N,N-Addition of Frustrated Lewis Pairs to Nitric Oxide: An Easy Entry to a Unique Family of Aminoxyl Radicals

The chemistry of some reactive frustrated Lewis pairs (FLPs) is reported. This includes intramolecular P/B and N/B FLPs, some of which were used as catalysts for the hydrogenation of electron-rich olefin substrates. Some advanced intermolecular FLPs are reported, which includes systems derived from very bulky alkenyl boranes obtained from 1,1-carboboration reactions of 1-alkynes with tris(pentafluorophenyl)borane. Some such systems activate dihydrogen and transfer the resulting proton/hydride pair even to some electron-poor alkynes. Eventually, we report on the reaction of our intramolecular ethylene-bridged P/B FLP with nitric oxide (NO). N,B-addition of the P-Lewis base/B-Lewis acid combination is observed to form a new type of a persistent aminoxyl radical. Some of the chemistry of the new FLP-NO radicals is presented and discussed.

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Bifunctional Fluorophosphonium Triflates as Intramolecular Frustrated Lewis Pairs: Reversible CO 2 Sequestration and Binding of Carbonyls, Nitriles and Acetylenes

Chemistry - A European Journal ◽

10.1002/chem.202102382 ◽

2021 ◽

Author(s):

Chun‐Xiang Guo ◽

Kai Schwedtmann ◽

Jannis Fidelius ◽

Felix Hennersdorf ◽

Arne Dickschat ◽

...

Keyword(s):

Frustrated Lewis Pairs ◽

Lewis Pairs

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Bis(perchlorocatecholato)silane and Heteroleptic Bidonors: Hidden Frustrated Lewis Pairs by Ring Strain

Chemical Communications ◽

10.1039/d1cc03452a ◽

2021 ◽

Author(s):

Deborah Hartmann ◽

Sven Braner ◽

Lutz Greb

Keyword(s):

Ammonia Borane ◽

Frustrated Lewis Pairs ◽

Ring Strain ◽

Frustrated Lewis Pair ◽

Lewis Pairs

Bis(perchlorocatecholato)silane and bidentate N,N- or N,P-heteroleptic donors form hexacoordinated complexes. Depending on the ring strain and hemilability in the adducts, Frustrated Lewis pair reactivity with aldehydes and catalytic ammonia borane...

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Supramolecular Systems Containing B–N Frustrated Lewis Pairs of Tris(pentafluorophenyl)borane and Triphenylamine Derivatives

Organic Materials ◽

10.1055/s-0041-1727235 ◽

2021 ◽

Vol 03 (02) ◽

pp. 174-183

Author(s):

P. Chidchob ◽

S. A. H. Jansen ◽

S. C. J. Meskers ◽

E. Weyandt ◽

N. P. van Leest ◽

...

Keyword(s):

Materials Science ◽

Supramolecular Polymers ◽

Frustrated Lewis Pairs ◽

Paramagnetic Resonance ◽

Donor And Acceptor ◽

Donor Acceptor ◽

Noncovalent Polymers ◽

Electron Paramagnetic ◽

Supramolecular Polymerization ◽

Lewis Pairs

The introduction of a chemical additive to supramolecular polymers holds high potential in the development of new structures and functions. In this regard, various donor- and acceptor-based molecules have been applied in the design of these noncovalent polymers. However, the incorporation of boron–nitrogen frustrated Lewis pairs in such architectures is still rare despite their many intriguing properties in catalysis and materials science. The limited choices of suitable boron derivatives represent one of the main limitations for the advancement in this direction. Here, we examine the use of the commercially available tris(pentafluorophenyl)borane with various triphenylamine derivatives to create supramolecular B–N charge transfer systems. Our results highlight the importance of a proper balance between the donor/acceptor strength and the driving force for supramolecular polymerization to achieve stable, long-range ordered B–N systems. Detailed analyses using electron paramagnetic resonance and optical spectroscopy suggest that tris(pentafluorophenyl)borane displays complex behavior with the amide-based triphenylamine supramolecular polymers and may interact in dimers or larger chiral aggregates, depending on the specific structure of the triphenylamines.

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