Hyperpolarization of Frozen Hydrocarbon Gases by Dynamic Nuclear Polarization at 1.2 K

详细信息    查看全文

• 作者：Basile Vuichoud ; Estel Canet ; Jonas Milani ; Aurélien Bornet ; David Baudouin ; Laurent Veyre ; David Gajan ; Lyndon Emsley ; Anne Lesage ; Christophe Copéret ; Chloé Thieuleux ; Geoffrey Bodenhausen ; Igor Koptyug ; Sami Jannin
• 刊名：The Journal of Physical Chemistry Letters
• 出版年：2016
• 出版时间：August 18, 2016
• 年：2016
• 卷：7
• 期：16
• 页码：3235-3239
• 全文大小：299K
• 年卷期：0
• ISSN：1948-7185

文摘

We report a simple and general method for the hyperpolarization of condensed gases by dynamic nuclear polarization (DNP). The gases are adsorbed in the pores of structured mesoporous silica matrices known as HYPSOs (HYper Polarizing SOlids) that have paramagnetic polarizing agents covalently bound to the surface of the mesopores. DNP is performed at low temperatures and moderate magnetic fields (T = 1.2 K and B₀ = 6.7 T). Frequency-modulated microwave irradiation is applied close to the electron spin resonance frequency (f = 188.3 GHz), and the electron spin polarization of the polarizing agents of HYPSO is transferred to the nuclear spins of the frozen gas. A proton polarization as high as P(¹H) = 70% can be obtained, which can be subsequently transferred to ¹³C in natural abundance by cross-polarization, yielding up to P(¹³C) = 27% for ethylene.