仲氢诱导极化(Parahydrogen Induced Polarization,PHIP)技术能够极大地增强核磁共振信号,在化学、生物、医学等多方面具有广阔的应用前景.但在实际应用中,通过PHIP技术获得的核磁共振(NMR)信号增强倍数往往受到实际反应条件的影响.该文中以己炔的加氢反应为例,考察了氢气通入方式、反应温度和反应压强对PHIP实验中核磁共振信号增强倍数的影响.
Parahydrogen-induced polarization (PHIP) can enhance NMR signals significantly, and thus has shown great prospects in chemistry, biology, medical science and so on. In practice, the amplitude of NMR signal enhancement by PHIP, however, is often limited by experiment setup. In this work, it was demonstrated the signal enhancement in PHIP experiments can be optimized by choosing appropriate experimental conditions, including temperature, pressure and the way to introduce parahydrogen into the PHIP experiment. The reaction system of 1-hexyne and [Rh(COD)(dppb)]BF4 was chosen as the example to illustrate how to optimize experimental conditions in PHIP experiments.