Table 1. qHyper-CEST results of Xe exchange kinetic and binding parameters for three Xe–host systems: CrA in DMSO, CrA in water and CB6 in water (at T = 295 K). Listed parameters are: the solvent, the Xe concentration in this solvent, [Xe] (determined by the Xe Ostwald solubility coefficient), the Xe host molecule, the host molecule concentration, [host], the relative chemical shift between free and bound Xe, Δδ, the ratio of bound and free Xe, f_B, the Xe exchange rate, k_BA, the Xe host occupancy, β, the Xe binding (association) constant, K_A, the host concentration occupied by Xe, [host_occ] = β[host], and the host system efficiency for Hyper-CEST detection in terms of the maximal ¹²⁹Xe depolarization rate per μM host concentration at a given Xe concentration (the gas turnover rate, β k_BA).

Solvent	[Xe] a (μM)	host	[hosttot] (μM)	Δδ (ppm)	f B (10–4)	k BA (s–1)	β b (%)	K A c (M–1)	[hostocc] (μM)	β k BA (% s–1)
Water	390	CB6	3.4	–96.1 ± 0.1	43 ± 1	2100 ± 300	49	2500 ± 400	1.7	1029
Water	390	CrA	11	–132.06 ± 0.02	70 ± 11	38 ± 6	29	850 ± 250	3.2	11
DMSO	2340	CrA	50	–166.37 ± 0.04	18 ± 1	250 ± 130	9	38 ± 4	4.5	23

^aCalculation given in the Experimental Section.

^bAs given by eqn (3) in ref. 27.

^cAs given by eqn (4) in ref. 27.