zn(II) enhances the antimicrobial potency of piscidin 3, showing that not only piscidin 3 alone but also its metal complexes have a different mode of action than piscidins 1 and 2.
{"title":"Zn(II) and Cu(II) Coordination Enhances the Antimicrobial Activity of Piscidin 3, but Not That of Piscidins 1 and 2.","authors":"Miller Adriana, Mikołajczyk Aleksandra, Bellotti Denise, Garstka Kinga, Wątły Joanna, Hecel Aleksandra, Wieczorek Robert, Matera-Witkiewicz Agnieszka, Rowińska-Żyrek Magdalena","doi":"10.1021/acs.inorgchem.4c01659","DOIUrl":"https://doi.org/10.1021/acs.inorgchem.4c01659","url":null,"abstract":"<p><p>Piscidins, antimicrobial peptides isolated from fish, are potent against a variety of human pathogens; they show minimum inhibitory concentration values comparable to those of commercially used antimicrobials. Piscidins 1 and 2 are generally more effective than piscidin 3 when applied alone; the contrary is observed for their metal complexes: Zn(II) and Cu(II) coordination does not enhance the efficacy of piscidins 1 and 2, while a moderate enhancement is observed for piscidin 3. All three piscidins bind Cu(II) in a so-called albumin-like binding mode, while for Zn(II) complexes, two coordination modes are observed: piscidins 1 and 2 bind Zn(II) by imidazole nitrogens from His4, His11, and His17 side chains; piscidin 3 coordinates Zn(II) by His3, His4, and His11 imidazole nitrogens and additionally supports the interaction, formed by carbonyl oxygen from His4. Most likely, the high antimicrobial activity of piscidin complexes is due to neither the stability of their complexes nor the change in their secondary structure. Copper(II) complexes with piscidins 1 and 2 can form hydroxyl radicals, which could be responsible for the antimicrobial membrane damaging activity of these complexes. Clearly, a different mechanism (most likely an intercellular targeted one) is observed for piscidin 3 metal complexes; in most cases, the coordination of Cu(II) and Zn(II) enhances the antimicrobial potency of piscidin 3, showing that not only piscidin 3 alone but also its metal complexes have a different mode of action than piscidins 1 and 2.</p>","PeriodicalId":40,"journal":{"name":"Inorganic Chemistry","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141464267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.1021/acs.inorgchem.4c01715
Alessandro Nucera, Maria Ludovica Macchia, Zsolt Baranyai, Fabio Carniato, Lorenzo Tei, Mauro Ravera, Mauro Botta
In recent years, the coordination chemistry of high-spin Fe(III) complexes has increasingly attracted interest due to their potential as effective alternatives to Gd(III)-based MRI contrast agents. This paper discusses the results from our study on Fe(III) complexes with two EDTA derivatives, each modified with either one (EDTA-BOM) or two (EDTA-BOM2) benzyloxymethylene (BOM) groups on the acetic arm(s). These pendant hydrophobic groups enable the complexes to form noncovalent adducts with human serum albumin (HSA), leading to an observed increase in relaxivity due to the reduction in molecular tumbling. Our research involved detailed relaxometric measurements and analyses of both 1H and 17O NMR data at varying temperatures and magnetic field strengths, which is conducted with and without the presence of a protein. A significant finding of this study is the effect of electronic relaxation time on the effectiveness of [Fe(EDTA-BOM)(H2O)]- and [Fe(EDTA-BOM2)(H2O)]- as diagnostic MRI probes. By integrating these relaxometric results with comprehensive thermodynamic, kinetic, and electrochemical data, we have thoroughly characterized how structural modifications to the EDTA base ligand influence the properties of the complexes.
{"title":"Comprehensive Investigation of [Fe(EDTA)]<sup>-</sup>-Functionalized Derivatives and their Supramolecular Adducts with Human Serum Albumin.","authors":"Alessandro Nucera, Maria Ludovica Macchia, Zsolt Baranyai, Fabio Carniato, Lorenzo Tei, Mauro Ravera, Mauro Botta","doi":"10.1021/acs.inorgchem.4c01715","DOIUrl":"https://doi.org/10.1021/acs.inorgchem.4c01715","url":null,"abstract":"<p><p>In recent years, the coordination chemistry of high-spin Fe(III) complexes has increasingly attracted interest due to their potential as effective alternatives to Gd(III)-based MRI contrast agents. This paper discusses the results from our study on Fe(III) complexes with two EDTA derivatives, each modified with either one (EDTA-BOM) or two (EDTA-BOM<sub>2</sub>) benzyloxymethylene (BOM) groups on the acetic arm(s). These pendant hydrophobic groups enable the complexes to form noncovalent adducts with human serum albumin (HSA), leading to an observed increase in relaxivity due to the reduction in molecular tumbling. Our research involved detailed relaxometric measurements and analyses of both <sup>1</sup>H and <sup>17</sup>O NMR data at varying temperatures and magnetic field strengths, which is conducted with and without the presence of a protein. A significant finding of this study is the effect of electronic relaxation time on the effectiveness of [Fe(EDTA-BOM)(H<sub>2</sub>O)]<sup>-</sup> and [Fe(EDTA-BOM<sub>2</sub>)(H<sub>2</sub>O)]<sup>-</sup> as diagnostic MRI probes. By integrating these relaxometric results with comprehensive thermodynamic, kinetic, and electrochemical data, we have thoroughly characterized how structural modifications to the EDTA base ligand influence the properties of the complexes.</p>","PeriodicalId":40,"journal":{"name":"Inorganic Chemistry","volume":null,"pages":null},"PeriodicalIF":4.3,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141464250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}