title: Dependence of nuclear spin singlet lifetimes on RF spin-locking power.
abstract: We measure the lifetime of long-lived nuclear spin singlet states as a function of the strength of the RF spin-locking field and present a simple theoretical model that agrees well with our measurements, including the low-RF-power regime. We also measure the lifetime of a long-lived coherence between singlet and triplet states that does not require a spin-locking field for preservation. Our results indicate that for many molecules, singlet states can be created using weak RF spin-locking fields: more than two orders of magnitude lower RF power than in previous studies. Our findings suggest that for many endogenous biomolecules, singlets and related states with enhanced lifetimes might be achievable in vivo with safe levels of RF power.
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford St., Cambridge, MA 02138, USA. devience@fas.harvard.edu
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: DeVience
authors.forename: Ronald L
authors.initials: RL
authors.lastname: Walsworth
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Rosen
mesh_terms: D000465:Algorithms; D001224:Aspartic Acid / Q000737:chemistry; D019343:Citric Acid / Q000737:chemistry; D017666:Deuterium Oxide / Q000737:chemistry; D004574:Electromagnetic Fields; D008956:Models, Chemical; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D010226:Parabens / Q000737:chemistry; D011522:Protons; D011846:Radio Waves
chemical_list: D010226:Parabens; D011522:Protons; D019343:Citric Acid; D001224:Aspartic Acid; D017666:Deuterium Oxide; C038193:4-hydroxybenzoic acid