Zero-valent nickel complexes of bis(phosphino)-o-carboranes

Röhrscheid, Freimund; Holm, R. H.

doi:10.1016/s0022-328x(00)88844-0

Cited by 22 publications

(7 citation statements)

References 13 publications

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“…Ligand Properties of Anionic Carboranyl Phosphines. The inductive effects of the C-functionalized neutral clusters H 2 C 2 B 10 H 10 and HC 2 B 8 H 10 , which are isoelectronic with 3 and 4, were first elucidated by Holm 126 and Zhakharkin, 127 respectively. Both of these clusters are strong electron-withdrawing groups when C-functionalized, more so than a benzene ring.…”

Section: Closo-carborane Anions As Ligand Substituents For Phosphinesmentioning

confidence: 99%

Nonclassical Applications of closo-Carborane Anions: From Main Group Chemistry and Catalysis to Energy Storage

et al. 2019

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Classically closo-carborane anions, particularly [HCB11H11]− and [HCB9H9]−, and their derivatives have primarily been used as weakly coordinating anions to isolate reactive intermediates, platforms for stoichiometric and catalytic functionalization, counteranions for simple Lewis acid catalysis, and components of materials like liquid crystals. The aim of this article is to educate the reader on the contemporary nonclassical applications of these anions. Specifically, this review will cover new directions in main group catalysis utilized to achieve some of the most challenging catalytic reactions such as C–F, C–H, and C–C functionalizations that are difficult or impossible to realize with transition metals. In addition, the review will cover the utilization of the clusters as dianionic C σ-bound ligands for coordination chemistry, ligand substituents for coordination chemistry and advanced catalyst design, and covalently bound spectator substituents to stabilize radicals. Furthermore, their applications as solution-based and solid-state electrolytes for Li, Na, and Mg batteries will be discussed.

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Section: Closo-carborane Anions As Ligand Substituents For Phosphinesmentioning

confidence: 99%

Nonclassical Applications of closo-Carborane Anions: From Main Group Chemistry and Catalysis to Energy Storage

et al. 2019

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“…The lithiated intermediate product was isolated and coupled with chlorodiphenylphosphine (Scheme ). ,, In the next step, the proligand P 2 - o CB was coupled with silver hexafluorophosphate (AgPF 6 ) in ethanol for 1 h, and then, the bridging ligand tpbz was added. The stochiometric ratio of the reactants, P 2 - o CB:AgPF 6 :tpbz, was kept to 2:2:1.…”

mentioning

confidence: 99%

Dinuclear Ag(I) Complex Designed for Highly Efficient Thermally Activated Delayed Fluorescence

Shafikov

Suleymanova

Schinabeck

et al. 2018

J. Phys. Chem. Lett.

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The dinuclear Ag(I) complex has been designed to show thermally activated delayed fluorescence (TADF) of high efficiency. Strongly electron-donating terminal ligands are introduced to destabilize the d orbitals of the Ag ions. Consequently, the orbitals distinctly contribute to the HOMO, whereas the LUMO is localized on the bridging ligand. This ensures charge transfer character of the lowest excited singlet S and triplet T states. Accordingly, a small energy gap ΔE(S-T) is obtained, being essential for TADF behavior. Photophysical investigations show that at ambient temperature the complex exhibits TADF reaching a quantum yield of Φ = 70% with the decay time of only τ = 1.9 μs, manifesting one of the fastest TADF decays observed so far. Such an outstanding TADF efficiency is based on a small value of ΔE(S-T) = 480 cm combined with a large transition rate of k(S → S) = 2.2 × 10 s.

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“…The IR stretching vibration frequencies of the CO groups in [SiCCSi]Ni(CO) 2 were observed at ν =1982 and 1934 cm −1 . These observed frequencies are red‐shifted compared to [LSi:(CH 2 )NHCNi(CO) 2 ] ( ν =1952, 1887 cm −1 ) and [(NHC Cy ) 2 Ni(CO) 2 ] ( ν =1949, 1878 cm −1 ; Cy=cyclohexyl) but blue‐shifted compared to {[(R 2 PC) 2 B 10 H 10 ]Ni(CO) 2 } (R=Ph: ν =2021 and 1966 cm −1 ; R=Et: ν =2013 and 1955 cm −1 ), and [(NHC Mes ) 2 Ni(CO) 2 ] ( ν =2051, 1887 cm −1 ; Mes=2,4,6‐Me 3 C 6 H 2 ) . This suggests that the σ‐donor strength of SiCCSi can be larger than that of NHC or phosphine ligands and even exceeds that of the [SiFcSi] ligand D in [SiFcSi]NiBr 2 , which was synthesized and structurally characterized as well (see Figure S15 and Table S6 in the Supporting Information).…”

Section: Methodsmentioning

confidence: 90%

A Bis(silylene)‐Substituted ortho‐Carborane as a Superior Ligand in the Nickel‐Catalyzed Amination of Arenes

et al. 2016

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The synthesis and structure of the first 1,2-bis-(NHSi)-substituted ortho-carborane [(LSi:)C] 2 B 10 H 10 (termed SiCCSi)i sr eported (NHSi = N-heterocyclic silylene;L = PhC(NtBu) 2 ). Its suitability to serve as ar eliable bis(silylene) chelating ligand for transition metals is demonstrated by the formation of [SiCCSi]NiBr 2 and [SiCCSi]Ni(CO) 2 complexes. The CO stretching vibration modes of the latter indicate that the Si II atoms in the SiCCSi ligand are even stronger s donors than the P III atoms in phosphines and C II atoms in Nheterocyclic carbene (NHC) ligands.M oreover,t he strong donor character of the [SiCCSi]ligand enables [SiCCSi]NiBr 2 to act as an outstanding precatalyst (0.5 mol %loading) in the catalytic aminations of arenes,s urpassing the activity of previously knownm olecular Ni-based precatalysts (1-10 mol %). Scheme 1. Multidentate NHSi ligands.

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Zero-valent nickel complexes of bis(phosphino)-o-carboranes

Cited by 22 publications

References 13 publications

Nonclassical Applications of closo-Carborane Anions: From Main Group Chemistry and Catalysis to Energy Storage

Nonclassical Applications of closo-Carborane Anions: From Main Group Chemistry and Catalysis to Energy Storage

Dinuclear Ag(I) Complex Designed for Highly Efficient Thermally Activated Delayed Fluorescence

A Bis(silylene)‐Substituted ortho‐Carborane as a Superior Ligand in the Nickel‐Catalyzed Amination of Arenes

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