Magnetization transfer technique

Brown and coworkers [128] have studied the exchange process for the enamide complex 103, using magnetization transfer techniques (Figure 1.28). Compound 103 represents the catalytic resting state in the asymmetric homogeneous hydroge-... 

The corresponding parameters for the BS process in these systems cannot be evaluated using 19F NMR experiments because the rate is too slow. However, kinetic parameters for the BS process in heptafluorocycloocta-1,3,5,7-tetraene 116 have been shown by magnetization transfer techniques to be... 

NMR has the capability, using magnetization transfer techniques, to measure very rapid metabolic fluxes in vivo, of the order of 1(F3 M s-1. A magnetization transfer experiment, in which exchange between ATP and Pj was measured in yeast... 

Atalay K, Diren HB, Gelmez S, Incesu L, Terzi M (2005) The effectiveness of magnetization transfer technique in the evaluation of acute plaques in the central nervous system of multiple sclerosis patients and its correlation with the clinical findings. Diagn Interv Radiol 11 137-141. 

The exchange in solution of free CO with Co2(CO>8 was studied by C magnetization transfer techniques up to 7.5 MPa CO pressure [98]. The rate of CO dissociation was found to be independent of CO pressure. A slightly faster CO exchange was observed for Co(CH3COXCO)4. Ibese results suggest that the loss of CO is accompanied by the formation of an t -CH3CO-Co(CO)3 intermediate. 

The advent and popularization of more sophisticated NMR experiments, such as magnetization transfer techniques [43], was a great asset for kinetic studies. Using these techniques the equilibrium involving insertion/deinsertion in the complex [RhH(C2H4)(PPr3)2] has been studied in detail [44]. A hydride complex is the only species observed by NMR from —90 to 0°C. Its resonances... 

Rudin, M., Sauter, A. Measurement of Reaction Rates In-Vivo Using Magnetization Transfer Techniques. Vol. 27, pp. 257-293... 

Ethylene insertion into the Rh-H bond in traw5-[HRh(C2H4)(P(/-Pr3)2)] (26) has been studied using a magnetization transfer technique. In toluene-d the insertion rate is independent of added phosphine or ethylene, and therefore is truly intramolecular. The mechanism consists of very rapid trans cis equilibration of (26), followed by reversible hydride migration in the cis form. The migration step has the following activation parameters AH = 13.0 kcal moP and A5 = -2 cal moP. ... 

Figure 6 Magnetization transfer technique. (A) Two-pool model used for the evaluation. This is certainly a simplification of reality, although imaging data quality does not justify further elaboration. (B) MTC imaging sequence. A gradient-recalled echo data acquisition is used once more. The spoiler shown is used to dephase residual transverse magnetization after the end of the off-resonance irradiation period (of length t). Practical sequences of all types use pulses like this to eliminate the unwanted signals from spins pursuing complex patterns of excitation and recovery.

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