Progresses of Ring Expansion Reaction of Small Transitional Metallacyclic Compounds

过渡金属杂环化合物特别是过渡金属杂小环化合物(成环原子数小于6)在金属有机化学和配位化学领域中具有重要的地位,它们是许多过渡金属催化反应包括烯烃复分解反应、炔烃聚合反应的中间体.通常过渡金属杂小环化合物具有较大的环张力,因此极易与不饱和化合物反应生成环张力较小的扩环产物.针对过渡金属杂小环化学研究现状,综述了几类典型的过渡金属杂三、四、五元环的扩环反应.Metallacycles, especially those small rings, play an important role in the field of organometallic and coordination chemistry.They are considered as reactive intermediates in metal promoted or catalyzed reactions including olefin metathesis reactions and alkyne polymerization reactions.Due to the high ring strain, small metallacycles can easily react with unsaturated compounds to produce ring expansion products with lower ring strain.To further understand the importance of small metallacycle intermediates in the catalytic reactions and synthesis methodology, the ring expansion reactions of several typical three-, four- and five-membered metallacycles is summarize.国家自然科学基金(No.21272193); 福建省自然科学基金(No.2011J05031)资助项目~

Constraint of a ruthenium-carbon triple bond to a five-membered ring

含过渡金属碳三键(M≡C)的金属卡拜化合物是许多有机反应的催化剂或关键中间体。对其合成及性质的研究是金属有机化学的热点之一。由于卡拜碳的sp杂化方式，大部分金属卡拜化合物均为链状结构（卡拜碳键角理想值为180 °），环内金属卡拜化合物因存在很大的环张力而难于合成。夏海平教授课题组发展了由链状多炔（称之为碳龙）构筑碳龙配合物的高效方法（Nature Communications, 2017, 8, 1912），实现了锇杂戊搭炔/烯及其衍生物的一锅法合成。现在，他们把该方法进一步拓展到了第二过渡系金属钌，通过碳龙与市售的RuCl2(PPh3)3反应一锅合成了钌杂戊搭炔I。本研究是碳龙化学的进一步延伸和发展，首次把碳龙化学的金属中心由锇拓展到了其它金属，展示了碳龙化学广阔的发展空间。该研究工作在夏海平教授指导下完成，能源材料化学协同创新中心（iChEM）博士后卓庆德和张弘副教授为共同第一作者。iChEM博士后周小茜、博士生陈志昕、林剑锋、卓凯玥、硕士康慧君、林鑫磊参与了部分实验工作。博士生华煜晖负责理论计算。【Abstract】The incorporation of a metal-carbon triple bond into a ring system is challenging because of the linear nature of triple bonds. To date, the synthesis of these complexes has been limited to those containing third-row transition metal centers, namely, osmium and rhenium. We report the synthesis and full characterization of the first cyclic metal carbyne complex with a second-row transition metal center, ruthenapentalyne. It shows a bond angle of 130.2(3)° around the sp-hybridized carbyne carbon, which represents the recorded smallest angle of second-row transition metal carbyne complexes, as it deviates nearly 50° from the original angle (180°). Density functional theory calculations suggest that the inherent aromatic nature of these metallacycles with bent Ru≡C–C moieties enhances their stability. Reactivity studies showed striking observations, such as ambiphilic reactivity, a metal-carbon triple bond shift, and a [2 + 2] cycloaddition reaction with alkyne and cascade cyclization reactions with ambident nucleophiles.This research was supported by the National Key R&D Program of China (2017YFA0204902) and the National Natural Science Foundation of China (nos. 21490573,21332002, and 21561162001). 研究工作得到国家自然科学基金项目（21490573、21332002 和21561162001）和国家重点研发计划（2017YFA0204902）的资助

Successive modification of polydentate complexes gives access to planar carbon-and nitrogen-based ligands

以碳和氮为键合原子的多齿螯合物是配合物家族中非常重要的一类。具有更高齿数的平面构型NC螯合物实例相对较少，代表性的例子为四齿金属碳卟啉类化合物，这类螯合物以其独特的结构和丰富的物理化学性质引起广泛关注。然而平面五齿、六齿的NC螯合物由于几何构型“拥挤”导致合成难度高，该工作从含三元环内金属卡宾结构的CCCC型碳龙配合物出发，利用经典有机反应（炔烃对金属卡宾的插入反应），成功地实现了CCCCN/NCCCN型平面五齿螯合物的合成。这一研究为高配位型螯合物的合成提供了新思路并为平面五齿螯合物家族添加新成员。特别是，这些高配位型螯合物在可见光和近红外区域均有较好的吸收，表现出良好的光声成像、光热转换及声动力学性能。 该研究工作在张弘教授指导下完成，第一作者为iChEM博士后周小茜。该工作充分体现了多学科协同研究优势：相关化合物的合成、表征及理论计算工作由周小茜博士完成；声动力学性能研究由厦门大学公共卫生学院庞鑫博士及刘刚教授完成；光声成像研究由厦门大学公共卫生学院聂立铭教授完成。iChEM fellow卓庆德博士、博士生卓凯玥、陈志昕参与了部分实验工作。夏海平教授、香港科技大学林振阳教授和南京大学朱从青教授对研究工作给予了大力支持。【Abstract】Polydentate complexes containing combinations of nitrogen and carbon (N and C) ligating atoms are among the most fundamental and ubiquitous molecules in coordination chemistry, yet the formation of such complexes with planar high-coordinate N/C sites remains challenging. Herein, we demonstrate an efficient route to access related complexes with tetradentate CCCN and pentadentate CCCCN and NCCCN cores by successive modification of the coordinating atoms in complexes with a CCCC core. Combined experimental and computational studies reveal that the rich reactivity of metal-carbon bonds and the inherent aromaticity of the metallacyclic skeletons play key roles in these transformations. This strategy addresses the paucity of synthetic approaches to mixed N/C planar pentadentate chelating species and provides valuable insights into the synthesis of carbon-based high-coordinate complexes. Furthermore, the resulting complexes are the examples of organometallic species with combined photoacoustic, photothermal, and sonodynamic properties, which makes them promising for application in related areas.This research was supported by the National Natural Science Foundation of China (Nos. 21572185, 21561162001, and 81571744), the Research Grants Council of Hong Kong (N_HKUST603/15), the Excellent Youth Foundation of Fujian Scientific Committee (2018J06024), and the Fundamental Research Funds for the Central Universities (20720170065).该工作得到国家自然科学基金委、香港研究资助局、福建省自然科学基金、厦门大学校长基金的资助

Multiyne chains chelating osmium via three metal-carbon σ bonds

碳是最常见的元素之一，是有机化学、金属有机化学中的最基本元素。有趣的是，尽管碳在配位化学中同样广泛存在，其很少作为配位原子，多齿配合物中的配位原子通常为N/O/P/S等杂原子；配位原子均为碳的碳多齿配合物的构筑是个挑战。尽管如此，与大多数杂原子配位多齿配合物可由多齿配体与金属原子直接螯合制备不同，此前报道的碳龙配合物只能通过金属杂环衍生化获得。最近，夏海平教授课题组提出了通过配位化学方法构筑碳龙配合物的新思路——由多齿碳链配体或配体前体直接螯合金属制备碳龙配合物。他们设计合成了一类全新的链状多炔化合物，其可在室温、空气氛下与市售金属配合物OsCl2(PPh3)3、甚至无机盐K2OsCl6反应，一锅法克级制备碳龙配合物，简化了碳龙配合物的合成路线，大大降低了碳龙化学的研究门槛。该方法具有可拓展性，通过碳龙的变化可合成结构多样的碳龙配合物，进一步丰富了碳龙配合物的种类；此外，碳龙配合物金属品种的拓展工作也正在进行中。该工作首次实现了由有机碳链直接螯合金属中心构筑三齿及三齿以上碳多齿螯合物，深化和拓展了人们对碳配位能力的认识。 该研究工作在夏海平教授指导下完成，第一作者为厦门大学化学化工学院博士后卓庆德。卓庆德，本科毕业于南昌大学，2010年考入厦门大学化学化工学院有机化学专业攻读硕士，师从夏海平教授和张弘副教授。2012年提前攻博，期间主要致力于新型金属有机化合物的合成、反应性及性能研究。2016年3月进入化学工程与技术博士后流动站从事博士后研究，合作导师夏海平教授。目前，已发表第一作者论文4篇；申请中国发明专利2项；PCT国际专利1项；并获得中国博士后科学基金（60批）的资助。【Abstract】Although the formation of metal–carbon σ bonds is a fundamental principle in organometallic chemistry, the direct bonding of one organic molecule with one metal center to generate more than two metal–carbon σ bonds remains a challenge. Herein, we report an aromaticity-driven method whereby multiyne chains are used to construct three metal–carbon σ bonds in a one-pot reaction under mild conditions. In this method, multiyne chains act as ligand precursors capable of chelating an osmium center to yield planar metallapolycycles, which exhibit aromaticity and good stability. The direct assembly of various multiyne chains with commercially available metal complexes or even simple metal salts provides a convenient and efficient strategy for constructing all carbon-ligated chelates on the gram scale.This research was supported by the National Natural Science Foundation of China (Nos. 21490573 and 21332002) and Project funded by China Postdoctoral Science Foundation (No. 2016M602069). 研究工作得到国家自然科学基金重大项目（21490573 ）和重点项目（21332002），以及中国博士后科学基金（2016M602069）的资助

Determination of the number of ψ(3686) events taken at BESIII

The number of ψ(3686) events collected by the BESIII detector during the 2021 run period is determined to be (2259.3±11.1)×106 by counting inclusive ψ(3686) hadronic events. The uncertainty is systematic and the statistical uncertainty is negligible. Meanwhile, the numbers of ψ(3686) events collected during the 2009 and 2012 run periods are updated to be (107.7±0.6)×106 and (345.4±2.6)×106, respectively. Both numbers are consistent with the previous measurements within one standard deviation. The total number of ψ(3686) events in the three data samples is (2712.4±14.3)×10^

Measurement of integrated luminosity of data collected at 3.773 GeV by BESIII from 2021 to 2024

We present a measurement of the integrated luminosity e+e- of collision data collected by the BESIII detector at the BEPCII collider at a center-of-mass energy of Ecm = 3.773 GeV. The integrated luminosities of the datasets taken from December 2021 to June 2022, from November 2022 to June 2023, and from October 2023 to February 2024 were determined to be 4.995±0.019 fb-1, 8.157±0.031 fb-1, and 4.191±0.016 fb-1, respectively, by analyzing large angle Bhabha scattering events. The uncertainties are dominated by systematic effects, and the statistical uncertainties are negligible. Our results provide essential input for future analyses and precision measurements