Static distortion of radical cations of cyclopropane at 4.2 K: e.s.r. evidence

Iwasaki, Machio; Toriyama, Kazumi; Nunome, Keichi

doi:10.1039/c39830000202

Cited by 72 publications

(58 citation statements)

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“…The distortion to D 2h symmetry can, in fact, be detected experimentally in a matrix at low temperatures. [100] The ESR spectra of C 6 H 6 in a freon matrix indicate an increased spin density at atoms C 1 and C 4 at 4.2 K but an equivalent spin density at 100 K (Figure 19). Thus, the question arises whether the D 2h structure is static and destabilized at higher temper- Figure 19.…”

Section: Benzenementioning

confidence: 96%

Chemical Applications of Zero Kinetic Energy (ZEKE) Photoelectron Spectroscopy

Müller‐Dethlefs

Schlag

1998

Angewandte Chemie International Edition

130

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The extremely improved resolution of ZEKE spectroscopy is one of its main advantages over conventional photoelectron (PE) spectroscopy. A good illustration of this is provided by the comparison of the photoelectron spectrum of NO with the corresponding ZEKE spectrum (shown on the right). ZEKE spectroscopy can be used to characterize large organic molecules such as benzene and para‐difluorobenzene, hydroden‐bonded complexes such as phenol–water, transition metal clusters such as Nb3O, van der Waals complexes such as benzene–argon, and even reactive intermediates.

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Section: Benzenementioning

confidence: 96%

Chemical Applications of Zero Kinetic Energy (ZEKE) Photoelectron Spectroscopy

Müller‐Dethlefs

Schlag

1998

Angewandte Chemie International Edition

130

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“…Before we discuss the obtained HFI fields in Table II for individual organics, we compare our calculations with well-documented experimental data of the HFI strengths in benzene cation 22 and C 60 anion. 23 For benzene cation, the removal of one electron causes a Jahn-Teller distortion of molecular structure from D 6h to D 2h symmetry.…”

Section: A Organics Containing Only H Nuclear Spinmentioning

confidence: 99%

Hyperfine interaction and its effects on spin dynamics in organic solids

Ding

Wang

2013

Phys. Rev. B

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Hyperfine interaction (HFI) and spin-orbit coupling are two major sources that affect electron spin dynamics. Here we present a systematic study of the HFI and its role in organic spintronic applications. For electron spin dynamics in disordered π-conjugated organics, the HFI can be characterized by an effective magnetic field whose modular square is a weighted sum of contact and dipolar contributions. We determine the effective HFI fields of some common π-conjugated organics studied in the literature via first-principles calculations. Most of them are found to be less than 2 mT. While the H atoms are the major source of the HFI in organics containing only the C and H atoms, many organics contain other nuclear spins, such as Al and N in tris-(8-hydroxyquinoline) aluminum, that contribute to the total HFI. Consequently the deuteration effect on the HFI in the latter may be much weaker than in the former. The HFI gives rise to multiple resonance peaks in electron spin resonance. In disordered organic solids, these individual resonances are unresolved, leading to a broad peak whose width is proportional to the effective HFI field. As electrons hop among adjacent organic molecules, they experience a randomly varying local HFI field, inducing electron spin relaxation and diffusion. This is analyzed rigorously based on master equations. Electron spin relaxation undergoes a crossover along the ratio between the electron hopping rateη and the Larmor frequency Ω of the HFI field. The spin relaxation rate increases (decreases) with η whenη ≪ Ω (η ≫ Ω). A coherent beating of electron spin at Ω is possible when the external field is small compared to the HFI. In this regime, the magnetic field is found to enhance the spin relaxation.

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“…The approximate independence of the yield of on the chain length suggests that the process of formation occurs at chain ends, as follows from studies on the structure and reactions of radical cations in freon matrices [5][6][7][8]. In the cited publications, it was found that the radical cations of linear alkanes in CFCI 3 and SF 6 matrices exhibited a planar extended zigzag structure ( transtrans conformers).…”

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confidence: 99%