Isolation and characterization of diazoolefins

Varava, Paul; Dong, Zhaowen; Scopelliti, Rosario; Fadaei‐Tirani, Farzaneh; Severin, Kay

doi:10.1038/s41557-021-00790-3

Cited by 49 publications

(92 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…One obvious reason might be the missing synthetic access, which was highlighted by Stang in 1978, suggesting diazoalkenes (R 2 C=C=N 2 ) to be the best vinylidene precursors. 28 However, stable diazoalkenes were unknown until we reported our recent synthesis of the first room-temperature-stable representative, 29 , 30 which now enables the entry point into this fundamental compound class. Here, we report the photogeneration and characterization of a ground-state triplet vinylidene using electron paramagnetic resonance (EPR) spectroscopy.…”

Section: Introductionmentioning

confidence: 99%

Characterization of a Triplet Vinylidene

et al. 2021

View full text Add to dashboard Cite

Singlet vinylidenes (R 2 C=C:) are proposed as intermediates in a series of organic reactions, and very few have been studied by matrix isolation or gas-phase spectroscopy. Triplet vinylidenes, however, featuring two unpaired electrons at a monosubstituted carbon atom are thus far only predicted as electronically excited-state species and represent an unexplored class of carbon-centered diradicals. We report the photochemical generation and low-temperature EPR/ENDOR characterization of the first ground-state high-spin (triplet) vinylidene. The zero-field splitting parameters ( D = 0.377 cm –1 and | E| / D = 0.028) were determined, and the 13 C hyperfine coupling tensor was obtained by 13 C-ENDOR measurements. Most strikingly, the isotropic 13 C hyperfine coupling constant (50 MHz) is far smaller than the characteristic values of triplet carbenes, demonstrating a unique electronic structure which is supported by quantum chemical calculations.

show abstract

Section: Introductionmentioning

confidence: 99%

Characterization of a Triplet Vinylidene

et al. 2021

View full text Add to dashboard Cite

show abstract

“…However, first studies with late transition metal complexes had shown that N-heterocyclic diazoolefins can bind to the metal center intact, that is without loss of dinitrogen. 29 Below, we demonstrate that neutral vinylidene complexes are obtained by combining N-heterocyclic diazoolefins with an early transition metal complex, VCl 3 (THF) 3 . Structural and theoretical analyses show that N-heterocyclic vinylidenes are unique C-donor ligands, with strong σ- and π-donor abilities.…”

mentioning

confidence: 81%

“…Reaction of the imidazole-based diazoolefin 1 29 with VCl 3 (THF) 3 in Et 2 O resulted in the formation of the vinylidene complex 2 , which could be isolated in 56% yield (Scheme 1, Dipp = 2,6-C 6 H 3 iPr 2 ). In a related fashion, the vinylidene complex 4 was obtained in 82% yield from the mesoionic diazoolefin 3 .…”

mentioning

confidence: 99%

See 1 more Smart Citation

Vanadium complexes with N-heterocyclic vinylidene ligands

et al. 2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…NHOs 48,49 with similar structural parameters and spectroscopic characteristics. Further studies were carried to explore the reactivity of diazoolefins derived from mNHOs (Scheme 3).…”

Section: Perspective Dalton Transactionsmentioning

confidence: 93%