Dalton Transactions最新文献

{"title":"Electrostatic vs Electronic interactions within oxidized multinuclear Pt(bipyridine)(dithiolene) complexes","authors":"Khalil Youssef, Antoine Vacher, Thanaphon Khrueawatthanawet, Thierry Roisnel, Frederic Barriere, Dominique Lorcy","doi":"10.1039/d4dt02514h","DOIUrl":"https://doi.org/10.1039/d4dt02514h","url":null,"abstract":"Bi- and trimetallic platinum(bipyridine)(dithiolene) complexes involving different organic linkers between the redox active platinum(dithiolene) moieties have been synthesized and studied by electrochemistry and spectroelectrochemistry. Cyclic voltammetry experiments carried out on these multinuclear complexes in dichloromethane using [NBu4][PF6] as the supporting salt show only one oxidation process involving the metallacycles. Nevertheless, spectro-electrochemical studies, carried out under the same conditions, show a different evolution of the spectra during oxidation depending on the position of the metallacycles on the phenyl ring. For instance, only the 1,3-disubtituted (Pt21,3-P) and 1,3,5-trisubstituted (Pt31,3,5-P) complexes show the growth of an absorption band in the NIR region upon oxidation while it was not observed for the other complexes. In contrast, electrochemical studies carried out using the poorly coordinating supporting electrolyte, [Na][B(C6H4(CF3)2)4], indicate sequential oxidation of the redox centers with ΔE values varying according to the nature of the bridge and the distance between metal centers. For all the investigated multinuclear complexes, spectro-electrochemical experiments performed in the presence of [Na][B(C6H4(CF3)2)4] show an absorption band in the NIR region consistent with appreciable electrostatic effects and charge delocalization in the mixed valent intermediates.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142574324","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}

{"title":"Beyond the Triple Bond: Unlocking Dinitrogen Activation with Tai-lored Superbase Phosphines","authors":"Cherumuttathu Hariharan Suresh, V. U. Krishnapriya","doi":"10.1039/d4dt02703e","DOIUrl":"https://doi.org/10.1039/d4dt02703e","url":null,"abstract":"Activating atmospheric dinitrogen (N2<small></small>), a molecule with a remarkably strong triple bond, remains a major challenge in chemistry. This theoretical study explores the potential of superbase phosphines, specifically those decorated with imidazolin-2-imine ((ImN)<small>₃</small>P) and imidazolin-2-methylidene ((ImCH)<small>₃</small>P) to facilitate N2 activation and subsequent hydrazine (H<small>₂</small>NNH<small>₂</small>) formation. Us-ing density functional theory (DFT) at the M06L/6-311++G(d,p) level, we investigated the interactions between these phosphines and N2. Mono-phosphine-N2 complexes exhibit weak, noncovalent interactions (-0.6 to -7.1 kcal/mol). Notably, two superbasic phosphines also form high-energy hypervalent complexes with N2, albeit at significantly higher energies. The superbasic nature and potential for hypervalency of these phosphines lead to substantial N<small>₂</small> activation in bis-phosphine-N<small>₂</small> complexes, where N<small>₂</small> is \"sand-wiched\" between two phosphine moieties through hypervalent P-N bonds. Among the phosphines studied, only (ImN)<small>₃</small>P forms an exothermic sandwich complex with N<small>₂</small>, stabilized by hydrogen bonding between the ImN- substituents and the central N2 molecule. A two-step, exothermic hydrogen transfer pathway from (ImN)3P to N2 results in the formation of a bis-phosphine-diimine (HNNH) sandwich complex. Subsequent hydrogen transfers lead to the formation of a bis-phosphine-hydrazine (H<small>₂</small>NNH<small>₂</small>) complex, a process that, although endothermic, exhibits surmountable activation barriers. The relatively low energy requirements for this overall trans-formation suggest its potential feasibility under optimized conditions. This theoretical exploration highlights the promise of super-base phosphines as a strategy for metal-free N<small>₂</small> activation, opening doors for the development of more efficient and sustainable ni-trogen fixation and utilization methods.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142574345","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}

{"title":"A Mechanistic Study of Chiral Manganese Porphyrin-Catalyzed Enantioselective C−H Hydroxylation Reaction","authors":"Jing-Kun Gao, Wandong Chen, Junjie Tai, Zhengwei Chen, Hang Liu, Yuxin Du, Yiting Jiang, Yuanbin She, Yun-Fang Yang","doi":"10.1039/d4dt02452d","DOIUrl":"https://doi.org/10.1039/d4dt02452d","url":null,"abstract":"We employed density functional theory (DFT) calculations to elucidate the mechanism and origin of enantioselectivity in the C−H hydroxylation reaction catalyzed by a chiral manganese porphyrin complex. Our study reveals that the chiral manganese porphyrin forms a two-point hydrogen bonding interaction with the substrate. Specifically, the hydrogen atom abstraction of the pro-(<em>S</em>) C−H bond of the methylene pro-(<em>S</em>) C−H bond at the heterocyclic C-3 position is 1.9 kcal mol-1 favored over the hydrogen atom abstraction of the pro-(<em>R</em>) C−H bond. This preferential reactivity results in the predominant formation of (<em>S</em>)-hydroxylated products. Our DFT calculations are consistent with the experimental findings of high enantioselectivity in the chiral manganese porphyrin catalyzed C(sp<small>³</small>)−H hydroxylation of lactam derivatives. The observed enantioselectivity arises from the formation of two-point hydrogen bonding between lactam derivatives and manganese porphyrin catalysts. Moreover, our computations indicate varying degrees of substrate distortion upon attack by high-valent manganese oxygen complexes at different hydrogen atoms.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142574327","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}

{"title":"Water soluble photocatalysts based on porphyrin-carbon dots conjugates produce H2 under visible light irradiation","authors":"Athanassios G. Coutsolelos, Katerina Achilleos, Anna Katsari, Emmanouil Nikoloudakis, Foteini Chatzipetri, Dimitrios Tsikritzis, Kalliopi Ladomenou, Georgios Charalambidis, Emmanuel Stratakis","doi":"10.1039/d4dt02101k","DOIUrl":"https://doi.org/10.1039/d4dt02101k","url":null,"abstract":"Herein we report the visible-light-induced hydrogen generation from aqueous protons utilizing a novel hybrid photocatalytic nanomaterial comprising of porphyrin-carbon dot conjugates. Amide coupling between metallated tetra-carboxyphenyl porphyrins (MTCPP) and nitrogen doped carbon dots (NCDots) was perfomed to afford M-TCPP-NCDots hybrids which were applied in hydrogen evolution photocatalysis under visible irradiation. H2 was obtained in the presence of approriate sacrificial electron donors and with no additional metalic co-catalysts. Noteworthy, the covallent attachement as well as the zinc-metallation of the porphyrin moiety were proved vital for the efficiency of the present system. The present study consist an innovative approach for artificial photosynthesis avoiding the use of costly materials such as noble metals.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142574325","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}

{"title":"A new family of thiolate-bridged bimetallic complexes featuring a benzimidazole moiety: synthesis, structure and redox reactivity.","authors":"Kai Di, Dawei Yang, Linan Su, Ronghuan Du, Shengbin Dong, Baomin Wang, Jingping Qu","doi":"10.1039/d4dt02484b","DOIUrl":"https://doi.org/10.1039/d4dt02484b","url":null,"abstract":"<p><p>Thiolate-bridged bimetallic complexes have attracted considerable attention owing to their extensive applications in bioinspired catalysis as biological metalloenzymes. Compared with bimetallic complexes supported by common thiolate ligands, those featuring functional groups that may adopt different patterns to coordinate to the metal centers are usually difficult to access, limiting their exploration. The benzimidazole moiety is a multi-faceted functional group; for example, it can act as a biomolecule-responsive ligand for the development of transition metal complexes with anticancer and antitumor properties. However, so far, there has been no report on thiolate-bridged bimetallic complexes featuring a benzimidazole moiety as the functional group. In this work, we use half-sandwich type monometallic (iron, cobalt or ruthenium) complexes as precursors to synthesize a series of thiolate-bridged bimetallic complexes <i>via</i> reactions with benzimidazolylmethyl disulfide (bzmds) and benzimidazol-2-ylmethanethiol (bzmt). X-ray crystallographic analyses show that diiron and dicobalt complexes feature two bzmt ligands in a <i>syn</i> configuration, which are bridged to the two M^III centers through the sulfur and nitrogen atoms. In contrast, the diruthenium complex possesses <i>syn</i>- and <i>anti</i>-configuration isomers in both solution- and solid-state, and the corresponding ratio of the two isomers varies upon employing different solvents. Electrochemical studies reveal that these complexes possess two or more redox couples. In particular, an Fe^IIIFe^III complex can undergo one-electron reduction to give an isolable Fe^IIFe^III species. In addition, we investigated their electronic structures by UV/vis spectroscopy and density functional theory (DFT).</p>","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":null,"pages":null},"PeriodicalIF":3.5,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142566394","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}

{"title":"Evidence for a boride–borylene-ligand-tautomerism leading to a remote C–C-bond and concomitant boryl ligand formation","authors":"Frerk-Ulfert Wehmeyer, Yinwu Li, Anne Schlossarek, Zhuofeng Ke, Robert Langer","doi":"10.1039/d4dt02997f","DOIUrl":"https://doi.org/10.1039/d4dt02997f","url":null,"abstract":"A rhodium PBP-type pincer complex with boron-based donor ligand of the type Py2BH (Py = pyridine) and its deprotonation is reported, which led to a boryl complex under concomitant formation of a new C—C-bond. Mechanistic investigations indicate the presence of a tautomerism between two deprotonated species, giving rise to a ligand-stabilized boride and a ligand-stabilized borylene motif.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142562068","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}

{"title":"Chemistry of organometallic nucleic acid components: personal perspective and prospects for the future","authors":"Konrad Kowalski, Mateusz Klarek","doi":"10.1039/d4dt02634a","DOIUrl":"https://doi.org/10.1039/d4dt02634a","url":null,"abstract":"Article summarizes over the 12 years of studies into organometallic nucleic acid components, which have been carried out in our laboratory at the University of Łódź. It focuses mainly on synthesis and chemical transformations, but the biological activity of the obtained compounds are also presented. This article serves also as a guide for future studies, as it emphasizes some goals in the field of organometallic nucleic acid components chemistry that have yet to be achieved.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142561796","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}

{"title":"Modification of cobalt bis(dicarbollide) ion with nitrile groups on carbon atoms: a unique low-temperature skeletal rearrangement due to specific electron-donor character of the CN substitution.","authors":"Ece Tüzün, Drahomír Hnyk, Dmytro Bavol, Miroslava Litecká, Jindřich Fanfrlík, Bohumir Gruner","doi":"10.1039/d4dt02588a","DOIUrl":"https://doi.org/10.1039/d4dt02588a","url":null,"abstract":"Herein we report on synthesis and stereochemistry of mono- and isomeric dinitrile derivatives of [(1,2-C2B9H11)2-3,3’-Co]- ion. The shape and electronic properties of CN groups are apparently able to surmount the strain associated with substitution of two vicinal carbon positions. Due to electron donation to the cage, this results in a substituent induced rearrangement of one of the carbon atoms to the upper pentagon belt. The molecular structure of this isomer is confirmed by sc-XRD and DFT chemical computations.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142562067","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}

{"title":"Evaluation of Structurally Related Acyclic Ligands OBETA, EHDTA, and EGTA for Stable Mn²⁺ Complex Formation","authors":"Elena Grattoni, Fabio Travagin, Ferenc Krisztián Kálmán, Zsolt Baranyai, Roberto Negri, Fabio Carniato, Giovanni Battista Giovenzana, Carlos Platas-Iglesias, Mauro Botta","doi":"10.1039/d4dt02761b","DOIUrl":"https://doi.org/10.1039/d4dt02761b","url":null,"abstract":"In recent years, significant research efforts have been dedicated to finding efficient and safe alternatives to the currently used gadolinium (Gd)-based MRI contrast agents. Among the most explored alternatives are paramagnetic chelates of the earth-abundant Mn²⁺, which form a prominent class of metal complexes. The design of Mn²⁺-complexes with enhanced relaxation properties and improved safety profiles hinges on a delicate balance between thermodynamic and kinetic stability, as well as the presence of coordinated water molecules. In this study, we present a comprehensive investigation into the coordination chemistry of three structurally related polyetheraminocarboxylic chelating agents. Our aim is to elucidate the structural features, paramagnetic properties, and thermodynamic and kinetic inertness of the corresponding Mn²⁺-complexes. The most significant finding is the considerable difference in the dissociation rates of the complexes, with the octadentate EGTA complex being the most labile. The observed dissociation rates correlate well with the nitrogen inversion dynamics, as assessed through NMR spectral analysis of the analogous Zn²⁺ complexes.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142562132","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}

{"title":"Multifunctional self-supporting LLTO/C interlayer for high-performance lithium-sulfur battery","authors":"Yufei Zhang, Xinhang Liu, Qi Jin, Chi Zhang, Fengfeng Han, Yang Zhao, Lirong Zhang, Lili Wu, Xitian Zhang","doi":"10.1039/d4dt02429j","DOIUrl":"https://doi.org/10.1039/d4dt02429j","url":null,"abstract":"Lithium-sulfur (Li-S) batteries are recognized as an encouraging alternative for future power storage technologies. However, their practical application is hindered by several significant challenges, including slow redox kinetics, the shuttle effect, and the formation of lithium dendrites. Here a binder-free, self-supporting multifunctional interlayer composed of lithium lanthanum titanate (LLTO) with amorphous carbon nanofiber matrices for Li-S batteries has been constructed. This multifunctional interlayer has been designed to facilitate the redox kinetics of lithium polysulfides (LiPSs), promote the nucleation of lithium sulfide (Li2S), and hinder the formation of lithium dendrites. The electrocatalytic properties of the interlayer were subjected to systematic evaluation through electrochemical testing, and the lithium deposition was assessed by examining the surface evolution of lithium metal in symmetric cells. The LLTO carbon matrices interlayer sustained a high specific capacity of 703.3 mAh g-1 after 200 cycles at 0.1 C, with a sulfur loading of 5.5 mg cm-2. Furthermore, it demonstrated a high capacity of 905.9 mAh g-1 with a decay rate of 0.069% per cycle over 1000 cycles at a current density of 5 C with sulfur loading of 1 mg cm-2. This investigation highlights the potential of LLTO carbon composite materials as multifunctional interlayers, which could facilitate the optimization of advanced Li-S batteries.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142561976","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}