Magnetization/saturation transfer techniques

Brown, J. M. Chaloner, P. A. The catalytic resting state of asymmetric homogeneous hydrogenation. Exchange processes delineated by nuclear magnetic resonance saturation-transfer (DANTE) techniques. /. Chem. Soc., Perkin Trans. II1987,1583-1588. 

The technique of saturation transfer has been used to measure in vivo the unidirectional rates of the ATPase and creatine kinase reactions, which will be discussed in later sections. In this technique, developed and first applied by Forsen and Hoffman (1963), the nuclear spin magnetization of one chemical species is perturbed from its equilibrium value and the appearance of nonequilibrium magnetization in a second, product, species is monitored to determine the reaction rate. The technique measures reaction rates in equilibrium or steady state conditions and has a time resolution of 1 s or less. Consider a second-order reaction ... 

The second approach is the use of the dynamic nuclear polarization (DNP) detection principle. Dorn and co-workers have pioneered the application of this technique [9,10], Whereas the NOE enhancement of 13C nuclei in the conventional 13C H recording is dependent upon the 7h/7c ratio (NOE = Th/ Tc = 2 1), the DNP enhancement relates to the ye/yuc ratio (2640 1). In an electron-nucleus spinsystem, the electron-electron transitions are saturated by microwave irradiation and magnetization transfer from electron to nucleus (Overhauser effect) occurs via a scalar and/or dipolar mechanism. The DNP enhancement, A, is described by the following equation ... 

---