Search

Comprehensive Summary: The reaction between tripodal trisamidophosphine ligand H3PN3Ar and V(Mes)3(THF) (Mes = mesityl) yields the vanadium(III) complex (PN3Ar)V (1) with an open site in the axial position, which could coordinate with THF, pyridine, and NH3 to form the corresponding adducts (2—4). The vanadium(III) center is redox‐active, as demonstrated by cyclic voltammetry methods and chemical oxidation or reduction. Notably, a novel dinitrogen divanadium complex with a bridging N2 ligand, {K(THF)}2{[PN3Ar]V}2(μ‐N2) (6), was synthesized via treatment of 1 with 1 equivalent of potassium naphthalenide in THF under a N2 atmosphere. The electronic structures and binding properties of 6 are evaluated and discussed based on its DFT calculations. Additionally, these vanadium complexes (1, 5, 6) can serve as catalysts for the conversion of N2 into N(SiMe3)3 in the presence of reductants and Me3SiCl. [ABSTRACT FROM AUTHOR]

Iron-metal clusters are crucial in a variety of critical biological and material systems, including metalloenzymes, catalysts, and magnetic storage devices. However, a synthetic high-nuclear iron cluster has been absent due to the extreme difficulty in stabilizing species with direct iron−iron bonding. In this work, we have synthesized, crystallized, and characterized a (Tp*)4W4S12(Fe@Fe12) cluster (Tp* = tris(3,5-dimethyl-1-pyrazolyl)borate(1−)), which features a rare trideca-nuclear, icosahedral [Fe@Fe12] cluster core with direct multicenter iron−iron bonding between the interstitial iron (Fei) and peripheral irons (Fep), as well as Fep···Fep ferromagnetic coupling. Quantum chemistry studies reveal that the stability of the cluster arises from the 18-electron shell-closing of the [Fe@Fe12]16+ core, assisted by its bonding interactions with the peripheral tridentate [(Tp*)WS3]4− ligands which possess both S→Fe donation and spin-polarized Fe−W σ bonds. The ground-state electron spin is theoretically predicted to be S = 32/2 for the cluster. The existence of low oxidation-state (OS ∼ +1.23) iron in this compound may find interesting applications in magnetic storage, spintronics, redox chemistry, and cluster catalysis. [ABSTRACT FROM AUTHOR]

Constructing ambient‐stable, single‐atom‐layered metal‐based materials with atomic precision and understanding their underlying stability mechanisms are challenging. Here, stable single‐atom‐layered nanoclusters of Pd were synthesized and precisely characterized through electrospray ionization mass spectrometry and single‐crystal X‐ray crystallography. A pseudo‐pentalene‐like Pd8 unit was found in the nanocluster, interacting with two syn PPh units through nonmetal‐to‐metal ‐ring coordination. The unexpected coordination, which is distinctly different from the typical organoring‐to‐metal coordination in half‐sandwich‐type organometallic compounds, contributes to the ambient stability of the as‐obtained single‐atom‐layered nanocluster as revealed through theoretical and experimental analyses. Furthermore, quantum chemical calculations revealed dominant electron transition along the horizontal x‐direction of the Pd8 plane, indicating high photothermal conversion efficiency (PCE) of the nanocluster, which was verified by the experimental PCE of 73.3 %. Therefore, this study unveils the birth of a novel type of compound and the finding of the unusual nonmetal‐to‐metal ‐ring coordination and has important implications for future syntheses, structures, properties, and structure–property correlations of single‐atom‐layered metal‐based materials. [ABSTRACT FROM AUTHOR]

Di‐ and multinuclear hafnium complexes bridged by ligands have been rarely reported. In this article, a novel 3,5‐disubstituted pyrazolate‐bridged ligand LH5 with two [N2N]2−‐type chelating side arms was designed and synthesized, which supported a series of dinuclear hafnium complexes. Dinuclear hafnium azides [LHf2(μ‐1,1‐N3)2(N3)2][Na(THF)4] 3 and [LHf2(μ‐1,1‐N3)2(N3)2][Na(2,2,2‐Kryptofix)] 4 were further synthesized and structurally characterized, featuring two sets of terminal and bridging azido ligands like jellyfishes. The reactivity of 3 under reduction conditions was conducted, leading to a formation of a tetranuclear hafnium imido complex [L1Hf2(μ1‐NH)(N3){μ2‐K}]25. DFT calculations revealed that the mixed imido azide 5 was generated via an intramolecular C−H insertion from a putative dinuclear HfIV‐nitridyl intermediate. [ABSTRACT FROM AUTHOR]

High-valence Ti(IV)-based metallocalixarene coordination cages that are linked by oriented ancillary ligands are unknown so far. Herein, the first family of tunable calixarene-based coordination cages of Ti(IV) with a framework formula [Ti12(OiPr)12(TBC[4])6L6] have been assembled from six {Ti2(OiPr)2(TBC[4])}2+ nodes and six pyridinedicarboxylic ligands. Furthermore, the {Ti12L6} cage showed strong photocatalytic H2 evolution activity, and DFT studies were performed to explore its electronic structure. [ABSTRACT FROM AUTHOR]

Atropisomers with multiple stereogenic axes have attracted much attention due to their increasing significance in the fields of natural products, chiral materials, and drug discoveries. However, the catalytic stereoselective construction of axially chiral ring scaffolds with more than two axes on a single benzene ring remains a challenging task. Herein, we present an efficient method for synthesizing triaxially chiral polysubstituted naphthalene scaffolds via sequential Ni(II)‐catalyzed Diels–Alder reaction of isobenzofurans and TfOH‐promoted dehydrative aromatization reaction. Using 1,3‐biarylisobenzofurans and β‐aryl‐substituted α,β‐unsaturated N‐acyl pyrazoles as modular reaction partners, a series of naphthalenes with 1,3,4‐triaxes were synthesized with excellent enantioselectivities and diastereoselectivities. Furthermore, by attaching two pyrene chromophores to this novel triaxially chiral ring scaffold, a circularly polarized luminescence (CPL)‐active dye exhibiting a remarkable luminescence dissymmetry factor (glum=−0.019) and high fluorescence quantum efficiency (ØFL=0.29) was obtained, highlighting the potential applications of atropisomers with multiple stereogenic axes in the design of chiroptical organic materials. [ABSTRACT FROM AUTHOR]

While a series of trinuclear rare-earth metal methylene (divalent >CH 2 ) complexes with the so-called "ionic carbene" have been known for decades, the nature of metal-carbene interactions in this class of compounds remains elusive. Herein, a quantum chemical investigation has been performed to reveal the bonding nature in typical trimetallic "ionic carbene" species with the [M 3 (μ 3 -CH 2 )] (M = Sc, Y, La, and Ac) cluster core. Through various chemical bonding analyses, we have demonstrated that there exists a non-negligible covalent interaction between μ 3 -CH 2 and M 3 moieties, and the chemical bonding can be accounted for with two three-center two-electron (3c-2e) bonds. The chemical bonding analyses reveal that the metal d-electron configuration plays an important role in stabilizing various μ 3 -coordinated carbene complexes. The late transition metals do not favor such a μ 3 -coordination geometry, thus explaining why ionic carbene complexes are usually found for rare-earth and early transition metals. A series of ionic carbene complexes with early transition metals, lanthanides, and actinides are predicted to be stable as well. These reactive ionic carbene complexes may have characteristic properties for organic synthesis and catalysis.