Long-lived nuclear singlet order in near-equivalent 13C spin pairs

Giuseppe Pileio; Joseph T. Hill-Cousins; Sam Mitchell; Ilya Kuprov; Lynda J. Brown; Richard C.D. Brown; Malcolm H. Levitt

doi:https://doi.org/10.1021/ja3089873

Long-lived nuclear singlet order in near-equivalent ¹³C spin pairs

Giuseppe Pileio, Joseph T. Hill-Cousins, Sam Mitchell, Ilya Kuprov, Lynda J. Brown, Richard C.D. Brown, Malcolm H. Levitt

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

Abstract

Molecules that support ¹³C singlet states with lifetimes of over 10 min in solution have been designed and synthesized. The ¹³C ₂ spin pairs in the asymmetric alkyne derivatives are close to magnetic equivalence, so the ¹³C long-lived singlet states are stable in high magnetic field and do not require maintenance by a radiofrequency spin-locking field. We suggest a model of singlet relaxation by fluctuating chemical shift anisotropy tensors combined with leakage associated with slightly broken magnetic equivalence. Theoretical estimates of singlet relaxation rates are compared with experimental values. Relaxation due to antisymmetric shielding tensor components is significant.

Original language	English
Pages (from-to)	17494-17497
Number of pages	4
Journal	Journal of the American Chemical Society
Volume	134
Issue number	42
DOIs	https://doi.org/10.1021/ja3089873
State	Published - 24 Oct 2012
Externally published	Yes

All Science Journal Classification (ASJC) codes

Catalysis
General Chemistry
Biochemistry
Colloid and Surface Chemistry

Access to Document

https://doi.org/10.1021/ja3089873

Cite this

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title = "Long-lived nuclear singlet order in near-equivalent 13C spin pairs",

abstract = "Molecules that support 13C singlet states with lifetimes of over 10 min in solution have been designed and synthesized. The 13C 2 spin pairs in the asymmetric alkyne derivatives are close to magnetic equivalence, so the 13C long-lived singlet states are stable in high magnetic field and do not require maintenance by a radiofrequency spin-locking field. We suggest a model of singlet relaxation by fluctuating chemical shift anisotropy tensors combined with leakage associated with slightly broken magnetic equivalence. Theoretical estimates of singlet relaxation rates are compared with experimental values. Relaxation due to antisymmetric shielding tensor components is significant.",

author = "Giuseppe Pileio and Hill-Cousins, {Joseph T.} and Sam Mitchell and Ilya Kuprov and Brown, {Lynda J.} and Brown, {Richard C.D.} and Levitt, {Malcolm H.}",

year = "2012",

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doi = "https://doi.org/10.1021/ja3089873",

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volume = "134",

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journal = "Journal of the American Chemical Society",

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TY - JOUR

T1 - Long-lived nuclear singlet order in near-equivalent 13C spin pairs

AU - Pileio, Giuseppe

AU - Hill-Cousins, Joseph T.

AU - Mitchell, Sam

AU - Kuprov, Ilya

AU - Brown, Lynda J.

AU - Brown, Richard C.D.

AU - Levitt, Malcolm H.

PY - 2012/10/24

Y1 - 2012/10/24

N2 - Molecules that support 13C singlet states with lifetimes of over 10 min in solution have been designed and synthesized. The 13C 2 spin pairs in the asymmetric alkyne derivatives are close to magnetic equivalence, so the 13C long-lived singlet states are stable in high magnetic field and do not require maintenance by a radiofrequency spin-locking field. We suggest a model of singlet relaxation by fluctuating chemical shift anisotropy tensors combined with leakage associated with slightly broken magnetic equivalence. Theoretical estimates of singlet relaxation rates are compared with experimental values. Relaxation due to antisymmetric shielding tensor components is significant.

AB - Molecules that support 13C singlet states with lifetimes of over 10 min in solution have been designed and synthesized. The 13C 2 spin pairs in the asymmetric alkyne derivatives are close to magnetic equivalence, so the 13C long-lived singlet states are stable in high magnetic field and do not require maintenance by a radiofrequency spin-locking field. We suggest a model of singlet relaxation by fluctuating chemical shift anisotropy tensors combined with leakage associated with slightly broken magnetic equivalence. Theoretical estimates of singlet relaxation rates are compared with experimental values. Relaxation due to antisymmetric shielding tensor components is significant.

UR - http://www.scopus.com/inward/record.url?scp=84867837926&partnerID=8YFLogxK

U2 - https://doi.org/10.1021/ja3089873

DO - https://doi.org/10.1021/ja3089873

M3 - مقالة

SN - 0002-7863

VL - 134

SP - 17494

EP - 17497

JO - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

IS - 42