Published: Mar 22, 2014 by K. E. Claytor

Longer-Lived Singlet States in Chemically Equivalent Spin Systems via Deuteration

2014 ENC Poster:

Welcome to the digital home of Kevin Claytor’s 2014 ENC poster. Feel free to download a pdf version of the poster. You can also find supporting information, such as animations and references further on this page.

Animated Singlet-Triplet Transitions:

These simulations show the effect of the SLIC and adSLIC pulses to the density matrix in a chemically equivalent system. This Bloch Sphere is a re-mapping of the Zeeman basis. Instead, the -z direction is the triplet state, while the +z direction is the singlet state.

The Hamiltonian is; H = H0 + Hrf. 1) The total Hamiltonian, H, is represented in blue, 2) the couplings, H0, in red, 3) and then RF field in orange, Note that with the basis transform Hrf acts along the z-axis.

SLIC Sequence:

In the SLIC sequence, a CW RF pulse balances out the carbon-carbon coupling. This allows the small off-diagonal term, the out of pair J-coupling difference, to move population from the triplet to the singlet state.

adSLIC Sequence:

In the adSLIC sequence, the amplitude of the CW RF pulse is adiabatically increased. In this manner the population adiabatically follows the Hamiltonian from the triplet to the singlet state.

References:

• Claytor, K., Theis, T., Feng, Y. & Warren, W. “Measuring long-lived (13)C2 state lifetimes at natural abundance.” J. Magn. Reson. 239, 81-6 (2014). WEB
• Theis, T., Feng, Y., Wu, T. & Warren, W. S. “Composite and shaped pulses for efficient and robust pumping of disconnected eigenstates in magnetic resonance.” J. Chem. Phys. 140, 014201 (2014). WEB
• Feng, Y. et al. “Storage of hydrogen spin polarization in long-lived 13C2 singlet order and implications for hyperpolarized magnetic resonance imaging.” J. Am. Chem. Soc. 135, 9632-5 (2013). WEB
• DeVience, S. J., Walsworth, R. L. & Rosen, M. S. “Preparation of Nuclear Spin Singlet States Using Spin-Lock Induced Crossing.” Phys. Rev. Lett. 111, 173002 (2013). WEB
• Feng, Y., Davis, R. & Warren, W. “Accessing long-lived nuclear singlet states between chemically equivalent spins without breaking symmetry.” Nat. Phys. 8, 831-837 (2012). WEB
• Pileio, G. et al. “Long-lived nuclear singlet order in near-equivalent 13C spin pairs.” J. Am. Chem. Soc. 134, 17494-7 (2012). WEB
• Pileio, G. & Levitt, M. H. “Isotropic filtering using polyhedral phase cycles: application to singlet state NMR.” J. Magn. Reson. 191, 148-55 (2008). WEB
• Carravetta, M. & Levitt, M. H. “Long-lived nuclear spin states in high-field solution NMR.” J. Am. Chem. Soc. 126, 6228-9 (2004). WEB