Generation and EPR Spectroscopy of the First Silenyl Radicals, R2C=Si.−R: Experiment and Theory

Daniel Pinchuk; Yosi Kratish; Jomon Mathew; Lieby Zborovsky; Dmitry Bravo-Zhivotovskii; Boris Tumanskii; Yitzhak Apeloig

doi:10.1002/anie.201901772

Generation and EPR Spectroscopy of the First Silenyl Radicals, R₂C=Si^.−R: Experiment and Theory

Daniel Pinchuk, Yosi Kratish, Jomon Mathew, Lieby Zborovsky, Dmitry Bravo-Zhivotovskii, Boris Tumanskii^*, Yitzhak Apeloig

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

4 Scopus citations

Abstract

The first two persistent silenyl radicals (R₂C=Si^.−R), with a half-life (t_1/2) of about 30 min, were generated and characterized by electron paramagnetic resonance (EPR) spectroscopy. The large hyperfine coupling constants (hfccs) (a(²⁹Si_α)=137.5–148.0 G) indicate that the unpaired electron has substantial s character. DFT calculations, which are in good agreement with the experimentally observed hfccs, predict a strongly bent structure (∡C=Si−R=134.7–140.7°). In contrast, the analogous vinyl radical, R₂C=C^.−R (t_1/2≈3 h), exhibits a small hfcc (a(¹³C_α)=26.6 G) and has a nearly linear geometry (∡C=C−R=168.7°).

Original language	English (US)
Pages (from-to)	7435-7439
Number of pages	5
Journal	Angewandte Chemie - International Edition
Volume	58
Issue number	22
DOIs	https://doi.org/10.1002/anie.201901772
State	Published - May 27 2019
Externally published	Yes

Keywords

EPR spectroscopy
metal-substituted silenes
silenyl radicals
silyl radicals
vinyl radicals

ASJC Scopus subject areas

Catalysis
Chemistry(all)

Access to Document

10.1002/anie.201901772

Cite this

@article{4e93f3e787be42bd9d1b8fb9e3b0b048,

title = "Generation and EPR Spectroscopy of the First Silenyl Radicals, R2C=Si.−R: Experiment and Theory",

abstract = "The first two persistent silenyl radicals (R2C=Si.−R), with a half-life (t1/2) of about 30 min, were generated and characterized by electron paramagnetic resonance (EPR) spectroscopy. The large hyperfine coupling constants (hfccs) (a(29Siα)=137.5–148.0 G) indicate that the unpaired electron has substantial s character. DFT calculations, which are in good agreement with the experimentally observed hfccs, predict a strongly bent structure (∡C=Si−R=134.7–140.7°). In contrast, the analogous vinyl radical, R2C=C.−R (t1/2≈3 h), exhibits a small hfcc (a(13Cα)=26.6 G) and has a nearly linear geometry (∡C=C−R=168.7°).",

keywords = "EPR spectroscopy, metal-substituted silenes, silenyl radicals, silyl radicals, vinyl radicals",

author = "Daniel Pinchuk and Yosi Kratish and Jomon Mathew and Lieby Zborovsky and Dmitry Bravo-Zhivotovskii and Boris Tumanskii and Yitzhak Apeloig",

note = "Funding Information: This research was supported by the Israel Science Foundation (ISF) and the Minerva Foundation in Munich. B.T. and D.B.-Z. are grateful to the Ministry of Immigrant Absorption, State of Israel, for a Kamea fellowship. Publisher Copyright: {\textcopyright} 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim",

year = "2019",

month = may,

day = "27",

doi = "10.1002/anie.201901772",

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T1 - Generation and EPR Spectroscopy of the First Silenyl Radicals, R2C=Si.−R

T2 - Experiment and Theory

AU - Pinchuk, Daniel

AU - Kratish, Yosi

AU - Mathew, Jomon

AU - Zborovsky, Lieby

AU - Bravo-Zhivotovskii, Dmitry

AU - Tumanskii, Boris

AU - Apeloig, Yitzhak

N1 - Funding Information: This research was supported by the Israel Science Foundation (ISF) and the Minerva Foundation in Munich. B.T. and D.B.-Z. are grateful to the Ministry of Immigrant Absorption, State of Israel, for a Kamea fellowship. Publisher Copyright: © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

PY - 2019/5/27

Y1 - 2019/5/27

N2 - The first two persistent silenyl radicals (R2C=Si.−R), with a half-life (t1/2) of about 30 min, were generated and characterized by electron paramagnetic resonance (EPR) spectroscopy. The large hyperfine coupling constants (hfccs) (a(29Siα)=137.5–148.0 G) indicate that the unpaired electron has substantial s character. DFT calculations, which are in good agreement with the experimentally observed hfccs, predict a strongly bent structure (∡C=Si−R=134.7–140.7°). In contrast, the analogous vinyl radical, R2C=C.−R (t1/2≈3 h), exhibits a small hfcc (a(13Cα)=26.6 G) and has a nearly linear geometry (∡C=C−R=168.7°).

AB - The first two persistent silenyl radicals (R2C=Si.−R), with a half-life (t1/2) of about 30 min, were generated and characterized by electron paramagnetic resonance (EPR) spectroscopy. The large hyperfine coupling constants (hfccs) (a(29Siα)=137.5–148.0 G) indicate that the unpaired electron has substantial s character. DFT calculations, which are in good agreement with the experimentally observed hfccs, predict a strongly bent structure (∡C=Si−R=134.7–140.7°). In contrast, the analogous vinyl radical, R2C=C.−R (t1/2≈3 h), exhibits a small hfcc (a(13Cα)=26.6 G) and has a nearly linear geometry (∡C=C−R=168.7°).

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