Optimized polarization build-up times in dissolution DNP-NMR using a benzyl amino derivative of BDPA

Abstract

A BAm-BDPA radical has proved to be a quick and efficient polarizing agent, showing optimum 13C NMR signal enhancements per polarization time unit.

13C Dynamic Nuclear Polarization using SA-BDPA at 6.7 T and 1.1 K: Coexistence of Pure Thermal Mixing and Well-Resolved Solid Effect

“…10.5 Å) to fulfill the cut-off frequency condition (∆ 0 = 142 MHz), and its g-tensor anisotropy results in electron spin packets matching the CE condition. The two mechanisms, working together, allow an efficient polarization transfer to 13 concentrations between 40 mM and 60 mM have been reported to yield excellent polarization levels in a very short time, [45][46][47] whereas SA-BDPA yielded high 13 C polarization only at very high radical concentration. Although the latter did not have any detrimental effect on the 13 C urea liquid state relaxation time (see Table 1), investigating whether this high amount of radical would present an issue for possible future applications remains to be determined.…”

“…At 3.35 T, the most common dDNP magnetic field strength, BDPA and its benzyl derivatives at concentrations between 40 and 60 mM have been reported to yield excellent polarization levels in a very short time, − whereas SA-BDPA yielded high 13 C polarization only at very high radical concentration. Although the latter did not have any detrimental effect on the 13 C urea liquid-state relaxation time (see Table ), investigating whether this high amount of radical would present an issue for possible future applications remains to be determined.…”

Verdazyls as Possible Building Blocks for Multifunctional Molecular Materials: A Case Study on 1,5-Diphenyl-3-(p-iodophenyl)-verdazyl Focusing on Magnetism, Electron Transfer and the Applicability of the Sonogashira-Hagihara Reaction

“…Finally, it is remarked that achieving strong enough magnetic interactions for real-life applications in MMMs remains challenging without implementing transition metal ions (TMI), using purely organic compounds like verdazyls, nitroxides, trityls, or other organic radicals instead. However, nitroxides and trityls have also found applications in numerous other fields [ 1 , 10 ], for example as spin label/spin probes in EPR spectroscopy and imaging [ 59 , 90 , 91 , 92 , 93 , 94 , 95 , 96 ], as polarizing agents in dynamic nuclear polarization enhanced NMR spectroscopy [ 97 , 98 , 99 , 100 , 101 , 102 ], in chemical synthesis [ 103 , 104 ] or as dopants in nanoparticles [ 105 , 106 ]. Owed to the in general lower toxicity of TMI free compounds, many of these applications are related to the increasingly important field of biochemistry.…”

SABRE‐enhanced real‐time pure shift NMR spectroscopy

“…In some cases, dDNP allows access to signals that would not otherwise be observable, but dDNP polarization durations are usually long. [11] Hyperpolarization techniques that utilize the singlet-state nuclear spin isomer of dihydrogen, parahydrogen (pH 2 ), as the external source of intrinsically high polarization are typically much faster. pH 2 -based methods have a much narrower substrate range than dDNP methods but require simpler infrastructure, provide hyperpolarization of a target molecule in seconds, and are compatible with NMR flow technologies which enables reaction monitoring.…”