Figure 27.

Impact of unequal R_2,GS and R_2,ES on off-resonance R_1ρ RD profiles for two-state exchange simulated using B-M equations. Variation of off-resonance R_1ρ RD profiles with ΔR₂ as function of k_ex for A) $\Delta \overline{\omega }{(}^{13}\text{C)}=15\text{\hspace{0.17em}ppm}$, B) $\Delta \overline{\omega }{(}^{13}\text{C)}=3\text{\hspace{0.17em}ppm}$ and C) $\Delta \overline{\omega }{(}^{13}\text{C)}=0\text{\hspace{0.17em}ppm}$. Different ΔR₂ values are color coded. Exchange parameters are specified in inset. For all simulations γ(¹H)B₀/2π = 700 MHz and R_1,GS = R_1,ES = 2.5 s⁻¹. Direction of initial alignment of the magnetization during B-M simulations was determined as described in Section 6.1. While fitting the mono-exponential decay, the magnetization for the first 0.05 s was not considered, in order to exclude the fast initial decay, as proposed by Kay et al.[187].