Cerium(III) yldiide complexes with divergent CO reactivity.

Synthesis of cerium yldiide complexes and their reactivity with CO is demonstrated. In the case of the sulphur-tethered yldiide, the ketenyl complex is formed with release of PPh, while PhPCCO is formed along with a sulfinato ligand in the case of the tosyl-substituted yldiide. Computational analysis shows that this diverging reactivity is due to the stability of the two isomers in the first step of each mechanism.

Synthesis, Structure, and Bonding of Actinide-Rhenium Polyhydrides.

The synthesis of actinide tetrarhenate complexes completes a series of iridate, osmate, and rhenate polyhydrides, allowing for structural and bonding comparisons to be made. Computational studies examine the bonding interactions, particularly between metals, in these complexes. Several factors─including metal oxidation state, coordination number, and dispersion effects─affect metal-metal distances and covalency in these actinide tetrametallates.

Reduction of CS to an ethanetetrathiolate by a hydride-bridged uranium-iridium heterobimetallic complex.

We report the synthesis of a heterobimetallic U(III)-Ir species which reacts with CS to form the novel ethanetetrathiolate fragment hydride insertion and C-C coupling. Computational studies suggest the formation of a radical intermediate, which may couple with another equivalent to form the final product.

Correction: Supramolecular nanocapsules as two-fold stabilizers of outer-cavity sub-nanometric Ru NPs and inner-cavity ultra-small Ru clusters.

Correction for 'Supramolecular nanocapsules as two-fold stabilizers of outer-cavity sub-nanometric Ru NPs and inner-cavity ultra-small Ru clusters' by Ernest Ubasart , , 2022, , 607-615, https://doi.org/10.1039/D1NH00677K.

CO cleavage by tantalum/M (M = iridium, osmium) heterobimetallic complexes.

A novel Ta/Os heterobimetallic complex, [Ta(CHBu)(μ-H)OsCp*], 2, is prepared by protonolysis of Ta(CHBu)(CHBu) with Cp*OsH. Treatment of 2 and its iridium analogue [Ta(CHBu)(μ-H)IrCp*], 1, with CO under mild conditions reveal the efficient cleavage of CO, driven by the formation of a tantalum oxo species in conjunction with CO transfer to the osmium or iridium fragments, to form Cp*Ir(CO)H and Cp*Os(CO)H, respectively. This bimetallic reactivity diverges from more classical CO insertion into metal-X (X = metal, hydride, alkyl) bonds.

Photolysis-driven bond activation by thorium and uranium tetraosmate polyhydride complexes.

Transition metal multimetallic complexes have seen intense study due to their unique bonding and potential for cooperative reactivity, but actinide-transition metal (An-TM) species are far less understood. We have synthesized uranium- and thorium-osmium heterometallic polyhydride complexes in order to study An-Os bonding and investigate the reactivity of An-Os interactions. Computational studies suggest the presence of a significant bonding interaction between the actinide center and the four coordinated osmium centers supported by bridging hydrides.

π-Bonding of Group 11 Metals to a Tantalum Alkylidyne Alkyl Complex Promotes Unusual Tautomerism to Bis-alkylidene and CO to Ketenyl Transformation.

A salt metathesis synthetic strategy is used to access rare tantalum/coinage metal (Cu, Ag, Au) heterobimetallic complexes. Specifically, complex [Li(THF)][Ta(CBu)(CHBu)], , reacts with (IPr)MCl (M = Cu, Ag, Au, IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) to afford the alkylidyne-bridged species [Ta(CHBu)(μ-CBu)M(IPr)] . Interestingly, π-bonding of group 11 metals to the Ta─C moiety promotes a rare alkylidyne alkyl to bis-alkylidene tautomerism, in which compounds are in equilibrium with [Ta(CHBu)(CHBu)(μ-CHBu)M(IPr)] .

Probing Basal and Prismatic Planes of Graphitic Materials for Metal Single Atom and Subnanometer Cluster Stabilization.

Supported metal single atom catalysis is a dynamic research area in catalysis science combining the advantages of homogeneous and heterogeneous catalysis. Understanding the interactions between metal single atoms and the support constitutes a challenge facing the development of such catalysts, since these interactions are essential in optimizing the catalytic performance. For conventional carbon supports, two types of surfaces can contribute to single atom stabilization: the basal planes and the prismatic surface; both of which can be decorated by defects and surface oxygen groups.

Oxidative Addition of E-H (E=C, N) Bonds to Transient Uranium(II) Centers.

Two-electron oxidative addition is one of the most important elementary reactions for d-block transition metals but it is uncommon for f-block elements. Here, we report the first examples of intermolecular oxidative addition of E-H (E=C, N) bonds to uranium(II) centers. The transient U(II) species was formed in-situ by reducing a heterometallic cluster featuring U(IV)-Pd(0) bonds with potassium-graphite (KC).

Planar Tetranuclear Uranium Hydride Cluster Supported by ansa-Bis(cyclopentadienyl) Ligands.

Polynuclear metal hydride clusters play important roles in various catalytic processes, with most of the reported polynuclear metal hydride clusters adopting a polyhedral three-dimensional structure. Herein, we report the first example of a planar tetranuclear uranium hydride cluster [(CpCMeCMeCp)U](μ-H)(μ-H) (UH). It was synthesized by reacting an ansa-bis(cyclopentadienyl) ligand-supported uranium chloride precursor [(CpCMeCMeCp)U](μ-Cl)(μ-Cl) with NaHBEt.

Multimetallic Uranium Nitride Cubane Clusters from Dinitrogen Cleavage.

Dinitrogen cleavage provides an attractive but poorly studied route to the assembly of multimetallic nitride clusters. Here, we show that the monoelectron reduction of the dinitrogen complex [{U(OCH-Bu-2,4,6)}(μ-η:η-N)], , allows us to generate, for the first time, a uranium complex presenting a rare triply reduced N moiety ((μ-η:η-N)). Importantly, the bound dinitrogen can be further reduced, affording the UN cubane cluster, , and the UN edge-shared cubane cluster, , thus showing that (N) can be an intermediate in nitride formation.

A binuclear guanidinate yttrium carbyne complex: unique reactivity toward unsaturated C-N, C-O and C-S bonds.

A guanidinato-stabilized binuclear yttrium carbyne complex [(PhCH)NC(NCHPr-2,6)]Y(μ-Me)(AlMe)(μ-CH) (1) was synthesized C-H bond activation and its versatile reactivities were investigated. Complex 1 underwent σ-bond metathesis with PhSSPh and nucleophilic addition with PhCN to form the corresponding yttrium thiolate complex 3 and aza-allyl complex 4 respectively. Additionally, the rare yttrium carbide complex 5 was also prepared by treatment of complex 1 with S.

Monodentate Alkoxy/Aryloxy Anchored Yttrium Dihydrides; Anticipated Outcomes and Surprises.

The synthesis, characterization, and solid-state structure of bulky alkoxy- and aryloxy-supported yttrium polynuclear hydrides are reported. Hydrogenolysis of the supertrityl alkoxy anchored yttrium dialkyl, Y(OTr*)(CHSiMe)(THF) () (Tr* = tris(3,5-di--butylphenyl)methyl), resulted in the clean conversion to the tetranuclear dihydride, [Y(OTr*)H(THF)] (). X-ray analysis revealed a highly symmetrical structure (̅ site symmetry) with the four Y atoms located on the corners of a compressed tetrahedron, each bonded to an OTr* and tetrahydrofuran (THF) ligand and the cluster held together by four face-capping, μ-H, and four edge-bridging, μ-H, hydrides.

An Experimental and Computational Investigation Rules Out Direct Nucleophilic Addition on the N Ligand in Manganese Dinitrogen Complex [Cp(CO) Mn(N )].

We have re-examined the reactivity of the manganese dinitrogen complex [Cp(CO) Mn(N )] (1, Cp=η -cyclopentadienyl, C H ) with phenylithium (PhLi). By combining experiment and density functional theory (DFT), we have found that, unlike previously reported, the direct nucleophilic attack of the carbanion onto coordinated dinitrogen does not occur. Instead, PhLi reacts with one of the CO ligands to provide an anionic acylcarbonyl dinitrogen metallate [Cp(CO)(N )MnCOPh]Li (3) that is stable only below -40 °C.

Synthesis and Reactivity of a Zinc Diazoalkyl Complex: [3+2] Cycloaddition Reaction with Carbon Monoxide.

This work reports the synthesis, characterization, and reactivity of the first example of a well-defined zinc α-diazoalkyl complex. Treatment of zinc(I)-zinc(I) bonded compound L Zn [L=CH C(2,6- Pr C H N)CHC(CH )(NCH CH PPh )] or zinc(II) hydride LZnH with trimethylsilyldiazomethane affords zinc diazoalkyl complex LZnC(N )SiMe . This complex liberates N in the presence of a nickel catalyst to form an α-zincated phosphorus ylide by reacting with the pendant phosphine.

Magnesium(I) Reduction of Aluminum(III) Hydride Complexes: Generation of Mixed Valence Aluminum (Al /Al ) Hydride Cluster Compounds, [Al H (NR ) {Mg(β-diketiminate)} ].

Reduction of a range of amido- and aryloxy-aluminum dihydride complexes, e.g. [AlH (NR ){N(SiMe ) }] (NR =NMe or N-methylpiperidine (NMP)), with β-diketiminato dimagnesium(I) reagents, [{( Nacnac)Mg} ] ( Nacnac=[HC(MeCNAr) ] , Ar=mesityl (Mes) or 2,6-xylyl (Xyl)), have afforded deep red mixed valence aluminum hydride cluster compounds, [Al H (NR ) {Mg( Nacnac)} ], which have an average Al oxidation state of +0.

1,2-Palladasilacyclobutene: The Missing Link in the Pd-Catalyzed Annulation of Alkynes for the Silirene-to-Silole Transformation.

The palladium-catalyzed annulation reaction of alkynes enables an attractive approach to siloles. Their access from silirenes and terminal alkynes proved rather general, involving reactive intermediates that have remained elusive to date. Starting from 1,2-bis(3-thienyl)silirene as a source of photochromic siloles, the mechanism of the annulation reaction has been revisited, and palladasilacyclobutenes resulting from the activation of the silirene could be isolated and thoroughly characterized (NMR, X-ray, and DFT).

Correction: Isolation of C1 through C4 derivatives from CO using heteroleptic uranium(iii) metallocene aryloxide complexes.

[This corrects the article DOI: 10.1039/D2SC06375A.].

Isolation of C1 through C4 derivatives from CO using heteroleptic uranium(iii) metallocene aryloxide complexes.

The conversion of C1 feedstock molecules such as CO into commodity chemicals is a desirable, but challenging, endeavour. When the U(iii) complex, [(CMe)U(O-2,6- Bu-4-MeCH)], is exposed to 1 atm of CO, only coordination is observed by IR spectroscopy as well as X-ray crystallography, unveiling a rare structurally characterized f element carbonyl. However, using [(CMe)(MesO)U (THF)], Mes = 2,4,6-MeCH, reaction with CO forms the bridging ethynediolate species, [{(CMe)(MesO)U}(μ-OCCO)].

A versatile strategy for the formation of hydride-bridged actinide-iridium multimetallics.

Reaction of the potassium pentamethylcyclopentadienyl iridate tris-hydride K[IrCp*H] with UCl and ThCl(DME) led to the complete replacement of the halide ligands to generate multimetallic complexes U{(μ-H)IrCp*} (1) and Th{[(μ-H)(H)IrCp*][(μ-H)IrCp*]} (2), respectively. These analogues feature a significant discrepancy in hydride bonding modes; 1 contains twelve bridging hydrides while 2 contains ten bridging hydrides and two terminal, Ir-bound hydrides. Use of a U(iii) starting material, UI(1,4-dioxane), resulted in the octanuclear complex {U[(μ-H)IrCp*][(μ-H)IrCp*]} (3).

Ruthenium nanoparticles canopied by heptagon-containing saddle-shaped nanographenes as efficient aromatic hydrogenation catalysts.

The search for new ligands capable of modifying the metal nanoparticle (MNP) catalytic behavior is of increasing interest. Herein we present the first example of RuNPs stabilized with non-planar heptagon-containing saddle-shaped nanographenes (Ru@1 and Ru@2). The resemblance to graphene-supported MNPs makes these non-planar nanographene-stabilized RuNPs very attractive systems to further investigate graphene-metal interactions.

Synthesis and Reactivity of Triangular Heterometallic Complexes Containing Zn-Zn Bond.

This work provides a facile access to a series of triangular [ZnM] (M = group 10 and 11 metals) clusters. Treatment of Zn-Zn-bonded compounds [Zn-Zn] ( = CHC(2,6-PrCHN)CHC(CH)(NCHCHPR); R = Ph, Pr) with zero-valent transition-metal reagents selectively afforded the corresponding triangular clusters [ZnM], where M = Ni(0), Pd(0), and Pt(0). Notably, the isoelectronic triangular clusters [ZnM], where M = Ag(I) and Cu(I), could also be obtained by reactions of [LZn-ZnL] with AgOTf and CuOTf, respectively.

Supramolecular nanocapsules as two-fold stabilizers of outer-cavity sub-nanometric Ru NPs and inner-cavity ultra-small Ru clusters.

The synthesis of metallic nanoparticles (MNP) with high surface area and controlled shape is of paramount importance to increase their catalytic performance. The detailed growing process of NP is mostly unknown and understanding the specific steps would pave the way for a rational synthesis of the desired MNP. Here we take advantage of the stabilization properties exerted by the tetragonal prismatic supramolecular nanocapsule 8·(BArF) to develop a synthetic methodology for sub-nanometric RuNP (0.

Rational Preparation of Well-Defined Multinuclear Iridium-Aluminum Polyhydride Clusters and Comparative Reactivity.

We report an original alkane elimination approach, entailing the protonolysis of triisobutylaluminum by the acidic hydrides from Cp*IrH. This strategy allows access to a series of well-defined tri- and tetranuclear iridium aluminum polyhydride clusters, depending on the stoichiometry: [Cp*IrHAl(Bu)] (), [Cp*IrHAl(Bu)] (), [(Cp*IrH)Al(Bu)] (), and [(Cp*IrH)Al] (). Contrary to most transition-metal aluminohydride complexes, which can be considered as [AlH] aluminates and LnM moieties, the situation here is reversed: These complexes have original structures that are best described as [Cp*IrH] iridate units surrounding cationic Al(III) fragments.

Hydroboration of vinyl halides with mesitylborane: a direct access to (mesityl)(alkyl)haloboranes.

The direct access to (mesityl)(alkyl)haloboranes (Mes(Alk)BX) (X = Br, Cl) from mesitylborane dimer and vinyl halides is presented. The involved hydroboration reaction results in the transfer of the halogen atom from the carbon of the starting material to the boron in the final product. The reactivity of the obtained Mes(Alk)BX has been evaluated for the synthesis of the bipyridyl boronium cations and 2-arylpyridine derived boron N^C-chelates.