共查询到20条相似文献,搜索用时 15 毫秒
1.
Dr. Sara Sabater Dr. David Schmidt Dr. Heidi Schmidt Dr. Maximilian W. Kuntze-Fechner Dr. Thomas Zell Connie J. Isaac Dr. Nasir A. Rajabi Harry Grieve Dr. William J. M. Blackaby Dr. John P. Lowe Prof. Stuart A. Macgregor Dr. Mary F. Mahon Prof. Dr. Udo Radius Prof. Michael K. Whittlesey 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(52):13221-13234
The addition of PPh2H, PPhMeH, PPhH2, P(para-Tol)H2, PMesH2 and PH3 to the two-coordinate Ni0 N-heterocyclic carbene species [Ni(NHC)2] (NHC=IiPr2, IMe4, IEt2Me2) affords a series of mononuclear, terminal phosphido nickel complexes. Structural characterisation of nine of these compounds shows that they have unusual trans [H−Ni−PR2] or novel trans [R2P−Ni−PR2] geometries. The bis-phosphido complexes are more accessible when smaller NHCs (IMe4>IEt2Me2>IiPr2) and phosphines are employed. P−P activation of the diphosphines R2P−PR2 (R2=Ph2, PhMe) provides an alternative route to some of the [Ni(NHC)2(PR2)2] complexes. DFT calculations capture these trends with P−H bond activation proceeding from unconventional phosphine adducts in which the H substituent bridges the Ni−P bond. P−P bond activation from [Ni(NHC)2(Ph2P−PPh2)] adducts proceeds with computed barriers below 10 kcal mol−1. The ability of the [Ni(NHC)2] moiety to afford isolable terminal phosphido products reflects the stability of the Ni−NHC bond that prevents ligand dissociation and onward reaction. 相似文献
2.
Robert J. Mangan Dr. Arnab Rit Dr. Christian P. Sindlinger Dr. Rémi Tirfoin Dr. Jesús Campos Dr. Jamie Hicks Dr. Kirsten E. Christensen Dr. Haoyu Niu Prof. Simon Aldridge 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(1):306-315
The synthesis of a boryl-substituted germanium(II) cation, [Ge{B(NDippCH)2}(IPrMe)]+, (Dipp=2,6-diisopropylphenyl) featuring a supporting N-heterocyclic carbene (NHC) donor, has been explored through chloride abstraction from the corresponding (boryl)(NHC)GeCl precursor. Crystallographic studies in the solid state and UV/Vis spectra in fluorobenzene solution show that this species dimerizes under such conditions to give [(IPrMe){(HCNDipp)2B}Ge=Ge{B(NDippCH)2}(IPrMe)]2+ (IPrMe = 1,3-diisopropyl-4,5-dimethylimidazolin-2-ylidene), which can be viewed as an imidazolium-functionalized digermene. The dimer is cleaved in the presence of donor solvents such as [D8]thf or [D5]pyridine, to give monomeric adducts of the type [Ge{B(NDippCH)2}(IPrMe)(L)]+. In the case of the thf adduct, the additional donor is shown to be sufficiently labile that it can act as a convenient in situ source of the monomeric complex [Ge{B(NDippCH)2}(IPrMe)]+ for oxidative bond-activation chemistry. Thus, [Ge{B(NDippCH)2}(IPrMe)(thf)]+ reacts with silanes and dihydrogen, leading to the formation of GeIV products, whereas the cleavage of the N−H bond in ammonia ultimately yields products containing C−H and B−N bonds. The facile reactivity observed in E−H bond activation is in line with the very small calculated HOMO–LUMO gap (132 kJ mol−1). 相似文献
3.
Nitric oxide reduction yielding N2O is known as a route to detoxify nitric oxide (NO) to relieve nitrosative stress in pathogenic bacteria and fungi. Nitric oxide enzymes are classified into Cu/Fe-heme NO reductases (NORs) and non-heme flavindiiron NO reductases (FNORs). In biological system, the mechanism of NO reduction generating N2O was proposed to involve NO coordination to metal centers prior to producing cis/trans-hyponitrite-bound intermediate, and the subsequent protonation of hyponitrite-bound-Fe/Cu intermediates releases N2O. In this review article, we compile the recently published biomimetic model studies of NO-to-[N2O2]2− transformation triggered by the designed transition-metal complexes. In biomimetic model study, the ON-NO bond coupling of metal-nitrosyl complexes yielding [N2O2]2−-bound species may occur via either the inter/intramolecular radical-[NO]−-radical-[NO]− coupling or metal-[NO]2− radical coupling with exogenous NO˙. The H-bonding interaction between hyponitrite and protic solvents promoting/stabilizing the formation of hyponitrite complexes was also demonstrated. In addition, the electronic structure of the designed transition-metal-nitrosyl complexes triggering the formation of [N2O2]2−-bound species and the detailed NO-to-[N2O2]2− formation pathways were delineated. 相似文献
4.
Yanwei Cao Jian-Gong Yang Dr. Yi Deng Shengchun Wang Qi Liu Dr. Chaoren Shen Prof. Dr. Wei Lu Prof. Dr. Chi-Ming Che Prof. Dr. Yong Chen Prof. Dr. Lin He 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(5):2096-2100
A sensitive amine-responsive disassembly of self-assembled AuI-CuI double salts was observed and its utilization for the synergistic catalysis was enlightened. Investigation of the disassembly of [Au(NHC)2][CuI2] revealed the contribution of Cu-assisted ligand exchange of N-heterocyclic carbene (NHC) by amine in [Au(NHC)2]+ and the capacity of [CuI2]− on the oxidative step. By integrating the implicative information coded in the responsive behavior and inherent catalytic functions of d10 metal complexes, a catalyst for the oxidative carbonylation of amines was developed. The advantages of this method were clearly reflected on mild reaction conditions and the significantly expanded scope (51 examples); both primary and steric secondary amines can be employed as substrates. The cooperative reactivity from Au and Cu centers, as an indispensable prerequisite for the excellent catalytic performance, was validated in the synthesis of (un)symmetric ureas and carbamates. 相似文献
5.
Poly-NHC (NHC = N-heterocyclic carbene) ligands emerged almost immediately after the first stable NHCs had been described. Macrocyclic ligands, featuring NHC donor groups and their metal complexes, however, remained rare until recently. This perspective highlights modern developments in the fields of synthesis and coordination chemistry of macrocyclic poly-NHC ligands. These include the synthesis of tetracarbene ligands which were obtained from complexes of β-functionalized isocyanides followed by cyclization of the coordinated iscocyanide ligands to NH,NH-functionalized NHCs and the subsequent metal template controlled bridging alkylation of the NH,NH-NHCs to yield the macrocycle. The template synthesis of ligands featuring a mixed NHC/phosphine donor set like [11]ane-P(2)C(NHC) and [16]ane-P(2)C(NHC)(2) by linkage of NH,NH-NHCs to different phosphines is also presented. Finally, methods for the preparation of cyclic polyazolium salts, their deprotonation and metalation and the different modes of coordination of such macrocyclic poly-NHC ligands are discussed. 相似文献
6.
Kritika Gour Gargi Kundu Soumya Ranjan Dash Dr. Kumar Vanka Dr. Srinu Tothadi Dr. Sakya S. Sen 《欧洲无机化学杂志》2023,26(21):e202300167
This paper describes the rare use of a 6-membered saturated N-heterocyclic carbene (NHC) known as 1,3-di(2,6-diisopropylphenyl) tetrahydropyrimidine-2-ylidene (abbreviated as 6-SIDipp) as a ligand in zinc chemistry. We report on the investigation of the reactions between 6-SIDipp and ZnX2, which resulted in a range of new monomeric 6-SIDipp⋅ZnX2 complexes (X=Et ( 1 ), Cl ( 2 ), Br ( 3 ), and I ( 4 )). We also prepared a new NHC zinc complex where the two substituents of the zinc atom are different, 6-SIDipp⋅Zn(Et)Br ( 7 ) through the reaction of the proligand [6-SIDippH]Br with ZnEt2. We have observed that the reactions of complex 1 with sulfur and HBpin led to the removal of the ZnEt2 moiety, resulting in the formation of a C=S double bond and a B−H activation product, respectively. Lastly, the reaction of 1 with five-membered NHCs led to the exchange of carbene and the formation of either 5-IDipp⋅ZnEt2 ( 8 ) or 5-SIDipp⋅ZnEt2 ( 9 ). 相似文献
7.
Dr. Joseph F. DeJesus Lindy M. Sherman Darius J. Yohannan Jeffrey C. Becca Shelby L. Strausser Leonhard F. P. Karger Dr. Lasse Jensen Dr. David M. Jenkins Dr. Jon P. Camden 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(19):7655-7660
The remarkable resilience of N-heterocyclic carbene (NHC) gold bonds has quickly made NHCs the ligand of choice when functionalizing gold surfaces. Despite rapid progress using deposition from free or CO2-protected NHCs, synthetic challenges hinder the functionalization of NHC surfaces with protic functional groups, such as alcohols and amines, particularly on larger nanoparticles. Here, we synthesize NHC-functionalized gold surfaces from gold(I) NHC complexes and aqueous nanoparticles without the need for additional reagents, enabling otherwise difficult functional groups to be appended to the carbene. The resilience of the NHC−Au bond allows for multi-step post-synthetic modification. Beginning with the nitro-NHC, we form an amine-NHC terminated surface, which further undergoes amide coupling with carboxylic acids. The simplicity of this approach, its compatibility with aqueous nanoparticle solutions, and its ability to yield protic functionality, greatly expands the potential of NHC-functionalized noble metal surfaces. 相似文献
8.
Dr. Felix Riedlberger Dr. Stefano Todisco Prof. Dr. Piero Mastrorilli Prof. Dr. Alexey Y. Timoshkin Dr. Michael Seidl Prof. Dr. Manfred Scheer 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(69):16251-16255
The first adducts of NHCs (=N-heterocyclic carbenes) with aromatic polyphosphorus complexes are reported. The reactions of [Cp*Fe(η5-P5)] ( 1 ) (Cp*=pentamethyl-cyclopentadienyl) with IMe (=1,3,4,5-tetramethylimidazolin-2-ylidene), IMes (=1,3-bis(2,4,6-trimethylphenyl)-imidazolin-2-ylidene) and IDipp (=1,3-bis(2,6-diisopropylphenyl)-imidazolin-2-ylidene) led to the corresponding neutral adducts which can be isolated in the solid state. However, in solution, they quickly undergo a dissociative equilibrium between the adduct and 1 including the corresponding NHC. The equilibrium is influenced by the bulkiness of the NHC. [Cp′′Ta(CO)2(η4-P4)] (Cp′′=1,3-di-tert-butylcyclopentadienyl) reacts with IMe under P atom abstraction to give an unprecedented cyclo-P3-containing anionic tantalum complex. DFT calculations shed light onto the energetics of the reaction pathways. 相似文献
9.
Nikolaos V. Tzouras Marina Saab Wim Janssens Thibault Cauwenbergh Prof. Dr. Kristof Van Hecke Dr. Fady Nahra Prof. Dr. Steven P. Nolan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(24):5541-5551
The discovery of sustainable and scalable synthetic protocols leading to gold–aryl compounds bearing N-heterocyclic carbene (NHC) ligands sparked an investigation of their reactivity and potential utility as organometallic synthons. The use of a mild base and green solvents provide access to these compounds, starting from widely available boronic acids and various [Au(NHC)Cl] complexes, with reactions taking place under air, at room temperature and leading to high yields with unprecedented ease. One compound, (N,N′-bis[2,6-(di-isopropyl)phenyl]imidazol-2-ylidene)(4-methoxyphenyl)gold, ([Au(IPr)(4-MeOC6H4)]), was synthesized on a multigram scale and used to gauge the reactivity of this class of compounds towards C−H/N−H bonds and with various acids, revealing simple pathways to gold–based species that possess attractive properties as materials, reagents and/or catalysts. 相似文献
10.
Saravanakumar S Oprea AI Kindermann MK Jones PG Heinicke J 《Chemistry (Weinheim an der Bergstrasse, Germany)》2006,12(11):3143-3154
Two novel anellated N-heterocyclic carbenes (NHC), 1,3-dineopentylnaphtho[2,3-d]imidazol-2-ylidene, and 1,3-dineopentyl-2-ylido-imidazolo[4,5-b]pyridine were obtained by reduction of the respective thiones with potassium, the former also by deprotonation of the corresponding naphthimidazolium hexafluorophosphate by using excess KH in THF. The use of equimolar amounts of KH provided an unexpected formal addition product of this NHC with KOH. X-ray crystal structure analysis of the adduct provided evidence for a distorted tetrameric N-heterocyclic alkoxide, stabilized by two THF molecules. In C(6)D(6) the compound undergoes disproportionation. Transition-metal complexes [(NHC)AgCl], [(NHC)Rh(cod)Cl], and (E)-[(NHC)(2)PdCl(2)] of the novel naphthimidazol-2-ylidene were synthesized. X-ray crystal structures and (1)H and (13)C NMR spectroscopic data provided detailed structural information. Comparing characteristic data with those of nonanellated and differently anellated NHCs or their complexes provides information on the influence of the extended anellation. 相似文献
11.
Guangrong Meng Lazaros Kakalis Steven P. Nolan Michal Szostak 《Tetrahedron letters》2019,60(4):378-381
The σ-donor properties of NHC ligands (NHC?=?N-heterocyclic carbene) are crucial in controlling their interaction with transition metals, and as a consequence, to determine the selectivity and reactivity of NHCs in transition-metal-catalysis. Herein, we report a simple NMR method for estimating the σ-donor properties of NHC ligands based on a straightforward 1H NMR measurement of ligand precursors. We present evaluation of σ-donating properties for a range of NHC ligands varied by structure and electronics that are relevant to transition-metal-catalysis. We expect that the simple measurement of σ-donating properties of NHCs, together with the known methods for evaluating sterics and π-backbonding, will enhance the understanding of the properties of NHCs in transition-metal-catalysis. 相似文献
12.
Ramn Azpíroz Mert Olgun Karata Vincenzo Passarelli Ismail
zdemir Jesús J. Prez-Torrente Ricardo Castarlenas 《Molecules (Basel, Switzerland)》2022,27(20)
A series of mixed bis-NHC rhodium(I) complexes of type RhCl(η2-olefin)(NHC)(NHC’) have been synthesized by a stepwise reaction of [Rh(μ-Cl)(η2-olefin)2]2 with two different NHCs (NHC = N-heterocyclic carbene), in which the steric hindrance of both NHC ligands and the η2-olefin is critical. Similarly, new mixed coumarin-functionalized bis-NHC rhodium complexes have been prepared by a reaction of mono NHC complexes of type RhCl(NHC-coumarin)(η2,η2-cod) with the corresponding azolium salt in the presence of an external base. Both synthetic procedures proceed selectively and allow the preparation of mixed bis-NHC rhodium complexes in good yields. 相似文献
13.
Pablo Ríos Hugo Fouilloux Dr. Josefina Díez Dr. Pietro Vidossich Prof. Dr. Agustí Lledós Dr. Salvador Conejero 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(48):11346-11355
Platinum complexes [Pt(NHC′)(NHC)][BArF] (in which NHC′ denotes a cyclometalated N-heterocyclic carbene ligand, NHC) react with primary silanes RSiH3 to afford the cyclometalated platinum(II) silyl complexes [Pt(NHC-SiHR′)(NHC)][BArF] through a process that involves the formation of C−Si and Pt−Si bonds with concomitant extrusion of H2. Low-temperature NMR studies indicate that the process proceeds through initial formation of the σ-SiH complexes [Pt(NHC′)(NHC)(HSiH2R)][BArF], which are stable at temperatures below −10 °C. At higher temperatures, activation of one Si−H bond followed by a C−Si coupling reaction generates an agostic SiH platinum hydride derivative [Pt(H)(NHC′-SiH2R)(NHC)][BArF], which undergoes a second Si−H bond activation to afford the final products. Computational modeling of the reaction mechanism indicates that the stereochemistry of the silyl/hydride ligands after the first Si−H bond cleavage dictates the nature of the products, favoring the formation of a C−Si bond over a C−H bond, in contrast to previous results obtained for tertiary silanes. Furthermore, the process involves a trans-to-cis isomerization of the NHC ligand before the second Si−H bond cleavage. 相似文献
14.
《Journal of organometallic chemistry》2005,690(24-25):5474-5484
In an effort to develop new tripodal N-heterocyclic carbene (NHC) ligands for small molecule activation, two new classes of tripodal NHC ligands TIMER and TIMENR have been synthesized. The carbon-anchored tris(carbene) ligand system TIMER (R = Me, t-Bu) forms bi- or polynuclear metal complexes. While the methyl derivative exclusively forms trinuclear 3:2 complexes [(TIMEMe)2M3]3+ with group 11 metal ions, the tert-butyl derivative yields a dinuclear 2:2 complex [(TIMEt-Bu)2Cu2]2+ with copper(I). The latter complex shows both “normal” and “abnormal” carbene binding modes and accordingly, is best formulated as a bis(carbene)alkenyl complex. The nitrogen-anchored tris(carbene) ligands TIMENR (R = alkyl, aryl) bind to a variety of first-row transition metal ions in 1:1 stoichiometry, affording monomeric complexes with a protected reactivity cavity at the coordinated metal center. Complexes of TIMENR with Cu(I)/(II), Ni(0)/(I), and Co(I)/(II)/(III) have been synthesized. The cobalt(I) complexes with the aryl-substituted TIMENR (R = mesityl, xylyl) ligands show great potential for small molecule activation. These complexes activate for instance dioxygen to form cobalt(III) peroxo complexes that, upon reaction with electrophilic organic substrates, transfer an oxygen atom. The cobalt(I) complexes are also precursors for terminal cobalt(III) imido complexes. These imido complexes were found to undergo unprecedented intra-molecular imido insertion reactions to form cobalt(II) imine species. The molecular and electronic structures of some representative metal NHC complexes as well as the nature of the metal–carbene bond of these metal NHC complexes was elucidated by X-ray and DFT computational methods and are discussed briefly. In contrast to the common assumption that NHCs are pure σ-donors, our studies revealed non-negligible and even significant π-backbonding in electron-rich metal NHC complexes. 相似文献
15.
《中国化学快报》2020,31(5):1342-1344
The limited knowledge on low-coordinate zero-valent transition-metal species has intrigued great synthetic efforts in developing ligand sets for their stabilization. While the combined ligand set of N-heterocyclic carbene (NHC) with vinylsilanes was the only known ligand system amenable to the stabilization of three-coordinate formal zero-valent cobalt, iron, and manganese complexes, the exploration on other ligands has proved that the ligand set of NHCs with styrene is equally effective in stabilizing three-coordinate formal zero-valent metal complexes in the form of (NHC)M(η2-CH2CHPh)2 (NHC = IPr, IMes; M = Co, Fe, Mn). These styrene complexes can be prepared by the one-pot reactions of MCl2 with styrene, NHC and KC8, and have been characterized by various spectroscopic methods. Preliminary reactivity study indicated that the interaction of [(IMes)Fe(η2-CH2CHPh)2] with DippN3 produces the iron(IV) bisimido complex [(IMes)Fe(NDipp)2] and styrene, which hints at the utility of these zero-valent metal styene complexes as synthons of the mono-coordinate species (NHC)M(0). 相似文献
16.
Dr. Dmitry B. Eremin Ekaterina A. Denisova Dr. Alexander Yu. Kostyukovich Dr. Jonathan Martens Dr. Giel Berden Prof. Dr. Jos Oomens Prof. Dr. Victor N. Khrustalev Prof. Dr. Victor M. Chernyshev Prof. Dr. Valentine P. Ananikov 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(72):16564-16572
N-Heterocyclic carbene (NHC) ligands are ubiquitously utilized in catalysis. A common catalyst design model assumes strong M–NHC binding in this metal–ligand framework. In contrast to this common assumption, we demonstrate here that lability and controlled cleavage of the M−NHC bond (rather than its stabilization) could be more important for high-performance catalysis at low catalyst concentrations. The present study reveals a dynamic stabilization mechanism with labile metal–NHC binding and [PdX3]−[NHC-R]+ ion pair formation. Access to reactive anionic palladium intermediates formed by dissociation of the NHC ligands and plausible stabilization of the molecular catalyst in solution by interaction with the [NHC-R]+ azolium ion is of particular importance for an efficient and recyclable catalyst. These ionic Pd/NHC complexes allowed for the first time the recycling of the complex in a well-defined form with isolation at each cycle. Computational investigation of the reaction mechanism confirms a facile formation of NHC-free anionic Pd in polar media through either Ph–NHC coupling or reversible H–NHC coupling. The present study formulates novel ideas for M/NHC catalyst design. 相似文献
17.
In the last decade, chemists have dedicated many efforts to investigate the coordination chemistry of N-heterocyclic carbenes (NHCs). Although most of that research activity has been devoted to mononuclear complexes, transition-metal carbonyl clusters have not escaped from these investigations. This critical review, which is focussed on the reactivity of NHCs (or their precursors) with transition-metal carbonyl clusters (mostly are of ruthenium and osmium) and on the transformations underwent by the NHC-containing species initially formed in those reactions, shows that the polynuclear character of these metallic compounds or, more precisely, the close proximity of one or more metal atoms to that which is or can be attached to the NHC ligand, is responsible for reactivity patterns that have no parallel in the NHC chemistry of mononuclear complexes (74 references). 相似文献
18.
Dr. Michał J. Białek Prof. Piotr J. Chmielewski Prof. Lechosław Latos-Grażyński 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(64):14536-14545
Taking advantage of the specific properties of azuliporphyrin and the reactivity of cobalt(II), activation of an azulene C(sp2)−H bond occurred and organometallic complexes with Co−C bonding were formed. The system allowed for macrocyclic aromaticity tuning through metal coordination and oxidation. Thanks to the CoII−C and parallel tested CuII−C reactivity and the affinity of metal centers to dioxygen, oxygen atom insertion into the M−C bond could be investigated. Insertion starts with an oxygen molecule coordination and leads to monomeric and dimeric complexes of specific electronic structures. Formation of unique paramagnetic σ/π-hybrid bimetallic complexes enabled spectroscopic and theoretical investigations of peculiar CoII⋅⋅⋅Ru0 interactions. 相似文献
19.
Sebastian Mummel Dr. Felix Lederle Prof. Dr. Eike G. Hübner Dr. Jan C. Namyslo Martin Nieger Prof. Dr. Andreas Schmidt 《European journal of organic chemistry》2023,26(18):e202300216
Sydnone methides represent an almost unknown class of mesoionic compounds which possess exocyclic carbon substituents instead of oxygen (sydnones) or nitrogen (sydnone imines) in the 5-position of a 1,2,3-oxadiazolium ring. Unsubstituted 4-positions give rise to the generation of anionic N-heterocyclic carbenes by deprotonation. Preparations of new sydnone methides are described here. They can be represented by mesomeric structures with either exocyclic carbanionic groups like −C(CN)2−, −C(CN)(COOMe)−, −C(CN)(CONH2)−, and −C(CN)(SO2Me)−, or with the corresponding exocyclic C=C double bonds as a common feature with mesoionic N-heterocyclic olefins. An X-ray single structure analysis revealed a length of 140.7(3) pm of the exocyclic bond in the solid state. From the coalescence temperature (55 °C) determined by a series of 13C NMR experiments (150 MHz) at various temperatures, an energy of rotation of 18.5 Kcal/mol was calculated for this bond. The 13C NMR signals of the anionic N-heterocyclic carbenes, from which the 2-mesityl-substituted anionic NHC proved to be stable up to 10 °C, are highly shifted upfield (δcarbene=157.9 ppm−160.5 ppm). The carbenes can be reacted in situ with elemental selenium and chlorophosphanes to yield sydnone methide selenoethers after methylation and 4-phosphanylsydnone methides in good to excellent yields, respectively. 相似文献
20.
Benedek Stadler Dr. Nikolaus Gorgas Dr. Andrew J. P. White Prof. Dr. Mark R. Crimmin 《Angewandte Chemie (International ed. in English)》2023,62(16):e202219212
Herein we present the first double deprotonation of acetonitrile (CH3CN) using two equivalents of a bimetallic iron-aluminium complex. The products of this reaction contain an exceeding simple yet rare [CHCN]2− dianion moiety that bridges two metal fragments. DFT calculations suggest that the bonding to the metal centres occurs through heavily polarised covalent interactions. Mechanistic studies reveal the intermediacy of a monomeric [CH2CN]− complex, which has been characterised in situ. Our findings provide an important example in which a bimetallic metal complex achieves a new type of reactivity not previously encountered with monometallic counterparts.[1, 2] The isolation of a [CHCN]2− dianion through simple deprotonation of CH3CN also offers the possibility of establishing a broader chemistry of this motif. 相似文献