title   
  

Liquid state DNP at high magnetic fields: instrumentation, experimental results and atomistic modelling by molecular dynamics simulations

Prisner, Thomas and Denysenkov, Vasyl and Sezer, Deniz (2016) Liquid state DNP at high magnetic fields: instrumentation, experimental results and atomistic modelling by molecular dynamics simulations. Journal of Magnetic Resonance, 264 . pp. 68-77. ISSN 1090-7807 (Print) 1096-0856 (Online)

[img]PDF - Registered users only - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
1881Kb

Official URL: http://dx.doi.org/10.1016/j.jmr.2015.11.004

Abstract

Dynamic nuclear polarization (DNP) at high magnetic fields has recently become one of the major research areas in magnetic resonance spectroscopy and imaging. Whereas much work has been devoted to experiments where the polarization transfer from the electron spin to the nuclear spin is performed in the solid state, only a few examples exist of experiments where the polarization transfer is performed in the liquid state. Here we describe such experiments at a magnetic field of 9.2 T, corresponding to a nuclear Larmor frequency of 400 MHz for proton spins and an excitation frequency of 263 GHz for the electron spins. The technical requirements to perform such experiments are discussed in the context of the double resonance structures that we have implemented. The experimental steps that allowed access to the enhancement factors for proton spins of several organic solvents with nitroxide radicals as polarizing agents are described. A computational scheme for calculating the coupling factors from molecular dynamics (MD) simulations is outlined and used to highlight the limitations of the classical models based on translational and rotational motion that are typically employed to quantify the observed coupling factors. The ability of MD simulations to predict enhancements for a variety of radicals and solvent molecules at any magnetic field strength should prove useful in optimizing experimental conditions for DNP in the liquid state.

Item Type:Article
Uncontrolled Keywords:Overhauser effect; Dynamic nuclear polarization; DNP resonator; Molecular dynamics simulations; Force-free hard-sphere model
Subjects:Q Science > QD Chemistry > QD450-801 Physical and theoretical chemistry
ID Code:29739
Deposited By:Deniz Sezer
Deposited On:04 Nov 2016 14:53
Last Modified:04 Nov 2016 14:53

Repository Staff Only: item control page