Highly Efficient Polarization of Spin-1/2 Insensitive NMR Nuclei by Adiabatic Passage through Level Anticrossings

详细信息    查看全文

• 作者：Andrey N. Pravdivtsev ; Alexandra V. Yurkovskaya ; Nikita N. Lukzen ; Konstantin L. Ivanov ; Hans-Martin Vieth
• 刊名：The Journal of Physical Chemistry Letters
• 出版年：2014
• 出版时间：October 2, 2014
• 年：2014
• 卷：5
• 期：19
• 页码：3421-3426
• 全文大小：313K
• ISSN：1948-7185

文摘

A method is proposed to transfer spin order from para-hydrogen, that is, the H₂ molecule in its singlet state, to spin-1/2 heteronuclei of a substrate molecule. The method is based on adiabatic passage through nuclear spin level anticrossings (LACs) in the doubly rotating frame of reference; the LAC conditions are fulfilled by applying resonant RF excitation at the NMR frequencies of protons and the heteronuclei. Efficient conversion of the para-hydrogen-induced polarization into net polarization of the heteronuclei is demonstrated; the achieved signal enhancements are about 6400 for ¹³C nuclei at natural abundance. The theory behind the technique is described; advantages of the method are discussed in detail.

Keywords:

NMR; heteronuclei; spin hyperpolarization; PHIP; avoided level crossings