Related Experiment Video
Updated: Sep 3, 2026

Hyperpolarized Xenon for NMR and MRI Applications
Published on: September 6, 2012
Optical Hyperpolarization of 1H and 19F Spins in Organic Liquids
Federico De Biasi1, Lorenzo Franco1, Marco Ruzzi1
1Department of Chemical Sciences, University of Padova, via Marzolo 135131Padova, Italy.
Abstract:
Optical dynamic nuclear polarization (oDNP) in liquids offers a microwave-free route to NMR signal enhancement but has so far relied on a limited number of dye-radical systems with restricted photostability, typically requiring high-power laser sources and sample flow to mitigate photobleaching of the dye. Here, we investigate porphyrin-BDPA pairs for oDNP in organic solvents using illumination from an incoherent light-emitting diode, providing 1H enhancement factors up to -7.5 at 0.35 T and -25 at 0.16 T in bulk solutions. Beyond 1H hyperpolarization, we show optical enhancement of 19F nuclei in bulk solutions (+5 at 0.37 T), with the positive enhancement indicating a significant scalar contribution to the electron-nuclear interaction. The improved photostability of porphyrins enables one- and two-dimensional oDNP experiments without sample flow, thereby simplifying the experimental implementation of oDNP at low magnetic fields.
Related Concept Videos
¹H NMR: Interpreting Distorted and Overlapping Signals
As Δν decreases and the signals move closer, the doublets appear increasingly distorted. The intensities of the inner lines increase at the cost of those of the outer lines as the signals are slanted or...
NMR Spectroscopy: Spin–Spin Coupling
Insensitive Nuclei Enhanced by Polarization Transfer (INEPT)
¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)
Other Nuclides: 31P, 19F, 15N NMR
While fluorine-19 and phosphorous-31 have high natural abundances (100%) and positive gyromagnetic ratios, nitrogen-15 has a low natural abundance and a negative gyromagnetic ratio. However, nitrogen-15 is still preferred over nitrogen-14 (which has a high...
Nuclear Overhauser Enhancement (NOE)

![Measuring the Spin-Lattice Relaxation Magnetic Field Dependence of Hyperpolarized [1-13C]pyruvate](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F59399.jpg&w=3840&q=50)