Experimental Characterization of Intermolecular Multiple-Quantum Coherence Pumping Efficiency in Solution NMR

Abstract

The behavior of intermolecular multiple-quantum coherences in a variety of simple liquids with different chemical and magnetic properties is investigated experimentally and modeled by numerical simulations based on modified Bloch equations. The effects of spin concentration, temperature, intramolecular conformational flexibility, chemical exchange, and spin-spin coupling on the formation of high-order coherences are examined. It is shown that any process that makes the Larmor frequency time-dependent may interfere with the formation of these coherences. Good agreement is achieved between experiments and simulation, using independently known values of the magnetization density, the rate constants for translational diffusion, spin-spin and spin-lattice relaxation, and radiation damping.

Magnetic resonance microscopic imaging based on high-order intermolecular multiple-quantum coherences

“…[26]; the explicit time dependence of the spectroscopic signals up to four-quantum coherences was further investigated in Ref. [11].…”

Nuclear magnetic resonance studies of quadrupolar nuclei and dipolar field effects

“…[ 77,309,310,311,312,313,314,315,316]. The long-range nature of iMQCs and DDF effects have made them useful probes of mesoscopic structure: e.g., as a contrast mechanism in magnetic resonance imaging [317,318,319,320,321,322,323,324,325]; in NMR multipleecho, scattering, and microscopy-type experiments [326,327,328,329,330,331,332,333]; and even in the direct mapping of the dipolar field or magnetization distribution in solution [334,335].…”