Close encounters of the weak kind: Investigations of electron-electron interactions between dissimilar spins in hybrid rotaxanesCitation formats

  • External authors:
  • Selena J Lockyer
  • Alistair J. Fielding
  • George F. S. Whitehead
  • Grigore A. Timco

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Close encounters of the weak kind: Investigations of electron-electron interactions between dissimilar spins in hybrid rotaxanes. / Lockyer, Selena J; Fielding, Alistair J.; Whitehead, George F. S.; Timco, Grigore A.; Winpenny, Richard E. P.; Mcinnes, Eric J.l.

In: Journal of the American Chemical Society, 2019.

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Lockyer, Selena J ; Fielding, Alistair J. ; Whitehead, George F. S. ; Timco, Grigore A. ; Winpenny, Richard E. P. ; Mcinnes, Eric J.l. / Close encounters of the weak kind: Investigations of electron-electron interactions between dissimilar spins in hybrid rotaxanes. In: Journal of the American Chemical Society. 2019.

Bibtex

@article{022f8234d7fa444c894e12f667423bfd,
title = "Close encounters of the weak kind: Investigations of electron-electron interactions between dissimilar spins in hybrid rotaxanes",
abstract = "We report a family of hybrid [2]rotaxanes based on inorganic [Cr7NiF8(O2CtBu)16]- (“{Cr7Ni}”) rings templated about organic threads that are terminated at one end with pyridyl groups. These rotaxanes can be coordinated to [Cu(hfac)2] (where hfac = 1,1,1,5,5,5-hexafluoroacetylacetone), to give 1:1 or 1:2 Cu:{Cr7Ni} adducts: {[Cu(hfac)2](py-CH2NH2CH2CH2Ph)[Cr7NiF8(O2CtBu)16]}, {[Cu(hfac)2][py-CH2NH2CH2CH3][Cr7NiF8(O2CtBu)16]}, {[Cu(hfac)2]([py-CH2CH2NH2CH2C6H4SCH3][Cr7NiF8(O2CtBu)16])2}, {[Cu(hfac)2]([py-C6H4-CH2NH2(CH2)4Ph][Cr7NiF8(O2CtBu)16])2}, and {[Cu(hfac)2]([3-py-CH2CH2NH2(CH2)3SCH3][Cr7NiF8(O2CtBu)16])2}, the structures of which have been determined by X-ray diffraction. The {Cr7Ni} rings and CuII ions both have electronic spin S = ½, but with very different g-values. Continuous-wave EPR spectroscopy reveals the exchange interactions between these dissimilar spins, and hence the communication between the different molecular components that comprise these supramolecular systems. The interactions are weak such that we observe AX or AX2 type spectra. The connectivity between the {Cr7Ni} ring and thread terminus is varied such that the magnitude of the exchange interaction J can be tuned. The coupling is shown to be dominated by through-bond rather than through-space mechanisms.",
keywords = "Supramolecular chemistry, rotaxanes, exchange coupling, EPR",
author = "Lockyer, {Selena J} and Fielding, {Alistair J.} and Whitehead, {George F. S.} and Timco, {Grigore A.} and Winpenny, {Richard E. P.} and Mcinnes, {Eric J.l.}",
year = "2019",
doi = "10.1021/jacs.9b05590",
language = "English",
journal = "American Chemical Society. Journal",
issn = "0002-7863",
publisher = "American Chemical Society",

}

RIS

TY - JOUR

T1 - Close encounters of the weak kind: Investigations of electron-electron interactions between dissimilar spins in hybrid rotaxanes

AU - Lockyer, Selena J

AU - Fielding, Alistair J.

AU - Whitehead, George F. S.

AU - Timco, Grigore A.

AU - Winpenny, Richard E. P.

AU - Mcinnes, Eric J.l.

PY - 2019

Y1 - 2019

N2 - We report a family of hybrid [2]rotaxanes based on inorganic [Cr7NiF8(O2CtBu)16]- (“{Cr7Ni}”) rings templated about organic threads that are terminated at one end with pyridyl groups. These rotaxanes can be coordinated to [Cu(hfac)2] (where hfac = 1,1,1,5,5,5-hexafluoroacetylacetone), to give 1:1 or 1:2 Cu:{Cr7Ni} adducts: {[Cu(hfac)2](py-CH2NH2CH2CH2Ph)[Cr7NiF8(O2CtBu)16]}, {[Cu(hfac)2][py-CH2NH2CH2CH3][Cr7NiF8(O2CtBu)16]}, {[Cu(hfac)2]([py-CH2CH2NH2CH2C6H4SCH3][Cr7NiF8(O2CtBu)16])2}, {[Cu(hfac)2]([py-C6H4-CH2NH2(CH2)4Ph][Cr7NiF8(O2CtBu)16])2}, and {[Cu(hfac)2]([3-py-CH2CH2NH2(CH2)3SCH3][Cr7NiF8(O2CtBu)16])2}, the structures of which have been determined by X-ray diffraction. The {Cr7Ni} rings and CuII ions both have electronic spin S = ½, but with very different g-values. Continuous-wave EPR spectroscopy reveals the exchange interactions between these dissimilar spins, and hence the communication between the different molecular components that comprise these supramolecular systems. The interactions are weak such that we observe AX or AX2 type spectra. The connectivity between the {Cr7Ni} ring and thread terminus is varied such that the magnitude of the exchange interaction J can be tuned. The coupling is shown to be dominated by through-bond rather than through-space mechanisms.

AB - We report a family of hybrid [2]rotaxanes based on inorganic [Cr7NiF8(O2CtBu)16]- (“{Cr7Ni}”) rings templated about organic threads that are terminated at one end with pyridyl groups. These rotaxanes can be coordinated to [Cu(hfac)2] (where hfac = 1,1,1,5,5,5-hexafluoroacetylacetone), to give 1:1 or 1:2 Cu:{Cr7Ni} adducts: {[Cu(hfac)2](py-CH2NH2CH2CH2Ph)[Cr7NiF8(O2CtBu)16]}, {[Cu(hfac)2][py-CH2NH2CH2CH3][Cr7NiF8(O2CtBu)16]}, {[Cu(hfac)2]([py-CH2CH2NH2CH2C6H4SCH3][Cr7NiF8(O2CtBu)16])2}, {[Cu(hfac)2]([py-C6H4-CH2NH2(CH2)4Ph][Cr7NiF8(O2CtBu)16])2}, and {[Cu(hfac)2]([3-py-CH2CH2NH2(CH2)3SCH3][Cr7NiF8(O2CtBu)16])2}, the structures of which have been determined by X-ray diffraction. The {Cr7Ni} rings and CuII ions both have electronic spin S = ½, but with very different g-values. Continuous-wave EPR spectroscopy reveals the exchange interactions between these dissimilar spins, and hence the communication between the different molecular components that comprise these supramolecular systems. The interactions are weak such that we observe AX or AX2 type spectra. The connectivity between the {Cr7Ni} ring and thread terminus is varied such that the magnitude of the exchange interaction J can be tuned. The coupling is shown to be dominated by through-bond rather than through-space mechanisms.

KW - Supramolecular chemistry

KW - rotaxanes

KW - exchange coupling

KW - EPR

U2 - 10.1021/jacs.9b05590

DO - 10.1021/jacs.9b05590

M3 - Article

JO - American Chemical Society. Journal

JF - American Chemical Society. Journal

SN - 0002-7863

ER -