Gan Xu, Yun-Shu Cui, Xue-Lian Jiang, Cong-Qiao Xu, Jun Li, Xu-Dong Chen
Iron-metal clusters are crucial in a variety of critical biological and material systems, including metalloenzymes, catalysts, and magnetic storage devices. However, synthetic high-nuclear iron cluster has been absent due to the extreme difficulty in stabilizing species with direct iron-iron bonding. In this work, we have synthesized, crystallized, and characterized a (Tp*)4W4S12(Fe@Fe12) cluster (Tp* = tris(3,5-dimethyl-1-pyrazolyl)borate(1−)), which features a rare trideca-nuclear, icosahedral [Fe@Fe12] cluster core with direct multicenter iron-iron bonding between the interstitial iron (Fei) and peripheral irons (Fep), as well as Fep···Fep ferromagnetic coupling. Quantum chemistry studies reveal that the stability of the cluster arises from the 18-electron shell-closing of the [Fe@Fe12]16+ core, assisted by its bonding interactions with the peripheral tridentate [(Tp*)WS3]4− ligands which possess both the S→Fe donation and spin-polarized Fe-W σ bonds. The ground-state electron spin is theoretically predicted to be S = 32/2 for the cluster. The existence of low oxidation-state (OS ∼ +1.23) iron in this compound may find interesting applications in magnetic storage, spintronics, redox chemistry, and cluster catalysis.
{"title":"Synthesis and Characterization of Iron Clusters with an Icosahedral [Fe@Fe12]16+ Core","authors":"Gan Xu, Yun-Shu Cui, Xue-Lian Jiang, Cong-Qiao Xu, Jun Li, Xu-Dong Chen","doi":"10.1093/nsr/nwad327","DOIUrl":"https://doi.org/10.1093/nsr/nwad327","url":null,"abstract":"Iron-metal clusters are crucial in a variety of critical biological and material systems, including metalloenzymes, catalysts, and magnetic storage devices. However, synthetic high-nuclear iron cluster has been absent due to the extreme difficulty in stabilizing species with direct iron-iron bonding. In this work, we have synthesized, crystallized, and characterized a (Tp*)4W4S12(Fe@Fe12) cluster (Tp* = tris(3,5-dimethyl-1-pyrazolyl)borate(1−)), which features a rare trideca-nuclear, icosahedral [Fe@Fe12] cluster core with direct multicenter iron-iron bonding between the interstitial iron (Fei) and peripheral irons (Fep), as well as Fep···Fep ferromagnetic coupling. Quantum chemistry studies reveal that the stability of the cluster arises from the 18-electron shell-closing of the [Fe@Fe12]16+ core, assisted by its bonding interactions with the peripheral tridentate [(Tp*)WS3]4− ligands which possess both the S→Fe donation and spin-polarized Fe-W σ bonds. The ground-state electron spin is theoretically predicted to be S = 32/2 for the cluster. The existence of low oxidation-state (OS ∼ +1.23) iron in this compound may find interesting applications in magnetic storage, spintronics, redox chemistry, and cluster catalysis.","PeriodicalId":18842,"journal":{"name":"National Science Review","volume":"1 1","pages":""},"PeriodicalIF":20.6,"publicationDate":"2023-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139054665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qirong Liu, Lei Liu, Yongping Zheng, Min Li, Baofu Ding, Xungang Diao, Hui-Ming Cheng, Yongbing Tang
Tunability of optical performance is one of key technology for adaptive optoelectronic applications, such as camouflage clothing, displays, and infrared shielding. High-precision spectral tunability is of great importance for some special applications with on-demand adaptability but remains challenging. Here we demonstrate a galvanostatic control strategy to achieve the goal, relying on the finding of the quantitative correlation between optical properties and electrochemical reactions within materials. An electrochromic electro-optical efficiency index is established to optically fingerprint and precisely identify electrochemical redox reactions in the electrochromic device. Consequently, the charge-transfer process during galvanostatic electrochemical reaction can be quantitatively regulated, permitting precise control over the final optical performance and on-demand adaptability of electrochromic devices as evidenced by an ultralow deviation of < 3.0%. These findings not only provide opportunities for future adaptive optoelectronic applications with strict demand on precise spectral tunability but also will promote in situ quantitative research in a wide range of spectroelectrochemistry, electrochemical energy storage, electrocatalysis, and material chemistry.
{"title":"On-demand engineerable visible spectrum by fine control of electrochemical reactions","authors":"Qirong Liu, Lei Liu, Yongping Zheng, Min Li, Baofu Ding, Xungang Diao, Hui-Ming Cheng, Yongbing Tang","doi":"10.1093/nsr/nwad323","DOIUrl":"https://doi.org/10.1093/nsr/nwad323","url":null,"abstract":"Tunability of optical performance is one of key technology for adaptive optoelectronic applications, such as camouflage clothing, displays, and infrared shielding. High-precision spectral tunability is of great importance for some special applications with on-demand adaptability but remains challenging. Here we demonstrate a galvanostatic control strategy to achieve the goal, relying on the finding of the quantitative correlation between optical properties and electrochemical reactions within materials. An electrochromic electro-optical efficiency index is established to optically fingerprint and precisely identify electrochemical redox reactions in the electrochromic device. Consequently, the charge-transfer process during galvanostatic electrochemical reaction can be quantitatively regulated, permitting precise control over the final optical performance and on-demand adaptability of electrochromic devices as evidenced by an ultralow deviation of &lt; 3.0%. These findings not only provide opportunities for future adaptive optoelectronic applications with strict demand on precise spectral tunability but also will promote in situ quantitative research in a wide range of spectroelectrochemistry, electrochemical energy storage, electrocatalysis, and material chemistry.","PeriodicalId":18842,"journal":{"name":"National Science Review","volume":"9 1","pages":""},"PeriodicalIF":20.6,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138825957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Iron catalysts are ideal transition metal catalysts because of the Earth abundant, cheap, biocompatible features of the iron salts. Iron catalysts often have unique open-shell structures that easily undergo spin crossover in chemical transformations, a feature rarely found in noble metal catalysts. Unfortunately, little is known currently about how the open-shell structure and spin crossover affect the reactivity and selectivity of iron catalysts, which makes the development of iron catalysts a low efficient trial-and-error program. In this paper, a combination of experiments and theoretical calculations revealed that the iron-catalyzed hydrosilylation of alkynes is typical spin-crossover catalysis. Deep insight into the electronic structures of a set of well-defined open-shell active formal Fe(0) catalysts revealed that the spin-delocalization between the iron center and the 1,10-phenanthroline ligand effectively regulates the iron center's spin and oxidation state to meet the opposite electrostatic requirements of oxidative addition and reductive elimination, respectively, and the spin crossover is essential for this electron transfer process. The triplet transition state was essential for achieving high regioselectivity through tuning the nonbonding interactions. These findings provide an important reference for understanding the effect of catalyst spin state on reaction. It is inspiring for the development of iron catalysts and other Earth-abundant metal catalysts, especially from the point of view of ligand development.
{"title":"Spin effect on redox acceleration and regioselectivity in Fe-catalyzed alkyne hydrosilylation","authors":"Peng He, Meng-Yang Hu, Jin-Hong Li, Tian-Zhang Qiao, Yi-Lin Lu, Shou-Fei Zhu","doi":"10.1093/nsr/nwad324","DOIUrl":"https://doi.org/10.1093/nsr/nwad324","url":null,"abstract":"Iron catalysts are ideal transition metal catalysts because of the Earth abundant, cheap, biocompatible features of the iron salts. Iron catalysts often have unique open-shell structures that easily undergo spin crossover in chemical transformations, a feature rarely found in noble metal catalysts. Unfortunately, little is known currently about how the open-shell structure and spin crossover affect the reactivity and selectivity of iron catalysts, which makes the development of iron catalysts a low efficient trial-and-error program. In this paper, a combination of experiments and theoretical calculations revealed that the iron-catalyzed hydrosilylation of alkynes is typical spin-crossover catalysis. Deep insight into the electronic structures of a set of well-defined open-shell active formal Fe(0) catalysts revealed that the spin-delocalization between the iron center and the 1,10-phenanthroline ligand effectively regulates the iron center's spin and oxidation state to meet the opposite electrostatic requirements of oxidative addition and reductive elimination, respectively, and the spin crossover is essential for this electron transfer process. The triplet transition state was essential for achieving high regioselectivity through tuning the nonbonding interactions. These findings provide an important reference for understanding the effect of catalyst spin state on reaction. It is inspiring for the development of iron catalysts and other Earth-abundant metal catalysts, especially from the point of view of ligand development.","PeriodicalId":18842,"journal":{"name":"National Science Review","volume":"32 1","pages":""},"PeriodicalIF":20.6,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138825885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Deep-time mass extinction helps understand the current biotic crisis","authors":"Shucheng Xie","doi":"10.1093/nsr/nwad322","DOIUrl":"https://doi.org/10.1093/nsr/nwad322","url":null,"abstract":"","PeriodicalId":18842,"journal":{"name":"National Science Review","volume":"112 40","pages":""},"PeriodicalIF":20.6,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138958586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Late Ordovician Mass Extinction was the earliest of the ‘big’ five and the earliest to affect the trajectory of metazoan life. Two phases have been identified near the start of the Hirnantian and in the middle. It was a massive taxonomic extinction, a weak phylogenetic extinction and a relatively benign ecological extinction. A rapid cooling triggering a major ice age that reduced the temperature of surface waters, prompted a sea level drop of some 100 m and introduced toxic bottom waters onto the shelves. These symptoms of more fundamental planetary processes have been associated with a range of factors with an underlying driver identified as volcanicity. Volcanic eruptions, and other products, may have extended back in time to at least the Sandbian and early Katian suggesting the extinctions were more protracted and influential than hitherto documented.
{"title":"Late Ordovician Mass Extinction: Earth, fire and ice.","authors":"David A T Harper","doi":"10.1093/nsr/nwad319","DOIUrl":"https://doi.org/10.1093/nsr/nwad319","url":null,"abstract":"The Late Ordovician Mass Extinction was the earliest of the ‘big’ five and the earliest to affect the trajectory of metazoan life. Two phases have been identified near the start of the Hirnantian and in the middle. It was a massive taxonomic extinction, a weak phylogenetic extinction and a relatively benign ecological extinction. A rapid cooling triggering a major ice age that reduced the temperature of surface waters, prompted a sea level drop of some 100 m and introduced toxic bottom waters onto the shelves. These symptoms of more fundamental planetary processes have been associated with a range of factors with an underlying driver identified as volcanicity. Volcanic eruptions, and other products, may have extended back in time to at least the Sandbian and early Katian suggesting the extinctions were more protracted and influential than hitherto documented.","PeriodicalId":18842,"journal":{"name":"National Science Review","volume":"3 1","pages":""},"PeriodicalIF":20.6,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138818389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuhui Hua, Ming Luo, Zhengyu Lu, Hong Zhang, Dafa Chen, Haiping Xia
The σ bond is an important concept in chemistry, and the metal–carbon (M–C) σ bond in particular is a central feature in organometallic chemistry. Synthesis of stable complexes with five coplanar M–C σ bonds is challenging. Here, we describe our synthesis of two different stable types of complexes with five coplanar M–C σ bonds, and examine the stability of such complexes which use rigid conjugated carbon chains to chelate with the metal center. Density functional theory (DFT) calculations showed that the M–C σ bonds in these complexes have primarily a covalent character. Besides the σ nature, there are also π conjugation component among the metal center and carbons, which causes delocalization. This work expanded the coplanar M–C σ bonds to five.
{"title":"Experimental and theoretical evidences for the formation of transition metal complexes with five coplanar metal–carbon σ bonds","authors":"Yuhui Hua, Ming Luo, Zhengyu Lu, Hong Zhang, Dafa Chen, Haiping Xia","doi":"10.1093/nsr/nwad325","DOIUrl":"https://doi.org/10.1093/nsr/nwad325","url":null,"abstract":"The σ bond is an important concept in chemistry, and the metal–carbon (M–C) σ bond in particular is a central feature in organometallic chemistry. Synthesis of stable complexes with five coplanar M–C σ bonds is challenging. Here, we describe our synthesis of two different stable types of complexes with five coplanar M–C σ bonds, and examine the stability of such complexes which use rigid conjugated carbon chains to chelate with the metal center. Density functional theory (DFT) calculations showed that the M–C σ bonds in these complexes have primarily a covalent character. Besides the σ nature, there are also π conjugation component among the metal center and carbons, which causes delocalization. This work expanded the coplanar M–C σ bonds to five.","PeriodicalId":18842,"journal":{"name":"National Science Review","volume":"36 7 1","pages":""},"PeriodicalIF":20.6,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138825889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Highly accurate potential energy surfaces are critically important for chemical reaction dynamics. The large number of degrees of freedom and the intricate symmetry adaption pose a big challenge to accurately representing potential energy surfaces (PESs) for polyatomic reactions. Recently, our group has made substantial progress in this direction by developing the fundamental invariant-neural network (FI-NN) approach. Here, we review these advances, demonstrating that the FI-NN approach can represent highly accurate, global, full-dimensional PESs for reactive systems with even more than 10 atoms. These multi-channel reactions typically involve many intermediates, transition states, and products. The complexity and ruggedness of this potential energy landscape present even greater challenges for full-dimensional PES representation. These PESs exhibit a high level of complexity, molecular size, and accuracy of fit. Dynamics simulations based on these PESs have unveiled intriguing and novel reaction mechanisms, providing deep insights into the intricate dynamics in combustion, atmospheric, and organic chemistry.
高精度势能面对化学反应动力学至关重要。大量的自由度和错综复杂的对称性适应性对精确表示多原子反应的势能面（PES）构成了巨大挑战。最近，我们的研究小组通过开发基本无变量神经网络（FI-NN）方法，在这一方向上取得了实质性进展。在此，我们回顾了这些进展，证明 FI-NN 方法可以为原子数甚至超过 10 个的反应体系表示高精度、全局、全维的 PES。这些多通道反应通常涉及许多中间体、过渡态和产物。这种势能图的复杂性和崎岖性给全维 PES 表征带来了更大的挑战。这些 PES 在复杂性、分子大小和拟合精度方面都表现出很高的水平。基于这些 PES 的动力学模拟揭示了有趣而新颖的反应机制，为燃烧、大气和有机化学中错综复杂的动力学提供了深刻的见解。
{"title":"Accurate fundamental invariant-neural network representation of ab initio potential energy surfaces","authors":"Bina Fu, Dong H Zhang","doi":"10.1093/nsr/nwad321","DOIUrl":"https://doi.org/10.1093/nsr/nwad321","url":null,"abstract":"Highly accurate potential energy surfaces are critically important for chemical reaction dynamics. The large number of degrees of freedom and the intricate symmetry adaption pose a big challenge to accurately representing potential energy surfaces (PESs) for polyatomic reactions. Recently, our group has made substantial progress in this direction by developing the fundamental invariant-neural network (FI-NN) approach. Here, we review these advances, demonstrating that the FI-NN approach can represent highly accurate, global, full-dimensional PESs for reactive systems with even more than 10 atoms. These multi-channel reactions typically involve many intermediates, transition states, and products. The complexity and ruggedness of this potential energy landscape present even greater challenges for full-dimensional PES representation. These PESs exhibit a high level of complexity, molecular size, and accuracy of fit. Dynamics simulations based on these PESs have unveiled intriguing and novel reaction mechanisms, providing deep insights into the intricate dynamics in combustion, atmospheric, and organic chemistry.","PeriodicalId":18842,"journal":{"name":"National Science Review","volume":"12 1","pages":""},"PeriodicalIF":20.6,"publicationDate":"2023-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138825824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mario Senden, Sacha J van Albada, Giovanni Pezzulo, Egidio Falotico, Ibrahim Hashim, Alexander Kroner, Anno C Kurth, Pablo Lanillos, Vaishnavi Narayanan, Cyriel Pennartz, Mihai A Petrovici, Lea Steffen, Tonio Weidler, Rainer Goebel
This Perspective presents the Modular-Integrative Modeling approach, a novel framework in neuroscience for developing brain models that blend biological realism with functional performance to provide a holistic view on brain function in interaction with the body and environment.
{"title":"Modular-integrative modeling: A new framework for building brain models that blend biological realism and functional performance","authors":"Mario Senden, Sacha J van Albada, Giovanni Pezzulo, Egidio Falotico, Ibrahim Hashim, Alexander Kroner, Anno C Kurth, Pablo Lanillos, Vaishnavi Narayanan, Cyriel Pennartz, Mihai A Petrovici, Lea Steffen, Tonio Weidler, Rainer Goebel","doi":"10.1093/nsr/nwad318","DOIUrl":"https://doi.org/10.1093/nsr/nwad318","url":null,"abstract":"This Perspective presents the Modular-Integrative Modeling approach, a novel framework in neuroscience for developing brain models that blend biological realism with functional performance to provide a holistic view on brain function in interaction with the body and environment.","PeriodicalId":18842,"journal":{"name":"National Science Review","volume":"32 1","pages":""},"PeriodicalIF":20.6,"publicationDate":"2023-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138825936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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