Determination of the anisotropy of rotational reorientation from ESR line width data

Jimmy S. Hwang; M. Habibur Rahman

doi:10.1016/0009-2614(92)80120-Z

Determination of the anisotropy of rotational reorientation from ESR line width data

Jimmy S. Hwang^*, M. Habibur Rahman

^*Corresponding author for this work

King Fahd University of Petroleum & Minerals

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

2 Scopus citations

Abstract

An ESR line width study of vanadyl acetylacetonate (abbreviated as VO(acac)₂) in toluene has been carried out as a function of temperature at 9.5 GHz. It was found that VO(acac)₂ was undergoing anisotropic reorientation with N=2.8±1 along a symmetry axis z′=Y, where N is the ratio of R_∥/R_⊥ and R_∥ is the rotational diffusion constant along the molecular Z axis and R_⊥ is the rotational diffusion constant perpendicular to the molecular Z axis. The N value obtained was found to be in agreement with N=3.0±1 obtained from the allowed-values equation with ρ{variant}_x=0.634ρ{variant}_y-0.910 with ρ{variant}_x=1 and ρ{variant}_y=3.0 and is consistent, within experimental error, with N predicted from the Stokes-Einstein model (N=2.1). The results of this study could be useful in simulating ESR spectra of VO(acac)₂ in the slow-tumbling region. It can also be used to determine the rotational hydrodynamic radius of the solvated vanadyl complex in neat solution.

Original language	English
Pages (from-to)	286-292
Number of pages	7
Journal	Chemical Physics Letters
Volume	199
Issue number	3-4
DOIs	https://doi.org/10.1016/0009-2614(92)80120-Z
State	Published - 6 Nov 1992

Bibliographical note

Funding Information:
The authors would like to thank Ring Fahd University of Petroleum and Minerals for support of this research.

ASJC Scopus subject areas

General Physics and Astronomy
Physical and Theoretical Chemistry

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10.1016/0009-2614(92)80120-Z

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title = "Determination of the anisotropy of rotational reorientation from ESR line width data",

abstract = "An ESR line width study of vanadyl acetylacetonate (abbreviated as VO(acac)2) in toluene has been carried out as a function of temperature at 9.5 GHz. It was found that VO(acac)2 was undergoing anisotropic reorientation with N=2.8±1 along a symmetry axis z′=Y, where N is the ratio of R∥/R⊥ and R∥ is the rotational diffusion constant along the molecular Z axis and R⊥ is the rotational diffusion constant perpendicular to the molecular Z axis. The N value obtained was found to be in agreement with N=3.0±1 obtained from the allowed-values equation with ρ\{variant\}x=0.634ρ\{variant\}y-0.910 with ρ\{variant\}x=1 and ρ\{variant\}y=3.0 and is consistent, within experimental error, with N predicted from the Stokes-Einstein model (N=2.1). The results of this study could be useful in simulating ESR spectra of VO(acac)2 in the slow-tumbling region. It can also be used to determine the rotational hydrodynamic radius of the solvated vanadyl complex in neat solution.",

author = "Hwang, \{Jimmy S.\} and \{Habibur Rahman\}, M.",

note = "Funding Information: The authors would like to thank Ring Fahd University of Petroleum and Minerals for support of this research.",

year = "1992",

month = nov,

day = "6",

doi = "10.1016/0009-2614(92)80120-Z",

language = "English",

volume = "199",

pages = "286--292",

journal = "Chemical Physics Letters",

issn = "0009-2614",

number = "3-4",

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T1 - Determination of the anisotropy of rotational reorientation from ESR line width data

AU - Hwang, Jimmy S.

AU - Habibur Rahman, M.

N1 - Funding Information: The authors would like to thank Ring Fahd University of Petroleum and Minerals for support of this research.

PY - 1992/11/6

Y1 - 1992/11/6

N2 - An ESR line width study of vanadyl acetylacetonate (abbreviated as VO(acac)2) in toluene has been carried out as a function of temperature at 9.5 GHz. It was found that VO(acac)2 was undergoing anisotropic reorientation with N=2.8±1 along a symmetry axis z′=Y, where N is the ratio of R∥/R⊥ and R∥ is the rotational diffusion constant along the molecular Z axis and R⊥ is the rotational diffusion constant perpendicular to the molecular Z axis. The N value obtained was found to be in agreement with N=3.0±1 obtained from the allowed-values equation with ρ{variant}x=0.634ρ{variant}y-0.910 with ρ{variant}x=1 and ρ{variant}y=3.0 and is consistent, within experimental error, with N predicted from the Stokes-Einstein model (N=2.1). The results of this study could be useful in simulating ESR spectra of VO(acac)2 in the slow-tumbling region. It can also be used to determine the rotational hydrodynamic radius of the solvated vanadyl complex in neat solution.

AB - An ESR line width study of vanadyl acetylacetonate (abbreviated as VO(acac)2) in toluene has been carried out as a function of temperature at 9.5 GHz. It was found that VO(acac)2 was undergoing anisotropic reorientation with N=2.8±1 along a symmetry axis z′=Y, where N is the ratio of R∥/R⊥ and R∥ is the rotational diffusion constant along the molecular Z axis and R⊥ is the rotational diffusion constant perpendicular to the molecular Z axis. The N value obtained was found to be in agreement with N=3.0±1 obtained from the allowed-values equation with ρ{variant}x=0.634ρ{variant}y-0.910 with ρ{variant}x=1 and ρ{variant}y=3.0 and is consistent, within experimental error, with N predicted from the Stokes-Einstein model (N=2.1). The results of this study could be useful in simulating ESR spectra of VO(acac)2 in the slow-tumbling region. It can also be used to determine the rotational hydrodynamic radius of the solvated vanadyl complex in neat solution.

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U2 - 10.1016/0009-2614(92)80120-Z

DO - 10.1016/0009-2614(92)80120-Z

M3 - Article

AN - SCOPUS:38249009075

SN - 0009-2614

VL - 199

SP - 286

EP - 292

JO - Chemical Physics Letters

JF - Chemical Physics Letters

IS - 3-4

ER -

Determination of the anisotropy of rotational reorientation from ESR line width data

Abstract

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ASJC Scopus subject areas

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