Selective magnetization transfer

Di Bari L, Kowalewski J and Bodenhausen G 1990 Magnetization transfer modes in scalar-coupled spin systems investigated by selective 2-dimensional nuclear magnetic resonance exchange experiments J. Chem. Rhys. 93 7698-705... 

Figure 7.25 Homoniiclear double-quantum filtered COSY spectrum (400 MHz) of 8-mMangiotensin II in H,0 recorded without phase cycling. Magnetic field gradient pulses have been used to select coherence transfer pathways. (Reprinted from J. Mag. Reson. 87, R. Hurd, 422, copyright (1990), with permission from Academic Press, Inc.)...

The earliest of the magnetization transfer experiments is the spin population inversion (SPI) experiment [27]. By selectively irradiating and inverting one of the 13C satellites of a proton resonance, the recorded proton spectrum is correspondingly perturbed and enhanced. Experiments of this type have been successfully utilized to solve complex structural assignments. They also form the basis for 2D-heteronuclear chemical shift correlation experiments that are discussed in more detail later in this chapter. 

The ID TOCSY-ROESY experiment is illustrated on the same molecule using the pulse sequence of fig. 7(d). This time the magnetization of H-4c was generated during the initial selective TOCSY transfer from H-lc (fig. 9(b), pulse sequence of fig. 7(b)). In the subsequent ID TOCSY-ROESY experiment, the ROE transfer from H-4c confirmed the expected... 

Using the procedure described above, signals of two spin systems are accumulated during the entire experiment and the individual subspectra are obtained after editing of the original spectra. This provides a two-fold reduction in the total experimental time when compared to 1D experiments which employ two selective pulses for the selection of the magnetization transfer pathway. 

Measurement of creatine kinase reaction rate in human brain using magnetization transfer image-selected in vivo spectroscopy (MT-ISIS) and a volume radiofre-... 

Magnetization transfer was used to detect fluxionality in the bimetallic complex 347 (Scheme 45).138 Both metals move in this case, and the reaction occurs at a considerably lower temperature than is required for 343. An intramolecular mechanism via an achiral intermediate (or transition state) as pictured in 358 was proposed based on selective isotopomer irradiation as described for 343. Stronger bonding of the Mo(CO)3 moiety to the tropylium ion in the transition state than to the distorted cycloheptatriene... 

---