Singlet nuclear magnetic resonance of nearly-equivalent spins
Tayler, Michael C.D. and Levitt, Malcolm H. (2011) Singlet nuclear magnetic resonance of nearly-equivalent spins. Physical Chemistry Chemical Physics, 13, (13), 5556-5560. (doi:10.1039/C0CP02293D).
Nuclear singlet states may display lifetimes that are an order of magnitude greater than conventional relaxation times. Existing methods for accessing these long-lived states require a resolved chemical shift difference between the nuclei involved. Here, we demonstrate a new method for accessing singlet states that works even when the nuclei are almost magnetically equivalent, such that the chemical shift difference is unresolved. The method involves trains of 180° pulses that are synchronized with the spin–spin coupling between the nuclei. We demonstrate experiments on the terminal glycine resonances of the tripeptide alanylglycylglycine (AGG) in aqueous solution, showing that the nuclear singlet order of this system is long-lived even when no resonant locking field is applied. Variation of the pulse sequence parameters allows the estimation of small chemical shift differences that are normally obscured by larger J-couplings.
|Subjects:||Q Science > QC Physics
Q Science > QD Chemistry
|Divisions:||University Structure - Pre August 2011 > School of Chemistry
Faculty of Natural and Environmental Sciences > Chemistry > Magnetic Resonance
|Date Deposited:||24 Mar 2011 13:49|
|Last Modified:||25 Apr 2013 23:52|
|Contributors:||Tayler, Michael C.D. (Author)
Levitt, Malcolm H. (Author)
|RDF:||RDF+N-Triples, RDF+N3, RDF+XML, Browse.|
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