Organometallics最新文献

Alternate Geometries in the Cobalt-Catalyzed Hydroacylation of Dienes Facilitate a High Spin Mechanism: A Density Functional Theory Study 钴催化的二烯烃加氢反应中的替代几何结构促进了高自旋机制：密度泛函理论研究

IF 2.8 3区化学

Organometallics Pub Date : 2024-09-20 DOI: 10.1021/acs.organomet.4c00215

Thomas E. Shoopman, Andrew T. Morehead, Jr., Andrew L. Sargent

{"title":"Alternate Geometries in the Cobalt-Catalyzed Hydroacylation of Dienes Facilitate a High Spin Mechanism: A Density Functional Theory Study","authors":"Thomas E. Shoopman, Andrew T. Morehead, Jr., Andrew L. Sargent","doi":"10.1021/acs.organomet.4c00215","DOIUrl":"https://doi.org/10.1021/acs.organomet.4c00215","url":null,"abstract":"In contrast to the more common rhodium-catalyzed hydroacylation reaction, which is widely accepted to proceed via a low-spin singlet mechanism that passes through the familiar steps of oxidative addition → alkene insertion → reductive elimination, the cobalt-catalyzed hydroacylation reaction of dienes reported by Dong et al. ( <cite>J. Am. Chem. Soc.</cite>, 2014) has been calculated to proceed via a high-spin triplet mechanism. The initial minimum energy pathway evaluated was the singlet, as two prior studies had also examined that pathway. The use of nudged elastic band methods enabled location of additional intermediates relative to the previous studies but also revealed that the isomeric product distribution was not accurately reproduced and that at least one intermediate appeared to prefer a different geometry. Subsequent examination of the triplet minimum energy pathway showed the intermediates are accompanied by geometries not typically associated with the singlet mechanism, which facilitates a very different pathway that involves oxidative cyclization and a direct reductive hydrogen atom transfer, thus avoiding the metal-hydride intermediates and reductive elimination steps that characterize the singlet pathway entirely.","PeriodicalId":56,"journal":{"name":"Organometallics","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

p-Aryl-Substituted Iminopyridine Chromium Complexes as Precatalysts for Ethylene Polymerization: The Question of the Physical Oxidation State Examined by Experimental and Density Functional Study in the Absence of Structural Data 作为乙烯聚合前催化剂的对芳基取代的氨基吡啶铬络合物：在缺乏结构数据的情况下通过实验和密度函数研究考察物理氧化态问题

IF 2.8 3区化学

Organometallics Pub Date : 2024-09-19 DOI: 10.1021/acs.organomet.4c00187

Giorgia Zanchin, Alessia Amodio, Alessandro Piovano, Virginia Guiotto, Giuseppe Leone, Laura Falivene, Elena Groppo

{"title":"p-Aryl-Substituted Iminopyridine Chromium Complexes as Precatalysts for Ethylene Polymerization: The Question of the Physical Oxidation State Examined by Experimental and Density Functional Study in the Absence of Structural Data","authors":"Giorgia Zanchin, Alessia Amodio, Alessandro Piovano, Virginia Guiotto, Giuseppe Leone, Laura Falivene, Elena Groppo","doi":"10.1021/acs.organomet.4c00187","DOIUrl":"https://doi.org/10.1021/acs.organomet.4c00187","url":null,"abstract":"Investigations into iminopyridine chromium complexes have unveiled their potential as precatalysts for the polymerization of (di)olefins (Organometallics 2018, 37, 4827–4840). A Cr-to-ligand electron transfer, with the ligand (L) in the monoanionic radical state and Cr in a physical trivalent oxidation state, proved to be fundamental for facilitating ethylene polymerization by the complex with the unsubstituted aldimine (Cr-pH, where X = H). In the absence of structural data, we embarked on a detailed study by ultraviolet–visible–near-infrared (UV–vis–NIR) spectroscopy and density functional theory to elucidate the structural and electronic features driving electron transfer in Cr-pH. The Cr-to-L electron transfer is facilitated by the presence of two tetrahydrofurans in the metal’s coordination sphere in the monoligated form or by the formation of a bis-ligated species. The UV–vis–NIR spectra of Cr-pH, coupled with electrospray ionization mass spectroscopy data, indicate the coexistence of multiple species. Successively, we enlarged the library of chromium complexes by appending different substituents (i.e., CH3, OCH3, and CF3) at the p-N-aryl 4-position. While Cr-pCH3 and Cr-pOCH3 display electronic features analogous to those of Cr-pH, Cr-pCF3 stands out as an exception, likely containing only monoligated species. Cr-pCF3 emerged as the most active catalyst, producing ultra-high-molecular weight poly(ethylene) with a unimodal and narrow molecular weight distribution event at 40 °C.","PeriodicalId":56,"journal":{"name":"Organometallics","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Flash Communication: Rhodium Complexes of Acetamide-Derived PAlP Pincer 快讯：乙酰胺衍生 PAlP 螯合物的铑络合物

IF 2.8 3区化学

Organometallics Pub Date : 2024-09-19 DOI: 10.1021/acs.organomet.4c00351

R. Noah Sladek, Nattamai Bhuvanesh, Oleg V. Ozerov

引用次数: 0

Association and Aggregation of Magnesium Organocuprates 有机合成镁的结合与聚合

IF 2.8 3区化学

Organometallics Pub Date : 2024-09-19 DOI: 10.1021/acs.organomet.4c00233

Sebastian Weske, Thomas Auth, Finn Kraft, Arne Winkler, Selina Schneider, Konrad Koszinowski

{"title":"Association and Aggregation of Magnesium Organocuprates","authors":"Sebastian Weske, Thomas Auth, Finn Kraft, Arne Winkler, Selina Schneider, Konrad Koszinowski","doi":"10.1021/acs.organomet.4c00233","DOIUrl":"https://doi.org/10.1021/acs.organomet.4c00233","url":null,"abstract":"Despite the frequent use of magnesium organocuprates derived from Grignard reagents in organic synthesis, the molecular composition of these important reagents is poorly understood. To achieve a better understanding of their speciation in solution, we apply here a combination of electrospray-ionization mass spectrometry, gas-phase fragmentation experiments, and quantum chemical calculations. For solutions of CuCl/2RMgCl (R = Ph, 2-thienyl, Bu, and Me3SiCH2) in tetrahydrofuran, we find anions of the type [CunRn+1]−, n = 1–6. Changing the copper precursor, increasing the amount of the Grignard reagent, and adding Me2S have only relatively minor effects. Gas-phase fragmentation of the [CunRn+1]− anions results in deaggregation reactions. In addition, [CunBun+1]− and [Cu(CH2SiMe3)2]− undergo β-hydrogen and β-methyl eliminations, respectively, as well. Presumably, these decomposition pathways (as well as unknown processes) also occur in solution and explain the depletion of organyl substituents in the observed [CunRn+1]− anions. The behavior of the magnesium cuprates deviates from that of the well-studied lithium cuprates, which display a higher tendency to form heteronuclear species. Our quantum chemical calculations for LiCuPh2·LiCl and MgClCuPh2·MgCl2 in THF show that the absence of analogous heteronuclear complexes in the case of the magnesium cuprates results from higher relative Gibbs energies of these species.","PeriodicalId":56,"journal":{"name":"Organometallics","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Fluorinated N-Heterocyclic Carbene Silver(I) Complexes with High Cancer Cell Selectivity 具有高癌细胞选择性的氟化 N-杂环羰基银（I）配合物

IF 2.8 3区化学

Organometallics Pub Date : 2024-09-19 DOI: 10.1021/acs.organomet.4c00292

Oliver S. King, Benjamin J. Hofmann, Aran E. Boakye-Smith, Amy J. Managh, Tameryn Stringer, Rianne M. Lord

{"title":"Fluorinated N-Heterocyclic Carbene Silver(I) Complexes with High Cancer Cell Selectivity","authors":"Oliver S. King, Benjamin J. Hofmann, Aran E. Boakye-Smith, Amy J. Managh, Tameryn Stringer, Rianne M. Lord","doi":"10.1021/acs.organomet.4c00292","DOIUrl":"https://doi.org/10.1021/acs.organomet.4c00292","url":null,"abstract":"This work presents the synthesis of five new functionalized (benz)imidazolium N-heterocyclic (NHC) ligands (L) and four new (benz)imidazole silver(I) NHC (Ag(I)-NHC) complexes of mononuclear [Ag(L)2](PF6) or binuclear [Ag2(L)2](PF6)2 type. The complexes have been fully characterized, including single crystal X-ray diffraction of three new structures. The complexes and their corresponding free NHC ligands have been screened against breast cancer and noncancerous cell lines, showing the mononuclear benzimidazole complex has the highest activity, while the binuclear benzimidazole complex has the highest cancer cell selectivity. The silver uptake was measured by ICP-MS and highlights a strong link between cytotoxicity and cellular uptake. DNA interaction studies, molecular docking, and evaluation of reactive oxygen species (ROS) have been conducted for the most promising complexes to identify modes of action. Overall, the binuclear benzimidazole complex is the most selective and promising candidate against the MDA-MD-231 (breast cancer) cell line and has potential to be developed for treatment of late-stage breast cancers.","PeriodicalId":56,"journal":{"name":"Organometallics","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Predicting the Hyperconjugative Aromaticity in Cyclopentadiene Containing Group 8 Transition Metal Substituents 预测含有第 8 族过渡金属取代基的环戊二烯的超共轭芳香性

IF 2.8 3区化学

Organometallics Pub Date : 2024-09-17 DOI: 10.1021/acs.organomet.4c00244

Jiaying Su, Yexinzi Jiang, Jun Zhu

引用次数: 0

Optimizing the Cation Binding Pocket in Nickel Phenoxyimine Catalysts Improves Ethylene Polymerization Efficiency 优化镍苯氧亚胺催化剂中的阳离子结合袋可提高乙烯聚合效率

IF 2.8 3区化学

Organometallics Pub Date : 2024-09-17 DOI: 10.1021/acs.organomet.4c00260

Lorenzo C. Ruiz De Castilla, Tuhin Ganguly, Babak Tahmouresilerd, Croix J. Laconsay, Judy I. Wu, Loi H. Do

引用次数: 0

16TMCONF543: An Automatically Generated Data Set of Conformational Energies of Transition Metal Complexes Relevant to Catalysis 16TMCONF543：自动生成的催化相关过渡金属配合物构象能数据集

IF 2.8 3区化学

Organometallics Pub Date : 2024-09-17 DOI: 10.1021/acs.organomet.4c00246

Arseniy A. Otlyotov, Timofey P. Rozov, Andrey D. Moshchenkov, Yury Minenkov

{"title":"16TMCONF543: An Automatically Generated Data Set of Conformational Energies of Transition Metal Complexes Relevant to Catalysis","authors":"Arseniy A. Otlyotov, Timofey P. Rozov, Andrey D. Moshchenkov, Yury Minenkov","doi":"10.1021/acs.organomet.4c00246","DOIUrl":"https://doi.org/10.1021/acs.organomet.4c00246","url":null,"abstract":"A database of conformational energies (CEs) of 16 transition metal (TM) complexes relevant to catalysis is automatically created by employing the new conformer generator program Uniconf. The generation procedure starts from an arbitrary high-energy structure and consistently produces conformer(s) similar to or even more energetically favorable than the optimized reference conformer retrieved from the Cambridge Structural Database. The reference CEs obtained with common dispersion-corrected functionals are employed to test the low-cost semiempirical methods. The superiority of the GFNn-xTB schemes over PM6*/7 methods is confirmed by the basic statistical analysis of the CEs. In addition, the influence of the vibrational thermostatistical (ΔGtherm) and continuum solvation (ΔGsolv) corrections on the CEs is examined in the framework of the (modified) scaled rigid-rotor-harmonic oscillator, (m)sRRHO, approximation, and solvation model based on density (SMD). In general, conformational Gibbs free energies exhibit excellent correlation with the respective electronic energies, especially if a more robust msRRHO scheme is employed for the calculation of ΔGtherm and in the case of a nonpolar solvent. The deviations from the perfect correlation occur if reduced CE windows of <5 kcal mol–1 are considered, implying a greater influence of these effects on the sorting of the low-energy structures.","PeriodicalId":56,"journal":{"name":"Organometallics","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Rare-Earth Dialkyls Supported by Silaimine-Cp Ligand: Synthesis, Reactivity, and Catalytic Addition of Alkynes and Amines to Carbodiimides 硅烷-Cp 配体支持的稀土烷基：合成、反应活性以及炔烃和胺与碳二亚胺的催化加成

IF 2.8 3区化学

Organometallics Pub Date : 2024-09-16 DOI: 10.1021/acs.organomet.4c00335

Bing Jing, Cheng Zhu, Fen Wang, Jianfeng Li, Chunming Cui

{"title":"Rare-Earth Dialkyls Supported by Silaimine-Cp Ligand: Synthesis, Reactivity, and Catalytic Addition of Alkynes and Amines to Carbodiimides","authors":"Bing Jing, Cheng Zhu, Fen Wang, Jianfeng Li, Chunming Cui","doi":"10.1021/acs.organomet.4c00335","DOIUrl":"https://doi.org/10.1021/acs.organomet.4c00335","url":null,"abstract":"Rare-earth metal dialkyls have attracted considerable attention in a variety of chemical transformations, such as hydroelementation of unsaturated substrates and olefin polymerization. However, stable rare-earth dialkyls are still very limited in number because of their poor thermal stability. In this paper, silaimine-functionalized cyclopentadienyl ligands C5Me4H–Si(L)═NR (L = PhC(NtBu)2 and R = 2,6-iPr2C6H3 for 1 and SiMe3 for 2) were applied for the synthesis of yttrium and scandium dialkyls (3–5). σ-Bond metathesis reactions of silaimine-Cp yttrium dialkyl 3 with aniline and 2,6-dimethylpyridine yielded the yttrium diamide complex (6) and the C(sp3)–H bond-activated yttrium dibenzyl complex (7), respectively. The yttrium diamidinate complex (8) was generated from the reaction of 3 with N,N′-diisopropylcarbodiimide. The yttrium and scandium dialkyls 3 and 5 and the reaction products 6-thf, 7, and 8 have been structurally characterized by X-ray diffraction analysis. Notably, silaimine-Cp yttrium dialkyl 4 displayed high activity and excellent functional group tolerance in the catalytic addition of terminal alkynes and amines to carbodiimides.","PeriodicalId":56,"journal":{"name":"Organometallics","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Exploration of Organometallic Cobalt Intermediates in an Aminoquinoline-Directed Dehydrogenative Dimerization Reaction 探索氨基喹啉引导的脱氢二聚反应中的有机金属钴中间体

IF 2.8 3区化学

Organometallics Pub Date : 2024-09-16 DOI: 10.1021/acs.organomet.4c00313

Emily L. Nolan, Fengrui Qu, Melanie S. Sanford

引用次数: 0